draft-ietf-manet-dlep-29.txt   rfc8175.txt 
Mobile Ad hoc Networks Working Group S. Ratliff Internet Engineering Task Force (IETF) S. Ratliff
Internet-Draft VT iDirect Request for Comments: 8175 VT iDirect
Intended status: Standards Track S. Jury Category: Standards Track S. Jury
Expires: September 29, 2017 Cisco Systems ISSN: 2070-1721 Cisco Systems
D. Satterwhite D. Satterwhite
Broadcom Broadcom
R. Taylor R. Taylor
Airbus Defence & Space Airbus Defence & Space
B. Berry B. Berry
March 28, 2017 June 2017
Dynamic Link Exchange Protocol (DLEP) Dynamic Link Exchange Protocol (DLEP)
draft-ietf-manet-dlep-29
Abstract Abstract
When routing devices rely on modems to effect communications over When routing devices rely on modems to effect communications over
wireless links, they need timely and accurate knowledge of the wireless links, they need timely and accurate knowledge of the
characteristics of the link (speed, state, etc.) in order to make characteristics of the link (speed, state, etc.) in order to make
routing decisions. In mobile or other environments where these routing decisions. In mobile or other environments where these
characteristics change frequently, manual configurations or the characteristics change frequently, manual configurations or the
inference of state through routing or transport protocols does not inference of state through routing or transport protocols does not
allow the router to make the best decisions. DLEP describes a new allow the router to make the best decisions. This document
protocol for a bidirectional, event-driven communication channel introduces a new protocol called the Dynamic Link Exchange Protocol
between the router and the modem to facilitate communication of (DLEP), which provides a bidirectional, event-driven communication
changing link characteristics. channel between the router and the modem to facilitate communication
of changing link characteristics.
Status of This Memo Status of This Memo
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Introduction ....................................................4
2. Protocol Overview . . . . . . . . . . . . . . . . . . . . . . 7 2. Protocol Overview ...............................................7
2.1. Destinations . . . . . . . . . . . . . . . . . . . . . . 8 2.1. Destinations ...............................................8
2.2. Conventions and Terminology . . . . . . . . . . . . . . . 9 2.2. Conventions and Terminology ................................9
3. Requirements . . . . . . . . . . . . . . . . . . . . . . . . 9 3. Requirements ....................................................9
4. Implementation Scenarios . . . . . . . . . . . . . . . . . . 9 4. Implementation Scenarios .......................................10
5. Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . 10 5. Assumptions ....................................................10
6. Metrics . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 6. Metrics ........................................................11
7. DLEP Session Flow . . . . . . . . . . . . . . . . . . . . . . 12 7. DLEP Session Flow ..............................................12
7.1. Peer Discovery State . . . . . . . . . . . . . . . . . . 12 7.1. Peer Discovery State ......................................12
7.2. Session Initialization State . . . . . . . . . . . . . . 13 7.2. Session Initialization State ..............................14
7.3. In-Session State . . . . . . . . . . . . . . . . . . . . 14 7.3. In-Session State ..........................................14
7.3.1. Heartbeats . . . . . . . . . . . . . . . . . . . . . 14 7.3.1. Heartbeats .........................................15
7.4. Session Termination State . . . . . . . . . . . . . . . . 15 7.4. Session Termination State .................................15
7.5. Session Reset state . . . . . . . . . . . . . . . . . . . 15 7.5. Session Reset State .......................................16
7.5.1. Unexpected TCP connection termination . . . . . . . . 16 7.5.1. Unexpected TCP Connection Termination ..............16
8. Transaction Model . . . . . . . . . . . . . . . . . . . . . . 16 8. Transaction Model ..............................................16
9. Extensions . . . . . . . . . . . . . . . . . . . . . . . . . 17 9. Extensions .....................................................17
9.1. Experiments . . . . . . . . . . . . . . . . . . . . . . . 17 9.1. Experiments ...............................................18
10. Scalability . . . . . . . . . . . . . . . . . . . . . . . . . 18 10. Scalability ...................................................18
11. DLEP Signal and Message Structure . . . . . . . . . . . . . . 18 11. DLEP Signal and Message Structure .............................18
11.1. DLEP Signal Header . . . . . . . . . . . . . . . . . . . 18 11.1. DLEP Signal Header .......................................19
11.2. DLEP Message Header . . . . . . . . . . . . . . . . . . 19 11.2. DLEP Message Header ......................................20
11.3. DLEP Generic Data Item . . . . . . . . . . . . . . . . . 20 11.3. DLEP Generic Data Item ...................................20
12. DLEP Signals and Messages . . . . . . . . . . . . . . . . . . 20 12. DLEP Signals and Messages .....................................21
12.1. General Processing Rules . . . . . . . . . . . . . . . . 20 12.1. General Processing Rules .................................21
12.2. Status code processing . . . . . . . . . . . . . . . . . 21 12.2. Status Code Processing ...................................22
12.3. Peer Discovery Signal . . . . . . . . . . . . . . . . . 22 12.3. Peer Discovery Signal ....................................22
12.4. Peer Offer Signal . . . . . . . . . . . . . . . . . . . 22 12.4. Peer Offer Signal ........................................23
12.5. Session Initialization Message . . . . . . . . . . . . . 23 12.5. Session Initialization Message ...........................23
12.6. Session Initialization Response Message . . . . . . . . 24 12.6. Session Initialization Response Message ..................24
12.7. Session Update Message . . . . . . . . . . . . . . . . . 25 12.7. Session Update Message ...................................26
12.8. Session Update Response Message . . . . . . . . . . . . 27 12.8. Session Update Response Message ..........................27
12.9. Session Termination Message . . . . . . . . . . . . . . 27 12.9. Session Termination Message ..............................28
12.10. Session Termination Response Message . . . . . . . . . . 27 12.10. Session Termination Response Message ....................28
12.11. Destination Up Message . . . . . . . . . . . . . . . . . 28 12.11. Destination Up Message ..................................28
12.12. Destination Up Response Message . . . . . . . . . . . . 29 12.12. Destination Up Response Message .........................30
12.13. Destination Announce Message . . . . . . . . . . . . . . 30 12.13. Destination Announce Message ............................30
12.14. Destination Announce Response Message . . . . . . . . . 30 12.14. Destination Announce Response Message ...................31
12.15. Destination Down Message . . . . . . . . . . . . . . . . 32 12.15. Destination Down Message ................................32
12.16. Destination Down Response Message . . . . . . . . . . . 32 12.16. Destination Down Response Message .......................33
12.17. Destination Update Message . . . . . . . . . . . . . . . 32 12.17. Destination Update Message ..............................33
12.18. Link Characteristics Request Message . . . . . . . . . . 34 12.18. Link Characteristics Request Message ....................35
12.19. Link Characteristics Response Message . . . . . . . . . 34 12.19. Link Characteristics Response Message ...................35
12.20. Heartbeat Message . . . . . . . . . . . . . . . . . . . 35 12.20. Heartbeat Message .......................................36
13. DLEP Data Items . . . . . . . . . . . . . . . . . . . . . . . 36 13. DLEP Data Items ...............................................37
13.1. Status . . . . . . . . . . . . . . . . . . . . . . . . . 37 13.1. Status ...................................................38
13.2. IPv4 Connection Point . . . . . . . . . . . . . . . . . 39 13.2. IPv4 Connection Point ....................................41
13.3. IPv6 Connection Point . . . . . . . . . . . . . . . . . 40 13.3. IPv6 Connection Point ....................................42
13.4. Peer Type . . . . . . . . . . . . . . . . . . . . . . . 41 13.4. Peer Type ................................................43
13.5. Heartbeat Interval . . . . . . . . . . . . . . . . . . . 42 13.5. Heartbeat Interval .......................................45
13.6. Extensions Supported . . . . . . . . . . . . . . . . . . 43 13.6. Extensions Supported .....................................45
13.7. MAC Address . . . . . . . . . . . . . . . . . . . . . . 44 13.7. MAC Address ..............................................46
13.8. IPv4 Address . . . . . . . . . . . . . . . . . . . . . . 44 13.8. IPv4 Address .............................................47
13.8.1. IPv4 Address Processing . . . . . . . . . . . . . . 45 13.8.1. IPv4 Address Processing ...........................48
13.9. IPv6 Address . . . . . . . . . . . . . . . . . . . . . . 46 13.9. IPv6 Address .............................................49
13.9.1. IPv6 Address Processing . . . . . . . . . . . . . . 47 13.9.1. IPv6 Address Processing ...........................50
13.10. IPv4 Attached Subnet . . . . . . . . . . . . . . . . . . 48 13.10. IPv4 Attached Subnet ....................................51
13.10.1. IPv4 Attached Subnet Processing . . . . . . . . . . 49 13.10.1. IPv4 Attached Subnet Processing ..................52
13.11. IPv6 Attached Subnet . . . . . . . . . . . . . . . . . . 50 13.11. IPv6 Attached Subnet ....................................53
13.11.1. IPv6 Attached Subnet Processing . . . . . . . . . . 51 13.11.1. IPv6 Attached Subnet Processing ..................54
13.12. Maximum Data Rate (Receive) . . . . . . . . . . . . . . 52 13.12. Maximum Data Rate (Receive) .............................55
13.13. Maximum Data Rate (Transmit) . . . . . . . . . . . . . . 53 13.13. Maximum Data Rate (Transmit) ............................56
13.14. Current Data Rate (Receive) . . . . . . . . . . . . . . 54 13.14. Current Data Rate (Receive) .............................56
13.15. Current Data Rate (Transmit) . . . . . . . . . . . . . . 54 13.15. Current Data Rate (Transmit) ............................57
13.16. Latency . . . . . . . . . . . . . . . . . . . . . . . . 55 13.16. Latency .................................................58
13.17. Resources . . . . . . . . . . . . . . . . . . . . . . . 56 13.17. Resources ...............................................59
13.18. Relative Link Quality (Receive) . . . . . . . . . . . . 57 13.18. Relative Link Quality (Receive) .........................60
13.19. Relative Link Quality (Transmit) . . . . . . . . . . . . 57 13.19. Relative Link Quality (Transmit) ........................60
13.20. Maximum Transmission Unit (MTU) . . . . . . . . . . . . 58 13.20. Maximum Transmission Unit (MTU) .........................61
14. Security Considerations . . . . . . . . . . . . . . . . . . . 59 14. Security Considerations .......................................62
15. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 60 15. IANA Considerations ...........................................63
15.1. Registrations . . . . . . . . . . . . . . . . . . . . . 60 15.1. Registrations ............................................63
15.2. Signal Type Registration . . . . . . . . . . . . . . . . 60 15.2. Signal Type Registrations ................................63
15.3. Message Type Registration . . . . . . . . . . . . . . . 61 15.3. Message Type Registrations ...............................64
15.4. DLEP Data Item Registrations . . . . . . . . . . . . . . 61 15.4. DLEP Data Item Registrations .............................65
15.5. DLEP Status Code Registrations . . . . . . . . . . . . . 62 15.5. DLEP Status Code Registrations ...........................66
15.6. DLEP Extensions Registrations . . . . . . . . . . . . . 63 15.6. DLEP Extension Registrations .............................67
15.7. DLEP IPv4 Connection Point Flags . . . . . . . . . . . . 63 15.7. DLEP IPv4 Connection Point Flags .........................68
15.8. DLEP IPv6 Connection Point Flags . . . . . . . . . . . . 64 15.8. DLEP IPv6 Connection Point Flags .........................68
15.9. DLEP Peer Type Flag . . . . . . . . . . . . . . . . . . 64 15.9. DLEP Peer Type Flags .....................................68
15.10. DLEP IPv4 Address Flag . . . . . . . . . . . . . . . . . 64 15.10. DLEP IPv4 Address Flags .................................69
15.11. DLEP IPv6 Address Flag . . . . . . . . . . . . . . . . . 65 15.11. DLEP IPv6 Address Flags .................................69
15.12. DLEP IPv4 Attached Subnet Flag . . . . . . . . . . . . . 65 15.12. DLEP IPv4 Attached Subnet Flags .........................69
15.13. DLEP IPv6 Attached Subnet Flag . . . . . . . . . . . . . 65 15.13. DLEP IPv6 Attached Subnet Flags .........................70
15.14. DLEP Well-known Port . . . . . . . . . . . . . . . . . . 66 15.14. DLEP Well-Known Port ....................................70
15.15. DLEP IPv4 Link-local Multicast Address . . . . . . . . . 66 15.15. DLEP IPv4 Link-Local Multicast Address ..................70
15.16. DLEP IPv6 Link-local Multicast Address . . . . . . . . . 66 15.16. DLEP IPv6 Link-Local Multicast Address ..................70
16. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 66 16. References ....................................................71
17. References . . . . . . . . . . . . . . . . . . . . . . . . . 66 16.1. Normative References .....................................71
17.1. Normative References . . . . . . . . . . . . . . . . . . 66 16.2. Informative References ...................................71
17.2. Informative References . . . . . . . . . . . . . . . . . 67 Appendix A. Discovery Signal Flows ................................73
Appendix A. Discovery Signal Flows . . . . . . . . . . . . . . . 68 Appendix B. Peer-Level Message Flows ..............................73
Appendix B. Peer Level Message Flows . . . . . . . . . . . . . . 68 B.1. Session Initialization .....................................73
B.1. Session Initialization . . . . . . . . . . . . . . . . . 68 B.2. Session Initialization - Refused ...........................74
B.2. Session Initialization - Refused . . . . . . . . . . . . 69 B.3. Router Changes IP Addresses ................................74
B.3. Router Changes IP Addresses . . . . . . . . . . . . . . . 70 B.4. Modem Changes Session-Wide Metrics .........................75
B.4. Modem Changes Session-wide Metrics . . . . . . . . . . . 70 B.5. Router Terminates Session ..................................75
B.5. Router Terminates Session . . . . . . . . . . . . . . . . 70 B.6. Modem Terminates Session ...................................76
B.6. Modem Terminates Session . . . . . . . . . . . . . . . . 71 B.7. Session Heartbeats .........................................77
B.7. Session Heartbeats . . . . . . . . . . . . . . . . . . . 71 B.8. Router Detects a Heartbeat Timeout .........................78
B.8. Router Detects a Heartbeat timeout . . . . . . . . . . . 72 B.9. Modem Detects a Heartbeat Timeout ..........................78
B.9. Modem Detects a Heartbeat timeout . . . . . . . . . . . . 73 Appendix C. Destination-Specific Message Flows ....................79
Appendix C. Destination Specific Message Flows . . . . . . . . . 73 C.1. Common Destination Notification ............................79
C.1. Common Destination Notification . . . . . . . . . . . . . 73 C.2. Multicast Destination Notification .........................80
C.2. Multicast Destination Notification . . . . . . . . . . . 74 C.3. Link Characteristics Request ...............................81
C.3. Link Characteristics Request . . . . . . . . . . . . . . 75 Acknowledgments ...................................................82
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 76 Authors' Addresses ................................................82
1. Introduction 1. Introduction
There exist today a collection of modem devices that control links of There exist today a collection of modem devices that control links of
variable datarate and quality. Examples of these types of links variable data rate and quality. Examples of these types of links
include line-of-sight (LOS) terrestrial radios, satellite terminals, include line-of-sight (LOS) terrestrial radios, satellite terminals,
and broadband modems. Fluctuations in speed and quality of these and broadband modems. Fluctuations in speed and quality of these
links can occur due to configuration, or on a moment-to-moment basis, links can occur due to configuration, or on a moment-to-moment basis,
due to physical phenomena like multipath interference, obstructions, due to physical phenomena like multipath interference, obstructions,
rain fade, etc. It is also quite possible that link quality and rain fade, etc. It is also quite possible that link quality and
datarate vary with respect to individual destinations on a link, and data rate vary with respect to individual destinations on a link and
with the type of traffic being sent. As an example, consider the with the type of traffic being sent. As an example, consider the
case of an IEEE 802.11 access point, serving two associated laptop case of an IEEE 802.11 access point serving two associated laptop
computers. In this environment, the answer to the question "What is computers. In this environment, the answer to the question "What is
the datarate on the 802.11 link?" is "It depends on which associated the data rate on the 802.11 link?" is "It depends on which associated
laptop we're talking about, and on what kind of traffic is being laptop we're talking about and on what kind of traffic is being
sent." While the first laptop, being physically close to the access sent." While the first laptop, being physically close to the access
point, may have a datarate of 54Mbps for unicast traffic, the other point, may have a data rate of 54 Mbps for unicast traffic, the other
laptop, being relatively far away, or obstructed by some object, can laptop, being relatively far away or obstructed by some object, can
simultaneously have a datarate of only 32Mbps for unicast. However, simultaneously have a data rate of only 32 Mbps for unicast.
for multicast traffic sent from the access point, all traffic is sent However, for multicast traffic sent from the access point, all
at the base transmission rate (which is configurable, but depending traffic is sent at the base transmission rate (which is configurable
on the model of the access point, is usually 24Mbps or less). but, depending on the model of the access point, is usually 24 Mbps
or less).
In addition to utilizing variable datarate links, mobile networks are In addition to utilizing links that have variable data rates, mobile
challenged by the notion that link connectivity will come and go over networks are challenged by the notion that link connectivity will
time, without an effect on a router's interface state (Up or Down). come and go over time, without an effect on a router's interface
Effectively utilizing a relatively short-lived connection is state (Up or Down). Effectively utilizing a relatively short-lived
problematic in IP routed networks, as IP routing protocols tend to connection is problematic in IP routed networks, as IP routing
rely on interface state and independent timers to maintain network protocols tend to rely on interface state and independent timers to
convergence (e.g., HELLO messages and/or recognition of DEAD routing maintain network convergence (e.g., HELLO messages and/or recognition
adjacencies). These dynamic connections can be better utilized with of DEAD routing adjacencies). These dynamic connections can be
an event-driven paradigm, where acquisition of a new neighbor (or better utilized with an event-driven paradigm, where acquisition of a
loss of an existing one) is signaled, as opposed to a paradigm driven new neighbor (or loss of an existing one) is signaled, as opposed to
by timers and/or interface state. DLEP not only implements such an a paradigm driven by timers and/or interface state. DLEP not only
event-driven paradigm, but does so over a local (1 hop) TCP session, implements such an event-driven paradigm but does so over a local
which guarantees delivery of the event messages. (1-hop) TCP session, which guarantees delivery of the event messages.
Another complicating factor for mobile networks are the different Another complicating factor for mobile networks are the different
methods of physically connecting the modem devices to the router. methods of physically connecting the modem devices to the router.
Modems can be deployed as an interface card in a router's chassis, or Modems can be deployed as an interface card in a router's chassis, or
as a standalone device connected to the router via Ethernet or serial as a standalone device connected to the router via Ethernet or serial
link. In the case of Ethernet attachment, with existing protocols link. In the case of Ethernet attachment, with existing protocols
and techniques, routing software cannot be aware of convergence and techniques, routing software cannot be aware of convergence
events occurring on the radio link (e.g., acquisition or loss of a events occurring on the radio link (e.g., acquisition or loss of a
potential routing neighbor), nor can the router be aware of the potential routing neighbor), nor can the router be aware of the
actual capacity of the link. This lack of awareness, along with the actual capacity of the link. This lack of awareness, along with the
variability in datarate, leads to a situation where finding the variability in data rate, leads to a situation where finding the
(current) best route through the network to a given node is difficult (current) best route through the network to a given node is difficult
to establish and properly maintain. This is especially true of to establish and properly maintain. This is especially true of
demand-based access schemes such as Demand Assigned Multiple Access demand-based access schemes such as Demand Assigned Multiple Access
(DAMA) implementations used on some satellite systems. With a DAMA- (DAMA) implementations used on some satellite systems. With a
based system, additional datarate may be available, but will not be DAMA-based system, additional data rate may be available but will not
used unless the network devices emit traffic at a rate higher than be used unless the network devices emit traffic at a rate higher than
the currently established rate. Increasing the traffic rate does not the currently established rate. Increasing the traffic rate does not
guarantee additional datarate will be allocated; rather, it may guarantee that additional data rate will be allocated; rather, it may
result in data loss and additional retransmissions on the link. result in data loss and additional retransmissions on the link.
Addressing the challenges listed above, the Dynamic Link Exchange Addressing the challenges listed above, the Dynamic Link Exchange
Protocol, or DLEP, has been developed. The DLEP protocol runs Protocol, or DLEP, has been developed. DLEP runs between a router
between a router and its attached modem devices, allowing the modem and its attached modem devices, allowing the modem devices to
to communicate link characteristics as they change, and convergence communicate (1) link characteristics as they change and
events (acquisition and loss of potential routing next-hops). The (2) convergence events (acquisition and loss of potential routing
following diagrams are used to illustrate the scope of DLEP packets. next hops). Figures 1 and 2 illustrate the scope of DLEP packets.
|-------Local Node-------| |-------Remote Node------| |-------Local Node-------| |-------Remote Node------|
| | | | | | | |
+--------+ +-------+ +-------+ +--------+ +--------+ +-------+ +-------+ +--------+
| Router |=======| Modem |{~~~~~~~~}| Modem |=======| Router | | Router |=======| Modem |{~~~~~~~~}| Modem |=======| Router |
| | | Device| | Device| | | | | | Device| | Device| | |
+--------+ +-------+ +-------+ +--------+ +--------+ +-------+ +-------+ +--------+
| | | Link | | | | | | Link | | |
|-DLEP--| | Protocol | |-DLEP--| |-DLEP--| | Protocol | |-DLEP--|
| | | (e.g. | | | | | | (e.g., | | |
| | | 802.11) | | | | | | 802.11) | | |
Figure 1: DLEP Network Figure 1: DLEP Network
In Figure 1, when the local modem detects the presence of a remote In Figure 1, when the local modem detects the presence of a remote
node, it (the local modem) sends a message to its router via the DLEP node, it (the local modem) sends a message to its router via DLEP.
protocol. The message consists of an indication of what change has The message consists of an indication of what change has occurred on
occurred on the link (e.g., presence of a remote node detected), the link (e.g., the presence of a remote node detected), along with a
along with a collection of DLEP-defined data items that further collection of DLEP-defined Data Items that further describe the
describe the change. Upon receipt of the message, the local router change. Upon receipt of the message, the local router may take
may take whatever action it deems appropriate, such as initiating whatever action it deems appropriate, such as initiating discovery
discovery protocols, and/or issuing HELLO messages to converge the protocols and/or issuing HELLO messages to converge the network. On
network. On a continuing, as-needed basis, the modem devices use a continuing, as-needed basis, the modem devices use DLEP to report
DLEP to report any characteristics of the link (datarate, latency, any characteristics of the link (data rate, latency, etc.) that have
etc.) that have changed. DLEP is independent of the link type and changed. DLEP is independent of the link type and topology supported
topology supported by the modem. Note that the DLEP protocol is by the modem. Note that DLEP is specified to run only on the local
specified to run only on the local link between router and modem. link between router and modem. Some over-the-air signaling may be
Some over the air signaling may be necessary between the local and necessary between the local and remote modem in order to provide some
remote modem in order to provide some parameters in DLEP messages parameters in DLEP Messages between the local modem and local router,
between the local modem and local router, but DLEP does not specify but DLEP does not specify how such over-the-air signaling is carried
how such over the air signaling is carried out. Over the air out. Over-the-air signaling is purely a matter for the modem
signaling is purely a matter for the modem implementer. implementer.
Figure 2 shows how DLEP can support a configuration where routers are Figure 2 shows how DLEP can support a configuration where routers are
connected with different link types. In this example, Modem A connected with different link types. In this example, Modem Device
implements a point-to-point link, and Modem B is connected via a Type A implements a point-to-point link, and Modem Device Type B is
shared medium. In both cases, the DLEP protocol is used to report connected via a shared medium. In both cases, DLEP is used to report
the characteristics of the link (datarate, latency, etc.) to routers. the characteristics of the link (data rate, latency, etc.) to
The modem is also able to use the DLEP session to notify the router routers. The modem is also able to use the DLEP session to notify
when the remote node is lost, shortening the time required to re- the router when the remote node is lost, shortening the time required
converge the network. to reconverge the network.
+--------+ +--------+ +--------+ +--------+
+----+ Modem | | Modem +---+ +----+ Modem | | Modem +---+
| | Device | | Device | | | Device | | Device | |
| | Type A | <===== // ======> | Type A | | | | Type A | <===== // ======> | Type A | |
| +--------+ P-2-P Link +--------+ | | +--------+ Point-to-Point Link +--------+ |
+---+----+ +---+----+ +---+----+ +---+----+
| Router | | Router | | Router | | Router |
| | | | | | | |
+---+----+ +---+----+ +---+----+ +---+----+
| +--------+ +--------+ | | +--------+ +--------+ |
+-----+ Modem | | Modem | | +-----+ Modem | | Modem | |
| Device | o o o o o o o o | Device +--+ | Device | o o o o o o o o | Device +--+
| Type B | o Shared o | Type B | | Type B | o Shared o | Type B |
+--------+ o Medium o +--------+ +--------+ o Medium o +--------+
o o o o
skipping to change at page 7, line 43 skipping to change at page 7, line 43
+--------+ +--------+
Figure 2: DLEP Network with Multiple Modem Devices Figure 2: DLEP Network with Multiple Modem Devices
2. Protocol Overview 2. Protocol Overview
DLEP defines a set of Messages used by modems and their attached DLEP defines a set of Messages used by modems and their attached
routers to communicate events that occur on the physical link(s) routers to communicate events that occur on the physical link(s)
managed by the modem: for example, a remote node entering or leaving managed by the modem: for example, a remote node entering or leaving
the network, or that the link has changed. Associated with these the network, or that the link has changed. Associated with these
Messages are a set of Data Items - information that describes the Messages are a set of Data Items -- information that describes the
remote node (e.g., address information), and/or the characteristics remote node (e.g., address information) and/or the characteristics of
of the link to the remote node. Throughout this document, we refer the link to the remote node. Throughout this document, we refer to
to a modems/routers participating in a DLEP session as 'DLEP modems/routers participating in a DLEP session as "DLEP
Participants', unless a specific distinction (e.g. modem or router) Participants", unless a specific distinction (e.g., modem or router)
is required. is required.
DLEP uses a session-oriented paradigm between the modem device and DLEP uses a session-oriented paradigm between the modem device and
its associated router. If multiple modem devices are attached to a its associated router. If multiple modem devices are attached to a
router (as in Figure 2), or the modem supports multiple connections router (as in Figure 2) or the modem supports multiple connections
(via multiple logical or physical interfaces), then separate DLEP (via multiple logical or physical interfaces), then separate DLEP
sessions exist for each modem or connection. A router and modem form sessions exist for each modem or connection. A router and modem form
a session by completing the discovery and initialization process. a session by completing the discovery and initialization process.
This router-modem session persists unless or until it either (1) This router-modem session persists unless or until it either
times out, based on the absence of DLEP traffic (including (1) times out, based on the absence of DLEP traffic (including
heartbeats), or (2) is explicitly torn down by one of the DLEP heartbeats) or (2) is explicitly torn down by one of the DLEP
participants. participants.
While this document represents the best efforts of the working group While this document represents the best efforts of the working group
to be functionally complete, it is recognized that extensions to DLEP to be functionally complete, it is recognized that extensions to DLEP
will in all likelihood be necessary as more link types are used. will in all likelihood be necessary as more link types are used.
Such extensions are defined as additional Messages, Data Items and/or Such extensions are defined as additional Messages, Data Items,
status codes, and associated rules of behavior, that are not defined and/or status codes, and associated rules of behavior, that are not
in this document. DLEP contains a standard mechanism for router and defined in this document. DLEP contains a standard mechanism for
modem implementations to negotiate the available extensions to use on router and modem implementations to negotiate the available
a per-session basis. extensions to use on a per-session basis.
2.1. Destinations 2.1. Destinations
The router/modem session provides a carrier for information exchange The router-modem session provides a carrier for information exchange
concerning 'destinations' that are available via the modem device. concerning "destinations" that are available via the modem device.
Destinations can be identified by either the router or the modem, and Destinations can be identified by either the router or the modem and
represent a specific, addressable location that can be reached via represent a specific, addressable location that can be reached via
the link(s) managed by the modem. the link(s) managed by the modem.
The DLEP Messages concerning destinations thus become the way for The DLEP Messages concerning destinations thus become the way for
routers and modems to maintain, and notify each other about, an routers and modems to maintain, and notify each other about, an
information base representing the physical and logical destinations information base representing the physical and logical destinations
accessible via the modem device, as well as the link characteristics accessible via the modem device, as well as the link characteristics
to those destinations. to those destinations.
A destination can be either physical or logical. The example of a A destination can be either physical or logical. The example of a
physical destination would be that of a remote, far-end router physical destination would be that of a remote, far-end router
attached via the variable-quality network. It should be noted that attached via the variable-quality network. It should be noted that
for physical destinations the MAC address is the address of the far- for physical destinations the Media Access Control (MAC) address is
end router, not the modem. the address of the far-end router, not the modem.
The example of a logical destination is Multicast. Multicast traffic The example of a logical destination is Multicast. Multicast traffic
destined for the variable-quality network (the network accessed via destined for the variable-quality network (the network accessed via
the modem) is handled in IP networks by deriving a Layer 2 MAC the modem) is handled in IP networks by deriving a Layer 2 MAC
address based on the Layer 3 address. Leveraging on this scheme, address based on the Layer 3 address. Leveraging on this scheme,
multicast traffic is supported in DLEP simply by treating the derived multicast traffic is supported in DLEP simply by treating the derived
MAC address as any other destination in the network. MAC address as any other destination in the network.
To support these logical destinations, one of the DLEP participants To support these logical destinations, one of the DLEP participants
(typically, the router) informs the other as to the existence of the (typically, the router) informs the other as to the existence of the
logical destination. The modem, once it is aware of the existence of logical destination. The modem, once it is aware of the existence of
this logical destination, reports link characteristics just as it this logical destination, reports link characteristics just as it
would for any other destination in the network. The specific would for any other destination in the network. The specific
algorithms a modem would use to derive metrics on logical algorithms a modem would use to derive metrics on logical
destinations are outside the scope of this specification, and is left destinations are outside the scope of this specification; these
to specific implementations to decide. algorithms are left to specific implementations to decide.
In all cases, when this specification uses the term destination, it In all cases, when this specification uses the term "destination", it
refers to the addressable locations, either logical or physical, that refers to the addressable locations, either logical or physical, that
are accessible by the radio link(s). are accessible by the radio link(s).
2.2. Conventions and Terminology 2.2. Conventions and Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in
14, RFC 2119 [RFC2119]. BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
3. Requirements 3. Requirements
DLEP MUST be implemented on a single Layer 2 domain. The protocol DLEP MUST be implemented on a single Layer 2 domain. The protocol
identifies next-hop destinations by using the MAC address for identifies next-hop destinations by using the MAC address for
delivering data traffic. No manipulation or substitution is delivering data traffic. No manipulation or substitution is
performed; the MAC address supplied in all DLEP Messages is used as performed; the MAC address supplied in all DLEP Messages is used as
the Destination MAC address for frames emitted by the participating the Destination MAC address for frames emitted by the participating
router. MAC addresses MUST be unique within the context of router- router. MAC addresses MUST be unique within the context of the
modem session. router-modem session.
To enforce the single Layer 2 domain, implementations MUST support To enforce the single Layer 2 domain, implementations MUST support
The Generalized TTL Security Mechanism [RFC5082], and implementations the Generalized TTL Security Mechanism [RFC5082], and implementations
MUST adhere to this specification for all DLEP Messages. MUST adhere to this specification for all DLEP Messages.
DLEP specifies UDP multicast for single-hop discovery signaling, and DLEP specifies UDP multicast for single-hop discovery signaling and
TCP for transport of the Messages. Modems and routers participating TCP for transport of the Messages. Modems and routers participating
in DLEP sessions MUST have topologically consistent IP addresses in DLEP sessions MUST have topologically consistent IP addresses
assigned. It is RECOMMENDED that DLEP implementations utilize IPv6 assigned. It is RECOMMENDED that DLEP implementations utilize IPv6
link-local addresses to reduce the administrative burden of address link-local addresses to reduce the administrative burden of address
assignment. assignment.
DLEP relies on the guaranteed delivery of its Messages between router DLEP relies on the guaranteed delivery of its Messages between router
and modem, once the 1 hop discovery process is complete, hence, the and modem, once the 1-hop discovery process is complete -- hence, the
specification of TCP to carry the Messages. Other reliable specification of TCP to carry the Messages. Other reliable
transports for the protocol are possible, but are outside the scope transports for the protocol are possible but are outside the scope of
of this document. this document.
4. Implementation Scenarios 4. Implementation Scenarios
During development of this specification, two types of deployments During development of this specification, two types of deployments
were discussed. were discussed.
The first can be viewed as a "dedicated deployment". In this mode, The first can be viewed as a "dedicated deployment". In this mode,
DLEP routers and modems are either directly connected (e.g., using DLEP routers and modems are either directly connected (e.g., using
cross-over cables to connect interfaces), or are connected to a crossover cables to connect interfaces) or connected to a dedicated
dedicated switch. An example of this type of deployment would be a switch. An example of this type of deployment would be a router with
router with a line-of- sight radio connected into one interface, with a line-of-sight radio connected into one interface, with a satellite
a satellite modem connected into another interface. In mobile modem connected into another interface. In mobile environments, the
environments, the router and the connected modem(s) are placed into a router and the connected modem (or modems) are placed into a mobile
mobile platform (e.g., a vehicle, boat, or airplane). In this mode, platform (e.g., a vehicle, boat, or airplane). In this mode, when a
when a switch is used, it is possible that a small number of switch is used, it is possible that a small number of ancillary
ancillary devices (e.g., a laptop) are also plugged into the switch. devices (e.g., a laptop) are also plugged into the switch. But in
But in either event, the resulting network segment is constrained to either event, the resulting network segment is constrained to a small
a small number of devices, and is not generally accessible from number of devices and is not generally accessible from anywhere else
anywhere else in the network. in the network.
The other type of deployment envisioned can be viewed as a "networked The other type of deployment envisioned can be viewed as a "networked
deployment". In this type of scenario, the DLEP router and modem(s) deployment". In this type of scenario, the DLEP router and modem
are placed on a segment that is accessible from other points in the (or modems) are placed on a segment that is accessible from other
network. In this scenario, not only are the DLEP router and modem(s) points in the network. In this scenario, not only are the DLEP
accessible from other points in the network; the router and a given router and modem(s) accessible from other points in the network; the
modem could be multiple physical hops away from each other. This router and a given modem could be multiple physical hops away from
scenario necessitates the use of Layer 2 tunneling technology to each other. This scenario necessitates the use of Layer 2 tunneling
enforce the single-hop requirement of DLEP. technology to enforce the single-hop requirement of DLEP.
5. Assumptions 5. Assumptions
DLEP assumes that a signaling protocol exists between modems DLEP assumes that a signaling protocol exists between modems
participating in a network. The specification does not define the participating in a network. This specification does not define the
character or behavior of this over-the-air signaling, but does expect character or behavior of this over-the-air signaling but does expect
some information to be carried (or derived) by the signaling, such as some information to be carried (or derived) by the signaling,
the arrival and departure of modems from this network, and the such as the arrival and departure of modems from this network,
variation of the link characteristics between modems. This and the variation of the link characteristics between modems.
information is then assumed to be used by the modem to implement the This information is then assumed to be used by the modem to
DLEP protocol. implement DLEP.
The specification assumes that the link between router and modem is This specification assumes that the link between router and modem is
static with respect to datarate and latency, and that this link is static with respect to data rate and latency and that this link is
not likely to be the cause of a performance bottleneck. In not likely to be the cause of a performance bottleneck. In
deployments where the router and modem are physically separated by deployments where the router and modem are physically separated by
multiple network hops, served by Layer 2 tunneling technology, DLEP multiple network hops, served by Layer 2 tunneling technology, DLEP
statistics on the RF links could be insufficient for routing statistics on the RF links could be insufficient for routing
protocols to make appropriate routing decisions. This would protocols to make appropriate routing decisions. This would
especially become an issue in cases where the Layer 2 tunnel between especially become an issue in cases where the Layer 2 tunnel between
router and modem is itself served in part (or in total) with a router and modem is itself served in part (or in total) with a
wireless back-haul link. wireless backhaul link.
6. Metrics 6. Metrics
DLEP includes the ability for the router and modem to communicate DLEP includes the ability for the router and modem to communicate
metrics that reflect the characteristics (e.g., datarate, latency) of metrics that reflect the characteristics (e.g., data rate, latency)
the variable-quality link in use. DLEP does not specify how a given of the variable-quality link in use. DLEP does not specify how a
metric value is to be calculated, rather, the protocol assumes that given metric value is to be calculated; rather, the protocol assumes
metrics have been calculated by a 'best effort', incorporating all that metrics have been calculated by a "best effort", incorporating
pertinent data that is available to the modem device. Metrics based all pertinent data that is available to the modem device. Metrics
on large enough sample sizes will preclude short traffic bursts from based on large-enough sample sizes will preclude short traffic bursts
adversely skewing reported values. from adversely skewing reported values.
DLEP allows for metrics to be sent within two contexts - metrics for DLEP allows for metrics to be sent within two contexts -- metrics for
a specific destination within the network (e.g., a specific router), a specific destination within the network (e.g., a specific router),
and per-session (those that apply to all destinations accessed via and "per session" (those that apply to all destinations accessed via
the modem). Most metrics can be further subdivided into transmit and the modem). Most metrics can be further subdivided into transmit and
receive metrics. In cases where metrics are provided at session receive metrics. In cases where metrics are provided at the session
level, the router propagates the metrics to all entries in its level, the router propagates the metrics to all entries in its
information base for destinations that are accessed via the modem. information base for destinations that are accessed via the modem.
DLEP modems announce all metric Data Items that will be reported DLEP modems announce all metric Data Items that will be reported
during the session, and provide default values for those metrics, in during the session, and provide default values for those metrics, in
the Session Initialization Response Message (Section 12.6). In order the Session Initialization Response Message (Section 12.6). In order
to use a metric type that was not included in the Session to use a metric type that was not included in the Session
Initialization Response Message, modem implementations terminate the Initialization Response Message, modem implementations terminate the
session with the router (via the Session Terminate Message session with the router (via the Session Termination Message
(Section 12.9)), and establish a new session. (Section 12.9)) and establish a new session.
A DLEP modem can send metrics both in a session context, via the A DLEP modem can send metrics in both (1) a session context, via the
Session Update Message (Section 12.7), and a specific destination Session Update Message (Section 12.7) and (2) a specific destination
context, via the Destination Update Message (Section 12.17), at any context, via the Destination Update Message (Section 12.17), at any
time. The most recently received metric value takes precedence over time. The most recently received metric value takes precedence over
any earlier value, regardless of context - that is: any earlier value, regardless of context -- that is:
1. If the router receives metrics in a specific destination context 1. If the router receives metrics in a specific destination context
(via the Destination Update Message), then the specific (via the Destination Update Message), then the specific
destination is updated with the new metric. destination is updated with the new metric.
2. If the router receives metrics in a session-wide context (via the 2. If the router receives metrics in a session-wide context (via the
Session Update Message), then the metrics for all destinations Session Update Message), then the metrics for all destinations
accessed via the modem are updated with the new metric. accessed via the modem are updated with the new metric.
It is left to implementations to choose sensible default values based It is left to implementations to choose sensible default values based
on their specific characteristics. Modems having static (non- on their specific characteristics. Modems having static
changing) link metric characteristics can report metrics only once (non-changing) link metric characteristics can report metrics only
for a given destination (or once on a session-wide basis, if all once for a given destination (or once on a session-wide basis, if all
connections via the modem are of this static nature). connections via the modem are of this static nature).
In addition to communicating existing metrics about the link, DLEP In addition to communicating existing metrics about the link, DLEP
provides a Message allowing a router to request a different datarate provides a Message allowing a router to request a different data rate
or latency from the modem. This Message is the Link Characteristics or latency from the modem. This Message is the Link Characteristics
Request Message (Section 12.18), and gives the router the ability to Request Message (Section 12.18); it gives the router the ability to
deal with requisite increases (or decreases) of allocated datarate/ deal with requisite increases (or decreases) of allocated
latency in demand-based schemes in a more deterministic manner. data rate/latency in demand-based schemes in a more deterministic
manner.
7. DLEP Session Flow 7. DLEP Session Flow
All DLEP participants of a session transition through a number of All DLEP participants of a session transition through a number of
distinct states during the lifetime of a DLEP session: distinct states during the lifetime of a DLEP session:
o Peer Discovery o Peer Discovery
o Session Initialization o Session Initialization
o In-Session o In-Session
o Session Termination o Session Termination
o Session Reset o Session Reset
Modems, and routers supporting DLEP discovery, transition through all Modems, and routers supporting DLEP discovery, transition through all
five (5) of the above states. Routers that rely on preconfigured TCP five of the above states. Routers that rely on preconfigured TCP
address/port information start in the Session Initialization state. address/port information start in the Session Initialization state.
Modems MUST support the Peer Discovery state. Modems MUST support the Peer Discovery state.
7.1. Peer Discovery State 7.1. Peer Discovery State
Modems MUST support DLEP Peer Discovery; routers MAY support the Modems MUST support DLEP Peer Discovery; routers MAY support the
discovery signals, or rely on a priori configuration to locate discovery signals or rely on a priori configuration to locate modems.
modems. If a router chooses to support DLEP discovery, all signals If a router chooses to support DLEP discovery, all signals MUST be
MUST be supported. supported.
In the Peer Discovery state, routers that support DLEP discovery MUST In the Peer Discovery state, routers that support DLEP discovery MUST
send Peer Discovery Signals (Section 12.3) to initiate modem send Peer Discovery Signals (Section 12.3) to initiate modem
discovery. discovery.
The router implementation then waits for a Peer Offer Signal The router implementation then waits for a Peer Offer Signal
(Section 12.4) response from a potential DLEP modem. While in the (Section 12.4) response from a potential DLEP modem. While in the
Peer Discovery state, Peer Discovery Signals MUST be sent repeatedly Peer Discovery state, Peer Discovery Signals MUST be sent repeatedly
by a DLEP router, at regular intervals. It is RECOMMENDED that this by a DLEP router, at regular intervals. It is RECOMMENDED that this
interval be set to 60 seconds. The interval MUST be a minimum of one interval be set to 60 seconds. The interval MUST be a minimum of
second; it SHOULD be a configurable parameter. Note that this 1 second; it SHOULD be a configurable parameter. Note that this
operation (sending Peer Discovery and waiting for Peer Offer) is operation (sending Peer Discovery and waiting for Peer Offer) is
outside the DLEP Transaction Model (Section 8), as the Transaction outside the DLEP transaction model (Section 8), as the transaction
Model only describes Messages on a TCP session. model only describes Messages on a TCP session.
Routers receiving a Peer Offer Signal MUST use one of the modem Routers receiving a Peer Offer Signal MUST use one of the modem
address/port combinations from the Peer Offer Signal to establish a address/port combinations from the Peer Offer Signal to establish a
TCP connection to the modem, even if a priori configuration exists. TCP connection to the modem, even if a priori configuration exists.
If multiple connection point Data Items exist in the received Peer If multiple Connection Point Data Items exist in the received Peer
Offer Signal, routers SHOULD prioritize IPv6 connection points over Offer Signal, routers SHOULD prioritize IPv6 connection points over
IPv4 connection points. If multiple connection points exist with the IPv4 connection points. If multiple connection points exist with the
same transport (e.g. IPv6 or IPv4), implementations MAY use their same transport (e.g., IPv6 or IPv4), implementations MAY use their
own heuristics to determine the order in which they are tried. If a own heuristics to determine the order in which they are tried. If a
TCP connection cannot be achieved using any of the address/port TCP connection cannot be achieved using any of the address/port
combinations and the Discovery mechanism is in use, then the router combinations and the Discovery mechanism is in use, then the router
SHOULD resume issuing Peer Discovery Signals. If no Connection Point SHOULD resume issuing Peer Discovery Signals. If no Connection Point
Data Items are included in the Peer Offer Signal, the router MUST use Data Items are included in the Peer Offer Signal, the router MUST use
the source address of the UDP packet containing the Peer Offer Signal the source address of the UDP packet containing the Peer Offer Signal
as the IP address, and the DLEP well-known port number. as the IP address, and the DLEP well-known port number.
In the Peer Discovery state, the modem implementation MUST listen for In the Peer Discovery state, the modem implementation MUST listen for
incoming Peer Discovery Signals on the DLEP well-known IPv6 and/or incoming Peer Discovery Signals on the DLEP well-known IPv6 and/or
IPv4 link-local multicast address and port. On receipt of a valid IPv4 link-local multicast address and port. On receipt of a valid
Peer Discovery Signal, it MUST reply with a Peer Offer Signal. Peer Discovery Signal, it MUST reply with a Peer Offer Signal.
Modems MUST be prepared to accept a TCP connection from a router that Modems MUST be prepared to accept a TCP connection from a router that
is not using the Discovery mechanism, i.e. a connection attempt that is not using the Discovery mechanism, i.e., a connection attempt that
occurs without a preceding Peer Discovery Signal. occurs without a preceding Peer Discovery Signal.
Implementations of DLEP SHOULD implement, and use, TLS [RFC5246] to Implementations of DLEP SHOULD implement, and use, Transport Layer
protect the TCP session. The "dedicated deployments" discussed in Security (TLS) [RFC5246] to protect the TCP session. The "dedicated
Implementation Scenarios (Section 4) MAY consider use of DLEP without deployments" discussed in "Implementation Scenarios" (Section 4) MAY
TLS. For all "networked deployments" (again, discussed in consider the use of DLEP without TLS. For all "networked
Implementation Scenarios), implementation and use of TLS is STRONGLY deployments" (again, discussed in "Implementation Scenarios"), the
RECOMMENDED. If TLS is to be used then the TLS session MUST be implementation and use of TLS are STRONGLY RECOMMENDED. If TLS is to
established before any Messages are passed between peers. Routers be used, then the TLS session MUST be established before any Messages
supporting TLS MUST prioritize connection points using TLS over those are passed between peers. Routers supporting TLS MUST prioritize
that do not. connection points using TLS over those that do not.
Upon establishment of a TCP connection, and TLS session if TLS is in Upon establishment of a TCP connection, and the establishment of a
use, both modem and router enter the Session Initialization state. TLS session if TLS is in use, both modem and router enter the Session
It is up to the router implementation if Peer Discovery Signals Initialization state. It is up to the router implementation if Peer
continue to be sent after the device has transitioned to the Session Discovery Signals continue to be sent after the device has
Initialization state. Modem implementations MUST silently ignore transitioned to the Session Initialization state. Modem
Peer Discovery Signals from a router with which it already has a TCP implementations MUST silently ignore Peer Discovery Signals from a
router with which a given implementation already has a TCP
connection. connection.
7.2. Session Initialization State 7.2. Session Initialization State
On entering the Session Initialization state, the router MUST send a On entering the Session Initialization state, the router MUST send a
Session Initialization Message (Section 12.5) to the modem. The Session Initialization Message (Section 12.5) to the modem. The
router MUST then wait for receipt of a Session Initialization router MUST then wait for receipt of a Session Initialization
Response Message (Section 12.6) from the modem. Receipt of the Response Message (Section 12.6) from the modem. Receipt of the
Session Initialization Response Message containing a Status Data Item Session Initialization Response Message containing a Status Data Item
(Section 13.1) with status code set to 0 'Success', see Table 2, (Section 13.1) with status code set to 0 'Success' (see Table 2 in
indicates that the modem has received and processed the Session Section 13.1) indicates that the modem has received and processed the
Initialization Message, and the router MUST transition to the In- Session Initialization Message, and the router MUST transition to the
Session state. In-Session state.
On entering the Session Initialization state, the modem MUST wait for On entering the Session Initialization state, the modem MUST wait for
receipt of a Session Initialization Message from the router. Upon receipt of a Session Initialization Message from the router. Upon
receipt of a Session Initialization Message, the modem MUST send a receipt of a Session Initialization Message, the modem MUST send a
Session Initialization Response Message, and the session MUST Session Initialization Response Message, and the session MUST
transition to the In-Session state. If the modem receives any transition to the In-Session state. If the modem receives any
Message other than Session Initialization, or it fails to parse the Message other than Session Initialization or it fails to parse the
received Message, it MUST NOT send any Message, and MUST terminate received Message, it MUST NOT send any Message, and it MUST terminate
the TCP connection and transition to the Session Reset state. the TCP connection and transition to the Session Reset state.
DLEP provides an extension negotiation capability to be used in the DLEP provides an extension negotiation capability to be used in the
Session Initialization state, see Section 9. Extensions supported by Session Initialization state; see Section 9. Extensions supported by
an implementation MUST be declared to potential DLEP participants an implementation MUST be declared to potential DLEP participants
using the Extensions Supported Data Item (Section 13.6). Once both using the Extensions Supported Data Item (Section 13.6). Once both
DLEP participants have exchanged initialization Messages, an DLEP participants have exchanged initialization Messages, an
implementation MUST NOT emit any Message, Signal, Data Item or status implementation MUST NOT emit any Message, Signal, Data Item, or
code associated with an extension that was not specified in the status code associated with an extension that was not specified in
received initialization Message from its peer. the received initialization Message from its peer.
7.3. In-Session State 7.3. In-Session State
In the In-Session state, Messages can flow in both directions between In the In-Session state, Messages can flow in both directions between
DLEP participants, indicating changes to the session state, the DLEP participants, indicating changes to the session state, the
arrival or departure of reachable destinations, or changes of the arrival or departure of reachable destinations, or changes of the
state of the links to the destinations. state of the links to the destinations.
The In-Session state is maintained until one of the following The In-Session state is maintained until one of the following
conditions occur: conditions occurs:
o The implementation terminates the session by sending a Session o The implementation terminates the session by sending a Session
Termination Message (Section 12.9), or, Termination Message (Section 12.9), or
o Its peer terminates the session, indicated by receiving a Session o Its peer terminates the session, indicated by receiving a Session
Termination Message. Termination Message.
The implementation MUST then transition to the Session Termination The implementation MUST then transition to the Session Termination
state. state.
7.3.1. Heartbeats 7.3.1. Heartbeats
In order to maintain the In-Session state, periodic Heartbeat In order to maintain the In-Session state, periodic Heartbeat
Messages (Section 12.20) MUST be exchanged between router and modem. Messages (Section 12.20) MUST be exchanged between router and modem.
These Messages are intended to keep the session alive, and to verify These Messages are intended to keep the session alive and to verify
bidirectional connectivity between the two DLEP participants. It is bidirectional connectivity between the two DLEP participants. It is
RECOMMENDED that the interval timer between heartbeat messages be set RECOMMENDED that the interval timer between Heartbeat Messages be set
to 60 seconds. The interval MUST be a minimum of one second; it to 60 seconds. The interval MUST be a minimum of 1 second; it SHOULD
SHOULD be a configurable parameter. be a configurable parameter.
Each DLEP participant is responsible for the creation of Heartbeat Each DLEP participant is responsible for the creation of Heartbeat
Messages. Messages.
Receipt of any valid DLEP Message MUST reset the heartbeat interval Receipt of any valid DLEP Message MUST reset the heartbeat interval
timer (i.e., valid DLEP Messages take the place of, and obviate the timer (i.e., valid DLEP Messages take the place of, and obviate the
need for, additional Heartbeat Messages). need for, additional Heartbeat Messages).
Implementations MUST allow a minimum of two (2) heartbeat intervals An implementation MUST allow a minimum of 2 heartbeat intervals to
to expire with no Messages from its peer before terminating the expire with no Messages from its peer before terminating the session.
session. When terminating the session, a Session Termination Message When terminating the session, a Session Termination Message
containing a Status Data Item (Section 13.1) with status code set to containing a Status Data Item (Section 13.1) with status code set to
132 'Timed Out', see Table 2, MUST be sent, and then the 132 'Timed Out' (see Table 2) MUST be sent, and then the
implementation MUST transition to the Session Termination state. implementation MUST transition to the Session Termination state.
7.4. Session Termination State 7.4. Session Termination State
When an implementation enters the Session Termination state after When an implementation enters the Session Termination state after
sending a Session Termination Message (Section 12.9) as the result of sending a Session Termination Message (Section 12.9) as the result of
an invalid Message or error, it MUST wait for a Session Termination an invalid Message or error, it MUST wait for a Session Termination
Response Message (Section 12.10) from its peer. Senders SHOULD allow Response Message (Section 12.10) from its peer. A sender SHOULD
four (4) heartbeat intervals to expire before assuming that its peer allow 4 heartbeat intervals to expire before assuming that its peer
is unresponsive, and continuing with session termination. Any other is unresponsive and before continuing with session termination. Any
Message received while waiting MUST be silently ignored. other Message received while waiting MUST be silently ignored.
When the sender of the Session Termination Message receives a Session When the sender of the Session Termination Message receives a Session
Termination Response Message from its peer, or times out, it MUST Termination Response Message from its peer or times out, it MUST
transition to the Session Reset state. transition to the Session Reset state.
When an implementation receives a Session Termination Message from When an implementation receives a Session Termination Message from
its peer, it enters the Session Termination state and then it MUST its peer, it enters the Session Termination state, and then it MUST
immediately send a Session Termination Response and transition to the immediately send a Session Termination Response and transition to the
Session Reset state. Session Reset state.
7.5. Session Reset state 7.5. Session Reset State
In the Session Reset state the implementation MUST perform the In the Session Reset state, the implementation MUST perform the
following actions: following actions:
o Release all resources allocated for the session. o Release all resources allocated for the session.
o Eliminate all destinations in the information base represented by o Eliminate all destinations in the information base represented by
the session. Destination Down Messages (Section 12.15) MUST NOT the session. Destination Down Messages (Section 12.15) MUST NOT
be sent. be sent.
o Terminate the TCP connection. o Terminate the TCP connection.
Having completed these actions the implementation SHOULD return to Having completed these actions, the implementation SHOULD return to
the relevant initial state: Peer Discovery for modems; either Peer the relevant initial state:
Discovery or Session Initialization for routers, depending on
configuration.
7.5.1. Unexpected TCP connection termination o For modems: Peer Discovery.
o For routers: either Peer Discovery or Session Initialization,
depending on configuration.
7.5.1. Unexpected TCP Connection Termination
If the TCP connection between DLEP participants is terminated when an If the TCP connection between DLEP participants is terminated when an
implementation is not in the Session Reset state, the implementation implementation is not in the Session Reset state, the implementation
MUST immediately transition to the Session Reset state. MUST immediately transition to the Session Reset state.
8. Transaction Model 8. Transaction Model
DLEP defines a simple Message transaction model: Only one request per DLEP defines a simple Message transaction model: only one request per
destination may be in progress at a time per session. A Message destination may be in progress at a time per session. A Message
transaction is considered complete when a response matching a transaction is considered complete when a response matching a
previously issued request is received. If a DLEP participant previously issued request is received. If a DLEP participant
receives a request for a destination for which there is already an receives a request for a destination for which there is already an
outstanding request, the implementation MUST terminate the session by outstanding request, the implementation MUST terminate the session by
issuing a Session Termination Message (Section 12.9) containing a issuing a Session Termination Message (Section 12.9) containing a
Status Data Item (Section 13.1) with status code set to 129 Status Data Item (Section 13.1) with status code set to
'Unexpected Message', see Table 2, and transition to the Session 129 'Unexpected Message' (see Table 2) and transition to the Session
Termination state. There is no restriction to the total number of Termination state. There is no restriction on the total number of
Message transactions in progress at a time, as long as each Message transactions in progress at a time, as long as each
transaction refers to a different destination. transaction refers to a different destination.
It should be noted that some requests may take a considerable amount It should be noted that some requests may take a considerable amount
of time for some DLEP participants to complete, for example, a modem of time for some DLEP participants to complete; for example, a modem
handling a multicast destination up request may have to perform a handling a multicast Destination Up request may have to perform a
complex network reconfiguration. A sending implementation MUST be complex network reconfiguration. A sending implementation MUST be
able to handle such long running transactions gracefully. able to handle such long-running transactions gracefully.
Additionally, only one session request, e.g. a Session Initialization Additionally, only one session request, e.g., a Session
Message (Section 12.5), may be in progress at a time per session. As Initialization Message (Section 12.5), may be in progress at a time
above, a session transaction is considered complete when a response per session. As noted above for Message transactions, a session
matching a previously issued request is received. If a DLEP transaction is considered complete when a response matching a
participant receives a session request while there is already a previously issued request is received. If a DLEP participant
session request in progress, it MUST terminate the session by issuing receives a session request while there is already a session request
a Session Termination Message containing a Status Data Item with in progress, it MUST terminate the session by issuing a Session
status code set to 129 'Unexpected Message', and transition to the Termination Message containing a Status Data Item with status code
Session Termination state. Only the Session Termination Message may set to 129 'Unexpected Message' and transition to the Session
be issued when a session transaction is in progress. Heartbeat Termination state. Only the Session Termination Message may be
Messages (Section 12.20) MUST NOT be considered part of a session issued when a session transaction is in progress. Heartbeat Messages
transaction. (Section 12.20) MUST NOT be considered part of a session transaction.
DLEP transactions do not time out and are not cancellable, except for DLEP transactions do not time out and are not cancellable, except for
transactions in-flight when the DLEP session is reset. If the transactions in flight when the DLEP session is reset. If the
session is terminated, canceling transactions in progress MUST be session is terminated, canceling transactions in progress MUST be
performed as part of resetting the state machine. An implementation performed as part of resetting the state machine. An implementation
can detect if its peer has failed in some way by use of the session can detect if its peer has failed in some way by use of the session
heartbeat mechanism during the In-Session state, see Section 7.3. heartbeat mechanism during the In-Session state; see Section 7.3.
9. Extensions 9. Extensions
Extensions MUST be negotiated on a per-session basis during session Extensions MUST be negotiated on a per-session basis during session
initialization via the Extensions Supported mechanism. initialization via the Extensions Supported mechanism.
Implementations are not required to support any extension in order to Implementations are not required to support any extensions in order
be considered DLEP compliant. to be considered DLEP compliant.
If interoperable protocol extensions are required, they will need to If interoperable protocol extensions are required, they will need to
be standardized either as an update to this document, or as an be standardized as either (1) an update to this document or (2) an
additional stand-alone specification. The requests for IANA- additional standalone specification. The IANA registries defined in
controlled registries in this document contain sufficient Reserved Section 15 of this document contain sufficient unassigned space for
space for DLEP Signals, Messages, Data Items and status codes to DLEP Signals, Messages, Data Items, and status codes to accommodate
accommodate future extensions to the protocol. future extensions to the protocol.
As multiple protocol extensions MAY be announced during session As multiple protocol extensions MAY be announced during session
initialization, authors of protocol extensions need to consider the initialization, authors of protocol extensions need to consider the
interaction of their extension with other published extensions, and interaction of their extensions with other published extensions and
specify any incompatibilities. specify any incompatibilities.
9.1. Experiments 9.1. Experiments
This document requests Private Use numbering space in the DLEP This document registers Private Use [RFC5226] numbering space in the
Signal, Message, Data Item and status code registries for DLEP Signal, Message, Data Item, and status code registries for
experimental extensions. The intent is to allow for experimentation experimental extensions. The intent is to allow for experimentation
with new Signals, Messages, Data Items, and/or status codes, while with new Signals, Messages, Data Items, and/or status codes while
still retaining the documented DLEP behavior. still retaining the documented DLEP behavior.
Use of the Private Use Signals, Messages, Data Items, status codes, During session initialization, the use of the Private Use Signals,
or behaviors MUST be announced as DLEP Extensions, during session Messages, Data Items, status codes, or behaviors MUST be announced as
initialization, using extension identifiers from the Private Use DLEP extensions, using extension identifiers from the Private Use
space in the Extensions Supported registry (Table 3), with a value space in the "Extension Type Values" registry (Table 3), with a value
agreed upon (a priori) between the participants. DLEP extensions agreed upon (a priori) between the participants. DLEP extensions
using the Private Use numbering space are commonly referred to as using the Private Use numbering space are commonly referred to as
Experiments. "experiments".
Multiple experiments MAY be announced in the Session Initialization Multiple experiments MAY be announced in the Session Initialization
Messages. However, use of multiple experiments in a single session Messages. However, the use of multiple experiments in a single
could lead to interoperability issues or unexpected results (e.g., session could lead to interoperability issues or unexpected results
clashes of experimental Signals, Messages, Data Items and/or status (e.g., clashes of experimental Signals, Messages, Data Items, and/or
code types), and is therefore discouraged. It is left to status code types) and is therefore discouraged. It is left to
implementations to determine the correct processing path (e.g., a implementations to determine the correct processing path (e.g., a
decision on whether to terminate the session, or to establish a decision on whether to terminate the session or establish a
precedence of the conflicting definitions) if such conflicts arise. precedence of the conflicting definitions) if such conflicts arise.
10. Scalability 10. Scalability
The protocol is intended to support thousands of destinations on a The protocol is intended to support thousands of destinations on a
given modem/router pair. At large scale, implementations should given modem/router pair. On a large scale, an implementation should
consider employing techniques to prevent flooding its peer with a consider employing techniques to prevent flooding its peer with a
large number of Messages in a short time. For example, a dampening large number of Messages in a short time. For example, a dampening
algorithm could be employed to prevent a flapping device from algorithm could be employed to prevent a flapping device from
generating a large number of Destination Up/Destination Down generating a large number of Destination Up / Destination Down
Messages. Messages.
Also, use of techniques such as a hysteresis can lessen the impact of Also, the use of techniques such as a hysteresis can lessen the
rapid, minor fluctuations in link quality. The specific algorithms impact of rapid, minor fluctuations in link quality. The specific
for handling flapping destinations and minor changes in link quality algorithms for handling flapping destinations and minor changes in
are outside the scope of this specification. link quality are outside the scope of this specification.
11. DLEP Signal and Message Structure 11. DLEP Signal and Message Structure
DLEP defines two protocol units used in two different ways: Signals DLEP defines two protocol units used in two different ways: Signals
and Messages. Signals are only used in the Discovery mechanism and and Messages. Signals are only used in the Discovery mechanism and
are carried in UDP datagrams. Messages are used bidirectionally over are carried in UDP datagrams. Messages are used bidirectionally over
a TCP connection between the participants, in the Session a TCP connection between the participants, in the Session
Initialization, In-Session and Session Termination states. Initialization, In-Session, and Session Termination states.
Both Signals and Messages consist of a Header followed by an Both Signals and Messages consist of a Header followed by an
unordered list of Data Items. Headers consist of Type and Length unordered list of Data Items. Headers consist of Type and Length
information, while Data Items are encoded as TLV (Type-Length-Value) information, while Data Items are encoded as TLV (Type-Length-Value)
structures. In this document, the Data Items following a Signal or structures. In this document, the Data Items following a Signal or
Message Header are described as being 'contained in' the Signal or Message Header are described as being "contained in" the Signal or
Message. Message.
There is no restriction on the order of Data Items following a There is no restriction on the order of Data Items following a
Header, and the acceptability of duplicate Data Items is defined by Header, and the acceptability of duplicate Data Items is defined by
the definition of the Signal or Message declared by the type in the the definition of the Signal or Message declared by the type in the
Header. Header.
All integers in Header fields and values MUST be in network byte- All integers in Header fields and values MUST be in network byte
order. order.
11.1. DLEP Signal Header 11.1. DLEP Signal Header
The DLEP Signal Header contains the following fields: The DLEP Signal Header contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 'D' | 'L' | 'E' | 'P' | | 'D' | 'L' | 'E' | 'P' |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Signal Type | Length | | Signal Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: DLEP Signal Header Figure 3: DLEP Signal Header
"DLEP": Every Signal MUST start with the characters: U+0044, U+004C, "DLEP": Every Signal MUST start with the following characters:
U+0045, U+0050. U+0044, U+004C, U+0045, U+0050.
Signal Type: A 16-bit unsigned integer containing one of the DLEP Signal Type: A 16-bit unsigned integer containing one of the DLEP
Signal Type values defined in this document. Signal Type values defined in this document.
Length: The length in octets, expressed as a 16-bit unsigned Length: The length in octets, expressed as a 16-bit unsigned
integer, of all of the DLEP Data Items contained in this Signal. integer, of all of the DLEP Data Items contained in this Signal.
This length MUST NOT include the length of the Signal Header This length MUST NOT include the length of the Signal Header
itself. itself.
The DLEP Signal Header is immediately followed by zero or more DLEP The DLEP Signal Header is immediately followed by zero or more DLEP
skipping to change at page 20, line 23 skipping to change at page 20, line 46
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Value... : | Value... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: DLEP Generic Data Item Figure 5: DLEP Generic Data Item
Data Item Type: A 16-bit unsigned integer field specifying the type Data Item Type: A 16-bit unsigned integer field specifying the type
of Data Item being sent. of Data Item being sent.
Length: The length in octets, expressed as a 16-bit unsigned Length: The length in octets, expressed as a 16-bit unsigned
integer, of the Value field of the Data Item. This length MUST integer, of the Value field of the Data Item. This length
NOT include the length of the Data Item Type and Length fields. MUST NOT include the length of the Data Item Type and Length
fields.
Value: A field of <Length> octets, which contains data specific to a Value: A field of <Length> octets that contains data specific to a
particular Data Item. particular Data Item.
12. DLEP Signals and Messages 12. DLEP Signals and Messages
12.1. General Processing Rules 12.1. General Processing Rules
If an unrecognized, or unexpected Signal is received, or a received If an unrecognized or unexpected Signal is received or if a received
Signal contains unrecognized, invalid, or disallowed duplicate Data Signal contains unrecognized, invalid, or disallowed duplicate Data
Items, the receiving implementation MUST ignore the Signal. Items, the receiving implementation MUST ignore the Signal.
If a Signal is received with a TTL value that is NOT equal to 255, If a Signal is received with a TTL value that is NOT equal to 255,
the receiving implementation MUST ignore the Signal. the receiving implementation MUST ignore the Signal.
If an unrecognized Message is received, the receiving implementation If an unrecognized Message is received, the receiving implementation
MUST issue a Session Termination Message (Section 12.9) containing a MUST issue a Session Termination Message (Section 12.9) containing a
Status Data Item (Section 13.1) with status code set to 128 'Unknown Status Data Item (Section 13.1) with status code set to 128 'Unknown
Message', see Table 2, and transition to the Session Termination Message' (see Table 2) and transition to the Session Termination
state. state.
If an unexpected Message is received, the receiving implementation If an unexpected Message is received, the receiving implementation
MUST issue a Session Termination Message containing a Status Data MUST issue a Session Termination Message containing a Status Data
Item with status code set to 129 'Unexpected Message', and transition Item with status code set to 129 'Unexpected Message' and transition
to the Session Termination state. to the Session Termination state.
If a received Message contains unrecognized, invalid, or disallowed If a received Message contains unrecognized, invalid, or disallowed
duplicate Data Items, the receiving implementation MUST issue a duplicate Data Items, the receiving implementation MUST issue a
Session Termination Message containing a Status Data Item with status Session Termination Message containing a Status Data Item with status
code set to 130 'Invalid Data', and transition to the Session code set to 130 'Invalid Data' and transition to the Session
Termination state. Termination state.
If a packet in the TCP stream is received with a TTL value other than If a packet in the TCP stream is received with a TTL value other than
255, the receiving implementation MUST immediately transition to the 255, the receiving implementation MUST immediately transition to the
Session Reset state. Session Reset state.
Prior to the exchange of Destination Up (Section 12.11) and Prior to the exchange of Destination Up (Section 12.11) and
Destination Up Response (Section 12.12) Messages, or Destination Destination Up Response (Section 12.12) Messages, or Destination
Announce (Section 12.13) and Destination Announce Response Announce (Section 12.13) and Destination Announce Response
(Section 12.14) Messages, no Messages concerning a destination may be (Section 12.14) Messages, no Messages concerning a destination may be
sent. An implementation receiving any Message with such an sent. An implementation receiving any Message with such an
unannounced destination MUST terminate the session by issuing a unannounced destination MUST terminate the session by issuing a
Session Termination Message containing a Status Data Item with status Session Termination Message containing a Status Data Item with status
code set to 131 'Invalid Destination', and transition to the Session code set to 131 'Invalid Destination' and transition to the Session
Termination state. Termination state.
After exchanging Destination Down (Section 12.15) and Destination After exchanging Destination Down (Section 12.15) and Destination
Down Response (Section 12.16) Messages, no Messages concerning a Down Response (Section 12.16) Messages, no Messages concerning a
destination may be a sent until a new Destination Up or Destination destination may be sent until a new Destination Up or Destination
Announce Message is sent. An implementation receiving a Message Announce Message is sent. An implementation receiving a Message
about a destination previously announced as 'down' MUST terminate the about a destination previously announced as 'down' MUST terminate the
session by issuing a Session Termination Message containing a Status session by issuing a Session Termination Message containing a Status
Data Item with status code set to 131 'Invalid Destination', and Data Item with status code set to 131 'Invalid Destination' and
transition to the Session Termination state. transition to the Session Termination state.
12.2. Status code processing 12.2. Status Code Processing
The behavior of a DLEP participant receiving a Message containing a The behavior of a DLEP participant receiving a Message containing a
Status Data Item (Section 13.1) is defined by the failure mode Status Data Item (Section 13.1) is defined by the failure mode
associated with the value of the status code field, see Table 2. All associated with the value of the status code field; see Table 2. All
status code values less than 100 have a failure mode of 'Continue', status code values less than 100 have a failure mode of 'Continue';
all other status codes have a failure mode of 'Terminate'. all other status codes have a failure mode of 'Terminate'.
A DLEP participant receiving any Message apart from Session A DLEP participant receiving any Message apart from a Session
Termination Message (Section 12.9) containing a Status Data Item with Termination Message (Section 12.9) containing a Status Data Item with
a status code value with failure mode 'Terminate' MUST immediately a status code value with failure mode 'Terminate' MUST immediately
issue a Session Termination Message echoing the received Status Data issue a Session Termination Message echoing the received Status Data
Item, and then transition to the Session Termination state. Item and then transition to the Session Termination state.
A DLEP participant receiving a Message containing a Status Data Item A DLEP participant receiving a Message containing a Status Data Item
with a status code value with failure mode 'Continue' can continue with a status code value with failure mode 'Continue' can continue
normal operation of the session. normal operation of the session.
12.3. Peer Discovery Signal 12.3. Peer Discovery Signal
A Peer Discovery Signal SHOULD be sent by a DLEP router to discover A Peer Discovery Signal SHOULD be sent by a DLEP router to discover
DLEP modems in the network, see Section 7.1. DLEP modems in the network; see Section 7.1.
A Peer Discovery Signal MUST be encoded within a UDP packet. The A Peer Discovery Signal MUST be encoded within a UDP packet. The
destination MUST be set to the DLEP well-known address and port destination MUST be set to the DLEP well-known address and port
number. For routers supporting both IPv4 and IPv6 DLEP operation, it number. For routers supporting both IPv4 and IPv6 DLEP operation, it
is RECOMMENDED that IPv6 be selected as the transport. The source IP is RECOMMENDED that IPv6 be selected as the transport. The source IP
address MUST be set to the router IP address associated with the DLEP address MUST be set to the router IP address associated with the DLEP
interface. There is no DLEP-specific restriction on source port. interface. There is no DLEP-specific restriction on source port.
To construct a Peer Discovery Signal, the Signal Type value in the To construct a Peer Discovery Signal, the Signal Type value in the
Signal Header is set to 1 (see Signal Type Registration Signal Header is set to 1 (see "Signal Type Registration"
(Section 15.2)). (Section 15.2)).
The Peer Discovery Signal MAY contain a Peer Type Data Item The Peer Discovery Signal MAY contain a Peer Type Data Item
(Section 13.4). (Section 13.4).
12.4. Peer Offer Signal 12.4. Peer Offer Signal
A Peer Offer Signal MUST be sent by a DLEP modem in response to a A Peer Offer Signal MUST be sent by a DLEP modem in response to a
properly formatted and addressed Peer Discovery Signal properly formatted and addressed Peer Discovery Signal
(Section 12.3). (Section 12.3).
A Peer Offer Signal MUST be encoded within a UDP packet. The IP A Peer Offer Signal MUST be encoded within a UDP packet. The IP
source and destination fields in the packet MUST be set by swapping source and destination fields in the packet MUST be set by swapping
the values received in the Peer Discovery Signal. The Peer Offer the values received in the Peer Discovery Signal. The Peer Offer
Signal completes the discovery process, see Section 7.1. Signal completes the discovery process; see Section 7.1.
To construct a Peer Offer Signal, the Signal Type value in the Signal To construct a Peer Offer Signal, the Signal Type value in the Signal
Header is set to 2 (see Signal Type Registration (Section 15.2)). Header is set to 2 (see "Signal Type Registration" (Section 15.2)).
The Peer Offer Signal MAY contain a Peer Type Data Item The Peer Offer Signal MAY contain a Peer Type Data Item
(Section 13.4). (Section 13.4).
The Peer Offer Signal MAY contain one or more of any of the following The Peer Offer Signal MAY contain one or more of any of the following
Data Items, with different values: Data Items, with different values:
o IPv4 Connection Point (Section 13.2) o IPv4 Connection Point (Section 13.2)
o IPv6 Connection Point (Section 13.3) o IPv6 Connection Point (Section 13.3)
The IP Connection Point Data Items indicate the unicast address the The IPv4 and IPv6 Connection Point Data Items indicate the unicast
router MUST use when connecting the DLEP TCP session. address the router MUST use when connecting the DLEP TCP session.
12.5. Session Initialization Message 12.5. Session Initialization Message
A Session Initialization Message MUST be sent by a DLEP router as the A Session Initialization Message MUST be sent by a DLEP router as the
first Message of the DLEP TCP session. It is sent by the router first Message of the DLEP TCP session. It is sent by the router
after a TCP connect to an address/port combination that was obtained after a TCP connect to an address/port combination that was obtained
either via receipt of a Peer Offer, or from a priori configuration. either via receipt of a Peer Offer or from a priori configuration.
To construct a Session Initialization Message, the Message Type value To construct a Session Initialization Message, the Message Type value
in the Message Header is set to 1 (see Message Type Registration in the Message Header is set to 1 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Session Initialization Message MUST contain one of each of the The Session Initialization Message MUST contain one of each of the
following Data Items: following Data Items:
o Heartbeat Interval Data Item (Section 13.5) o Heartbeat Interval (Section 13.5)
o Peer Type (Section 13.4) o Peer Type (Section 13.4)
The Session Initialization Message MUST contain an Extensions If DLEP extensions are supported, the Session Initialization Message
Supported Data Item (Section 13.6), if DLEP extensions are supported. MUST contain an Extensions Supported Data Item (Section 13.6).
The Session Initialization Message MAY contain one or more of each of The Session Initialization Message MAY contain one or more of each of
the following Data Items, with different values, and the data item the following Data Items, with different values and with the Add/Drop
Add flag set to 1: (A) flag (Section 13) set to 1:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
o IPv6 Address (Section 13.9) o IPv6 Address (Section 13.9)
o IPv4 Attached Subnet (Section 13.10) o IPv4 Attached Subnet (Section 13.10)
o IPv6 Attached Subnet (Section 13.11) o IPv6 Attached Subnet (Section 13.11)
If any optional extensions are supported by the implementation, they If any optional extensions are supported by the implementation, they
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Extensions Supported Data Item does not exist in a Session Extensions Supported Data Item does not exist in a Session
Initialization Message, the modem MUST conclude that there is no Initialization Message, the modem MUST conclude that there is no
support for extensions in the router. support for extensions in the router.
DLEP Heartbeats are not started until receipt of the Session DLEP Heartbeats are not started until receipt of the Session
Initialization Response Message (Section 12.6), and therefore Initialization Response Message (Section 12.6), and therefore
implementations MUST use their own timeout heuristics for this implementations MUST use their own timeout heuristics for this
Message. Message.
As an exception to the general rule governing an implementation As an exception to the general rule governing an implementation
receiving an unrecognized Data Item in a Message, see Section 12.1, receiving an unrecognized Data Item in a Message (see Section 12.1),
if a Session Initialization Message contains one or more Extension if a Session Initialization Message contains one or more Extensions
Supported Data Items announcing support for extensions that the Supported Data Items announcing support for extensions that the
implementation does not recognize, then the implementation MAY ignore implementation does not recognize, then the implementation MAY ignore
Data Items it does not recognize. Data Items it does not recognize.
12.6. Session Initialization Response Message 12.6. Session Initialization Response Message
A Session Initialization Response Message MUST be sent by a DLEP A Session Initialization Response Message MUST be sent by a DLEP
modem in response to a received Session Initialization Message modem in response to a received Session Initialization Message
(Section 12.5). (Section 12.5).
To construct a Session Initialization Response Message, the Message To construct a Session Initialization Response Message, the Message
Type value in the Message Header is set to 2 (see Message Type Type value in the Message Header is set to 2 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Session Initialization Response Message MUST contain one of each The Session Initialization Response Message MUST contain one of each
of the following Data Items: of the following Data Items:
o Status (Section 13.1) o Status (Section 13.1)
o Peer Type (Section 13.4) o Peer Type (Section 13.4)
o Heartbeat Interval (Section 13.5) o Heartbeat Interval (Section 13.5)
o Maximum Data Rate (Receive) (Section 13.12) o Maximum Data Rate (Receive) (Section 13.12)
o Maximum Data Rate (Transmit) (Section 13.13) o Maximum Data Rate (Transmit) (Section 13.13)
o Current Data Rate (Receive) (Section 13.14) o Current Data Rate (Receive) (Section 13.14)
o Current Data Rate (Transmit) (Section 13.15) o Current Data Rate (Transmit) (Section 13.15)
o Latency (Section 13.16) o Latency (Section 13.16)
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lifetime of the session: lifetime of the session:
o Resources (Section 13.17) o Resources (Section 13.17)
o Relative Link Quality (Receive) (Section 13.18) o Relative Link Quality (Receive) (Section 13.18)
o Relative Link Quality (Transmit) (Section 13.19) o Relative Link Quality (Transmit) (Section 13.19)
o Maximum Transmission Unit (MTU) (Section 13.20) o Maximum Transmission Unit (MTU) (Section 13.20)
The Session Initialization Response Message MUST contain an If DLEP extensions are supported, the Session Initialization Response
Extensions Supported Data Item (Section 13.6), if DLEP extensions are Message MUST contain an Extensions Supported Data Item
supported. (Section 13.6).
The Session Initialization Response Message MAY contain one or more The Session Initialization Response Message MAY contain one or more
of each of the following Data Items, with different values, and the of each of the following Data Items, with different values and with
data item Add flag set to 1: the Add/Drop (A) flag (Section 13) set to 1:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
o IPv6 Address (Section 13.9) o IPv6 Address (Section 13.9)
o IPv4 Attached Subnet (Section 13.10) o IPv4 Attached Subnet (Section 13.10)
o IPv6 Attached Subnet (Section 13.11) o IPv6 Attached Subnet (Section 13.11)
The Session Initialization Response Message completes the DLEP The Session Initialization Response Message completes the DLEP
session establishment; the modem should transition to the In-Session session establishment; the modem should transition to the In-Session
state when the Message is sent, and the router should transition to state when the Message is sent, and the router should transition to
the In-Session state upon receipt of an acceptable Session the In-Session state upon receipt of an acceptable Session
Initialization Response Message. Initialization Response Message.
All supported metric Data Items MUST be included in the Session All supported metric Data Items MUST be included in the Session
Initialization Response Message, with default values to be used on a Initialization Response Message, with default values to be used on a
session-wide basis. This can be viewed as the modem 'declaring' all session-wide basis. This can be viewed as the modem "declaring" all
supported metrics at DLEP session initialization. Receipt of any supported metrics at DLEP session initialization. Receipt of any
further DLEP Message containing a metric Data Item not included in further DLEP Message containing a metric Data Item not included in
the Session Initialization Response Message MUST be treated as an the Session Initialization Response Message MUST be treated as an
error, resulting in the termination of the DLEP session between error, resulting in the termination of the DLEP session between
router and modem. router and modem.
If any optional extensions are supported by the modem, they MUST be If any optional extensions are supported by the modem, they MUST be
enumerated in the Extensions Supported Data Item. If an Extensions enumerated in the Extensions Supported Data Item. If an Extensions
Supported Data Item does not exist in a Session Initialization Supported Data Item does not exist in a Session Initialization
Response Message, the router MUST conclude that there is no support Response Message, the router MUST conclude that there is no support
for extensions in the modem. for extensions in the modem.
After the Session Initialization/Session Initialization Response After the Session Initialization / Session Initialization Response
Messages have been successfully exchanged, implementations MUST only Messages have been successfully exchanged, implementations MUST only
use extensions that are supported by both DLEP participants, see use extensions that are supported by both DLEP participants; see
Section 7.2. Section 7.2.
12.7. Session Update Message 12.7. Session Update Message
A Session Update Message MAY be sent by a DLEP participant to A Session Update Message MAY be sent by a DLEP participant, on a
indicate local Layer 3 address changes, or metric changes on a session-wide basis, to indicate local Layer 3 address changes and/or
session-wide basis. metric changes.
To construct a Session Update Message, the Message Type value in the To construct a Session Update Message, the Message Type value in the
Message Header is set to 3 (see Message Type Registration Message Header is set to 3 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Session Update Message MAY contain one or more of each of the The Session Update Message MAY contain one or more of each of the
following Data Items, with different values: following Data Items, with different values:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
o IPv6 Address (Section 13.9) o IPv6 Address (Section 13.9)
o IPv4 Attached Subnet (Section 13.10) o IPv4 Attached Subnet (Section 13.10)
skipping to change at page 26, line 42 skipping to change at page 27, line 21
o Resources (Section 13.17) o Resources (Section 13.17)
o Relative Link Quality (Receive) (Section 13.18) o Relative Link Quality (Receive) (Section 13.18)
o Relative Link Quality (Transmit) (Section 13.19) o Relative Link Quality (Transmit) (Section 13.19)
o Maximum Transmission Unit (MTU) (Section 13.20) o Maximum Transmission Unit (MTU) (Section 13.20)
If metrics are supplied with the Session Update Message (e.g., If metrics are supplied with the Session Update Message (e.g.,
Maximum Data Rate), these metrics are considered to be session-wide, Maximum Data Rate), these metrics are considered to be session-wide
and therefore MUST be applied to all destinations in the information and therefore MUST be applied to all destinations in the information
base associated with the DLEP session. This includes destinations base associated with the DLEP session. This includes destinations
for which metrics may have been stored based on received Destination for which metrics may have been stored based on received Destination
Update messages. Update messages.
It should be noted that Session Update Messages can be sent by both It should be noted that Session Update Messages can be sent by both
routers and modems. For example, addition of an IPv4 address on the routers and modems. For example, the addition of an IPv4 address on
router MAY prompt a Session Update Message to its attached modems. the router MAY prompt a Session Update Message to its attached
Also, for example, a modem that changes its Maximum Data Rate modems. Also, for example, a modem that changes its Maximum Data
(Receive) for all destinations MAY reflect that change via a Session Rate (Receive) for all destinations MAY reflect that change via a
Update Message to its attached router(s). Session Update Message to its attached router(s).
Concerning Layer 3 addresses and subnets: If the modem is capable of Concerning Layer 3 addresses and subnets: if the modem is capable of
understanding and forwarding this information (via mechanisms not understanding and forwarding this information (via mechanisms not
defined by DLEP), the update would prompt any remote DLEP-enabled defined by DLEP), the update would prompt any remote DLEP-enabled
modems to issue a Destination Update Message (Section 12.17) to their modems to issue a Destination Update Message (Section 12.17) to their
local routers with the new (or deleted) addresses and subnets. local routers with the new (or deleted) addresses and subnets.
12.8. Session Update Response Message 12.8. Session Update Response Message
A Session Update Response Message MUST be sent by a DLEP participant A Session Update Response Message MUST be sent by a DLEP participant
when a Session Update Message (Section 12.7) is received. when a Session Update Message (Section 12.7) is received.
To construct a Session Update Response Message, the Message Type To construct a Session Update Response Message, the Message Type
value in the Message Header is set to 4 (see Message Type value in the Message Header is set to 4 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Session Update Response Message MUST contain a Status Data Item The Session Update Response Message MUST contain a Status Data Item
(Section 13.1). (Section 13.1).
12.9. Session Termination Message 12.9. Session Termination Message
When a DLEP participant determines the DLEP session needs to be When a DLEP participant determines that the DLEP session needs to be
terminated, the participant MUST send (or attempt to send) a Session terminated, the participant MUST send (or attempt to send) a Session
Termination Message. Termination Message.
To construct a Session Termination Message, the Message Type value in To construct a Session Termination Message, the Message Type value in
the Message Header is set to 5 (see Message Type Registration the Message Header is set to 5 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Session Termination Message MUST contain Status Data Item The Session Termination Message MUST contain a Status Data Item
(Section 13.1). (Section 13.1).
It should be noted that Session Termination Messages can be sent by It should be noted that Session Termination Messages can be sent by
both routers and modems. both routers and modems.
12.10. Session Termination Response Message 12.10. Session Termination Response Message
A Session Termination Response Message MUST be sent by a DLEP A Session Termination Response Message MUST be sent by a DLEP
participant when a Session Termination Message (Section 12.9) is participant when a Session Termination Message (Section 12.9) is
received. received.
To construct a Session Termination Response Message, the Message Type To construct a Session Termination Response Message, the Message Type
value in the Message Header is set to 6 (see Message Type value in the Message Header is set to 6 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
There are no valid Data Items for the Session Termination Response There are no valid Data Items for the Session Termination Response
Message. Message.
Receipt of a Session Termination Response Message completes the tear- Receipt of a Session Termination Response Message completes the
down of the DLEP session, see Section 7.4. teardown of the DLEP session; see Section 7.4.
12.11. Destination Up Message 12.11. Destination Up Message
Destination Up Messages MAY be sent by a modem to inform its attached Destination Up Messages MAY be sent by a modem to inform its attached
router of the presence of a new reachable destination. router of the presence of a new reachable destination.
To construct a Destination Up Message, the Message Type value in the To construct a Destination Up Message, the Message Type value in the
Message Header is set to 7 (see Message Type Registration Message Header is set to 7 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Destination Up Message MUST contain a MAC Address Data Item The Destination Up Message MUST contain a MAC Address Data Item
(Section 13.7). (Section 13.7).
The Destination Up Message SHOULD contain one or more of each of the The Destination Up Message SHOULD contain one or more of each of the
following Data Items, with different values: following Data Items, with different values:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
skipping to change at page 29, line 17 skipping to change at page 29, line 49
o IPv4 Attached Subnet (Section 13.10) o IPv4 Attached Subnet (Section 13.10)
o IPv6 Attached Subnet (Section 13.11) o IPv6 Attached Subnet (Section 13.11)
A router receiving a Destination Up Message allocates the necessary A router receiving a Destination Up Message allocates the necessary
resources, creating an entry in the information base with the resources, creating an entry in the information base with the
specifics (MAC Address, Latency, Data Rate, etc.) of the destination. specifics (MAC Address, Latency, Data Rate, etc.) of the destination.
The information about this destination will persist in the router's The information about this destination will persist in the router's
information base until a Destination Down Message (Section 12.15) is information base until a Destination Down Message (Section 12.15) is
received, indicating that the modem has lost contact with the remote received, indicating that the modem has lost contact with the remote
node, or the implementation transitions to the Session Termination node or that the implementation transitions to the Session
state. Termination state.
12.12. Destination Up Response Message 12.12. Destination Up Response Message
A router MUST send a Destination Up Response Message when a A router MUST send a Destination Up Response Message when a
Destination Up Message (Section 12.11) is received. Destination Up Message (Section 12.11) is received.
To construct a Destination Up Response Message, the Message Type To construct a Destination Up Response Message, the Message Type
value in the Message Header is set to 8 (see Message Type value in the Message Header is set to 8 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Destination Up Response Message MUST contain one of each of the The Destination Up Response Message MUST contain one of each of the
following Data Items: following Data Items:
o MAC Address (Section 13.7) o MAC Address (Section 13.7)
o Status (Section 13.1) o Status (Section 13.1)
A router that wishes to receive further information concerning the A router that wishes to receive further information concerning the
destination identified in the corresponding Destination Up Message destination identified in the corresponding Destination Up Message
MUST set the status code of the included Status Data Item to 0 MUST set the status code of the included Status Data Item to
'Success', see Table 2. 0 'Success'; see Table 2.
If the router has no interest in the destination identified in the If the router has no interest in the destination identified in the
corresponding Destination Up Message, then it MAY set the status code corresponding Destination Up Message, then it MAY set the status code
of the included Status Data Item to 1 'Not Interested'. of the included Status Data Item to 1 'Not Interested'.
A modem receiving a Destination Up Response Message containing a A modem receiving a Destination Up Response Message containing a
Status Data Item with status code of any value other than 0 'Success' Status Data Item with a status code of any value other than
MUST NOT send further Destination messages about the destination, 0 'Success' MUST NOT send further Destination Messages about the
e.g. Destination Down (Section 12.15) or Destination Update destination, e.g., Destination Down (Section 12.15) or Destination
(Section 12.17) with the same MAC address. Update (Section 12.17) with the same MAC address.
12.13. Destination Announce Message 12.13. Destination Announce Message
Usually a modem will discover the presence of one or more remote Usually, a modem will discover the presence of one or more remote
router/modem pairs and announce each destination's arrival by sending router/modem pairs and announce each destination's arrival by sending
a corresponding Destination Up Message (Section 12.11) to the router. a corresponding Destination Up Message (Section 12.11) to the router.
However, there may be times when a router wishes to express an However, there may be times when a router wishes to express an
interest in a destination that has yet to be announced, typically a interest in a destination that has yet to be announced, typically a
multicast destination. Destination Announce Messages MAY be sent by multicast destination. Destination Announce Messages MAY be sent by
a router to announce such an interest. a router to announce such an interest.
A Destination Announce Message MAY also be sent by a router to A Destination Announce Message MAY also be sent by a router to
request information concerning a destination in which it has request information concerning a destination (1) in which the router
previously declined interest, via the 1 'Not Interested' status code has previously declined interest, via the 1 'Not Interested' status
in a Destination Up Response Message (Section 12.12), see Table 2, or code in a Destination Up Response Message (Section 12.12) (see
declared as 'down', via the Destination Down Message (Section 12.15). Table 2) or (2) that was previously declared as 'down', via the
Destination Down Message (Section 12.15).
To construct a Destination Announce Message, the Message Type value To construct a Destination Announce Message, the Message Type value
in the Message Header is set to 9 (see Message Type Registration in the Message Header is set to 9 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Destination Announce Message MUST contain a MAC Address Data Item The Destination Announce Message MUST contain a MAC Address Data Item
(Section 13.7). (Section 13.7).
The Destination Announce Message MAY contain zero or more of the The Destination Announce Message MAY contain zero or more of the
following Data Items, with different values: following Data Items, with different values:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
o IPv6 Address (Section 13.9) o IPv6 Address (Section 13.9)
One of the advantages of implementing DLEP is to leverage the modem's One of the advantages of implementing DLEP is to leverage the modem's
knowledge of the links between remote destinations allowing routers knowledge of the links between remote destinations, allowing routers
to avoid using probed neighbor discovery techniques, therefore modem to avoid using probed neighbor discovery techniques; therefore, modem
implementations SHOULD announce available destinations via the implementations SHOULD announce available destinations via the
Destination Up Message, rather than relying on Destination Announce Destination Up Message, rather than relying on Destination Announce
Messages. Messages.
12.14. Destination Announce Response Message 12.14. Destination Announce Response Message
A modem MUST send a Destination Announce Response Message when a A modem MUST send a Destination Announce Response Message when a
Destination Announce Message (Section 12.13) is received. Destination Announce Message (Section 12.13) is received.
To construct a Destination Announce Response Message, the Message To construct a Destination Announce Response Message, the Message
Type value in the Message Header is set to 10 (see Message Type Type value in the Message Header is set to 10 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Destination Announce Response Message MUST contain one of each of The Destination Announce Response Message MUST contain one of each of
the following Data Items: the following Data Items:
o MAC Address (Section 13.7) o MAC Address (Section 13.7)
o Status (Section 13.1) o Status (Section 13.1)
The Destination Announce Response Message MAY contain one or more of The Destination Announce Response Message MAY contain one or more of
each of the following Data Items, with different values: each of the following Data Items, with different values:
skipping to change at page 31, line 45 skipping to change at page 32, line 29
o Resources (Section 13.17) o Resources (Section 13.17)
o Relative Link Quality (Receive) (Section 13.18) o Relative Link Quality (Receive) (Section 13.18)
o Relative Link Quality (Transmit) (Section 13.19) o Relative Link Quality (Transmit) (Section 13.19)
o Maximum Transmission Unit (MTU) (Section 13.20) o Maximum Transmission Unit (MTU) (Section 13.20)
If a modem is unable to report information immediately about the If a modem is unable to report information immediately about the
requested information, if the destination is not currently reachable, requested information -- for example, if the destination is not
for example, the status code in the Status Data Item MUST be set to 2 currently reachable -- the status code in the Status Data Item MUST
'Request Denied', see Table 2. be set to 2 'Request Denied'; see Table 2.
After sending a Destination Announce Response Message containing a After sending a Destination Announce Response Message containing a
Status Data Item with status code of 0 'Success', a modem then Status Data Item with a status code of 0 'Success', a modem then
announces changes to the link to the destination via Destination announces changes to the link to the destination via Destination
Update Messages. Update Messages.
When a successful Destination Announce Response Message is received, When a successful Destination Announce Response Message is received,
the router should add knowledge of the available destination to its the router should add knowledge of the available destination to its
information base. information base.
12.15. Destination Down Message 12.15. Destination Down Message
A modem MUST send a Destination Down Message to report when a A modem MUST send a Destination Down Message to report when a
destination (a remote node or a multicast group) is no longer destination (a remote node or a multicast group) is no longer
reachable. reachable.
A router MAY send a Destination Down Message to report when it no A router MAY send a Destination Down Message to report when it
longer requires information concerning a destination. no longer requires information concerning a destination.
To construct a Destination Down Message, the Message Type value in To construct a Destination Down Message, the Message Type value in
the Message Header is set to 11 (see Message Type Registration the Message Header is set to 11 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Destination Down Message MUST contain a MAC Address Data Item The Destination Down Message MUST contain a MAC Address Data Item
(Section 13.7). (Section 13.7).
It should be noted that both modem and router may send a Destination It should be noted that both modem and router may send a Destination
Down Message to their peer, regardless of which participant initially Down Message to their peer, regardless of which participant initially
indicated the destination to be 'up'. indicated the destination to be 'up'.
12.16. Destination Down Response Message 12.16. Destination Down Response Message
A Destination Down Response MUST be sent by the recipient of a A Destination Down Response Message MUST be sent by the recipient of
Destination Down Message (Section 12.15) to confirm that the relevant a Destination Down Message (Section 12.15) to confirm that the
data concerning the destination has been removed from the information relevant data concerning the destination has been removed from the
base. information base.
To construct a Destination Down Response Message, the Message Type To construct a Destination Down Response Message, the Message Type
value in the Message Header is set to 12 (see Message Type value in the Message Header is set to 12 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Destination Down Response Message MUST contain one of each of the The Destination Down Response Message MUST contain one of each of the
following Data Items: following Data Items:
o MAC Address (Section 13.7) o MAC Address (Section 13.7)
o Status (Section 13.1) o Status (Section 13.1)
12.17. Destination Update Message 12.17. Destination Update Message
A modem SHOULD send the Destination Update Message when it detects A modem SHOULD send a Destination Update Message when it detects some
some change in the information base for a given destination (remote change in the information base for a given destination (remote node
node or multicast group). Some examples of changes that would prompt or multicast group). Some examples of changes that would prompt a
a Destination Update Message are: Destination Update Message are as follows:
o Change in link metrics (e.g., Data Rates) o Change in link metrics (e.g., data rates)
o Layer 3 addressing change o Layer 3 addressing change
To construct a Destination Update Message, the Message Type value in To construct a Destination Update Message, the Message Type value in
the Message Header is set to 13 (see Message Type Registration the Message Header is set to 13 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
The Destination Update Message MUST contain a MAC Address Data Item The Destination Update Message MUST contain a MAC Address Data Item
(Section 13.7). (Section 13.7).
The Destination Update Message MAY contain one of each of the The Destination Update Message MAY contain one of each of the
following Data Items: following Data Items:
o Maximum Data Rate (Receive) (Section 13.12) o Maximum Data Rate (Receive) (Section 13.12)
skipping to change at page 33, line 51 skipping to change at page 34, line 40
following Data Items, with different values: following Data Items, with different values:
o IPv4 Address (Section 13.8) o IPv4 Address (Section 13.8)
o IPv6 Address (Section 13.9) o IPv6 Address (Section 13.9)
o IPv4 Attached Subnet (Section 13.10) o IPv4 Attached Subnet (Section 13.10)
o IPv6 Attached Subnet (Section 13.11) o IPv6 Attached Subnet (Section 13.11)
Metrics supplied in this message overwrite metrics provided in a Metrics supplied in this Message overwrite metrics provided in a
previously received Session or Destination Up Messages. previously received Session Message, Destination Message, or Link
Characteristics Message (e.g., Session Initialization,
Destination Up, Link Characteristics Response).
It should be noted that this Message has no corresponding response. It should be noted that this Message has no corresponding response.
12.18. Link Characteristics Request Message 12.18. Link Characteristics Request Message
The Link Characteristics Request Message MAY be sent by a router to The Link Characteristics Request Message MAY be sent by a router to
request that the modem initiate changes for specific characteristics request that the modem initiate changes for specific characteristics
of the link. The request can reference either a real destination of the link. The request can reference either a real destination
(e.g., a remote node), or a logical destination (e.g., a multicast (e.g., a remote node) or a logical destination (e.g., a multicast
group) within the network. group) within the network.
To construct a Link Characteristics Request Message, the Message Type To construct a Link Characteristics Request Message, the Message Type
value in the Message Header is set to 14 (see Message Type value in the Message Header is set to 14 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Link Characteristics Request Message MUST contain one of the
following Data Items:
o MAC Address (Section 13.7) The Link Characteristics Request Message MUST contain a MAC Address
Data Item (Section 13.7).
The Link Characteristics Request Message MUST contain at least one of The Link Characteristics Request Message MUST also contain at least
each of the following Data Items: one of each of the following Data Items:
o Current Data Rate (Receive) (Section 13.14) o Current Data Rate (Receive) (Section 13.14)
o Current Data Rate (Transmit) (Section 13.15) o Current Data Rate (Transmit) (Section 13.15)
o Latency (Section 13.16) o Latency (Section 13.16)
The Link Characteristics Request Message MAY contain either a Current The Link Characteristics Request Message MAY contain either a Current
Data Rate (CDRR or CDRT) Data Item to request a different datarate Data Rate (Receive) (CDRR) or Current Data Rate (Transmit) (CDRT)
than is currently allocated, a Latency Data Item to request that Data Item to request a different data rate than is currently
traffic delay on the link not exceed the specified value, or both. allocated, a Latency Data Item to request that traffic delay on the
link not exceed the specified value, or both.
The router sending a Link Characteristics Request Message should be The router sending a Link Characteristics Request Message should be
aware that a request may take an extended period of time to complete. aware that a request may take an extended period of time to complete.
12.19. Link Characteristics Response Message 12.19. Link Characteristics Response Message
A modem MUST send a Link Characteristics Response Message when a Link A modem MUST send a Link Characteristics Response Message when a Link
Characteristics Request Message (Section 12.18) is received. Characteristics Request Message (Section 12.18) is received.
To construct a Link Characteristics Response Message, the Message To construct a Link Characteristics Response Message, the Message
Type value in the Message Header is set to 15 (see Message Type Type value in the Message Header is set to 15 (see "Message Type
Registration (Section 15.3)). Registration" (Section 15.3)).
The Link Characteristics Response Message MUST contain one of each of The Link Characteristics Response Message MUST contain one of each of
the following Data Items: the following Data Items:
o MAC Address (Section 13.7) o MAC Address (Section 13.7)
o Status (Section 13.1) o Status (Section 13.1)
The Link Characteristics Response Message SHOULD contain one of each The Link Characteristics Response Message SHOULD contain one of each
of the following Data Items: of the following Data Items:
o Maximum Data Rate (Receive) (Section 13.12) o Maximum Data Rate (Receive) (Section 13.12)
o Maximum Data Rate (Transmit) (Section 13.13) o Maximum Data Rate (Transmit) (Section 13.13)
o Current Data Rate (Receive) (Section 13.14) o Current Data Rate (Receive) (Section 13.14)
o Current Data Rate (Transmit) (Section 13.15) o Current Data Rate (Transmit) (Section 13.15)
skipping to change at page 35, line 42 skipping to change at page 36, line 37
The Link Characteristics Response Message MUST contain a complete set The Link Characteristics Response Message MUST contain a complete set
of metric Data Items, referencing all metrics declared in the Session of metric Data Items, referencing all metrics declared in the Session
Initialization Response Message (Section 12.6). The values in the Initialization Response Message (Section 12.6). The values in the
metric Data Items in the Link Characteristics Response Message MUST metric Data Items in the Link Characteristics Response Message MUST
reflect the link characteristics after the request has been reflect the link characteristics after the request has been
processed. processed.
If an implementation is not able to alter the characteristics of the If an implementation is not able to alter the characteristics of the
link in the manner requested, then the status code of the Status Data link in the manner requested, then the status code of the Status Data
Item MUST be set to 2 'Request Denied', see Table 2. Item MUST be set to 2 'Request Denied'; see Table 2.
12.20. Heartbeat Message 12.20. Heartbeat Message
A Heartbeat Message MUST be sent by a DLEP participant every N A Heartbeat Message MUST be sent by a DLEP participant every
milliseconds, where N is defined in the Heartbeat Interval Data Item N milliseconds, where N is defined in the Heartbeat Interval Data
(Section 13.5) of the Session Initialization Message (Section 12.5) Item (Section 13.5) of the Session Initialization Message
or Session Initialization Response Message (Section 12.6). (Section 12.5) or Session Initialization Response Message
(Section 12.6).
To construct a Heartbeat Message, the Message Type value in the To construct a Heartbeat Message, the Message Type value in the
Message Header is set to 16 (see Message Type Registration Message Header is set to 16 (see "Message Type Registration"
(Section 15.3)). (Section 15.3)).
There are no valid Data Items for the Heartbeat Message. There are no valid Data Items for the Heartbeat Message.
The Message is used by DLEP participants to detect when a DLEP The Heartbeat Message is used by DLEP participants to detect when a
session peer (either the modem or the router) is no longer DLEP session peer (either the modem or the router) is no longer
communicating, see Section 7.3.1. communicating; see Section 7.3.1.
13. DLEP Data Items 13. DLEP Data Items
The core DLEP Data Items are: The core DLEP Data Items are as follows:
+-------------+-----------------------------------------------------+ +-------------+-----------------------------------------------------+
| Type Code | Description | | Type Code | Description |
+-------------+-----------------------------------------------------+ +-------------+-----------------------------------------------------+
| 0 | Reserved | | 0 | Reserved |
| | |
| 1 | Status (Section 13.1) | | 1 | Status (Section 13.1) |
| | |
| 2 | IPv4 Connection Point (Section 13.2) | | 2 | IPv4 Connection Point (Section 13.2) |
| | |
| 3 | IPv6 Connection Point (Section 13.3) | | 3 | IPv6 Connection Point (Section 13.3) |
| | |
| 4 | Peer Type (Section 13.4) | | 4 | Peer Type (Section 13.4) |
| | |
| 5 | Heartbeat Interval (Section 13.5) | | 5 | Heartbeat Interval (Section 13.5) |
| | |
| 6 | Extensions Supported (Section 13.6) | | 6 | Extensions Supported (Section 13.6) |
| | |
| 7 | MAC Address (Section 13.7) | | 7 | MAC Address (Section 13.7) |
| | |
| 8 | IPv4 Address (Section 13.8) | | 8 | IPv4 Address (Section 13.8) |
| | |
| 9 | IPv6 Address (Section 13.9) | | 9 | IPv6 Address (Section 13.9) |
| | |
| 10 | IPv4 Attached Subnet (Section 13.10) | | 10 | IPv4 Attached Subnet (Section 13.10) |
| | |
| 11 | IPv6 Attached Subnet (Section 13.11) | | 11 | IPv6 Attached Subnet (Section 13.11) |
| | |
| 12 | Maximum Data Rate (Receive) (MDRR) (Section 13.12) | | 12 | Maximum Data Rate (Receive) (MDRR) (Section 13.12) |
| | |
| 13 | Maximum Data Rate (Transmit) (MDRT) (Section 13.13) | | 13 | Maximum Data Rate (Transmit) (MDRT) (Section 13.13) |
| | |
| 14 | Current Data Rate (Receive) (CDRR) (Section 13.14) | | 14 | Current Data Rate (Receive) (CDRR) (Section 13.14) |
| | |
| 15 | Current Data Rate (Transmit) (CDRT) (Section 13.15) | | 15 | Current Data Rate (Transmit) (CDRT) (Section 13.15) |
| | |
| 16 | Latency (Section 13.16) | | 16 | Latency (Section 13.16) |
| | |
| 17 | Resources (RES) (Section 13.17) | | 17 | Resources (RES) (Section 13.17) |
| 18 | Relative Link Quality (Receive) (RLQR) (Section | | | |
| | 13.18) | | 18 | Relative Link Quality (Receive) (RLQR) |
| 19 | Relative Link Quality (Transmit) (RLQT) (Section | | | (Section 13.18) |
| | 13.19) | | | |
| 19 | Relative Link Quality (Transmit) (RLQT) |
| | (Section 13.19) |
| | |
| 20 | Maximum Transmission Unit (MTU) (Section 13.20) | | 20 | Maximum Transmission Unit (MTU) (Section 13.20) |
| 21-65407 | Reserved for future extensions | | | |
| 65408-65534 | Private Use. Available for experiments | | 21-65407 | Unassigned (available for future extensions) |
| | |
| 65408-65534 | Reserved for Private Use (available for |
| | experiments) |
| | |
| 65535 | Reserved | | 65535 | Reserved |
+-------------+-----------------------------------------------------+ +-------------+-----------------------------------------------------+
Table 1: DLEP Data Item types Table 1: DLEP Data Item Types
13.1. Status 13.1. Status
For the Session Termination Message (Section 12.9), the Status Data For the Session Termination Message (Section 12.9), the Status Data
Item indicates a reason for the termination. For all response Item indicates a reason for the termination. For all response
Messages, the Status Data Item is used to indicate the success or messages, the Status Data Item is used to indicate the success or
failure of the previously received Message. failure of the previously received Message.
The Status Data Item includes an optional Text field that can be used The Status Data Item includes an optional Text field that can be used
to provide a textual description of the status. The use of the Text to provide a textual description of the status. The use of the Text
field is entirely up to the receiving implementation, e.g., it could field is entirely up to the receiving implementation, e.g., it could
be output to a log file or discarded. If no Text field is supplied be output to a log file or discarded. If no Text field is supplied
with the Status Data Item, the Length field MUST be set to 1. with the Status Data Item, the Length field MUST be set to 1.
The Status Data Item contains the following fields: The Status Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Code | Text... : | Status Code | Text... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 1 Data Item Type: 1
Length: 1 + Length of text, in octets Length: 1 + Length of Text, in octets.
Status Code: One of the codes defined in Table 2 below. Status Code: One of the status codes defined in Table 2 below.
Text: UTF-8 encoded string of UNICODE [RFC3629] characters, Text: UTF-8 encoded string of Unicode [RFC3629] characters,
describing the cause, used for implementation defined purposes. describing the cause, used for implementation-defined purposes.
Since this field is used for description, implementations SHOULD Since this field is used for description purposes, implementations
limit characters in this field to printable characters. SHOULD limit characters in this field to printable characters.
An implementation MUST NOT assume the Text field is a NUL-terminated An implementation MUST NOT assume that the Text field is a
string of printable characters. NUL-terminated string of printable characters.
+----------+-------------+------------------+-----------------------+ +----------+-------------+------------------+-----------------------+
| Status | Failure | Description | Reason | | Status | Failure | Description | Reason |
| Code | Mode | | | | Code | Mode | | |
+----------+-------------+------------------+-----------------------+ +----------+-------------+------------------+-----------------------+
| 0 | Continue | Success | The Message was | | 0 | Continue | Success | The Message was |
| | | | processed | | | | | processed |
| | | | successfully. | | | | | successfully. |
| | | | |
| 1 | Continue | Not Interested | The receiver is not | | 1 | Continue | Not Interested | The receiver is not |
| | | | interested in this | | | | | interested in this |
| | | | Message subject, e.g. | | | | | Message subject, |
| | | | in a Destination Up | | | | | e.g., in a |
| | | | Destination Up |
| | | | Response Message | | | | | Response Message |
| | | | (Section 12.12) to | | | | | (Section 12.12) to |
| | | | indicate no further | | | | | indicate no further |
| | | | Messages about the | | | | | Messages about the |
| | | | destination. | | | | | destination. |
| | | | |
| 2 | Continue | Request Denied | The receiver refuses | | 2 | Continue | Request Denied | The receiver refuses |
| | | | to complete the | | | | | to complete the |
| | | | request. | | | | | request. |
| | | | |
| 3 | Continue | Inconsistent | One or more Data | | 3 | Continue | Inconsistent | One or more Data |
| | | Data | Items in the Message | | | | Data | Items in the Message |
| | | | describe a logically | | | | | describe a logically |
| | | | inconsistent state in | | | | | inconsistent state in |
| | | | the network. For | | | | | the network -- for |
| | | | example, in the | | | | | example, in the |
| | | | Destination Up | | | | | Destination Up |
| | | | Message (Section | | | | | Message |
| | | | 12.11) when an | | | | | (Section 12.11) when |
| | | | announced subnet | | | | | an announced subnet |
| | | | clashes with an | | | | | clashes with an |
| | | | existing destination | | | | | existing destination |
| | | | subnet. | | | | | subnet. |
| 4-111 | Continue | <Reserved> | Reserved for future | | | | | |
| 4-111 | Continue | <Unassigned> | Available for future |
| | | | extensions. | | | | | extensions. |
| 112-127 | Continue | <Private Use> | Available for | | | | | |
| | | | experiments. | | 112-127 | Continue | <Reserved for | Available for |
| | | Private Use> | experiments. |
| | | | |
| 128 | Terminate | Unknown Message | The Message was not | | 128 | Terminate | Unknown Message | The Message was not |
| | | | recognized by the | | | | | recognized by the |
| | | | implementation. | | | | | implementation. |
| | | | |
| 129 | Terminate | Unexpected | The Message was not | | 129 | Terminate | Unexpected | The Message was not |
| | | Message | expected while the | | | | Message | expected while the |
| | | | device was in the | | | | | device was in the |
| | | | current state, e.g., | | | | | current state, e.g., |
| | | | a Session | | | | | a Session |
| | | | Initialization | | | | | Initialization |
| | | | Message (Section | | | | | Message |
| | | | 12.5) in the In- | | | | | (Section 12.5) in |
| | | | Session state. | | | | | the In-Session state. |
| | | | |
| 130 | Terminate | Invalid Data | One or more Data | | 130 | Terminate | Invalid Data | One or more Data |
| | | | Items in the Message | | | | | Items in the Message |
| | | | are invalid, | | | | | are invalid, |
| | | | unexpected or | | | | | unexpected, or |
| | | | incorrectly | | | | | incorrectly |
| | | | duplicated. | | | | | duplicated. |
| | | | |
| 131 | Terminate | Invalid | The destination | | 131 | Terminate | Invalid | The destination |
| | | Destination | included in the | | | | Destination | included in the |
| | | | Message does not | | | | | Message does not |
| | | | match a previously | | | | | match a previously |
| | | | announced | | | | | announced destination |
| | | | destination. For | | | | | -- for example, in |
| | | | example, in the Link | | | | | the Link |
| | | | Characteristic | | | | | Characteristics |
| | | | Response Message | | | | | Response Message |
| | | | (Section 12.19). | | | | | (Section 12.19). |
| 132 | Terminate | Timed Out | The session has timed | | | | | |
| | | | out. | | 132 | Terminate | Timed Out | The session has |
| 133-239 | Terminate | <Reserved> | Reserved for future | | | | | timed out. |
| | | | |
| 133-239 | Terminate | <Unassigned> | Available for future |
| | | | extensions. | | | | | extensions. |
| 240-254 | Terminate | <Private Use> | Available for | | | | | |
| | | | experiments. | | 240-254 | Terminate | <Reserved for | Available for |
| 255 | Terminate | <Reserved> | Reserved. | | | | Private Use> | experiments. |
| | | | |
| 255 | Terminate | Shutting Down | The peer is |
| | | | terminating the |
| | | | session, as it is |
| | | | shutting down. |
+----------+-------------+------------------+-----------------------+ +----------+-------------+------------------+-----------------------+
Table 2: DLEP Status Codes Table 2: DLEP Status Codes
13.2. IPv4 Connection Point 13.2. IPv4 Connection Point
The IPv4 Connection Point Data Item indicates the IPv4 address and, The IPv4 Connection Point Data Item indicates the IPv4 address and,
optionally, the TCP port number on the modem available for optionally, the TCP port number on the modem available for
connections. If provided, the router MUST use this information to connections. If provided, the router MUST use this information to
initiate the TCP connection to the modem. initiate the TCP connection to the modem.
skipping to change at page 39, line 41 skipping to change at page 41, line 36
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | IPv4 Address... : | Flags | IPv4 Address... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: ...cont. | TCP Port Number (optional) | : ...cont. | TCP Port Number (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 2 Data Item Type: 2
Length: 5 (or 7 if TCP Port included) Length: 5 (or 7 if TCP Port Number included).
Flags: Flags field, defined below. Flags: Flags field, defined below.
IPv4 Address: The IPv4 address listening on the modem. IPv4 Address: The IPv4 address listening on the modem.
TCP Port Number: TCP Port number on the modem. TCP Port Number: TCP port number on the modem.
If the Length field is 7, the port number specified MUST be used to If the Length field is 7, the port number specified MUST be used to
establish the TCP session. If the TCP Port Number is omitted, i.e. establish the TCP session. If the TCP Port Number is omitted, i.e.,
the Length field is 5, the router MUST use the DLEP well-known port the Length field is 5, the router MUST use the DLEP well-known port
number (Section 15.14) to establish the TCP connection. number (Section 15.14) to establish the TCP connection.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |T| | Reserved |T|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
T: Use TLS flag, indicating whether the TCP connection to the given T: Use TLS flag, indicating whether the TCP connection to the given
address and port requires the use of TLS [RFC5246] (1), or not address and port requires the use of TLS [RFC5246] (1) or
(0). not (0).
Reserved: MUST be zero. Left for future assignment. Reserved: MUST be zero. Left for future assignment.
13.3. IPv6 Connection Point 13.3. IPv6 Connection Point
The IPv6 Connection Point Data Item indicates the IPv6 address and, The IPv6 Connection Point Data Item indicates the IPv6 address and,
optionally, the TCP port number on the modem available for optionally, the TCP port number on the modem available for
connections. If provided, the router MUST use this information to connections. If provided, the router MUST use this information to
initiate the TCP connection to the modem. initiate the TCP connection to the modem.
skipping to change at page 40, line 48 skipping to change at page 42, line 45
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Address : : IPv6 Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Address : : IPv6 Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: ...cont. | TCP Port Number (optional) | : ...cont. | TCP Port Number (optional) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 3 Data Item Type: 3
Length: 17 (or 19 if TCP Port included) Length: 17 (or 19 if TCP Port Number included).
Flags: Flags field, defined below. Flags: Flags field, defined below.
IPv6 Address: The IPv6 address listening on the modem. IPv6 Address: The IPv6 address listening on the modem.
TCP Port Number: TCP Port number on the modem. TCP Port Number: TCP port number on the modem.
If the Length field is 19, the port number specified MUST be used to If the Length field is 19, the port number specified MUST be used to
establish the TCP session. If the TCP Port Number is omitted, i.e. establish the TCP session. If the TCP Port Number is omitted, i.e.,
the Length field is 17, the router MUST use the DLEP well-known port the Length field is 17, the router MUST use the DLEP well-known port
number (Section 15.14) to establish the TCP connection. number (Section 15.14) to establish the TCP connection.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |T| | Reserved |T|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
T: Use TLS flag, indicating whether the TCP connection to the given T: Use TLS flag, indicating whether the TCP connection to the given
address and port requires the use of TLS [RFC5246] (1), or not address and port requires the use of TLS [RFC5246] (1) or
(0). not (0).
Reserved: MUST be zero. Left for future assignment. Reserved: MUST be zero. Left for future assignment.
13.4. Peer Type 13.4. Peer Type
The Peer Type Data Item is used by the router and modem to give The Peer Type Data Item is used by the router and modem to give
additional information as to its type and the properties of the over- additional information as to its type and the properties of the
the-air control-plane. over-the-air control plane.
With some devices, access to the shared RF medium is strongly With some devices, access to the shared RF medium is strongly
controlled. One example of this would be satellite modems - where controlled. One example of this would be satellite modems -- where
protocols, proprietary in nature, have been developed to insure a protocols, proprietary in nature, have been developed to ensure that
given modem has authorization to connect to the shared medium. a given modem has authorization to connect to the shared medium.
Another example of this class of modems is governmental/military Another example of this class of modems is governmental/military
devices, where elaborate mechanisms have been developed to ensure devices, where elaborate mechanisms have been developed to ensure
that only authorized devices can connect to the shared medium. that only authorized devices can connect to the shared medium.
Contrasting with the above, there are modems where no such access Contrasting with the above, there are modems where no such access
control is used. An example of this class of modem would be one that control is used. An example of this class of modem would be one that
supports the 802.11 ad-hoc mode of operation. The Secured Medium supports the 802.11 ad hoc mode of operation. The Secured Medium (S)
flag is used to indicate if access control is in place. flag is used to indicate if access control is in place.
The Peer Type Data Item includes a textual description of the peer The Peer Type Data Item includes a textual description of the peer;
that is envisioned to be used for informational purposes (e.g., as it is envisioned that the text will be used for informational
output in a display command). purposes (e.g., as output in a display command).
The Peer Type Data Item contains the following fields: The Peer Type Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | Description... : | Flags | Description... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 4 Data Item Type: 4
Length: 1 + Length of Peer Type string, in octets. Length: 1 + Length of Description, in octets.
Flags: Flags field, defined below. Flags: Flags field, defined below.
Description: UTF-8 encoded string of UNICODE [RFC3629] characters. Description: UTF-8 encoded string of Unicode [RFC3629] characters.
For example, a satellite modem might set this variable to For example, a satellite modem might set this variable to
"Satellite terminal". Since this Data Item is intended to provide "Satellite terminal". Since this Data Item is intended to provide
additional information for display commands, sending additional information for display commands, sending
implementations SHOULD limit the data to printable characters. implementations SHOULD limit the data to printable characters.
An implementation MUST NOT assume the Description field is a NUL- An implementation MUST NOT assume that the Description field is a
terminated string of printable characters. NUL-terminated string of printable characters.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |S| | Reserved |S|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
S: Secured Medium flag, used by a modem to indicate if the shared RF S: Secured Medium flag, used by a modem to indicate whether the
medium implements access control (1), or not (0). The Secured shared RF medium implements access control (1) or not (0). The
Medium flag only has meaning in Signals and Messages sent by a Secured Medium flag only has meaning in Signals and Messages sent
modem. by a modem.
Reserved: MUST be zero. Left for future assignment. Reserved: MUST be zero. Left for future assignment.
13.5. Heartbeat Interval 13.5. Heartbeat Interval
The Heartbeat Interval Data Item is used to specify a period in The Heartbeat Interval Data Item is used to specify a period in
milliseconds for Heartbeat Messages (Section 12.20). milliseconds for Heartbeat Messages (Section 12.20).
The Heartbeat Interval Data Item contains the following fields: The Heartbeat Interval Data Item contains the following fields:
skipping to change at page 43, line 18 skipping to change at page 45, line 25
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Heartbeat Interval | | Heartbeat Interval |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 5 Data Item Type: 5
Length: 4 Length: 4
Heartbeat Interval: The interval in milliseconds, expressed as a Heartbeat Interval: The interval in milliseconds, expressed as a
32-bit unsigned integer, for Heartbeat Messages. This value MUST 32-bit unsigned integer, for Heartbeat Messages. This value
NOT be 0. MUST NOT be 0.
As mentioned before, receipt of any valid DLEP Message MUST reset the As mentioned before, receipt of any valid DLEP Message MUST reset the
heartbeat interval timer (e.g., valid DLEP Messages take the place heartbeat interval timer (i.e., valid DLEP Messages take the place
of, and obviate the need for, additional Heartbeat Messages). of, and obviate the need for, additional Heartbeat Messages).
13.6. Extensions Supported 13.6. Extensions Supported
The Extensions Supported Data Item is used by the router and modem to The Extensions Supported Data Item is used by the router and modem to
negotiate additional optional functionality they are willing to negotiate additional optional functionality they are willing to
support. The Extensions List is a concatenation of the types of each support. The Extensions List is a concatenation of the types of each
supported extension, found in the IANA DLEP Extensions repository. supported extension, found in the IANA registry titled "Extension
Each Extension Type definition includes which additional Signals and Type Values". Each Extension Type definition includes which
Data Items are supported. additional Signals and Data Items are supported.
The Extensions Supported Data Item contains the following fields: The Extensions Supported Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Extensions List... : | Extensions List... :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 6 Data Item Type: 6
Length: Length of the extensions list in octets. This is twice (2x) Length: Length of the Extensions List in octets. This is twice (2x)
the number of extensions. the number of extensions.
Extension List: A list of extensions supported, identified by their Extensions List: A list of extensions supported, identified by their
2-octet value as listed in the extensions registry. 2-octet values as listed in the "Extension Type Values" registry.
13.7. MAC Address 13.7. MAC Address
The MAC Address Data Item contains the address of the destination on The MAC Address Data Item contains the address of the destination on
the remote node. the remote node.
DLEP can support MAC addresses in either EUI-48 or EUI-64 format, DLEP can support MAC addresses in either EUI-48 or EUI-64 format
with the restriction that all MAC addresses for a given DLEP session ("EUI" stands for "Extended Unique Identifier"), with the restriction
MUST be in the same format, and MUST be consistent with the MAC that all MAC addresses for a given DLEP session MUST be in the same
address format of the connected modem (e.g., if the modem is format and MUST be consistent with the MAC address format of the
connected to the router with an EUI-48 MAC, all destination addresses connected modem (e.g., if the modem is connected to the router with
via that modem MUST be expressed in EUI-48 format). an EUI-48 MAC, all destination addresses via that modem MUST be
expressed in EUI-48 format).
Examples of a virtual destination would be a multicast MAC address, Examples of a virtual destination would be (1) a multicast MAC
or the broadcast MAC (FF:FF:FF:FF:FF:FF). address or (2) the broadcast MAC address (FF:FF:FF:FF:FF:FF).
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MAC Address : | MAC Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: MAC Address : (if EUI-64 used) | : MAC Address : (if EUI-64 used) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 44, line 29 skipping to change at page 47, line 4
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MAC Address : | MAC Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: MAC Address : (if EUI-64 used) | : MAC Address : (if EUI-64 used) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 7 Data Item Type: 7
Length: 6 for EUI-48 format, or 8 for EUI-64 format Length: 6 for EUI-48 format or 8 for EUI-64 format.
MAC Address: MAC Address of the destination. MAC Address: MAC address of the destination.
13.8. IPv4 Address 13.8. IPv4 Address
When included in the Session Update Message, this Data Item contains When included in the Session Update Message, this Data Item contains
the IPv4 address of the peer. When included in Destination Messages, the IPv4 address of the peer. When included in Destination Messages,
this Data Item contains the IPv4 address of the destination. In this Data Item contains the IPv4 address of the destination. In
either case, the Data Item also contains an indication of whether either case, the Data Item also contains an indication of whether
this is a new or existing address, or is a deletion of a previously this is (1) a new or existing address or (2) a deletion of a
known address. previously known address.
The IPv4 Address Data Item contains the following fields: The IPv4 Address Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | IPv4 Address : | Flags | IPv4 Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 45, line 30 skipping to change at page 47, line 46
IPv4 Address: The IPv4 address of the destination or peer. IPv4 Address: The IPv4 address of the destination or peer.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |A| | Reserved |A|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
A: Add/Drop flag, indicating whether this is a new or existing A: Add/Drop flag, indicating whether this is a new or existing
address (1), or a withdrawal of an address (0). address (1) or a withdrawal of an address (0).
Reserved: MUST be zero. Reserved for future use. Reserved: MUST be zero. Reserved for future use.
13.8.1. IPv4 Address Processing 13.8.1. IPv4 Address Processing
Processing of the IPv4 Address Data Item MUST be done within the Processing of the IPv4 Address Data Item MUST be done within the
context of the DLEP Peer session on which it is presented. context of the DLEP peer session on which it is presented.
The handling of erroneous or logically inconsistent conditions The handling of erroneous or logically inconsistent conditions
depends upon the type of the message that contains the data item: depends upon the type of the message that contains the Data Item,
as follows:
If the containing message is a Session Message, e.g., Session If the containing message is a Session Message, e.g., a Session
Initialization Message (Section 12.5), or Session Update Message Initialization Message (Section 12.5) or Session Update Message
(Section 12.7), the receiver of inconsistent information MUST issue a (Section 12.7), the receiver of inconsistent information MUST issue a
Session Termination Message (Section 12.9) containing a Status Data Session Termination Message (Section 12.9) containing a Status Data
Item (Section 13.1) with status code set to 130 'Invalid Data', and Item (Section 13.1) with status code set to 130 'Invalid Data' and
transition to the Session Termination state. Examples of such transition to the Session Termination state. Examples of such
conditions are: conditions are:
o An address Drop operation referencing an address that is not o An address Drop operation referencing an address that is not
associated with the peer in the current session. associated with the peer in the current session.
o An address Add operation referencing an address that has already o An address Add operation referencing an address that has already
been added to the peer in the current session. been added to the peer in the current session.
If the containing message is a Destination Message, e.g., Destination If the containing message is a Destination Message, e.g., a
Up Message (Section 12.11), or Destination Update Message Destination Up Message (Section 12.11) or Destination Update Message
(Section 12.17), the receiver of inconsistent information MAY issue (Section 12.17), the receiver of inconsistent information MAY issue
the appropriate response message containing a Status Data Item, with the appropriate response message containing a Status Data Item with
status code set to 3 'Inconsistent Data', but MUST continue with status code set to 3 'Inconsistent Data' but MUST continue with
session processing. Examples of such conditions are: session processing. Examples of such conditions are:
o An address Add operation referencing an address that has already o An address Add operation referencing an address that has already
been added to the destination in the current session. been added to the destination in the current session.
o An address Add operation referencing an address that is associated o An address Add operation referencing an address that is associated
with a different destination or the peer in the current session. with a different destination or the peer in the current session.
o An address Add operation referencing an address that makes no o An address Add operation referencing an address that makes no
sense, for example defined as not forwardable in [RFC6890]. sense -- for example, defined as not forwardable in [RFC6890].
o An address Drop operation referencing an address that is not o An address Drop operation referencing an address that is not
associated with the destination in the current session. associated with the destination in the current session.
If no response message is appropriate, for example, the Destination If no response message is appropriate -- for example, the Destination
Update Message, then the implementation MUST continue with session Update Message -- then the implementation MUST continue with session
processing. processing.
Modems that do not track IPv4 addresses MUST silently ignore IPv4 Modems that do not track IPv4 addresses MUST silently ignore IPv4
Address Data Items. Address Data Items.
13.9. IPv6 Address 13.9. IPv6 Address
When included in the Session Update Message, this Data Item contains When included in the Session Update Message, this Data Item contains
the IPv6 address of the peer. When included in Destination Messages, the IPv6 address of the peer. When included in Destination Messages,
this Data Item contains the IPv6 address of the destination. In this Data Item contains the IPv6 address of the destination. In
either case, the Data Item also contains an indication of whether either case, the Data Item also contains an indication of whether
this is a new or existing address, or is a deletion of a previously this is (1) a new or existing address or (2) a deletion of a
known address. previously known address.
The IPv6 Address Data Item contains the following fields: The IPv6 Address Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | IPv6 Address : | Flags | IPv6 Address :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 47, line 27 skipping to change at page 49, line 38
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Address | : IPv6 Address |
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Data Item Type: 9 Data Item Type: 9
Length: 17 Length: 17
Flags: Flags field, defined below. Flags: Flags field, defined below.
IPv6 Address: IPv6 Address of the destination or peer. IPv6 Address: The IPv6 address of the destination or peer.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |A| | Reserved |A|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
A: Add/Drop flag, indicating whether this is a new or existing A: Add/Drop flag, indicating whether this is a new or existing
address (1), or a withdrawal of an address (0). address (1) or a withdrawal of an address (0).
Reserved: MUST be zero. Reserved for future use. Reserved: MUST be zero. Reserved for future use.
13.9.1. IPv6 Address Processing 13.9.1. IPv6 Address Processing
Processing of the IPv6 Address Data Item MUST be done within the Processing of the IPv6 Address Data Item MUST be done within the
context of the DLEP Peer session on which it is presented. context of the DLEP peer session on which it is presented.
The handling of erroneous or logically inconsistent conditions The handling of erroneous or logically inconsistent conditions
depends upon the type of the message that contains the data item: depends upon the type of the message that contains the Data Item,
as follows:
If the containing message is a Session Message, e.g., Session If the containing message is a Session Message, e.g., a Session
Initialization Message (Section 12.5), or Session Update Message Initialization Message (Section 12.5) or Session Update Message
(Section 12.7), the receiver of inconsistent information MUST issue a (Section 12.7), the receiver of inconsistent information MUST issue a
Session Termination Message (Section 12.9) containing a Status Data Session Termination Message (Section 12.9) containing a Status Data
Item (Section 13.1) with status code set to 130 'Invalid Data', and Item (Section 13.1) with status code set to 130 'Invalid Data' and
transition to the Session Termination state. Examples of such transition to the Session Termination state. Examples of such
conditions are: conditions are:
o An address Drop operation referencing an address that is not o An address Drop operation referencing an address that is not
associated with the peer in the current session. associated with the peer in the current session.
o An address Add operation referencing an address that has already o An address Add operation referencing an address that has already
been added to the peer in the current session. been added to the peer in the current session.
If the containing message is a Destination Message, e.g., Destination If the containing message is a Destination Message, e.g., a
Up Message (Section 12.11), or Destination Update Message Destination Up Message (Section 12.11) or Destination Update Message
(Section 12.17), the receiver of inconsistent information MAY issue (Section 12.17), the receiver of inconsistent information MAY issue
the appropriate response message containing a Status Data Item, with the appropriate response message containing a Status Data Item with
status code set to 3 'Inconsistent Data', but MUST continue with status code set to 3 'Inconsistent Data' but MUST continue with
session processing. Examples of such conditions are: session processing. Examples of such conditions are:
o An address Add operation referencing an address that has already o An address Add operation referencing an address that has already
been added to the destination in the current session. been added to the destination in the current session.
o An address Add operation referencing an address that is associated o An address Add operation referencing an address that is associated
with a different destination or the peer in the current session. with a different destination or the peer in the current session.
o An address Add operation referencing an address that makes no o An address Add operation referencing an address that makes no
sense, for example defined as not forwardable in [RFC6890]. sense -- for example, defined as not forwardable in [RFC6890].
o An address Drop operation referencing an address that is not o An address Drop operation referencing an address that is not
associated with the destination in the current session. associated with the destination in the current session.
If no response message is appropriate, for example, the Destination If no response message is appropriate -- for example, the Destination
Update Message, then the implementation MUST continue with session Update Message -- then the implementation MUST continue with session
processing. processing.
Modems that do not track IPv6 addresses MUST silently ignore IPv6 Modems that do not track IPv6 addresses MUST silently ignore IPv6
Address Data Items. Address Data Items.
13.10. IPv4 Attached Subnet 13.10. IPv4 Attached Subnet
The DLEP IPv4 Attached Subnet allows a device to declare that it has The DLEP IPv4 Attached Subnet Data Item allows a device to declare
an IPv4 subnet (e.g., a stub network) attached, that it has become that it has an IPv4 subnet (e.g., a stub network) attached, that it
aware of an IPv4 subnet being present at a remote destination, or has become aware of an IPv4 subnet being present at a remote
that it has become aware of the loss of a subnet at the remote destination, or that it has become aware of the loss of a subnet at
destination. the remote destination.
The DLEP IPv4 Attached Subnet Data Item contains the following The DLEP IPv4 Attached Subnet Data Item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | IPv4 Attached Subnet : | Flags | IPv4 Attached Subnet :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: ...cont. |Prefix Length | : ...cont. |Prefix Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 10 Data Item Type: 10
Length: 6 Length: 6
Flags: Flags field, defined below. Flags: Flags field, defined below.
IPv4 Subnet: The IPv4 subnet reachable at the destination. IPv4 Attached Subnet: The IPv4 subnet reachable at the destination.
Prefix Length: Length of the prefix (0-32) for the IPv4 subnet. A Prefix Length: Length of the prefix (0-32) for the IPv4 subnet. A
prefix length outside the specified range MUST be considered as prefix length outside the specified range MUST be considered as
invalid. invalid.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |A| | Reserved |A|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
A: Add/Drop flag, indicating whether this is a new or existing subnet A: Add/Drop flag, indicating whether this is a new or existing
address (1), or a withdrawal of a subnet address (0). subnet address (1) or a withdrawal of a subnet address (0).
Reserved: MUST be zero. Reserved for future use. Reserved: MUST be zero. Reserved for future use.
13.10.1. IPv4 Attached Subnet Processing 13.10.1. IPv4 Attached Subnet Processing
Processing of the IPv4 Attached Subnet Data Item MUST be done within Processing of the IPv4 Attached Subnet Data Item MUST be done within
the context of the DLEP Peer session on which it is presented. the context of the DLEP peer session on which it is presented.
If the containing message is a Session Message, e.g., Session If the containing message is a Session Message, e.g., a Session
Initialization Message (Section 12.5), or Session Update Message Initialization Message (Section 12.5) or Session Update Message
(Section 12.7), the receiver of inconsistent information MUST issue a (Section 12.7), the receiver of inconsistent information MUST issue a
Session Termination Message (Section 12.9) containing a Status Data Session Termination Message (Section 12.9) containing a Status Data
Item (Section 13.1) with status code set to 130 'Invalid Data', and Item (Section 13.1) with status code set to 130 'Invalid Data' and
transition to the Session Termination state. Examples of such transition to the Session Termination state. Examples of such
conditions are: conditions are:
o A subnet Drop operation referencing a subnet that is not o A subnet Drop operation referencing a subnet that is not
associated with the peer in the current session. associated with the peer in the current session.
o A subnet Add operation referencing a subnet that has already been o A subnet Add operation referencing a subnet that has already been
added to the peer in the current session. added to the peer in the current session.
If the containing message is a Destination Message, e.g., Destination If the containing message is a Destination Message, e.g., a
Up Message (Section 12.11), or Destination Update Message Destination Up Message (Section 12.11) or Destination Update Message
(Section 12.17), the receiver of inconsistent information MAY issue (Section 12.17), the receiver of inconsistent information MAY issue
the appropriate response message containing a Status Data Item, with the appropriate response message containing a Status Data Item with
status code set to 3 'Inconsistent Data', but MUST continue with status code set to 3 'Inconsistent Data' but MUST continue with
session processing. Examples of such conditions are: session processing. Examples of such conditions are:
o A subnet Add operation referencing a subnet that has already been o A subnet Add operation referencing a subnet that has already been
added to the destination in the current session. added to the destination in the current session.
o A subnet Add operation referencing a subnet that is associated o A subnet Add operation referencing a subnet that is associated
with a different destination in the current session. with a different destination in the current session.
o An subnet Add operation referencing an subnet that makes no sense, o A subnet Add operation referencing a subnet that makes no sense --
for example defined as not forwardable in [RFC6890]. for example, defined as not forwardable in [RFC6890].
o A subnet Drop operation referencing a subnet that is not o A subnet Drop operation referencing a subnet that is not
associated with the destination in the current session. associated with the destination in the current session.
If no response message is appropriate, for example, the Destination If no response message is appropriate -- for example, the Destination
Update Message, then the implementation MUST continue with session Update Message -- then the implementation MUST continue with session
processing. processing.
Modems that do not track IPv4 subnets MUST silently ignore IPv4 Modems that do not track IPv4 subnets MUST silently ignore IPv4
Attached Subnet Data Items. Attached Subnet Data Items.
13.11. IPv6 Attached Subnet 13.11. IPv6 Attached Subnet
The DLEP IPv6 Attached Subnet allows a device to declare that it has The DLEP IPv6 Attached Subnet Data Item allows a device to declare
an IPv6 subnet (e.g., a stub network) attached, that it has become that it has an IPv6 subnet (e.g., a stub network) attached, that it
aware of an IPv6 subnet being present at a remote destination, or has become aware of an IPv6 subnet being present at a remote
that it has become aware of the loss of a subnet at the remote destination, or that it has become aware of the loss of a subnet at
destination. the remote destination.
The DLEP IPv6 Attached Subnet Data Item contains the following The DLEP IPv6 Attached Subnet Data Item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Flags | IPv6 Attached Subnet : | Flags | IPv6 Attached Subnet :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Attached Subnet : : IPv6 Attached Subnet :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Attached Subnet : : IPv6 Attached Subnet :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: IPv6 Attached Subnet : : IPv6 Attached Subnet :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: ...cont. | Prefix Len. | : ...cont. | Prefix Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 11 Data Item Type: 11
Length: 18 Length: 18
Flags: Flags field, defined below. Flags: Flags field, defined below.
IPv6 Attached Subnet: The IPv6 subnet reachable at the destination. IPv6 Attached Subnet: The IPv6 subnet reachable at the destination.
skipping to change at page 51, line 40 skipping to change at page 54, line 12
prefix length outside the specified range MUST be considered as prefix length outside the specified range MUST be considered as
invalid. invalid.
The Flags field is defined as: The Flags field is defined as:
0 1 2 3 4 5 6 7 0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
| Reserved |A| | Reserved |A|
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
A: Add/Drop flag, indicating whether this is a new or existing subnet A: Add/Drop flag, indicating whether this is a new or existing
address (1), or a withdrawal of a subnet address (0). subnet address (1) or a withdrawal of a subnet address (0).
Reserved: MUST be zero. Reserved for future use. Reserved: MUST be zero. Reserved for future use.
13.11.1. IPv6 Attached Subnet Processing 13.11.1. IPv6 Attached Subnet Processing
Processing of the IPv6 Attached Subnet Data Item MUST be done within Processing of the IPv6 Attached Subnet Data Item MUST be done within
the context of the DLEP Peer session on which it is presented. the context of the DLEP peer session on which it is presented.
If the containing message is a Session Message, e.g., Session If the containing message is a Session Message, e.g., a Session
Initialization Message (Section 12.5), or Session Update Message Initialization Message (Section 12.5) or Session Update Message
(Section 12.7), the receiver of inconsistent information MUST issue a (Section 12.7), the receiver of inconsistent information MUST issue a
Session Termination Message (Section 12.9) containing a Status Data Session Termination Message (Section 12.9) containing a Status Data
Item (Section 13.1) with status code set to 130 'Invalid Data', and Item (Section 13.1) with status code set to 130 'Invalid Data' and
transition to the Session Termination state. Examples of such transition to the Session Termination state. Examples of such
conditions are: conditions are:
o A subnet Drop operation referencing a subnet that is not o A subnet Drop operation referencing a subnet that is not
associated with the peer in the current session. associated with the peer in the current session.
o A subnet Add operation referencing a subnet that has already been o A subnet Add operation referencing a subnet that has already been
added to the peer in the current session. added to the peer in the current session.
If the containing message is a Destination Message, e.g., Destination If the containing message is a Destination Message, e.g., a
Up Message (Section 12.11), or Destination Update Message Destination Up Message (Section 12.11) or Destination Update Message
(Section 12.17), the receiver of inconsistent information MAY issue (Section 12.17), the receiver of inconsistent information MAY issue
the appropriate response message containing a Status Data Item, with the appropriate response message containing a Status Data Item with
status code set to 3 'Inconsistent Data', but MUST continue with status code set to 3 'Inconsistent Data' but MUST continue with
session processing. Examples of such conditions are: session processing. Examples of such conditions are:
o A subnet Add operation referencing a subnet that has already been o A subnet Add operation referencing a subnet that has already been
added to the destination in the current session. added to the destination in the current session.
o A subnet Add operation referencing a subnet that is associated o A subnet Add operation referencing a subnet that is associated
with a different destination in the current session. with a different destination in the current session.
o An subnet Add operation referencing an subnet that makes no sense, o A subnet Add operation referencing a subnet that makes no sense --
for example defined as not forwardable in [RFC6890]. for example, defined as not forwardable in [RFC6890].
o A subnet Drop operation referencing a subnet that is not o A subnet Drop operation referencing a subnet that is not
associated with the destination in the current session. associated with the destination in the current session.
If no response message is appropriate, for example, the Destination If no response message is appropriate -- for example, the Destination
Update Message, then the implementation MUST continue with session Update Message -- then the implementation MUST continue with session
processing. processing.
Modems that do not track IPv6 subnets MUST silently ignore IPv6 Modems that do not track IPv6 subnets MUST silently ignore IPv6
Attached Subnet Data Items. Attached Subnet Data Items.
13.12. Maximum Data Rate (Receive) 13.12. Maximum Data Rate (Receive)
The Maximum Data Rate (Receive) (MDRR) Data Item is used to indicate The Maximum Data Rate (Receive) (MDRR) Data Item is used to indicate
the maximum theoretical data rate, in bits per second, that can be the maximum theoretical data rate, in bits per second (bps), that can
achieved while receiving data on the link. be achieved while receiving data on the link.
The Maximum Data Rate (Receive) Data Item contains the following The Maximum Data Rate (Receive) Data Item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MDRR (bps) : | MDRR (bps) :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: MDRR (bps) | : MDRR (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 12 Data Item Type: 12
Length: 8 Length: 8
Maximum Data Rate (Receive): A 64-bit unsigned integer, representing Maximum Data Rate (Receive): A 64-bit unsigned integer, representing
the maximum theoretical data rate, in bits per second (bps), that the maximum theoretical data rate, in bits per second, that can be
can be achieved while receiving on the link. achieved while receiving on the link.
13.13. Maximum Data Rate (Transmit) 13.13. Maximum Data Rate (Transmit)
The Maximum Data Rate (Transmit) (MDRT) Data Item is used to indicate The Maximum Data Rate (Transmit) (MDRT) Data Item is used to indicate
the maximum theoretical data rate, in bits per second, that can be the maximum theoretical data rate, in bits per second, that can be
achieved while transmitting data on the link. achieved while transmitting data on the link.
The Maximum Data Rate (Transmit) Data Item contains the following The Maximum Data Rate (Transmit) Data Item contains the following
fields: fields:
skipping to change at page 53, line 47 skipping to change at page 56, line 29
| MDRT (bps) : | MDRT (bps) :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: MDRT (bps) | : MDRT (bps) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 13 Data Item Type: 13
Length: 8 Length: 8
Maximum Data Rate (Transmit): A 64-bit unsigned integer, Maximum Data Rate (Transmit): A 64-bit unsigned integer,
representing the maximum theoretical data rate, in bits per second representing the maximum theoretical data rate, in bits per
(bps), that can be achieved while transmitting on the link. second, that can be achieved while transmitting on the link.
13.14. Current Data Rate (Receive) 13.14. Current Data Rate (Receive)
The Current Data Rate (Receive) (CDRR) Data Item is used to indicate The Current Data Rate (Receive) (CDRR) Data Item is used to indicate
the rate at which the link is currently operating for receiving the rate at which the link is currently operating for receiving
traffic. traffic.
When used in the Link Characteristics Request Message When used in the Link Characteristics Request Message
(Section 12.18), Current Data Rate (Receive) represents the desired (Section 12.18), Current Data Rate (Receive) represents the desired
receive rate, in bits per second, on the link. receive rate, in bits per second, on the link.
skipping to change at page 54, line 38 skipping to change at page 57, line 28
Data Item Type: 14 Data Item Type: 14
Length: 8 Length: 8
Current Data Rate (Receive): A 64-bit unsigned integer, representing Current Data Rate (Receive): A 64-bit unsigned integer, representing
the current data rate, in bits per second, that can currently be the current data rate, in bits per second, that can currently be
achieved while receiving traffic on the link. achieved while receiving traffic on the link.
If there is no distinction between Current Data Rate (Receive) and If there is no distinction between Current Data Rate (Receive) and
Maximum Data Rate (Receive) (Section 13.12), Current Data Rate Maximum Data Rate (Receive) (Section 13.12), Current Data Rate
(Receive) MUST be set equal to the Maximum Data Rate (Receive). The (Receive) MUST be set equal to Maximum Data Rate (Receive). Current
Current Data Rate (Receive) MUST NOT exceed the Maximum Data Rate Data Rate (Receive) MUST NOT exceed Maximum Data Rate (Receive).
(Receive).
13.15. Current Data Rate (Transmit) 13.15. Current Data Rate (Transmit)
The Current Data Rate (Transmit) (CDRT) Data Item is used to indicate The Current Data Rate (Transmit) (CDRT) Data Item is used to indicate
the rate at which the link is currently operating for transmitting the rate at which the link is currently operating for transmitting
traffic. traffic.
When used in the Link Characteristics Request Message When used in the Link Characteristics Request Message
(Section 12.18), Current Data Rate (Transmit) represents the desired (Section 12.18), Current Data Rate (Transmit) represents the desired
transmit rate, in bits per second, on the link. transmit rate, in bits per second, on the link.
skipping to change at page 55, line 28 skipping to change at page 58, line 14
Data Item Type: 15 Data Item Type: 15
Length: 8 Length: 8
Current Data Rate (Transmit): A 64-bit unsigned integer, Current Data Rate (Transmit): A 64-bit unsigned integer,
representing the current data rate, in bits per second, that can representing the current data rate, in bits per second, that can
currently be achieved while transmitting traffic on the link. currently be achieved while transmitting traffic on the link.
If there is no distinction between Current Data Rate (Transmit) and If there is no distinction between Current Data Rate (Transmit) and
Maximum Data Rate (Transmit) (Section 13.13), Current Data Rate Maximum Data Rate (Transmit) (Section 13.13), Current Data Rate
(Transmit) MUST be set equal to the Maximum Data Rate (Transmit). (Transmit) MUST be set equal to Maximum Data Rate (Transmit).
The Current Data Rate (Transmit) MUST NOT exceed the Maximum Data Current Data Rate (Transmit) MUST NOT exceed Maximum Data Rate
Rate (Transmit). (Transmit).
13.16. Latency 13.16. Latency
The Latency Data Item is used to indicate the amount of latency, in The Latency Data Item is used to indicate the amount of latency, in
microseconds, on the link. microseconds, on the link.
The Latency value is reported as transmission delay. The calculation The Latency value is reported as transmission delay. The calculation
of latency is implementation dependent. For example, the latency may of latency is implementation dependent. For example, the latency may
be a running average calculated from the internal queuing. be a running average calculated from the internal queuing.
skipping to change at page 56, line 16 skipping to change at page 59, line 9
Length: 8 Length: 8
Latency: A 64-bit unsigned integer, representing the transmission Latency: A 64-bit unsigned integer, representing the transmission
delay, in microseconds, that a packet encounters as it is delay, in microseconds, that a packet encounters as it is
transmitted over the link. transmitted over the link.
13.17. Resources 13.17. Resources
The Resources (RES) Data Item is used to indicate the amount of The Resources (RES) Data Item is used to indicate the amount of
finite resources available for data transmission and reception at the finite resources available for data transmission and reception at the
destination as a percentage, with 0 meaning 'no resources remaining', destination as a percentage, with 0 meaning 'no resources remaining'
and 100 meaning 'a full supply', assuming that when Resources reaches and 100 meaning 'a full supply', assuming that when Resources reaches
0 data transmission and/or reception will cease. 0 data transmission and/or reception will cease.
An example of such resources might be battery life, but could equally An example of such resources is battery life, but this could also
be magic beans. The list of resources that might be considered is include resources such as available memory for queuing, or CPU idle
beyond the scope of this document, and is left to implementations to percentage. The specific criteria to be used for this metric is out
decide. of scope for this specification and is implementation specific.
This Data Item is designed to be used as an indication of some This Data Item is designed to be used as an indication of some
capability of the modem and/or router at the destination. capability of the modem and/or router at the destination.
The Resources Data Item contains the following fields: The Resources Data Item contains the following fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
skipping to change at page 56, line 46 skipping to change at page 59, line 39
+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+
Data Item Type: 17 Data Item Type: 17
Length: 1 Length: 1
Resources: An 8-bit unsigned integer percentage, 0-100, representing Resources: An 8-bit unsigned integer percentage, 0-100, representing
the amount of resources available. Any value greater than 100 the amount of resources available. Any value greater than 100
MUST be considered as invalid. MUST be considered as invalid.
If a device cannot calculate Resources, this Data Item MUST NOT be If a device cannot calculate Resources, this Data Item MUST NOT
issued. be issued.
13.18. Relative Link Quality (Receive) 13.18. Relative Link Quality (Receive)
The Relative Link Quality (Receive) (RLQR) Data Item is used to The Relative Link Quality (Receive) (RLQR) Data Item is used to
indicate the quality of the link to a destination for receiving indicate the quality of the link to a destination for receiving
traffic, with 0 meaning 'worst quality', and 100 meaning 'best traffic, with 0 meaning 'worst quality' and 100 meaning 'best
quality'. quality'.
Quality in this context is defined as an indication of the stability Quality in this context is defined as an indication of the stability
of a link for reception; a destination with high Relative Link of a link for reception; a destination with high Relative Link
Quality (Receive) is expected to have generally stable DLEP metrics, Quality (Receive) is expected to have generally stable DLEP metrics,
and the metrics of a destination with low Relative Link Quality and the metrics of a destination with low Relative Link Quality
(Receive) can be expected to rapidly fluctuate over a wide range. (Receive) can be expected to rapidly fluctuate over a wide range.
The Relative Link Quality (Receive) Data Item contains the following The Relative Link Quality (Receive) Data Item contains the following
fields: fields:
skipping to change at page 57, line 38 skipping to change at page 60, line 38
Data Item Type: 18 Data Item Type: 18
Length: 1 Length: 1
Relative Link Quality (Receive): A non-dimensional unsigned 8-bit Relative Link Quality (Receive): A non-dimensional unsigned 8-bit
integer, 0-100, representing relative quality of the link for integer, 0-100, representing relative quality of the link for
receiving traffic. Any value greater than 100 MUST be considered receiving traffic. Any value greater than 100 MUST be considered
as invalid. as invalid.
If a device cannot calculate the Relative Link Quality (Receive), If a device cannot calculate Relative Link Quality (Receive), this
this Data Item MUST NOT be issued. Data Item MUST NOT be issued.
13.19. Relative Link Quality (Transmit) 13.19. Relative Link Quality (Transmit)
The Relative Link Quality (Transmit) (RLQT) Data Item is used to The Relative Link Quality (Transmit) (RLQT) Data Item is used to
indicate the quality of the link to a destination for transmitting indicate the quality of the link to a destination for transmitting
traffic, with 0 meaning 'worst quality', and 100 meaning 'best traffic, with 0 meaning 'worst quality' and 100 meaning 'best
quality'. quality'.
Quality in this context is defined as an indication of the stability Quality in this context is defined as an indication of the stability
of a link for transmission; a destination with high Relative Link of a link for transmission; a destination with high Relative Link
Quality (Transmit) is expected to have generally stable DLEP metrics, Quality (Transmit) is expected to have generally stable DLEP metrics,
and the metrics of a destination with low Relative Link Quality and the metrics of a destination with low Relative Link Quality
(Transmit) can be expected to rapidly fluctuate over a wide range. (Transmit) can be expected to rapidly fluctuate over a wide range.
The Relative Link Quality (Transmit) Data Item contains the following The Relative Link Quality (Transmit) Data Item contains the following
fields: fields:
skipping to change at page 58, line 25 skipping to change at page 61, line 25
Data Item Type: 19 Data Item Type: 19
Length: 1 Length: 1
Relative Link Quality (Transmit): A non-dimensional unsigned 8-bit Relative Link Quality (Transmit): A non-dimensional unsigned 8-bit
integer, 0-100, representing relative quality of the link for integer, 0-100, representing relative quality of the link for
transmitting traffic. Any value greater than 100 MUST be transmitting traffic. Any value greater than 100 MUST be
considered as invalid. considered as invalid.
If a device cannot calculate the Relative Link Quality (Transmit), If a device cannot calculate Relative Link Quality (Transmit), this
this Data Item MUST NOT be issued. Data Item MUST NOT be issued.
13.20. Maximum Transmission Unit (MTU) 13.20. Maximum Transmission Unit (MTU)
The Maximum Transmission Unit (MTU) Data Item is used to indicate the The Maximum Transmission Unit (MTU) Data Item is used to indicate the
maximum size, in octets, of an IP packet that can be transmitted maximum size, in octets, of an IP packet that can be transmitted
without fragmentation, including headers, but excluding any lower without fragmentation, including headers, but excluding any
layer headers. lower-layer headers.
The Maximum Transmission Unit Data Item contains the following The Maximum Transmission Unit Data Item contains the following
fields: fields:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Data Item Type | Length | | Data Item Type | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MTU | | MTU |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Data Item Type: 20 Data Item Type: 20
Length: 2 Length: 2
Maximum Transmission Unit: The maximum size, in octets, of an IP Maximum Transmission Unit: The maximum size, in octets, of an
packet that can be transmitted without fragmentation, including IP packet that can be transmitted without fragmentation, including
headers, but excluding any lower layer headers. headers, but excluding any lower-layer headers.
If a device cannot calculate the Maximum Transmission Unit, this Data If a device cannot calculate Maximum Transmission Unit, this Data
Item MUST NOT be issued. Item MUST NOT be issued.
14. Security Considerations 14. Security Considerations
The potential security concerns when using DLEP are: The potential security concerns when using DLEP are as follows:
1. An attacker might pretend to be a DLEP participant, either at 1. An attacker might pretend to be a DLEP participant, either at
DLEP session initialization, or by injection of DLEP Messages DLEP session initialization or by injection of DLEP Messages once
once a session has been established. a session has been established.
2. DLEP Data Items could be altered by an attacker, causing the 2. DLEP Data Items could be altered by an attacker, causing the
receiving implementation to inappropriately alter its information receiving implementation to inappropriately alter its information
base concerning network status. base concerning network status.
3. An attacker could join an unsecured radio network and inject 3. An attacker could join an unsecured radio network and inject
over-the-air signals that maliciously influence the information over-the-air signals that maliciously influence the information
reported by a DLEP modem, causing a router to forward traffic to reported by a DLEP modem, causing a router to forward traffic to
an inappropriate destination. an inappropriate destination.
The implications of attacks on DLEP peers are directly proportional The implications of attacks on DLEP peers are directly proportional
to the extent to which DLEP data is used within the control plane. to the extent to which DLEP data is used within the control plane.
While the use of DLEP data in other control plane components is out While the use of DLEP data in other control-plane components is out
of scope for this document, as an example, if DLEP statistics are of scope for this document, as an example, if DLEP statistics are
incorporated into route cost calculations, adversaries masquerading incorporated into route cost calculations, adversaries masquerading
as a DLEP peer, and injecting malicious data via DLEP, could cause as a DLEP peer and injecting malicious data via DLEP could cause
suboptimal route selection, adversely impacting network performance. suboptimal route selection, adversely impacting network performance.
Similar issues can arise if DLEP data is used as an input to policing Similar issues can arise if DLEP data is used as an input to policing
algorithms - injection of malicious data via DLEP can cause those algorithms -- injection of malicious data via DLEP can cause those
policing algorithms to make incorrect decisions, degrading network policing algorithms to make incorrect decisions, degrading network
throughput. throughput.
For these reasons, security of the DLEP transport must be considered For these reasons, security of the DLEP transport must be considered
at both the transport layer, and at Layer 2. at both the transport layer and Layer 2.
At the transport layer, when TLS is in use, each peer SHOULD check At the transport layer, when TLS is in use, each peer SHOULD check
the validity of credentials presented by the other peer during TLS the validity of credentials presented by the other peer during TLS
session establishment. Implementations following the "dedicated session establishment. Implementations following the "dedicated
deployments" model attempting to use TLS MAY need to consider use of deployments" model attempting to use TLS MAY (1) need to consider the
pre-shared keys for credentials, and provide specialized techniques use of pre-shared keys for credentials, (2) provide specialized
for peer identity validation, and MAY refer to [RFC5487] for techniques for peer identity validation, and (3) refer to [RFC5487]
additional details. Implementations following the "networked for additional details. Implementations following the "networked
deployment" model described in Implementation Scenarios SHOULD refer deployment" model described in "Implementation Scenarios" (Section 4)
to [RFC7525] for additional details. SHOULD refer to [RFC7525] for additional details.
At layer 2 - since DLEP is restricted to operation over a single At Layer 2, since DLEP is restricted to operation over a single
(possibly logical) hop, implementations SHOULD also secure the Layer (possibly logical) hop, implementations SHOULD also secure the
2 link. Examples of technologies that can be deployed to secure the Layer 2 link. Examples of technologies that can be deployed to
Layer 2 link include [IEEE-802.1AE] and [IEEE-802.1X]. secure the Layer 2 link include [IEEE-802.1AE] and [IEEE-802.1X].
By examining the Secured Medium flag in the Peer Type Data Item By examining the Secured Medium flag in the Peer Type Data Item
(Section 13.4), a router can decide if it is able to trust the (Section 13.4), a router can decide if it is able to trust the
information supplied via a DLEP modem. If this is not the case, then information supplied via a DLEP modem. If this is not the case, then
the router SHOULD consider restricting the size of attached subnets, the router SHOULD consider restricting the size of attached subnets,
announced in IPv4 Attached Subnet Data Items (Section 13.10) and/or announced in IPv4 Attached Subnet Data Items (Section 13.10) and/or
IPv6 Attached Subnet Data Items (Section 13.11), that are considered IPv6 Attached Subnet Data Items (Section 13.11), that are considered
for route selection. for route selection.
To avoid potential denial of service attack, it is RECOMMENDED that To avoid potential denial-of-service attacks, it is RECOMMENDED that
implementations using the Peer Discovery mechanism maintain an implementations using the Peer Discovery mechanism (1) maintain an
information base of hosts that persistently fail Session information base of hosts that persistently fail Session
Initialization having provided an acceptable Peer Discovery Signal, Initialization, even though those hosts have provided an acceptable
and ignore subsequent Peer Discovery Signals from such hosts. Peer Discovery Signal and (2) ignore any subsequent Peer Discovery
Signals from such hosts.
This specification does not address security of the data plane, as it This specification does not address security of the data plane, as it
(the data plane) is not affected, and standard security procedures (the data plane) is not affected, and standard security procedures
can be employed. can be employed.
15. IANA Considerations 15. IANA Considerations
15.1. Registrations 15.1. Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new protocol registry for the Dynamic Link
protocol registry for Dynamic Link Exchange Protocol (DLEP). The Exchange Protocol (DLEP). The remainder of this section details the
remainder of this section requests the creation of new DLEP specific new DLEP-specific registries.
registries.
15.2. Signal Type Registration 15.2. Signal Type Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Signal Type Values".
DLEP registry, named "Signal Type Values".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+--------------+-------------------------+ +--------------+--------------------------------------+
| Type Code | Description/Policy | | Type Code | Description/Policy |
+--------------+-------------------------+ +--------------+--------------------------------------+
| 0 | Reserved | | 0 | Reserved |
| 1 | Peer Discovery Signal | | 1 | Peer Discovery Signal |
| 2 | Peer Offer Signal | | 2 | Peer Offer Signal |
| 3-65519 | Specification Required | | 3-65519 | Unassigned / Specification Required |
| 65520-65534 | Private Use | | 65520-65534 | Reserved for Private Use |
| 65535 | Reserved | | 65535 | Reserved |
+--------------+-------------------------+ +--------------+--------------------------------------+
15.3. Message Type Registration 15.3. Message Type Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Message Type Values".
DLEP registry, named "Message Type Values".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+--------------+------------------------------------------+ +--------------+------------------------------------------+
| Type Code | Description/Policy | | Type Code | Description/Policy |
+--------------+------------------------------------------+ +--------------+------------------------------------------+
| 0 | Reserved | | 0 | Reserved |
| | |
| 1 | Session Initialization Message | | 1 | Session Initialization Message |
| | |
| 2 | Session Initialization Response Message | | 2 | Session Initialization Response Message |
| | |
| 3 | Session Update Message | | 3 | Session Update Message |
| | |
| 4 | Session Update Response Message | | 4 | Session Update Response Message |
| | |
| 5 | Session Termination Message | | 5 | Session Termination Message |
| | |
| 6 | Session Termination Response Message | | 6 | Session Termination Response Message |
| | |
| 7 | Destination Up Message | | 7 | Destination Up Message |
| | |
| 8 | Destination Up Response Message | | 8 | Destination Up Response Message |
| | |
| 9 | Destination Announce Message | | 9 | Destination Announce Message |
| | |
| 10 | Destination Announce Response Message | | 10 | Destination Announce Response Message |
| | |
| 11 | Destination Down Message | | 11 | Destination Down Message |
| | |
| 12 | Destination Down Response Message | | 12 | Destination Down Response Message |
| | |
| 13 | Destination Update Message | | 13 | Destination Update Message |
| | |
| 14 | Link Characteristics Request Message | | 14 | Link Characteristics Request Message |
| | |
| 15 | Link Characteristics Response Message | | 15 | Link Characteristics Response Message |
| | |
| 16 | Heartbeat Message | | 16 | Heartbeat Message |
| 17-65519 | Specification Required | | | |
| 65520-65534 | Private Use | | 17-65519 | Unassigned / Specification Required |
| | |
| 65520-65534 | Reserved for Private Use |
| | |
| 65535 | Reserved | | 65535 | Reserved |
+--------------+------------------------------------------+ +--------------+------------------------------------------+
15.4. DLEP Data Item Registrations 15.4. DLEP Data Item Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Data Item Type Values".
DLEP registry, named "Data Item Type Values".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+-------------------+------------------------------------------+ +-------------------+------------------------------------------+
| Type Code | Description/Policy | | Type Code | Description/Policy |
+-------------------+------------------------------------------+ +-------------------+------------------------------------------+
| 0 | Reserved | | 0 | Reserved |
| | |
| 1 | Status | | 1 | Status |
| | |
| 2 | IPv4 Connection Point | | 2 | IPv4 Connection Point |
| | |
| 3 | IPv6 Connection Point | | 3 | IPv6 Connection Point |
| | |
| 4 | Peer Type | | 4 | Peer Type |
| | |
| 5 | Heartbeat Interval | | 5 | Heartbeat Interval |
| | |
| 6 | Extensions Supported | | 6 | Extensions Supported |
| | |
| 7 | MAC Address | | 7 | MAC Address |
| | |
| 8 | IPv4 Address | | 8 | IPv4 Address |
| | |
| 9 | IPv6 Address | | 9 | IPv6 Address |
| | |
| 10 | IPv4 Attached Subnet | | 10 | IPv4 Attached Subnet |
| | |
| 11 | IPv6 Attached Subnet | | 11 | IPv6 Attached Subnet |
| | |
| 12 | Maximum Data Rate (Receive) (MDRR) | | 12 | Maximum Data Rate (Receive) (MDRR) |
| | |
| 13 | Maximum Data Rate (Transmit) (MDRT) | | 13 | Maximum Data Rate (Transmit) (MDRT) |
| | |
| 14 | Current Data Rate (Receive) (CDRR) | | 14 | Current Data Rate (Receive) (CDRR) |
| | |
| 15 | Current Data Rate (Transmit) (CDRT) | | 15 | Current Data Rate (Transmit) (CDRT) |
| | |
| 16 | Latency | | 16 | Latency |
| | |
| 17 | Resources (RES) | | 17 | Resources (RES) |
| | |
| 18 | Relative Link Quality (Receive) (RLQR) | | 18 | Relative Link Quality (Receive) (RLQR) |
| | |
| 19 | Relative Link Quality (Transmit) (RLQT) | | 19 | Relative Link Quality (Transmit) (RLQT) |
| | |
| 20 | Maximum Transmission Unit (MTU) | | 20 | Maximum Transmission Unit (MTU) |
| 21-65407 | Specification Required | | | |
| 65408-65534 | Private Use | | 21-65407 | Unassigned / Specification Required |
| | |
| 65408-65534 | Reserved for Private Use |
| | |
| 65535 | Reserved | | 65535 | Reserved |
+-------------------+------------------------------------------+ +-------------------+------------------------------------------+
15.5. DLEP Status Code Registrations 15.5. DLEP Status Code Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Status Code Values".
DLEP registry, named "Status Code Values".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+--------------+---------------+-------------------------+ +--------------+---------------+------------------------------------+
| Status Code | Failure Mode | Description/Policy | | Status Code | Failure Mode | Description/Policy |
+--------------+---------------+-------------------------+ +--------------+---------------+------------------------------------+
| 0 | Continue | Success | | 0 | Continue | Success |
| 1 | Continue | Not Interested | | | | |
| 2 | Continue | Request Denied | | 1 | Continue | Not Interested |
| 3 | Continue | Inconsistent Data | | | | |
| 4-111 | Continue | Specification Required | | 2 | Continue | Request Denied |
| 112-127 | Continue | Private Use | | | | |
| 128 | Terminate | Unknown Message | | 3 | Continue | Inconsistent Data |
| 129 | Terminate | Unexpected Message | | | | |
| 130 | Terminate | Invalid Data | | 4-111 | Continue | Unassigned / Specification |
| 131 | Terminate | Invalid Destination | | | | Required |
| 132 | Terminate | Timed Out | | | | |
| 133-239 | Terminate | Specification Required | | 112-127 | Continue | Private Use |
| 240-254 | Terminate | Private Use | | | | |
| 255 | Terminate | Reserved | | 128 | Terminate | Unknown Message |
+--------------+---------------+-------------------------+ | | | |
| 129 | Terminate | Unexpected Message |
| | | |
| 130 | Terminate | Invalid Data |
| | | |
| 131 | Terminate | Invalid Destination |
| | | |
| 132 | Terminate | Timed Out |
| | | |
| 133-239 | Terminate | Unassigned / Specification |
| | | Required |
| | | |
| 240-254 | Terminate | Reserved for Private Use |
| | | |
| 255 | Terminate | Shutting Down |
+--------------+---------------+------------------------------------+
15.6. DLEP Extensions Registrations 15.6. DLEP Extension Registrations
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Extension Type Values".
DLEP registry, named "Extension Type Values".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+--------------+---------------------------+ +--------------+--------------------------------------+
| Code | Description/Policy | | Code | Description/Policy |
+--------------+---------------------------+ +--------------+--------------------------------------+
| 0 | Reserved | | 0 | Reserved |
| 1-65519 | Specification Required | | 1-65519 | Unassigned / Specification Required |
| 65520-65534 | Private Use | | 65520-65534 | Reserved for Private Use |
| 65535 | Reserved | | 65535 | Reserved |
+--------------+---------------------------+ +--------------+--------------------------------------+
Table 3: DLEP Extension types Table 3: DLEP Extension Types
15.7. DLEP IPv4 Connection Point Flags 15.7. DLEP IPv4 Connection Point Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv4 Connection Point
DLEP registry, named "IPv4 Connection Point Flags". Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Use TLS [RFC5246] indicator | | 7 | Use TLS [RFC5246] indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.8. DLEP IPv6 Connection Point Flags 15.8. DLEP IPv6 Connection Point Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv6 Connection Point
DLEP registry, named "IPv6 Connection Point Flags". Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Use TLS [RFC5246] indicator | | 7 | Use TLS [RFC5246] indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.9. DLEP Peer Type Flag 15.9. DLEP Peer Type Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "Peer Type Flags".
DLEP registry, named "Peer Type Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Secured Medium indicator | | 7 | Secured Medium indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.10. DLEP IPv4 Address Flag 15.10. DLEP IPv4 Address Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv4 Address Flags".
DLEP registry, named "IPv4 Address Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Add/Drop indicator | | 7 | Add/Drop indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.11. DLEP IPv6 Address Flag 15.11. DLEP IPv6 Address Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv6 Address Flags".
DLEP registry, named "IPv6 Address Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Add/Drop indicator | | 7 | Add/Drop indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.12. DLEP IPv4 Attached Subnet Flag 15.12. DLEP IPv4 Attached Subnet Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv4 Attached Subnet
DLEP registry, named "IPv4 Attached Subnet Flags". Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+ +------------+--------------------------------------+
| Bit | Description/Policy | | Bit | Description/Policy |
+------------+------------------------------------+ +------------+--------------------------------------+
| 0-6 | Unassigned/Specification Required | | 0-6 | Unassigned / Specification Required |
| 7 | Add/Drop indicator | | 7 | Add/Drop indicator |
+------------+------------------------------------+ +------------+--------------------------------------+
15.13. DLEP IPv6 Attached Subnet Flag 15.13. DLEP IPv6 Attached Subnet Flags
Upon approval of this document, IANA is requested to create a new IANA has created a new DLEP registry, named "IPv6 Attached Subnet
DLEP registry, named "IPv6 Attached Subnet Flags". Flags".
The following table provides initial registry values and the The following table provides initial registry values and the
[RFC5226] defined policies that should apply to the registry: policies, as defined by [RFC5226], that apply to the registry:
+------------+------------------------------------+
| Bit | Description/Policy |
+------------+------------------------------------+
| 0-6 | Unassigned/Specification Required |
| 7 | Add/Drop indicator |
+------------+------------------------------------+
15.14. DLEP Well-known Port
Upon approval of this document, IANA is requested to assign a single
value in the "Service Name and Transport Protocol Port Number
Registry" found at https://www.iana.org/assignments/service-names-
port-numbers/service-names-port-numbers.xhtml for use by "DLEP", as
defined in this document. This assignment should be valid for TCP
and UDP.
15.15. DLEP IPv4 Link-local Multicast Address +------------+--------------------------------------+
| Bit | Description/Policy |
+------------+--------------------------------------+
| 0-6 | Unassigned / Specification Required |
| 7 | Add/Drop indicator |
+------------+--------------------------------------+
Upon approval of this document, IANA is requested to assign an IPv4 15.14. DLEP Well-Known Port
multicast address registry found at http://www.iana.org/assignments/
multicast-addresses for use as the "IPv4 DLEP Discovery Address".
15.16. DLEP IPv6 Link-local Multicast Address IANA has assigned the value 854 in the "Service Name and Transport
Protocol Port Number Registry" found at
<http://www.iana.org/assignments/service-names-port-numbers/> for use
by "DLEP", as defined in this document. This assignment is valid for
TCP and UDP.
Upon approval of this document, IANA is requested to assign an IPv6 15.15. DLEP IPv4 Link-Local Multicast Address
multicast address registry found at http://www.iana.org/assignments/
multicast-addresses for use as the "IPv6 DLEP Discovery Address".
16. Acknowledgments IANA has assigned the IPv4 multicast address 224.0.0.117 in the
registry found at
<http://www.iana.org/assignments/multicast-addresses> for use as
"DLEP Discovery".
We would like to acknowledge and thank the members of the DLEP design 15.16. DLEP IPv6 Link-Local Multicast Address
team, who have provided invaluable insight. The members of the
design team are: Teco Boot, Bow-Nan Cheng, John Dowdell, and Henning
Rogge.
We would also like to acknowledge the influence and contributions of IANA has assigned the IPv6 multicast address FF02:0:0:0:0:0:1:7 in
Greg Harrison, Chris Olsen, Martin Duke, Subir Das, Jaewon Kang, the registry found at
Vikram Kaul, Nelson Powell, Lou Berger, and Victoria Pritchard. <http://www.iana.org/assignments/ipv6-multicast-addresses> for use as
"DLEP Discovery".
17. References 16. References
17.1. Normative References 16.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November ISO 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629,
2003, <http://www.rfc-editor.org/info/rfc3629>. November 2003, <http://www.rfc-editor.org/info/rfc3629>.
[RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., Ed., and C. [RFC5082] Gill, V., Heasley, J., Meyer, D., Savola, P., Ed., and C.
Pignataro, "The Generalized TTL Security Mechanism Pignataro, "The Generalized TTL Security Mechanism
(GTSM)", RFC 5082, DOI 10.17487/RFC5082, October 2007, (GTSM)", RFC 5082, DOI 10.17487/RFC5082, October 2007,
<http://www.rfc-editor.org/info/rfc5082>. <http://www.rfc-editor.org/info/rfc5082>.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, (TLS) Protocol Version 1.2", RFC 5246,
DOI 10.17487/RFC5246, August 2008, DOI 10.17487/RFC5246, August 2008,
<http://www.rfc-editor.org/info/rfc5246>. <http://www.rfc-editor.org/info/rfc5246>.
17.2. Informative References [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in
RFC 2119 Key Words", BCP 14, RFC 8174,
DOI 10.17487/RFC8174, May 2017,
<http://www.rfc-editor.org/info/rfc8174>.
16.2. Informative References
[IEEE-802.1AE] [IEEE-802.1AE]
"IEEE Standards for Local and Metropolitan Area Networks: "IEEE Standards for Local and Metropolitan Area Networks:
Media Access Control (MAC) Security", Media Access Control (MAC) Security",
DOI 10.1109/IEEESTD.2006.245590, August 2006. DOI 10.1109/IEEESTD.2006.245590,
<http://ieeexplore.ieee.org/document/1678345/>.
[IEEE-802.1X] [IEEE-802.1X]
"IEEE Standards for Local and Metropolitan Area Networks: "IEEE Standards for Local and metropolitan area networks--
Port based Network Access Control", Port-Based Network Access Control",
DOI 10.1109/IEEESTD.2010.5409813, February 2010. DOI 10.1109/IEEESTD.2010.5409813,
<http://ieeexplore.ieee.org/document/5409813/>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
DOI 10.17487/RFC5226, May 2008, DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>. <http://www.rfc-editor.org/info/rfc5226>.
[RFC5487] Badra, M., "Pre-Shared Key Cipher Suites for TLS with SHA- [RFC5487] Badra, M., "Pre-Shared Key Cipher Suites for TLS with
256/384 and AES Galois Counter Mode", RFC 5487, SHA-256/384 and AES Galois Counter Mode", RFC 5487,
DOI 10.17487/RFC5487, March 2009, DOI 10.17487/RFC5487, March 2009,
<http://www.rfc-editor.org/info/rfc5487>. <http://www.rfc-editor.org/info/rfc5487>.
[RFC5578] Berry, B., Ed., Ratliff, S., Paradise, E., Kaiser, T., and
M. Adams, "PPP over Ethernet (PPPoE) Extensions for Credit
Flow and Link Metrics", RFC 5578, DOI 10.17487/RFC5578,
February 2010, <http://www.rfc-editor.org/info/rfc5578>.
[RFC6890] Cotton, M., Vegoda, L., Bonica, R., Ed., and B. Haberman, [RFC6890] Cotton, M., Vegoda, L., Bonica, R., Ed., and B. Haberman,
"Special-Purpose IP Address Registries", BCP 153, "Special-Purpose IP Address Registries", BCP 153,
RFC 6890, DOI 10.17487/RFC6890, April 2013, RFC 6890, DOI 10.17487/RFC6890, April 2013,
<http://www.rfc-editor.org/info/rfc6890>. <http://www.rfc-editor.org/info/rfc6890>.
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, [RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre,
"Recommendations for Secure Use of Transport Layer "Recommendations for Secure Use of Transport Layer
Security (TLS) and Datagram Transport Layer Security Security (TLS) and Datagram Transport Layer Security
(DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525,
2015, <http://www.rfc-editor.org/info/rfc7525>. May 2015, <http://www.rfc-editor.org/info/rfc7525>.
Appendix A. Discovery Signal Flows Appendix A. Discovery Signal Flows
Router Modem Signal Description Router Modem Signal Description
======================================================================== ========================================================================
| Router initiates discovery, starts | Router initiates discovery,
| a timer, send Peer Discovery | starts a timer, sends Peer
|-------Peer Discovery---->X Signal. |-------Peer Discovery---->X Discovery Signal.
~ ~ ~ ~ ~ ~ ~ Router discovery timer expires ~ ~ ~ ~ ~ ~ ~ Router discovery timer expires
without receiving Peer Offer. without receiving Peer Offer.
| Router sends another Peer | Router sends another Peer
|-------Peer Discovery---------->| Discovery Signal. |-------Peer Discovery---------->| Discovery Signal.
| |
| Modem receives Peer Discovery | Modem receives Peer Discovery
| Signal. | Signal.
| |
| Modem sends Peer Offer with | Modem sends Peer Offer with
|<--------Peer Offer-------------| Connection Point information. |<--------Peer Offer-------------| Connection Point information.
: :
: Router MAY cancel discovery timer : Router MAY cancel discovery timer
: and stop sending Peer Discovery : and stop sending Peer Discovery
: Signals. : Signals.
Appendix B. Peer Level Message Flows Appendix B. Peer-Level Message Flows
B.1. Session Initialization B.1. Session Initialization
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router connects to discovered or | Router connects to discovered or
| pre-configured Modem Connection | preconfigured Modem Connection
|--TCP connection established---> Point. |--TCP connection established---> Point.
| |
| Router sends Session | Router sends Session
|----Session Initialization----->| Initialization Message. |----Session Initialization----->| Initialization Message.
| |
| Modem receives Session | Modem receives Session
| Initialization Message. | Initialization Message.
| |
| Modem sends Session Initialization | Modem sends Session Initialization
|<--Session Initialization Resp.-| Response, with Success Status Data |<--Session Initialization Resp.-| Response with 'Success' Status
| | Item. | | Data Item.
| | | |
|<<============================>>| Session established. Heartbeats |<<============================>>| Session established.
: : begin. : : Heartbeats begin.
B.2. Session Initialization - Refused B.2. Session Initialization - Refused
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router connects to discovered or | Router connects to discovered or
| pre-configured Modem Connection | preconfigured Modem Connection
|--TCP connection established---> Point. |--TCP connection established---> Point.
| |
| Router sends Session | Router sends Session
|-----Session Initialization---->| Initialization Message. |-----Session Initialization---->| Initialization Message.
| |
| Modem receives Session | Modem receives Session
| Initialization Message, and will | Initialization Message and
| not support the advertised | will not support the advertised
| extensions. | extensions.
| |
| Modem sends Session Initialization | Modem sends Session Initialization
| Response, with 'Request Denied' | Response with 'Request Denied'
|<-Session Initialization Resp.--| Status Data Item. |<-Session Initialization Resp.--| Status Data Item.
| |
| |
| Router receives negative Session | Router receives negative Session
| Initialization Response, closes | Initialization Response, closes
||---------TCP close------------|| TCP connection. ||---------TCP close------------|| TCP connection.
B.3. Router Changes IP Addresses B.3. Router Changes IP Addresses
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router sends Session Update | Router sends Session Update
|-------Session Update---------->| Message to announce change of IP |-------Session Update---------->| Message to announce change of
| address | IP address.
| |
| Modem receives Session Update | Modem receives Session Update
| Message and updates internal | Message and updates internal
| state. | state.
| |
|<----Session Update Response----| Modem sends Session Update |<----Session Update Response----| Modem sends Session Update
| Response. | Response.
B.4. Modem Changes Session-wide Metrics B.4. Modem Changes Session-Wide Metrics
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Modem sends Session Update Message | Modem sends Session Update Message
| to announce change of modem-wide | to announce change of session-wide
|<--------Session Update---------| metrics |<--------Session Update---------| metrics.
| |
| Router receives Session Update | Router receives Session Update
| Message and updates internal | Message and updates internal
| state. | state.
| |
|----Session Update Response---->| Router sends Session Update |----Session Update Response---->| Router sends Session Update
| Response. | Response.
B.5. Router Terminates Session B.5. Router Terminates Session
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router sends Session Termination | Router sends Session Termination
|------Session Termination------>| Message with Status Data Item. |------Session Termination------>| Message with Status Data Item.
| | | |
|-------TCP shutdown (send)---> | Router stops sending Messages. |-------TCP shutdown (send)---> | Router stops sending Messages.
| |
| Modem receives Session | Modem receives Session
| Termination, stops counting | Termination, stops counting
skipping to change at page 71, line 14 skipping to change at page 75, line 33
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router sends Session Termination | Router sends Session Termination
|------Session Termination------>| Message with Status Data Item. |------Session Termination------>| Message with Status Data Item.
| | | |
|-------TCP shutdown (send)---> | Router stops sending Messages. |-------TCP shutdown (send)---> | Router stops sending Messages.
| |
| Modem receives Session | Modem receives Session
| Termination, stops counting | Termination, stops counting
| received heartbeats and stops | received heartbeats, and stops
| sending heartbeats. | sending heartbeats.
| |
| Modem sends Session Termination | Modem sends Session Termination
|<---Session Termination Resp.---| Response with Status 'Success'. |<---Session Termination Resp.---| Response with Status 'Success'.
| |
| Modem stops sending Messages. | Modem stops sending Messages.
| |
||---------TCP close------------|| Session terminated. ||---------TCP close------------|| Session terminated.
B.6. Modem Terminates Session B.6. Modem Terminates Session
skipping to change at page 71, line 36 skipping to change at page 76, line 17
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Modem sends Session Termination | Modem sends Session Termination
|<----Session Termination--------| Message with Status Data Item. |<----Session Termination--------| Message with Status Data Item.
| |
| Modem stops sending Messages. | Modem stops sending Messages.
| |
| Router receives Session | Router receives Session
| Termination, stops counting | Termination, stops counting
| received heartbeats and stops | received heartbeats, and stops
| sending heartbeats. | sending heartbeats.
| |
| Router sends Session Termination | Router sends Session Termination
|---Session Termination Resp.--->| Response with Status 'Success'. |---Session Termination Resp.--->| Response with Status 'Success'.
| |
| Router stops sending Messages. | Router stops sending Messages.
| |
||---------TCP close------------|| Session terminated. ||---------TCP close------------|| Session terminated.
B.7. Session Heartbeats B.7. Session Heartbeats
skipping to change at page 72, line 4 skipping to change at page 77, line 6
| sending heartbeats. | sending heartbeats.
| |
| Router sends Session Termination | Router sends Session Termination
|---Session Termination Resp.--->| Response with Status 'Success'. |---Session Termination Resp.--->| Response with Status 'Success'.
| |
| Router stops sending Messages. | Router stops sending Messages.
| |
||---------TCP close------------|| Session terminated. ||---------TCP close------------|| Session terminated.
B.7. Session Heartbeats B.7. Session Heartbeats
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
|----------Heartbeat------------>| Router sends heartbeat Message |----------Heartbeat------------>| Router sends Heartbeat Message.
| |
| Modem resets heartbeats missed | Modem resets heartbeats missed
| counter. | counter.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
|---------[Any Message]--------->| When the Modem receives any |---------[Any Message]--------->| When the Modem receives any
| Message from the Router. | Message from the Router.
| |
| Modem resets heartbeats missed | Modem resets heartbeats missed
| counter. | counter.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
|<---------Heartbeat-------------| Modem sends heartbeat Message |<---------Heartbeat-------------| Modem sends Heartbeat Message.
| |
| Router resets heartbeats missed | Router resets heartbeats missed
| counter. | counter.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
|<--------[Any Message]----------| When the Router receives any |<--------[Any Message]----------| When the Router receives any
| Message from the Modem. | Message from the Modem.
| |
| Modem resets heartbeats missed | Modem resets heartbeats missed
| counter. | counter.
B.8. Router Detects a Heartbeat timeout B.8. Router Detects a Heartbeat Timeout
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
X<----------------------| Router misses a heartbeat X<----------------------| Router misses a heartbeat.
| X<----------------------| Router misses too many heartbeats | X<----------------------| Router misses too many
| heartbeats.
| |
| |
|------Session Termination------>| Router sends Session Termination |------Session Termination------>| Router sends Session Termination
| Message with 'Timeout' Status | Message with 'Timeout' Status
| Data Item. | Data Item.
: :
: Termination proceeds... : Termination proceeds...
B.9. Modem Detects a Heartbeat timeout B.9. Modem Detects a Heartbeat Timeout
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
|---------------------->X Modem misses a heartbeat |---------------------->X Modem misses a heartbeat.
|---------------------->X | Modem misses too many heartbeats |---------------------->X | Modem misses too many
| heartbeats.
| |
| |
|<-----Session Termination-------| Modem sends Session Termination |<-----Session Termination-------| Modem sends Session Termination
| Message with 'Timeout' Status | Message with 'Timeout' Status
| Data Item. | Data Item.
: :
: Termination proceeds... : Termination proceeds...
Appendix C. Destination Specific Message Flows Appendix C. Destination-Specific Message Flows
C.1. Common Destination Notification C.1. Common Destination Notification
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Modem detects a new logical | Modem detects a new logical
| destination is reachable, and | destination is reachable and
|<-------Destination Up----------| sends Destination Up Message. |<-------Destination Up----------| sends Destination Up Message.
| |
|------Destination Up Resp.----->| Router sends Destination Up |------Destination Up Resp.----->| Router sends Destination Up
| Response. | Response.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Modem detects change in logical | Modem detects change in logical
| destination metrics, and sends | destination metrics and sends
|<-------Destination Update------| Destination Update Message. |<-------Destination Update------| Destination Update Message.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Modem detects change in logical | Modem detects change in logical
| destination metrics, and sends | destination metrics and sends
|<-------Destination Update------| Destination Update Message. |<-------Destination Update------| Destination Update Message.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Modem detects logical destination | Modem detects logical destination
| is no longer reachable, and sends | is no longer reachable and sends
|<-------Destination Down--------| Destination Down Message. |<-------Destination Down--------| Destination Down Message.
| |
| Router receives Destination Down, | Router receives Destination Down,
| updates internal state, and sends | updates internal state, and sends
|------Destination Down Resp.--->| Destination Down Response Message. |------Destination Down Resp.--->| Destination Down Response Message.
C.2. Multicast Destination Notification C.2. Multicast Destination Notification
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
| Router detects a new multicast | Router detects a new multicast
| destination is in use, and sends | destination is in use and sends
|-----Destination Announce------>| Destination Announce Message. |-----Destination Announce------>| Destination Announce Message.
| |
| Modem updates internal state to | Modem updates internal state to
| monitor multicast destination, and | monitor multicast destination and
|<-----Dest. Announce Resp.------| sends Destination Announce |<-----Dest. Announce Resp.------| sends Destination Announce
Response. Response.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Modem detects change in multicast | Modem detects change in multicast
| destination metrics, and sends | destination metrics and sends
|<-------Destination Update------| Destination Update Message. |<-------Destination Update------| Destination Update Message.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Modem detects change in multicast | Modem detects change in multicast
| destination metrics, and sends | destination metrics and sends
|<-------Destination Update------| Destination Update Message. |<-------Destination Update------| Destination Update Message.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
| Router detects multicast | Router detects multicast
| destination is no longer in use, | destination is no longer in use
|--------Destination Down------->| and sends Destination Down |--------Destination Down------->| and sends Destination Down
| Message. | Message.
| |
| Modem receives Destination Down, | Modem receives Destination Down,
| updates internal state, and sends | updates internal state, and sends
|<-----Destination Down Resp.----| Destination Down Response Message. |<-----Destination Down Resp.----| Destination Down Response Message.
C.3. Link Characteristics Request C.3. Link Characteristics Request
Router Modem Message Description Router Modem Message Description
======================================================================== ========================================================================
Destination has already been Destination has already been
~ ~ ~ ~ ~ ~ ~ announced by either peer. ~ ~ ~ ~ ~ ~ ~ announced by either peer.
| Router requires different | Router requires different
| Characteristics for the | characteristics for the
| destination, and sends Link | destination and sends Link
|--Link Characteristics Request->| Characteristics Request Message. |--Link Characteristics Request->| Characteristics Request Message.
| |
| Modem attempts to adjust link | Modem attempts to adjust link
| properties to meet the received | properties to meet the received
| request, and sends a Link | request and sends a Link
| Characteristics Response | Characteristics Response
|<---Link Characteristics Resp.--| Message with the new values. |<---Link Characteristics Resp.--| Message with the new values.
Acknowledgments
We would like to acknowledge and thank the members of the DLEP design
team, who have provided invaluable insight. The members of the
design team are Teco Boot, Bow-Nan Cheng, John Dowdell, and Henning
Rogge.
We would also like to acknowledge the influence and contributions of
Greg Harrison, Chris Olsen, Martin Duke, Subir Das, Jaewon Kang,
Vikram Kaul, Nelson Powell, Lou Berger, and Victoria Pritchard.
Authors' Addresses Authors' Addresses
Stan Ratliff Stan Ratliff
VT iDirect VT iDirect
13861 Sunrise Valley Drive, Suite 300 13861 Sunrise Valley Drive, Suite 300
Herndon, VA 20171 Herndon, VA 20171
USA United States of America
Email: sratliff@idirect.net Email: sratliff@idirect.net
Shawn Jury Shawn Jury
Cisco Systems Cisco Systems
170 West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
USA United States of America
Email: sjury@cisco.com Email: sjury@cisco.com
Darryl Satterwhite Darryl Satterwhite
Broadcom Broadcom
Email: dsatterw@broadcom.com Email: dsatterw@broadcom.com
Rick Taylor Rick Taylor
Airbus Defence & Space Airbus Defence & Space
Quadrant House Quadrant House
Celtic Springs Celtic Springs
Coedkernew Coedkernew
Newport NP10 8FZ Newport NP10 8FZ
UK United Kingdom
Email: rick.taylor@airbus.com Email: rick.taylor@airbus.com
Bo Berry Bo Berry
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