draft-ietf-netconf-udp-notif-00.txt   draft-ietf-netconf-udp-notif-01.txt 
NETCONF G. Zheng NETCONF G. Zheng
Internet-Draft T. Zhou Internet-Draft T. Zhou
Intended status: Standards Track Huawei Intended status: Standards Track Huawei
Expires: April 6, 2021 T. Graf Expires: 6 May 2021 T. Graf
Swisscom Swisscom
P. Francois P. Francois
INSA-Lyon INSA-Lyon
P. Lucente P. Lucente
NTT NTT
October 3, 2020 2 November 2020
UDP-based Transport for Configured Subscriptions UDP-based Transport for Configured Subscriptions
draft-ietf-netconf-udp-notif-00 draft-ietf-netconf-udp-notif-01
Abstract Abstract
This document describes an UDP-based notification mechanism to This document describes an UDP-based notification mechanism to
collect data from networking devices. A shim header is proposed to collect data from networking devices. A shim header is proposed to
facilitate the streaming of data directly from line cards to a facilitate the streaming of data directly from line cards to a
collector. The objective is to rely on a lightweight approach to collector. The objective is to rely on a lightweight approach to
allow for higher frequency and better transit performance compared to allow for higher frequency and better transit performance compared to
already established notification mechanisms. already established notification mechanisms.
skipping to change at page 1, line 47 skipping to change at page 1, line 47
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 6, 2021. This Internet-Draft will expire on 6 May 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Configured Subscription to UDP-Notif . . . . . . . . . . . . 4 2. Configured Subscription to UDP-Notif . . . . . . . . . . . . 4
3. UDP-Based Transport . . . . . . . . . . . . . . . . . . . . . 4 3. UDP-Based Transport . . . . . . . . . . . . . . . . . . . . . 4
3.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 4 3.1. Design Overview . . . . . . . . . . . . . . . . . . . . . 4
3.2. Format of the UDP-Notif Message Header . . . . . . . . . 5 3.2. Format of the UDP-Notif Message Header . . . . . . . . . 5
3.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3. Options . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.3.1. Fragmentation Option . . . . . . . . . . . . . . . . 6 3.3.1. Segmentation Option . . . . . . . . . . . . . . . . . 7
3.4. Data Encoding . . . . . . . . . . . . . . . . . . . . . . 7 3.4. Data Encoding . . . . . . . . . . . . . . . . . . . . . . 8
4. Congestion Control . . . . . . . . . . . . . . . . . . . . . 8 4. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 8 4.1. Congestion Control . . . . . . . . . . . . . . . . . . . 8
6. A YANG Data Model for Management of UDP-Notif . . . . . . . . 8 4.2. Message Size . . . . . . . . . . . . . . . . . . . . . . 9
7. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.3. Reliability . . . . . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 5. A YANG Data Model for Management of UDP-Notif . . . . . . . . 9
9. Security Considerations . . . . . . . . . . . . . . . . . . . 12 6. YANG Module . . . . . . . . . . . . . . . . . . . . . . . . . 10
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 12 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 12 8. Security Considerations . . . . . . . . . . . . . . . . . . . 13
11.1. Normative References . . . . . . . . . . . . . . . . . . 12 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13
11.2. Informative References . . . . . . . . . . . . . . . . . 14 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 13
11.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 14 10.1. Normative References . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 10.2. Informative References . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15
1. Introduction 1. Introduction
Sub-Notif [RFC8639] defines a mechanism that lets a collector Sub-Notif [RFC8639] defines a mechanism that lets a collector
subscribe to the publication of YANG-defined data maintained in a subscribe to the publication of YANG-defined data maintained in a
YANG [RFC7950] datastore. The mechanism separates the management and YANG [RFC7950] datastore. The mechanism separates the management and
control of subscriptions from the transport used to deliver the data. control of subscriptions from the transport used to deliver the data.
Three transport mechanisms, namely NETCONF transport [RFC8640], Three transport mechanisms, namely NETCONF transport [RFC8640],
RESTCONF transport [RFC8650], and HTTPS transport RESTCONF transport [RFC8650], and HTTPS transport
[I-D.ietf-netconf-https-notif] have been defined so far for such [I-D.ietf-netconf-https-notif] have been defined so far for such
notification messages. notification messages.
While powerful in its features and general in their architecture, the While powerful in their features and general in their architecture,
currently available transport mechanisms need to be complemented to the currently available transport mechanisms need to be complemented
support data publications at high velocity from devices that feature to support data publications at high velocity from devices that
a distributed architecture. The currently available transports are feature a distributed architecture. The currently available
based on TCP and lack the efficiency needed to continuously send transports are based on TCP and lack the efficiency needed to
notifications at high velocity. continuously send notifications at high velocity.
This document specifies a transport option for Sub-Notif that This document specifies a transport option for Sub-Notif that
leverages UDP. Specifically, it facilitates the distributed data leverages UDP. Specifically, it facilitates the distributed data
collection mechanism described in collection mechanism described in
[I-D.unyte-netconf-distributed-notif]. In the case of data [I-D.ietf-netconf-distributed-notif]. In the case of data
originating from multiple line cards, centralized designs require originating from multiple line cards, centralized designs require
data to be internally forwarded from those line cards to the push data to be internally forwarded from those line cards to the push
server, presumably on a route processor, which then combines the server, presumably on a route processor, which then combines the
individual data items into a single consolidated stream. The individual data items into a single consolidated stream. The
centralized data collection mechanism can result in a performance centralized data collection mechanism can result in a performance
bottleneck, especially when large amounts of data are involved. bottleneck, especially when large amounts of data are involved.
What is needed is the support for a mechanism that allows for What is needed is the support for a mechanism that allows for
directly pushing multiple substreams, e.g. one from each line card, directly pushing multiple substreams, e.g. one from each line card,
without passing them through an additional processing stage for without passing them through an additional processing stage for
internal consolidation. The proposed UDP-based transport allows for internal consolidation. The proposed UDP-based transport allows for
such a distributed data collection approach. such a distributed data collection approach.
o Firstly, a UDP approach reduces the burden of maintaining a large * Firstly, a UDP approach reduces the burden of maintaining a large
amount of active TCP connections at the collector, notably in amount of active TCP connections at the collector, notably in
cases where it collects data from the line cards of a large amount cases where it collects data from the line cards of a large amount
of networking devices. of networking devices.
o Secondly, as no connection state needs to be maintained, UDP * Secondly, as no connection state needs to be maintained, UDP
encapsulation can be easily implemented by the hardware of the encapsulation can be easily implemented by the hardware of the
publication streamer, which will further improve performance. publication streamer, which will further improve performance.
o Ultimately, such advantages allow for a larger data analysis * Ultimately, such advantages allow for a larger data analysis
feature set, as more voluminous, finer grained data sets can be feature set, as more voluminous, finer grained data sets can be
streamed to the collector. streamed to the collector.
The transport described in this document can be used for transmitting The transport described in this document can be used for transmitting
notification messages over both IPv4 and IPv6. notification messages over both IPv4 and IPv6.
This document describes the notification mechanism. It is intended This document describes the notification mechanism. It is intended
to be used in conjunction with [RFC8639], extended by to be used in conjunction with [RFC8639], extended by
[I-D.unyte-netconf-distributed-notif]. [I-D.ietf-netconf-distributed-notif].
Section 2 describes the control of the proposed transport mechanism. Section 2 describes the control of the proposed transport mechanism.
Section 3 details the notification mechanism and message format. Section 3 details the notification mechanism and message format.
Section 4 discusses congestion control. Section 5 covers the Section 4.1 discusses congestion control. Section 4 covers the
applicability of the proposed mechanism. applicability of the proposed mechanism.
2. Configured Subscription to UDP-Notif 2. Configured Subscription to UDP-Notif
This section describes how the proposed mechanism can be controlled This section describes how the proposed mechanism can be controlled
using subscription channels based on NETCONF or RESTCONF. using subscription channels based on NETCONF or RESTCONF.
Following the usual approach of Sub-Notif, configured subscriptions Following the usual approach of Sub-Notif, configured subscriptions
contain the location information of all the receivers, including the contain the location information of all the receivers, including the
IP address and the port number, so that the publisher can actively IP address and the port number, so that the publisher can actively
skipping to change at page 4, line 29 skipping to change at page 4, line 29
flowing. Then, the notifications can be sent immediately without flowing. Then, the notifications can be sent immediately without
delay. All the subscription state notifications, as defined in delay. All the subscription state notifications, as defined in
[RFC8639], MUST be encapsulated in separate notification messages. [RFC8639], MUST be encapsulated in separate notification messages.
3. UDP-Based Transport 3. UDP-Based Transport
In this section, we specify the UDP-Notif Transport behaviour. In this section, we specify the UDP-Notif Transport behaviour.
Section 3.1 describes the general design of the solution. Section 3.1 describes the general design of the solution.
Section 3.2 specifies the UDP-Notif message format. Section 3.3 Section 3.2 specifies the UDP-Notif message format. Section 3.3
describes a generic optional sub TLV format. Section 3.3.1 uses such describes a generic optional sub TLV format. Section 3.3.1 uses such
options to provide a fragmentation solution for large UDP-Notif options to provide a segmentation solution for large UDP-Notif
message payloads. Section 3.4 describes the encoding of the message message payloads. Section 3.4 describes the encoding of the message
payload. payload.
3.1. Design Overview 3.1. Design Overview
As specified in Sub-Notif, the telemetry data is encapsulated in the As specified in Sub-Notif, the telemetry data is encapsulated in the
NETCONF/RESTCONF notification message, which is then encapsulated and NETCONF/RESTCONF notification message, which is then encapsulated and
carried using transport protocols such as TLS or HTTP2. Figure 1 carried using transport protocols such as TLS or HTTP2. Figure 1
illustrates the the structure of an UDP-Notif message. illustrates the the structure of an UDP-Notif message.
o The Message Header contains information that facilitate the * The Message Header contains information that facilitate the
message transmission before deserializing the notification message transmission before deserializing the notification
message. message.
o Notification Message is the encoded content that the publication * Notification Message is the encoded content that the publication
stream transports. The common encoding methods include GPB [1], stream transports. The common encoding methods include, CBOR
CBOR [RFC7049], JSON, and XML. [RFC7049], JSON, and XML.
[I-D.ietf-netconf-notification-messages] describes the structure [I-D.ietf-netconf-notification-messages] describes the structure
of the Notification Message for single notifications and bundled of the Notification Message for single notifications and bundled
notifications. notifications.
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
| UDP | | Message | | Notification | | UDP | | Message | | Notification |
| | | Header | | Message | | | | Header | | Message |
+-------+ +--------------+ +--------------+ +-------+ +--------------+ +--------------+
Figure 1: UDP-Notif Message Overview Figure 1: UDP-Notif Message Overview
3.2. Format of the UDP-Notif Message Header 3.2. Format of the UDP-Notif Message Header
The UDP-Notif Message Header contains information that facilitate the The UDP-Notif Message Header contains information that facilitate the
message transmission before deserializing the notification message. message transmission before deserializing the notification message.
The data format is shown in Figure 2. The data format is shown in Figure 2.
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
+-------+-------+---------------+-------------------------------+ +-----+-+-------+---------------+-------------------------------+
| Vers. | ET | Header Len | Message Length | | Ver |S| ET | Header Len | Message Length |
+-------+-------+---------------+-------------------------------+ +-----+-+-------+---------------+-------------------------------+
| Message-Generator-ID | | Observation-Domain-ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
| Message ID | | Message-ID |
+---------------------------------------------------------------+ +---------------------------------------------------------------+
~ Options ~ ~ Options ~
+---------------------------------------------------------------+ +---------------------------------------------------------------+
Figure 2: UDP-Notif Message Header Format Figure 2: UDP-Notif Message Header Format
The Message Header contains the following field: The Message Header contains the following field:
o Version represents the PDU (Protocol Data Unit) encoding version. * Ver represents the PDU (Protocol Data Unit) encoding version. The
The initial version value is 0. initial version value is 0.
o ET is a 4 bit identifier to indicate the encoding type used for
the Notification Message. 16 types of encoding can be expressed:
* 0: GPB; * S represents the space of encoding type specified in the ET field.
When S is unset, ET represents the standard encoding types as
defined in this document. When S is set, ET represents a private
space to be freely used for non standard encodings.
* 1: CBOR; * ET is a 4 bit identifier to indicate the encoding type used for
the Notification Message. 16 types of encoding can be expressed.
When the S bit is unset, the following values apply:
* 2: JSON; - 0: CBOR;
* 3: XML; - 1: JSON;
* others are reserved. - 2: XML;
- others are reserved.
o Header Length is the length of the message header in octets, * Header Len is the length of the message header in octets,
including both the fixed header and the options. including both the fixed header and the options.
o Message Length is the total length of the message within one UDP * Message Length is the total length of the message within one UDP
datagram, measured in octets, including the message header. datagram, measured in octets, including the message header.
o Message-Generator-ID is a 32-bit identifier of the process which * Observation-Domain-ID is a 32-bit identifier of the Observation
created the notification message. This allows disambiguation of Domain that led to the production of the notification message, as
an information source, such as the identification of different defined in [I-D.ietf-netconf-notification-messages]. This allows
line cards sending the notification messages. The source IP disambiguation of an information source, such as the
address of the UDP datagrams SHOULD NOT be interpreted as the identification of different line cards sending the notification
identifier for the host that originated the UDP-Notif message. messages. The source IP address of the UDP datagrams SHOULD NOT
Indeed, the streamer sending the UDP-Notif message could be a be interpreted as the identifier for the host that originated the
relay for the actual source of data carried within UDP-Notif UDP-Notif message. Indeed, the streamer sending the UDP-Notif
messages. message could be a relay for the actual source of data carried
within UDP-Notif messages.
o The Message ID is generated continuously by the sender of UDP- * The Message ID is generated continuously by the sender of UDP-
Notif messages. Different subscribers share the same Message ID Notif messages. Different subscribers share the same Message ID
sequence. sequence.
o Options is a variable-length field in the TLV format. When the * Options is a variable-length field in the TLV format. When the
Header Length is larger than 12 octets, which is the length of the Header Length is larger than 12 octets, which is the length of the
fixed header, Options TLVs follow directly after the fixed message fixed header, Options TLVs follow directly after the fixed message
header (i.e., Message ID). The details of the options are header (i.e., Message ID). The details of the options are
described in the following section. described in the following section.
3.3. Options 3.3. Options
All the options are defined with the following format, illustrated in All the options are defined with the following format, illustrated in
Figure 3. Figure 3.
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
+---------------+---------------+-------------------------------- +---------------+---------------+--------------------------------
| Type | Length | Variable-length data | Type | Length | Variable-length data
+---------------+---------------+-------------------------------- +---------------+---------------+--------------------------------
Figure 3: Generic Option Format Figure 3: Generic Option Format
o Type: 1 octet describing the option type; * Type: 1 octet describing the option type;
o Length: 1 octet of the TLV Length, including the Type and Length * Length: 1 octet representing the total number of octets in the
fields; TLV, including the Type and Length fields;
o Variable-length data: 0 or more octets of TLV Value. * Variable-length data: 0 or more octets of TLV Value.
3.3.1. Fragmentation Option 3.3.1. Segmentation Option
The UDP payload length is limited to 65535. Application level The UDP payload length is limited to 65535. Application level
headers will make the actual payload shorter. Even though binary headers will make the actual payload shorter. Even though binary
encodings such as GPB and CBOR may not require more space than what encodings such as CBOR may not require more space than what is left,
is left, more voluminous encodings such as JSON and XML may suffer more voluminous encodings such as JSON and XML may suffer from this
from this size limitation. Although IPv4 and IPv6 senders can size limitation. Although IPv4 and IPv6 senders can fragment
fragment outgoing packets exceeding their Maximum Transmission outgoing packets exceeding their Maximum Transmission Unit(MTU),
Unit(MTU), fragmented IP packets may not be desired for operational fragmented IP packets may not be desired for operational and
and performance reasons. performance reasons.
Consequently, implementations of the mechanism SHOULD provide a Consequently, implementations of the mechanism SHOULD provide a
configurable max-fragment-size option to control the maximum size of configurable max-segment-size option to control the maximum size of a
a payload. payload.
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
+---------------+---------------+ +---------------+---------------+-----------------------------+-+
| Type | Length | | Type | Length | Segment Number |L|
+-------------------------------+---------------+-------------+-+ +---------------+---------------+-----------------------------+-+
| Fragment Number |L|
+-------------------------------------------------------------+-+
Figure 4: Fragmentation Option Format Figure 4: Segmentation Option Format
The Fragmentation Option is to be included when the message content The Segmentation Option is to be included when the message content is
is fragmented into multiple pieces. Different fragments of one segmented into multiple pieces. Different segments of one message
message share the same Message ID. An illustration is provided in share the same Message ID. An illustration is provided in Figure 4.
Figure 4. The fields of this TLV are: The fields of this TLV are:
o Type: indicates Fragmentation Option. The Type value is to be * Type: Generic option field which indicates a Segmentation Option.
asigned. The Type value is to be asigned.
o Length: is a fixed value of 6 octets. * Length: Generic option field which indicates the length of this
option. It is a fixed value of 4 octets for the Segmentation
Option.
o Fragment Number: indicates the sequence number of the current * Segment Number: 15-bit value indicating the sequence number of the
fragment. current segment. The first segment of a segmented message has a
Segment Number value of 0.
o L: is a flag to indicate whether the current fragment is the last * L: is a flag to indicate whether the current segment is the last
one. When 0 is set, the current fragment is not the last one, one of the message. When 0 is set, the current segment is not the
hence more fragments are expected. When 1 is set, the current last one. When 1 is set, the current segment is the last one,
fragment is the last one. meaning that the total number of segments used to transport this
message is the value of the current Segment Number + 1.
An implementation of this specification MUST NOT rely on IP
fragmentation by default to carry large messages. An implementation
of this specification MUST either restrict the size of individual
messages carried over this protocol, or support the segmentation
option.
3.4. Data Encoding 3.4. Data Encoding
UDP-Notif message data can be encoded in GPB, CBOR, XML or JSON UDP-Notif message data can be encoded in CBOR, XML or JSON format.
format. It is conceivable that additional encodings may be supported It is conceivable that additional encodings may be supported in the
in the future. This can be accomplished by augmenting the future. This can be accomplished by augmenting the subscription data
subscription data model with additional identity statements used to model with additional identity statements used to refer to requested
refer to requested encodings. encodings.
Implementation MAY support multiple encoding methods per Implementation MAY support multiple encoding methods per
subscription. When bundled notifications are supported between the subscription. When bundled notifications are supported between the
publisher and the receiver, only subscribed notifications with the publisher and the receiver, only subscribed notifications with the
same encoding can be bundled in a given message. same encoding can be bundled in a given message.
4. Congestion Control 4. Applicability
Congestion control mechanisms that respond to congestion by reducing In this section, we provide an applicability statement for the
traffic rates and establish a degree of fairness between flows that proposed mechanism, following the recommendations of [RFC8085].
share the same path are vital to the stable operation of the Internet
[RFC2914]. While efficient, UDP has no built-in congestion control
mechanism. Because streaming telemetry can generate unlimited
amounts of data, transferring this data over UDP may be considered
problematic. It is not recommended to use the proposed mechanism
over congestion-sensitive network paths. The only environments where
UDP-Notif is expected to be used are managed networks. The
deployments require that the network path has been explicitly
provisioned to handle the traffic through traffic engineering
mechanisms, such as rate limiting or capacity reservations. The UDP-
Notif Message ID can be used to deduce congestion based on packet
loss detection. Hence the collector can notify the device to use a
lower streaming rate. The interaction to control the streaming rate
on the device is out of the scope of this document.
5. Applicability The proposed mechanism falls in the category of UDP applications
"designed for use within the network of a single network operator or
on networks of an adjacent set of cooperating network operators, to
be deployed in controlled environments". Implementations of the
proposed mechanism should thus follow the recommendations in place
for such specific applications. In the following, we discuss
recommendations on congestion control, message size guildelines,
reliability considerations.
4.1. Congestion Control
The proposed application falls into the category of applications
performing transfer of large amounts of data. It is expected that
the operator using the solution configures QoS on its related flows.
As per [RFC8085], such applications MAY choose not to implement any
form of congestion control, but follow the following principles.
It is NOT RECOMMENDED to use the proposed mechanism over congestion-
sensitive network paths. The only environments where UDP-Notif is
expected to be used are managed networks. The deployments require
that the network path has been explicitly provisioned to handle the
traffic through traffic engineering mechanisms, such as rate limiting
or capacity reservations.
Implementation of the proposal SHOULD NOT push unlimited amounts of
traffic by default, and SHOULD require the users to explicitely
configure such a mode of operation.
Burst mitigation through packet pacing is RECOMMENDED. Disabling
burst mitigation SHOULD require the users to explicitely configure
such a mode of operation.
Applications SHOULD monitor packet losses and provide means to the
user for retrieving information on such losses. The UDP-Notif
Message ID can be used to deduce congestion based on packet loss
detection. Hence the collector can notify the device to use a lower
streaming rate. The interaction to control the streaming rate on the
device is out of the scope of this document.
4.2. Message Size
[RFC8085] recommends not to rely on IP fragmentation for messages
whose size result in IP packets exceeding the MTU along the path.
The segmentation option of the current specification permits to
perform segmentation of the UDP Notif message content so as to not
have to rely on IP fragmentation. Implementation of the current
specification SHOULD allow for the configuration of the MTU.
4.3. Reliability
The target application for UDP-Notif is the collection of data-plane The target application for UDP-Notif is the collection of data-plane
information. The lack of reliability of the data streaming mechanism information. The lack of reliability of the data streaming mechanism
is thus considered acceptable as the mechanism is to be used in is thus considered acceptable as the mechanism is to be used in
controlled environments, mitigating the risk of information loss, controlled environments, mitigating the risk of information loss,
while allowing for publication of very large amounts of data. while allowing for publication of very large amounts of data.
Moreover, in this context, sporadic events when incomplete data Moreover, in this context, sporadic events when incomplete data
collection is provided is not critical for the proper management of collection is provided is not critical for the proper management of
the network. the network, as information collected for the devices through the
means of the proposed mechanism is to be often refreshed.
6. A YANG Data Model for Management of UDP-Notif A collector implementation for this protocol SHOULD deal with
potential loss of packets carrying a part of segmented payload, by
discarding packets that were actually received, but cannot be re-
assembled as a complete message within a given amount of time. This
time SHOULD be configurable.
5. A YANG Data Model for Management of UDP-Notif
The YANG model defined in Section 9 has two leafs augmented into one The YANG model defined in Section 9 has two leafs augmented into one
place of Sub-Notif [RFC8639], plus one identity. place of Sub-Notif [RFC8639], plus one identity.
module: ietf-udp-subscribed-notifications module: ietf-udp-subscribed-notifications
augment /sn:subscriptions/sn:subscription/sn:receivers/sn:receiver: augment /sn:subscriptions/sn:subscription/sn:receivers/sn:receiver:
+--rw address inet:ip-address +--rw address inet:ip-address
+--rw port inet:port-number +--rw port inet:port-number
+--rw enable-fragment? boolean +--rw enable-fragment? boolean
+--rw max-fragment-size? uint32 +--rw max-fragment-size? uint32
7. YANG Module 6. YANG Module
<CODE BEGINS> file "ietf-udp-notif@2020-04-27.yang"
module ietf-udp-notif {
yang-version 1.1;
namespace
"urn:ietf:params:xml:ns:yang:ietf-udp-notif";
prefix un;
import ietf-subscribed-notifications {
prefix sn;
reference
"RFC 8639: Subscription to YANG Notifications";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
organization "IETF NETCONF (Network Configuration) Working Group";
contact
"WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Authors: Guangying Zheng <CODE BEGINS> file "ietf-udp-notif@2020-04-27.yang"
<mailto:zhengguangying@huawei.com> module ietf-udp-notif {
Tianran Zhou yang-version 1.1;
<mailto:zhoutianran@huawei.com> namespace
Thomas Graf "urn:ietf:params:xml:ns:yang:ietf-udp-notif";
<mailto:thomas.graf@swisscom.com> prefix un;
Pierre Francois import ietf-subscribed-notifications {
<mailto:pierre.francois@insa-lyon.fr> prefix sn;
Paolo Lucente reference
<mailto:paolo@ntt.net>"; "RFC 8639: Subscription to YANG Notifications";
}
import ietf-inet-types {
prefix inet;
reference
"RFC 6991: Common YANG Data Types";
}
description organization "IETF NETCONF (Network Configuration) Working Group";
"Defines UDP-Notif as a supported transport for subscribed contact
event notifications. "WG Web: <http:/tools.ietf.org/wg/netconf/>
WG List: <mailto:netconf@ietf.org>
Copyright (c) 2018 IETF Trust and the persons identified as authors Authors: Guangying Zheng
of the code. All rights reserved. <mailto:zhengguangying@huawei.com>
Tianran Zhou
<mailto:zhoutianran@huawei.com>
Thomas Graf
<mailto:thomas.graf@swisscom.com>
Pierre Francois
<mailto:pierre.francois@insa-lyon.fr>
Paolo Lucente
<mailto:paolo@ntt.net>";
Redistribution and use in source and binary forms, with or without description
modification, is permitted pursuant to, and subject to the license "Defines UDP-Notif as a supported transport for subscribed
terms contained in, the Simplified BSD License set forth in Section event notifications.
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the RFC Copyright (c) 2018 IETF Trust and the persons identified as authors
of the code. All rights reserved.
itself for full legal notices."; Redistribution and use in source and binary forms, with or without
modification, is permitted pursuant to, and subject to the license
terms contained in, the Simplified BSD License set forth in Section
4.c of the IETF Trust's Legal Provisions Relating to IETF Documents
(https://trustee.ietf.org/license-info).
revision 2020-04-27 { This version of this YANG module is part of RFC XXXX; see the RFC
description
"Initial version";
reference
"RFC XXXX: UDP-based Notifications for Streaming Telemetry";
}
identity udp-notif { itself for full legal notices.";
base sn:transport;
description
"UDP-Notif is used as transport for notification messages
and state change notifications.";
}
identity encode-cbor { revision 2020-04-27 {
base sn:encoding; description
description "Initial version";
"Encode data using CBOR as described in RFC 7049."; reference
reference "RFC XXXX: UDP-based Notifications for Streaming Telemetry";
"RFC 7049: Concise Binary Object Representation"; }
}
identity encode-gpb { identity udp-notif {
base sn:encoding; base sn:transport;
description description
"Encode data using GPB."; "UDP-Notif is used as transport for notification messages
} and state change notifications.";
}
grouping target-receiver { identity encode-cbor {
description base sn:encoding;
"Provides a reusable description of a UDP-Notif target receiver."; description
leaf address { "Encode data using CBOR as described in RFC 7049.";
type inet:ip-address; reference
mandatory true; "RFC 7049: Concise Binary Object Representation";
description }
"IP address of target UDP-Notif receiver, which can be an
IPv4 address or an IPV6 address.";
}
leaf port {
type inet:port-number;
mandatory true;
description
"Port number of target UDP-Notif receiver, if not specified,
the system should use default port number.";
} grouping target-receiver {
description
"Provides a reusable description of a UDP-Notif target receiver.";
leaf address {
type inet:ip-address;
mandatory true;
description
"IP address of target UDP-Notif receiver, which can be an
IPv4 address or an IPV6 address.";
}
leaf port {
type inet:port-number;
mandatory true;
description
"Port number of target UDP-Notif receiver, if not specified,
the system should use default port number.";
}
leaf enable-fragment { leaf enable-fragment {
type boolean; type boolean;
default false; default false;
description description
"The switch for the fragment feature. When disabled, the "The switch for the fragment feature. When disabled, the
publisher will not allow fragment for a very large data"; publisher will not allow fragment for a very large data";
} }
leaf max-fragment-size { leaf max-fragment-size {
when "../enable-fragment = true"; when "../enable-fragment = true";
type uint32; type uint32;
description "UDP-Notif provides a configurable max-fragment-size description "UDP-Notif provides a configurable max-fragment-size
to control the size of each message."; to control the size of each message.";
} }
} }
augment "/sn:subscriptions/sn:subscription/sn:receivers/sn:receiver" { augment "/sn:subscriptions/sn:subscription/sn:receivers/sn:receiver" {
description description
"This augmentation allows UDP-Notif specific parameters to be "This augmentation allows UDP-Notif specific parameters to be
exposed for a subscription."; exposed for a subscription.";
uses target-receiver; uses target-receiver;
} }
} }
<CODE ENDS> <CODE ENDS>
8. IANA Considerations 7. IANA Considerations
This RFC requests that IANA assigns one UDP port number in the This RFC requests that IANA assigns one UDP port number in the
"Registered Port Numbers" range with the service name "udp-notif". "Registered Port Numbers" range with the service name "udp-notif".
This port will be the default port for the UDP-based notification This port will be the default port for the UDP-based notification
Streaming Telemetry (UDP-Notif) for NETCONF and RESTCONF. Below is Streaming Telemetry (UDP-Notif) for NETCONF and RESTCONF. Below is
the registration template following the rules of [RFC6335]. the registration template following the rules of [RFC6335].
Service Name: udp-notif Service Name: udp-notif
Transport Protocol(s): UDP Transport Protocol(s): UDP
skipping to change at page 12, line 19 skipping to change at page 13, line 21
XML: N/A; the requested URI is an XML namespace. XML: N/A; the requested URI is an XML namespace.
This document also requests a new YANG module name in the YANG Module This document also requests a new YANG module name in the YANG Module
Names registry [RFC7950] with the following suggestion: Names registry [RFC7950] with the following suggestion:
name: ietf-udp-notif name: ietf-udp-notif
namespace: urn:ietf:params:xml:ns:yang:ietf-udp-notif namespace: urn:ietf:params:xml:ns:yang:ietf-udp-notif
prefix: un prefix: un
reference: RFC XXXX reference: RFC XXXX
9. Security Considerations 8. Security Considerations
TBD TBD
10. Acknowledgements 9. Acknowledgements
The authors of this documents would like to thank Alexander Clemm, The authors of this documents would like to thank Alexander Clemm,
Eric Voit, Huiyang Yang, Kent Watsen, Mahesh Jethanandani, Stephane Eric Voit, Huiyang Yang, Kent Watsen, Mahesh Jethanandani, Stephane
Frenot, Timothy Carey, Tim Jenkins, and Yunan Gu for their Frenot, Timothy Carey, Tim Jenkins, and Yunan Gu for their
constructive suggestions for improving this document. constructive suggestions for improving this document.
11. References 10. References
11.1. Normative References 10.1. 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,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2914] Floyd, S., "Congestion Control Principles", BCP 41, [RFC2914] Floyd, S., "Congestion Control Principles", BCP 41,
RFC 2914, DOI 10.17487/RFC2914, September 2000, RFC 2914, DOI 10.17487/RFC2914, September 2000,
<https://www.rfc-editor.org/info/rfc2914>. <https://www.rfc-editor.org/info/rfc2914>.
skipping to change at page 13, line 43 skipping to change at page 14, line 47
October 2013, <https://www.rfc-editor.org/info/rfc7049>. October 2013, <https://www.rfc-editor.org/info/rfc7049>.
[RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language",
RFC 7950, DOI 10.17487/RFC7950, August 2016, RFC 7950, DOI 10.17487/RFC7950, August 2016,
<https://www.rfc-editor.org/info/rfc7950>. <https://www.rfc-editor.org/info/rfc7950>.
[RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF
Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017,
<https://www.rfc-editor.org/info/rfc8040>. <https://www.rfc-editor.org/info/rfc8040>.
[RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage
Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085,
March 2017, <https://www.rfc-editor.org/info/rfc8085>.
[RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, [RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Subscription to YANG Notifications", E., and A. Tripathy, "Subscription to YANG Notifications",
RFC 8639, DOI 10.17487/RFC8639, September 2019, RFC 8639, DOI 10.17487/RFC8639, September 2019,
<https://www.rfc-editor.org/info/rfc8639>. <https://www.rfc-editor.org/info/rfc8639>.
[RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, [RFC8640] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard,
E., and A. Tripathy, "Dynamic Subscription to YANG Events E., and A. Tripathy, "Dynamic Subscription to YANG Events
and Datastores over NETCONF", RFC 8640, and Datastores over NETCONF", RFC 8640,
DOI 10.17487/RFC8640, September 2019, DOI 10.17487/RFC8640, September 2019,
<https://www.rfc-editor.org/info/rfc8640>. <https://www.rfc-editor.org/info/rfc8640>.
[RFC8650] Voit, E., Rahman, R., Nilsen-Nygaard, E., Clemm, A., and [RFC8650] Voit, E., Rahman, R., Nilsen-Nygaard, E., Clemm, A., and
A. Bierman, "Dynamic Subscription to YANG Events and A. Bierman, "Dynamic Subscription to YANG Events and
Datastores over RESTCONF", RFC 8650, DOI 10.17487/RFC8650, Datastores over RESTCONF", RFC 8650, DOI 10.17487/RFC8650,
November 2019, <https://www.rfc-editor.org/info/rfc8650>. November 2019, <https://www.rfc-editor.org/info/rfc8650>.
11.2. Informative References 10.2. Informative References
[I-D.ietf-netconf-distributed-notif]
Zhou, T., Zheng, G., Voit, E., Graf, T., and P. Francois,
"Subscription to Distributed Notifications", Work in
Progress, Internet-Draft, draft-ietf-netconf-distributed-
notif-01, June 2020, <https://tools.ietf.org/html/draft-
ietf-netconf-distributed-notif-01>.
[I-D.ietf-netconf-https-notif] [I-D.ietf-netconf-https-notif]
Jethanandani, M. and K. Watsen, "An HTTPS-based Transport Jethanandani, M. and K. Watsen, "An HTTPS-based Transport
for Configured Subscriptions", draft-ietf-netconf-https- for Configured Subscriptions", Work in Progress, Internet-
notif-04 (work in progress), July 2020. Draft, draft-ietf-netconf-https-notif-04, 27 July 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-netconf-
https-notif-04.txt>.
[I-D.ietf-netconf-notification-messages] [I-D.ietf-netconf-notification-messages]
Voit, E., Jenkins, T., Birkholz, H., Bierman, A., and A. Voit, E., Jenkins, T., Birkholz, H., Bierman, A., and A.
Clemm, "Notification Message Headers and Bundles", draft- Clemm, "Notification Message Headers and Bundles", Work in
ietf-netconf-notification-messages-08 (work in progress), Progress, Internet-Draft, draft-ietf-netconf-notification-
November 2019. messages-08, 17 November 2019, <http://www.ietf.org/
internet-drafts/draft-ietf-netconf-notification-messages-
[I-D.unyte-netconf-distributed-notif] 08.txt>.
Zhou, T., Zheng, G., Voit, E., Graf, T., and P. Francois,
"Subscription to Distributed Notifications", draft-unyte-
netconf-distributed-notif-00 (work in progress), June
2020.
11.3. URIs
[1] https://developers.google.com/protocol-buffers/
Authors' Addresses Authors' Addresses
Guangying Zheng Guangying Zheng
Huawei Huawei
101 Yu-Hua-Tai Software Road 101 Yu-Hua-Tai Software Road
Nanjing, Jiangsu Nanjing
Jiangsu,
China China
Email: zhengguangying@huawei.com Email: zhengguangying@huawei.com
Tianran Zhou Tianran Zhou
Huawei Huawei
156 Beiqing Rd., Haidian District 156 Beiqing Rd., Haidian District
Beijing Beijing
China China
skipping to change at page 15, line 4 skipping to change at page 16, line 20
Email: zhengguangying@huawei.com Email: zhengguangying@huawei.com
Tianran Zhou Tianran Zhou
Huawei Huawei
156 Beiqing Rd., Haidian District 156 Beiqing Rd., Haidian District
Beijing Beijing
China China
Email: zhoutianran@huawei.com Email: zhoutianran@huawei.com
Thomas Graf Thomas Graf
Swisscom Swisscom
Binzring 17 Binzring 17
Zuerich 8045 CH- Zuerich 8045
Switzerland Switzerland
Email: thomas.graf@swisscom.com Email: thomas.graf@swisscom.com
Pierre Francois Pierre Francois
INSA-Lyon INSA-Lyon
Lyon Lyon
France France
Email: pierre.francois@insa-lyon.fr Email: pierre.francois@insa-lyon.fr
Paolo Lucente Paolo Lucente
NTT NTT
Siriusdreef 70-72 Siriusdreef 70-72
Hoofddorp, WT 2132 Hoofddorp, WT 2132
NL Netherlands
Email: paolo@ntt.net Email: paolo@ntt.net
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