draft-ietf-pce-stateful-sync-optimizations-10.txt   rfc8232.txt 
PCE Working Group E. Crabbe Internet Engineering Task Force (IETF) E. Crabbe
Internet-Draft Oracle Request for Comments: 8232 Oracle
Intended status: Standards Track I. Minei Category: Standards Track I. Minei
Expires: September 28, 2017 Google, Inc. ISSN: 2070-1721 Google, Inc.
J. Medved J. Medved
Cisco Systems, Inc. Cisco Systems, Inc.
R. Varga R. Varga
Pantheon Technologies SRO Pantheon Technologies SRO
X. Zhang X. Zhang
D. Dhody D. Dhody
Huawei Technologies Huawei Technologies
March 27, 2017 September 2017
Optimizations of Label Switched Path State Synchronization Procedures Optimizations of Label Switched Path State Synchronization
for a Stateful PCE Procedures for a Stateful PCE
draft-ietf-pce-stateful-sync-optimizations-10
Abstract Abstract
A stateful Path Computation Element (PCE) has access to not only the A stateful Path Computation Element (PCE) has access to not only the
information disseminated by the network's Interior Gateway Protocol information disseminated by the network's Interior Gateway Protocol
(IGP), but also the set of active paths and their reserved resources (IGP) but also the set of active paths and their reserved resources
for its computation. The additional Label Switched Path (LSP) state for its computation. The additional Label Switched Path (LSP) state
information allows the PCE to compute constrained paths while information allows the PCE to compute constrained paths while
considering individual LSPs and their interactions. This requires a considering individual LSPs and their interactions. This requires a
state synchronization mechanism between the PCE and the network, PCE State Synchronization mechanism between the PCE and the network, the
and path computation clients (PCCs), and between cooperating PCEs. PCE and Path Computation Clients (PCCs), and cooperating PCEs. The
The basic mechanism for state synchronization is part of the stateful basic mechanism for State Synchronization is part of the stateful PCE
PCE specification. This document presents motivations for specification. This document presents motivations for optimizations
optimizations to the base state synchronization procedure and to the base State Synchronization procedure and specifies the
specifies the required Path Computation Element Communication required Path Computation Element Communication Protocol (PCEP)
Protocol (PCEP) extensions. extensions.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
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time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
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Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on September 28, 2017. Information about the current status of this document, any errata,
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Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction ....................................................4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language ......................................4
3. State Synchronization Avoidance . . . . . . . . . . . . . . . 4 2. Terminology .....................................................5
3.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 4 3. State Synchronization Avoidance .................................5
3.2. State Synchronization Avoidance Procedure . . . . . . . . 4 3.1. Motivation .................................................5
3.2.1. IP Address change during session re-establishment . . 9 3.2. State Synchronization Avoidance Procedure ..................5
3.3. PCEP Extensions . . . . . . . . . . . . . . . . . . . . . 10 3.2.1. IP Address Change during Session Re-establishment ..10
3.3.1. LSP State Database Version Number TLV . . . . . . . . 10 3.3. PCEP Extensions ...........................................11
3.3.2. Speaker Entity Identifier TLV . . . . . . . . . . . . 11 3.3.1. LSP-DB Version Number TLV ..........................11
4. Incremental State Synchronization . . . . . . . . . . . . . . 12 3.3.2. Speaker Entity Identifier TLV ......................12
4.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 12 4. Incremental State Synchronization ..............................13
4.2. Incremental Synchronization Procedure . . . . . . . . . . 13 4.1. Motivation ................................................13
5. PCE-triggered Initial Synchronization . . . . . . . . . . . . 16 4.2. Incremental Synchronization Procedure .....................14
5.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 16 5. PCE-Triggered Initial Synchronization ..........................17
5.2. PCE-triggered Initial State Synchronization Procedure . . 17 5.1. Motivation ................................................17
6. PCE-triggered Re-synchronization . . . . . . . . . . . . . . 18 5.2. PCE-Triggered Initial State Synchronization Procedure .....18
6.1. Motivation . . . . . . . . . . . . . . . . . . . . . . . 18 6. PCE-Triggered Resynchronization ................................19
6.2. PCE-triggered State Re-synchronization Procedure . . . . 18 6.1. Motivation ................................................19
7. Advertising Support of Synchronization Optimizations . . . . 19 6.2. PCE-Triggered State Resynchronization Procedure ...........19
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 7. Advertising Support of Synchronization Optimizations ...........20
8.1. PCEP-Error Object . . . . . . . . . . . . . . . . . . . . 20 8. IANA Considerations ............................................21
8.2. PCEP TLV Type Indicators . . . . . . . . . . . . . . . . 21 8.1. PCEP-Error Object .........................................21
8.3. STATEFUL-PCE-CAPABILITY TLV . . . . . . . . . . . . . . . 21 8.2. PCEP TLV Type Indicators ..................................22
9. Manageability Considerations . . . . . . . . . . . . . . . . 21 8.3. STATEFUL-PCE-CAPABILITY TLV ...............................22
9.1. Control of Function and Policy . . . . . . . . . . . . . 21 9. Manageability Considerations ...................................22
9.2. Information and Data Models . . . . . . . . . . . . . . . 21 9.1. Control of Function and Policy ............................22
9.3. Liveness Detection and Monitoring . . . . . . . . . . . . 22 9.2. Information and Data Models ...............................22
9.4. Verify Correct Operations . . . . . . . . . . . . . . . . 22 9.3. Liveness Detection and Monitoring .........................23
9.5. Requirements On Other Protocols . . . . . . . . . . . . . 22 9.4. Verify Correct Operations .................................23
9.6. Impact On Network Operations . . . . . . . . . . . . . . 22 9.5. Requirements on Other Protocols ...........................23
10. Security Considerations . . . . . . . . . . . . . . . . . . . 22 9.6. Impact on Network Operations ..............................23
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 23 10. Security Considerations .......................................23
12. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 23 11. References ....................................................24
13. References . . . . . . . . . . . . . . . . . . . . . . . . . 23 11.1. Normative References .....................................24
13.1. Normative References . . . . . . . . . . . . . . . . . . 23 11.2. Informative References ...................................24
13.2. Informative References . . . . . . . . . . . . . . . . . 24 Acknowledgments ...................................................25
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 24 Contributors ......................................................25
Authors' Addresses ................................................26
1. Introduction 1. Introduction
The Path Computation Element Communication Protocol (PCEP) provides The Path Computation Element Communication Protocol (PCEP) provides
mechanisms for Path Computation Elements (PCEs) to perform path mechanisms for Path Computation Elements (PCEs) to perform path
computations in response to Path Computation Clients (PCCs) requests. computations in response to Path Computation Client (PCC) requests.
[I-D.ietf-pce-stateful-pce] describes a set of extensions to PCEP to [RFC8231] describes a set of extensions to PCEP to provide stateful
provide stateful control. A stateful PCE has access to not only the control. A stateful PCE has access to not only the information
information carried by the network's Interior Gateway Protocol (IGP), carried by the network's Interior Gateway Protocol (IGP) but also the
but also the set of active paths and their reserved resources for its set of active paths and their reserved resources for its
computations. The additional state allows the PCE to compute computations. The additional state allows the PCE to compute
constrained paths while considering individual LSPs and their constrained paths while considering individual LSPs and their
interactions. This requires a state synchronization mechanism interactions. This requires a State Synchronization mechanism
between the PCE and the network, PCE and PCC, and between cooperating between the PCE and the network, the PCE and the PCC, and cooperating
PCEs. [I-D.ietf-pce-stateful-pce] describes the basic mechanism for PCEs. [RFC8231] describes the basic mechanism for State
state synchronization. This document specifies following Synchronization. This document specifies following optimizations for
optimizations for state synchronization and the corresponding PCEP State Synchronization and the corresponding PCEP procedures and
procedures and extensions: extensions:
o State Synchronization Avoidance: To skip state synchronization if o State Synchronization Avoidance: To skip State Synchronization if
the state has survived and not changed during session restart. the state has survived and not changed during session restart.
(See Section 3.) (See Section 3.)
o Incremental State Synchronization: To do incremental (delta) state o Incremental State Synchronization: To do incremental (delta) State
synchronization when possible. (See Section 4.) Synchronization when possible. (See Section 4.)
o PCE-triggered Initial Synchronization: To let PCE control the o PCE-Triggered Initial Synchronization: To let PCE control the
timing of the initial state synchronization. (See Section 5.) timing of the initial State Synchronization. (See Section 5.)
o PCE-triggered Re-synchronization: To let PCE re-synchronize the o PCE-Triggered Resynchronization: To let PCE resynchronize the
state for sanity check. (See Section 6.) state for sanity check. (See Section 6.)
Support for each of the synchronization optimization capabilities is Support for each of the synchronization optimization capabilities is
advertised during the PCEP initialization phase. See Section 7 for advertised during the PCEP initialization phase. See Section 7 for
the new flags defined in this document. The handling of each flag is the new flags defined in this document. The handling of each flag is
described in the relevant section. described in the relevant section.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Terminology 2. Terminology
This document uses the following terms defined in [RFC5440]: PCC, This document uses the following terms defined in [RFC5440]: PCC,
PCE, PCEP Peer. PCE, and PCEP Peer.
This document uses the following terms defined in [RFC8051]: Stateful This document uses the following terms defined in [RFC8051]: Stateful
PCE, Delegation, LSP State Database. PCE, Delegation, and LSP State Database (LSP-DB).
This document uses the following terms defined in This document uses the following terms defined in [RFC8231]:
[I-D.ietf-pce-stateful-pce]: Redelegation Timeout Interval, LSP State Redelegation Timeout Interval, LSP State Report, and LSP Update
Report, LSP Update Request. Request.
Within this document, when describing PCE-PCE communications, one of Within this document, when describing PCE-PCE communications, the
the PCEs fills the role of a PCC. This provides a saving in requesting PCE fills the role of a PCC as usual.
documentation without loss of function.
3. State Synchronization Avoidance 3. State Synchronization Avoidance
3.1. Motivation 3.1. Motivation
The purpose of state synchronization is to provide a checkpoint-in- The purpose of State Synchronization is to provide a
time state replica of a PCC's LSP state in a stateful PCE. State checkpoint-in-time state replica of a PCC's LSP state in a stateful
synchronization is performed immediately after the initialization PCE. State Synchronization is performed immediately after the
phase ([RFC5440]). [I-D.ietf-pce-stateful-pce] describes the basic initialization phase [RFC5440]. [RFC8231] describes the basic
mechanism for state synchronization. mechanism for State Synchronization.
State synchronization is not always necessary following a PCEP State Synchronization is not always necessary following a PCEP
session restart. If the state of both PCEP peers did not change, the session restart. If the state of both PCEP peers did not change, the
synchronization phase may be skipped. This can result in significant synchronization phase may be skipped. This can result in significant
savings in both control-plane data exchanges and the time it takes savings in both control-plane data exchanges and the time it takes
for the stateful PCE to become fully operational. for the stateful PCE to become fully operational.
3.2. State Synchronization Avoidance Procedure 3.2. State Synchronization Avoidance Procedure
State synchronization MAY be skipped following a PCEP session restart State Synchronization MAY be skipped following a PCEP session restart
if the state of both PCEP peers did not change during the period if the state of both PCEP peers did not change during the period
prior to session re-initialization. To be able to make this prior to session re-initialization. To be able to make this
determination, state must be exchanged and maintained by both PCE and determination, state must be exchanged and maintained by both PCE and
PCC during normal operation. This is accomplished by keeping track PCC during normal operation. This is accomplished by keeping track
of the changes to the LSP state database, using a version tracking of the changes to the LSP-DB, using a version tracking field called
field called the LSP State Database Version Number. the LSP-DB Version Number.
The INCLUDE-DB-VERSION (S) bit in the stateful PCE capability TLV The INCLUDE-DB-VERSION (S) bit in the STATEFUL-PCE-CAPABILITY TLV
(Section 7) is advertised on a PCEP session during session startup to (Section 7) is advertised on a PCEP session during session startup to
indicate that the LSP State Database Version Number is to be included indicate that the LSP-DB Version Number is to be included when the
when the LSPs are reported to the PCE. The LSP State Database LSPs are reported to the PCE. The LSP-DB Version Number, carried in
Version Number, carried in LSP-DB-VERSION TLV (see Section 3.3.1), is LSP-DB-VERSION TLV (see Section 3.3.1), is owned by a PCC, and it
owned by a PCC and it MUST be incremented by 1 for each successive MUST be incremented by 1 for each successive change in the PCC's LSP-
change in the PCC's LSP state database. The LSP State Database DB. The LSP-DB Version Number MUST start at 1 and may wrap around.
Version Number MUST start at 1 and may wrap around. Values 0 and
0xFFFFFFFFFFFFFFFF are reserved. If either of the two values are Values 0 and 0xFFFFFFFFFFFFFFFF are reserved. If either of the two
used during LSP state (re)-synchronization, the PCE speaker receiving values are used during LSP State (re)Synchronization, the PCE speaker
this value MUST send back a PCErr with Error-type 20 Error-value TBD6 receiving this value MUST send back a PCEP Error (PCErr) with Error-
(suggested value - 6) 'Received an invalid LSP DB Version Number', type=20 and Error-value=6 'Received an invalid LSP-DB Version
and close the PCEP session. Operations that trigger a change to the Number', and close the PCEP session. Operations that trigger a
local LSP state database include a change in the LSP operational change to the local LSP-DB include a change in the LSP operational
state, delegation of an LSP, removal or setup of an LSP or change in state, delegation of an LSP, removal or setup of an LSP, or change in
any of the LSP attributes that would trigger a report to the PCE. any of the LSP attributes that would trigger a report to the PCE.
If the include LSP DB version capability is enabled, a PCC MUST If the include LSP-DB version capability is enabled, a PCC MUST
increment its LSP State Database Version Number when the increment its LSP-DB Version Number when the 'Redelegation Timeout
'Redelegation Timeout Interval' timer expires (see Interval' timer expires (see [RFC8231] for the use of the
[I-D.ietf-pce-stateful-pce] for the use of the Redelegation Timeout Redelegation Timeout Interval).
Interval).
If both PCEP speakers set the S flag in the OPEN object's STATEFUL- If both PCEP speakers set the S flag in the OPEN object's
PCE-CAPABILITY TLV to 1, the PCC MUST include the LSP-DB-VERSION TLV STATEFUL-PCE-CAPABILITY TLV to 1, the PCC MUST include the LSP-DB-
in each LSP object of the PCRpt message. If the LSP-DB-VERSION TLV VERSION TLV in each LSP object of the Path Computation LSP State
is missing in a PCRpt message, the PCE will generate an error with Report (PCRpt) message. If the LSP-DB-VERSION TLV is missing in a
Error-Type 6 (mandatory object missing) and Error-Value TBD1 PCRpt message, the PCE will generate an error with Error-type=6
(suggested value - 12) 'LSP-DB-VERSION TLV missing' and close the (Mandatory Object missing) and Error-value=12 'LSP-DB-VERSION TLV
session. If the include LSP DB version capability has not been missing', and close the session. If the include LSP-DB version
enabled on a PCEP session, the PCC SHOULD NOT include the LSP-DB- capability has not been enabled on a PCEP session, the PCC SHOULD NOT
VERSION TLV in the LSP Object and the PCE MUST ignore it were it to include the LSP-DB-VERSION TLV in the LSP Object, and the PCE MUST
receive one. ignore it, were it to receive one.
If a PCE's LSP state database survived the restart of a PCEP session, If a PCE's LSP-DB survived the restart of a PCEP session, the PCE
the PCE will include the LSP-DB-VERSION TLV in its OPEN object, and will include the LSP-DB-VERSION TLV in its OPEN object, and the TLV
the TLV will contain the last LSP State Database Version Number will contain the last LSP-DB Version Number received on an LSP State
received on an LSP State Report from the PCC in the previous PCEP Report from the PCC in the previous PCEP session. If a PCC's LSP-DB
session. If a PCC's LSP State Database survived the restart of a survived the restart of a PCEP session, the PCC will include the LSP-
PCEP session, the PCC will include the LSP-DB-VERSION TLV in its OPEN DB-VERSION TLV in its OPEN object, and the TLV will contain the
object and the TLV will contain the latest LSP State Database Version latest LSP-DB Version Number. If a PCEP speaker's LSP-DB did not
Number. If a PCEP speaker's LSP state database did not survive the survive the restart of a PCEP session or at startup when the database
restart of a PCEP session or at startup when the database is empty, is empty, the PCEP speaker MUST NOT include the LSP-DB-VERSION TLV in
the PCEP speaker MUST NOT include the LSP-DB-VERSION TLV in the OPEN the OPEN object.
object.
If both PCEP speakers include the LSP-DB-VERSION TLV in the OPEN If both PCEP speakers include the LSP-DB-VERSION TLV in the OPEN
Object and the TLV values match, the PCC MAY skip state object and the TLV values match, the PCC MAY skip State
synchronization and the PCE does not wait for the end of Synchronization, and the PCE does not wait for the end-of-
synchronization marker [I-D.ietf-pce-stateful-pce]. Otherwise, the synchronization marker [RFC8231]. Otherwise, the PCC MUST perform
PCC MUST perform full state synchronization (see full State Synchronization (see [RFC8231]) or incremental State
[I-D.ietf-pce-stateful-pce]) or incremental state synchronization Synchronization (see Section 4 if this capability is advertised) to
(see Section 4 if this capability is advertised) to the stateful PCE. the stateful PCE. In other words, if the incremental State
In other words, if the incremental state synchronization capability Synchronization capability is not advertised by the peers, based on
is not advertised by the peers, based on the LSP database version the LSP-DB Version Number match, either the State Synchronization is
number match either the state synchronization is skipped or a full skipped or a full State Synchronization is performed. If the PCC
state synchronization is performed. If the PCC attempts to skip attempts to skip State Synchronization, by setting the SYNC flag to 0
state synchronization, by setting the SYNC Flag to 0 and PLSP-ID to a and PLSP-ID to a non-zero value on the first LSP State Report from
non-zero value on the first LSP State Report from the PCC as per the PCC as per [RFC8231], the PCE MUST send back a PCErr with Error-
[I-D.ietf-pce-stateful-pce], the PCE MUST send back a PCErr with type=20 and Error-value=2 'LSP-DB version mismatch', and close the
Error-Type 20 Error-Value TBD2 (suggested value - 2) 'LSP Database PCEP session.
version mismatch', and close the PCEP session.
If state synchronization is required, then prior to completing the If State Synchronization is required, then prior to completing the
initialization phase, the PCE MUST mark any LSPs in the LSP database initialization phase, the PCE MUST mark any LSPs in the LSP-DB that
that were previously reported by the PCC as stale. When the PCC were previously reported by the PCC as stale. When the PCC reports
reports an LSP during state synchronization, if the LSP already an LSP during State Synchronization, if the LSP already exists in the
exists in the LSP database, the PCE MUST update the LSP database and LSP-DB, the PCE MUST update the LSP-DB and clear the stale marker
clear the stale marker from the LSP. When it has finished state from the LSP. When it has finished State Synchronization, the PCC
synchronization, the PCC MUST immediately send an end of MUST immediately send an end-of-synchronization marker. The end-of-
synchronization marker. The end of synchronization marker is a Path synchronization marker is a PCRpt message with an LSP object
Computation State Report (PCRpt) message with an LSP object containing a PLSP-ID of 0 and with the SYNC flag set to 0 [RFC8231].
containing a PLSP-ID of 0 and with the SYNC flag set to 0 The LSP-DB-VERSION TLV MUST be included in this PCRpt message. On
([I-D.ietf-pce-stateful-pce]). The LSP-DB-VERSION TLV MUST be receiving this state report, the PCE MUST purge any LSPs from the
included in this PCRpt message. On receiving this state report, the LSP-DB that are still marked as stale.
PCE MUST purge any LSPs from the LSP database that are still marked
as stale.
Note that a PCE/PCC MAY force state synchronization by not including Note that a PCE/PCC MAY force State Synchronization by not including
the LSP-DB-VERSION TLV in its OPEN object. the LSP-DB-VERSION TLV in its OPEN object.
Since a PCE does not make changes to the LSP State Database Version Since a PCE does not make changes to the LSP-DB Version Number, a PCC
Number, a PCC should never encounter this TLV in a message from the should never encounter this TLV in a message from the PCE (other than
PCE (other than the OPEN message). A PCC SHOULD ignore the LSP-DB- the OPEN message). A PCC SHOULD ignore the LSP-DB-VERSION TLV, were
VERSION TLV, were it to receive one from a PCE. it to receive one from a PCE.
Figure 1 shows an example sequence where the state synchronization is Figure 1 shows an example sequence where the State Synchronization is
skipped. skipped.
+-+-+ +-+-+ +-+-+ +-+-+
|PCC| |PCE| |PCC| |PCE|
+-+-+ +-+-+ +-+-+ +-+-+
| | | |
|--Open--, | |--Open--, |
| DBv=42 \ ,---Open--| | DBv=42 \ ,---Open--|
| S=1 \ / DBv=42 | | S=1 \ / DBv=42 |
| \/ S=1 | | \/ S=1 |
skipping to change at page 7, line 29 skipping to change at page 8, line 29
| | | |
|--PCRpt,DBv=43,SYNC=0-->| (Regular |--PCRpt,DBv=43,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=44,SYNC=0-->| (Regular |--PCRpt,DBv=44,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=45,SYNC=0-->| |--PCRpt,DBv=45,SYNC=0-->|
| | | |
Figure 1: State Synchronization Skipped Figure 1: State Synchronization Skipped
Figure 2 shows an example sequence where the state synchronization is Figure 2 shows an example sequence where the State Synchronization is
performed due to LSP state database version mismatch during the PCEP performed due to LSP-DB version mismatch during the PCEP session
session setup. Note that the same state synchronization sequence setup. Note that the same State Synchronization sequence would
would happen if either the PCC or the PCE would not include the LSP- happen if either the PCC or the PCE would not include the LSP-DB-
DB-VERSION TLV in their respective Open messages. VERSION TLV in their respective Open messages.
+-+-+ +-+-+ +-+-+ +-+-+
|PCC| |PCE| |PCC| |PCE|
+-+-+ +-+-+ +-+-+ +-+-+
| | | |
|--Open--, | |--Open--, |
| DBv=46 \ ,---Open--| | DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 | | S=1 \ / DBv=42 |
| \/ S=1 | | \/ S=1 |
| /\ | | /\ |
| / `-------->| (Expect sync) | / `-------->| (Expect sync)
(Do sync) |<--------` | (Do sync) |<--------` |
| | | |
|--PCRpt,DBv=46,SYNC=1-->| (Sync start) |--PCRpt,DBv=46,SYNC=1-->| (Sync start)
| . | | . |
| . | | . |
| . | | . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done) |--PCRpt,DBv=46,SYNC=0-->| (Sync done)
| . |(Purge LSP State | . | (Purge LSP state
| . | if applicable) | . | if applicable)
| . | | . |
|--PCRpt,DBv=47,SYNC=0-->| (Regular |--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular |--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->| |--PCRpt,DBv=49,SYNC=0-->|
| | | |
Figure 2: State Synchronization Performed Figure 2: State Synchronization Performed
Figure 3 shows an example sequence where the state synchronization is Figure 3 shows an example sequence where the State Synchronization is
skipped, but because one or both PCEP speakers set the S Flag to 0, skipped, but because one or both PCEP speakers set the S flag to 0,
the PCC does not send LSP-DB-VERSION TLVs in subsequent PCRpt the PCC does not send LSP-DB-VERSION TLVs in subsequent PCRpt
messages to the PCE. If the current PCEP session restarts, the PCEP messages to the PCE. If the current PCEP session restarts, the PCEP
speakers will have to perform state synchronization, since the PCE speakers will have to perform State Synchronization, since the PCE
does not know the PCC's latest LSP State Database Version Number does not know the PCC's latest LSP-DB Version Number information.
information.
+-+-+ +-+-+ +-+-+ +-+-+
|PCC| |PCE| |PCC| |PCE|
+-+-+ +-+-+ +-+-+ +-+-+
| | | |
|--Open--, | |--Open--, |
| DBv=42 \ ,---Open--| | DBv=42 \ ,---Open--|
| S=0 \ / DBv=42 | | S=0 \ / DBv=42 |
| \/ S=0 | | \/ S=0 |
| /\ | | /\ |
skipping to change at page 9, line 26 skipping to change at page 10, line 26
| . | | . |
| . | | . |
| . | | . |
|------PCRpt,SYNC=0----->| (Regular |------PCRpt,SYNC=0----->| (Regular
| | LSP State Report) | | LSP State Report)
|------PCRpt,SYNC=0----->| (Regular |------PCRpt,SYNC=0----->| (Regular
| | LSP State Report) | | LSP State Report)
|------PCRpt,SYNC=0----->| |------PCRpt,SYNC=0----->|
| | | |
Figure 3: State Synchronization Skipped, no LSP-DB-VERSION TLVs sent Figure 3: State Synchronization Skipped;
from PCC No LSP-DB-VERSION TLVs Sent from the PCC
3.2.1. IP Address change during session re-establishment 3.2.1. IP Address Change during Session Re-establishment
There could be a case during PCEP session re-establishment when the There could be a case during PCEP session re-establishment when the
PCC's or PCE's IP address can change. This includes, but is not PCC's or PCE's IP address can change. This includes, but is not
limited to, the following cases: limited to, the following cases:
o A PCC could use a physical interface IP address to connect to the o A PCC could use a physical interface IP address to connect to the
PCE. In this case, if the line card that the PCC connects from PCE. In this case, if the line card that the PCC connects from
changes, then the PCEP session goes down and comes back up again, changes, then the PCEP session goes down and comes back up again,
with a different IP address associated with a new line card. with a different IP address associated with a new line card.
o The PCC or PCE may move in the network, either physically or o The PCC or PCE may move in the network, either physically or
logically, which may cause its IP address to change. For example, logically, which may cause its IP address to change. For example,
the PCE may be deployed as a virtual network function (VNF) and the PCE may be deployed as a virtual network function (VNF), and
another virtualized instance of the PCE may be populated with the another virtualized instance of the PCE may be populated with the
original PCE instance's state, but be given a different IP original PCE instance's state, but it may be given a different IP
address. address.
To ensure that a PCEP peer can recognize a previously connected peer, To ensure that a PCEP peer can recognize a previously connected peer,
each PCEP peer includes the SPEAKER-ENTITY-ID TLV described in each PCEP peer includes the SPEAKER-ENTITY-ID TLV described in
Section 3.3.2, in the OPEN message. Section 3.3.2 in the OPEN message.
This TLV is used during the state synchronization procedure to This TLV is used during the State Synchronization procedure to
identify the PCEP session as a re-establishment of a previous session identify the PCEP session as a re-establishment of a previous session
that went down. Then state synchronization optimizations such as that went down. Then State Synchronization optimizations such as
state sync avoidance can be applied to this session. Note that this state sync avoidance can be applied to this session. Note that this
usage is only applicable within the State Timeout Interval usage is only applicable within the State Timeout Interval [RFC8231].
[I-D.ietf-pce-stateful-pce]. After the State Timeout Interval After the State Timeout Interval expires, all state associated with
expires, all state associated with the PCEP session is removed, which the PCEP session is removed, which includes the SPEAKER-ENTITY-ID
includes the SPEAKER-ENTITY-ID received. Note that the PCEP session received. Note that the PCEP session initialization [RFC5440]
initialization [RFC5440] procedure remains unchanged. procedure remains unchanged.
3.3. PCEP Extensions 3.3. PCEP Extensions
A new INCLUDE-DB-VERSION (S) bit is added in the stateful A new INCLUDE-DB-VERSION (S) bit is added in the stateful
capabilities TLV (see Section 7 for details). capabilities TLV (see Section 7 for details).
3.3.1. LSP State Database Version Number TLV 3.3.1. LSP-DB Version Number TLV
The LSP State Database Version Number (LSP-DB-VERSION) TLV is an The LSP-DB Version Number (LSP-DB-VERSION) TLV is an optional TLV
optional TLV that MAY be included in the OPEN object and the LSP that MAY be included in the OPEN object and the LSP object.
object.
This TLV is included in the LSP object in the PCRpt message to This TLV is included in the LSP object in the PCRpt message to
indicate the LSP DB version at the PCC. This TLV SHOULD NOT be indicate the LSP-DB version at the PCC. This TLV SHOULD NOT be
included in other PCEP messages (PCUpd, PcReq, PCRep) and MUST be included in other PCEP messages (Path Computation Update Request
ignored if received. (PCUpd), Path Computation Request (PCReq), and Path Computation Reply
(PCRep)) and MUST be ignored if received.
The format of the LSP-DB-VERSION TLV is shown in the following The format of the LSP-DB-VERSION TLV is shown in the following
figure: figure:
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=TBD5 | Length=8 | | Type=23 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSP State DB Version Number | | LSP-DB Version Number |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: LSP-DB-VERSION TLV format Figure 4: LSP-DB-VERSION TLV Format
The type of the TLV is TBD5 and it has a fixed length of 8 octets. The type of the TLV is 23, and it has a fixed length of 8 octets.
The value contains a 64-bit unsigned integer, carried in network byte The value contains a 64-bit unsigned integer, carried in network byte
order, representing the LSP State DB Version Number. order, representing the LSP-DB Version Number.
3.3.2. Speaker Entity Identifier TLV 3.3.2. Speaker Entity Identifier TLV
The Speaker Entity Identifier TLV (SPEAKER-ENTITY-ID) is an optional The Speaker Entity Identifier TLV (SPEAKER-ENTITY-ID) is an optional
TLV that MAY be included in the OPEN Object when a PCEP speaker TLV that MAY be included in the OPEN object when a PCEP speaker
wishes to determine if state synchronization can be skipped when a wishes to determine if State Synchronization can be skipped when a
PCEP session is restarted. It contains a unique identifier for the PCEP session is restarted. It contains a unique identifier for the
node that does not change during the lifetime of the PCEP speaker. node that does not change during the lifetime of the PCEP speaker.
It identifies the PCEP speaker to its peers even if the speaker's IP It identifies the PCEP speaker to its peers even if the speaker's IP
address is changed. address is changed.
In case of a remote peer IP address change, a PCEP speaker would In case of a remote peer IP address change, a PCEP speaker would
learn the speaker entity identifier on receiving the open message but learn the Speaker Entity Identifier on receiving the open message,
it MAY have already sent its open message without realizing that it but it MAY have already sent its open message without realizing that
is a known PCEP peer. In such a case, either a full synchronization it is a known PCEP peer. In such a case, either a full
is done or PCEP session is terminated. This may be a local policy synchronization is done or the PCEP session is terminated. This may
decision. The new IP address is associated with the speaker entity be a local policy decision. The new IP address is associated with
identifier for future either way. In the latter case when PCEP the Speaker Entity Identifier for the future either way. In the
session is re-established, it would be correctly associated with latter case when the PCEP session is re-established, it would be
speaker entity identifier and not be considered as an unknown peer. correctly associated with the Speaker Entity Identifier and not be
considered as an unknown peer.
The format of the SPEAKER-ENTITY-ID TLV is shown in the following The format of the SPEAKER-ENTITY-ID TLV is shown in the following
figure: figure:
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=TBD13 | Length (variable) | | Type=24 | Length (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
// Speaker Entity Identifier // // Speaker Entity Identifier //
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: SPEAKER-ENTITY-ID TLV format Figure 5: SPEAKER-ENTITY-ID TLV Format
The type of the TLV is TBD13 and it has a variable length, which MUST The type of the TLV is 24, and it has a variable length, which MUST
be greater than 0. The Value is padded to 4-octet alignment. The be greater than 0. The value is padded to a 4-octet alignment. The
padding is not included in the Length field. The value contains the padding is not included in the Length field. The value contains the
entity identifier of the speaker transmitting this TLV. This Speaker Entity Identifier (an identifier of the PCEP speaker
identifier is required to be unique within its scope of visibility, transmitting this TLV). This identifier is required to be unique
which is usually limited to a single domain. It MAY be configured by within its scope of visibility, which is usually limited to a single
the operator. Alternatively, it can be derived automatically from a domain. It MAY be configured by the operator. Alternatively, it can
suitably-stable unique identifier, such as a MAC address, serial be derived automatically from a suitably stable unique identifier,
number, Traffic Engineering Router ID, or similar. In the case of such as a Media Access Control (MAC) address, serial number, Traffic
inter-domain connections, the speaker SHOULD prefix its usual Engineering Router ID, or similar. In the case of inter-domain
identifier with the domain identifier of its residence, such as connections, the speaker SHOULD prefix its usual identifier with the
Autonomous System number, IGP area identifier, or similar to make domain identifier of its residence, such as an Autonomous System
sure it remains unique. number, an IGP area identifier, or similar to make sure it remains
unique.
The relationship between this identifier and entities in the Traffic The relationship between this identifier and entities in the Traffic
Engineering database is intentionally left undefined. Engineering database is intentionally left undefined.
From a manageability point of view, a PCE or PCC implementation From a manageability point of view, a PCE or PCC implementation
SHOULD allow the operator to configure this Speaker Entity SHOULD allow the operator to configure this Speaker Entity
Identifier. Identifier.
If a PCEP speaker receives the SPEAKER-ENTITY-ID on a new PCEP If a PCEP speaker receives the SPEAKER-ENTITY-ID on a new PCEP
session, that matches with an existing alive PCEP session, the PCEP session, that matches with an existing alive PCEP session, the PCEP
speaker MUST send a PCErr with Error-type 20 Error-value TBD7 speaker MUST send a PCErr with Error-type=20 and Error-value=7
(suggested value - 7) 'Received an invalid Speaker Entity 'Received an invalid Speaker Entity Identifier', and close the PCEP
Identifier', and close the PCEP session. session.
4. Incremental State Synchronization 4. Incremental State Synchronization
[I-D.ietf-pce-stateful-pce] describes the LSP state synchronization [RFC8231] describes the LSP State Synchronization mechanism between
mechanism between PCCs and stateful PCEs. During the state PCCs and stateful PCEs. During the State Synchronization, a PCC
synchronization, a PCC sends the information of all its LSPs (i.e., sends the information of all its LSPs (i.e., the full LSP-DB) to the
the full LSP-DB) to the stateful PCE. In order to reduce the state stateful PCE. In order to reduce the State Synchronization overhead
synchronization overhead when there is a small number of LSP state when there is a small number of LSP state changes in the network
change in the network between PCEP session restart, this section between the PCEP session restart, this section defines a mechanism
defines a mechanism for incremental (Delta) LSP Database (LSP-DB) for incremental (Delta) LSP-DB synchronization.
synchronization.
4.1. Motivation 4.1. Motivation
According to [I-D.ietf-pce-stateful-pce], if a PCE restarts and its According to [RFC8231], if a PCE restarts and its LSP-DB survived,
LSP-DB survived, PCCs with mismatched LSP State Database Version PCCs with a mismatched LSP-DB Version Number will send all their LSPs
Number will send all their LSPs information (full LSP-DB) to the information (full LSP-DB) to the stateful PCE, even if only a small
stateful PCE, even if only a small number of LSPs underwent state number of LSPs underwent state change. It can take a long time and
change. It can take a long time and consume large communication consume large communication channel bandwidth.
channel bandwidth.
Figure 6 shows an example of LSP state synchronization. Figure 6 shows an example of LSP State Synchronization.
+-----+ +-----+
| PCE | | PCE |
+-----+ +-----+
/ /
/ /
/ /
/ /
+------+ +------+ +------+ +------+
| PCC1 |------------| PCC2 | | PCC1 |------------| PCC2 |
+------+ +------+ +------+ +------+
| | | |
| | | |
+------+ +------+ +------+ +------+
| PCC3 |------------| PCC4 | | PCC3 |------------| PCC4 |
+------+ +------+ +------+ +------+
Figure 6: Topology Example Figure 6: Topology Example
Assuming there are 320 LSPs in the network, with each PCC having 80 Assume that there are 320 LSPs in the network, with each PCC having
LSPs. During the time when the PCEP session is down, 20 LSPs of each 80 LSPs. During the time when the PCEP session is down, 20 LSPs of
PCC (i.e., 80 LSPs in total), are changed. Hence when PCEP session each PCC (i.e., 80 LSPs in total), are changed. Hence, when the PCEP
restarts, the stateful PCE needs to synchronize 320 LSPs with all session restarts, the stateful PCE needs to synchronize 320 LSPs with
PCCs. But actually, 240 LSPs stay the same. If performing full LSP all PCCs. But actually, 240 LSPs stay the same. If performing full
state synchronization, it can take a long time to carry out the LSP State Synchronization, it can take a long time to carry out the
synchronization of all LSPs. It is especially true when only a low synchronization of all LSPs. It is especially true when only a low
bandwidth communication channel is available (e.g., in-band control bandwidth communication channel is available (e.g., in-band control
channel for optical transport networks) and there is a substantial channel for optical transport networks), and there is a substantial
number of LSPs in the network. Another disadvantage of full LSP number of LSPs in the network. Another disadvantage of full LSP
synchronization is that it is a waste of communication bandwidth to synchronization is that it is a waste of communication bandwidth to
perform full LSP synchronization given the fact that the number of perform full LSP synchronization given the fact that the number of
LSP changes can be small during the time when PCEP session is down. LSP changes can be small during the time when the PCEP session is
down.
An incremental (Delta) LSP Database (LSP-DB) state synchronization is An incremental (Delta) LSP-DB State Synchronization is described in
described in this section, where only the LSPs underwent state change this section, where only the LSPs that underwent state change are
are synchronized between the session restart. This may include synchronized between the session restart. This may include
new/modified/deleted LSPs. new/modified/deleted LSPs.
4.2. Incremental Synchronization Procedure 4.2. Incremental Synchronization Procedure
[I-D.ietf-pce-stateful-pce] describes state synchronization and [RFC8231] describes State Synchronization and Section 3 of this
Section 3 of this document, describes state synchronization avoidance document describes State Synchronization avoidance by using
by using LSP-DB-VERSION TLV in its OPEN object. This section extends LSP-DB-VERSION TLV in its OPEN object. This section extends this
this idea to only synchronize the delta (changes) in case of version idea to only synchronize the delta (changes) in case of version
mismatch. mismatch.
If both PCEP speakers include the LSP-DB-VERSION TLV in the OPEN If both PCEP speakers include the LSP-DB-VERSION TLV in the OPEN
object and the LSP-DB-VERSION TLV values match, the PCC MAY skip object and the LSP-DB-VERSION TLV values match, the PCC MAY skip
state synchronization. Otherwise, the PCC MUST perform state State Synchronization. Otherwise, the PCC MUST perform State
synchronization. Incremental State synchronization capability is Synchronization. Incremental State Synchronization capability is
advertised on a PCEP session during session startup using the DELTA- advertised on a PCEP session during session startup using the
LSP-SYNC-CAPABILITY (D) bit in the capabilities TLV (see Section 7). DELTA-LSP-SYNC-CAPABILITY (D) bit in the capabilities TLV (see
Instead of dumping full LSP-DB to the stateful PCE again, the PCC Section 7). Instead of dumping full LSP-DB to the stateful PCE
synchronizes the delta (changes) as described in Figure 7 when D flag again, the PCC synchronizes the delta (changes) as described in
and S flag is set to 1 by both PCC and PCE. Other combinations of D Figure 7 when the D and S flags are set to 1 by both the PCC and PCE.
and S flags setting by PCC and PCE result in full LSP-DB Other combinations of D and S flags set by the PCC and PCE result in
synchronization procedure as described in full LSP-DB synchronization procedures as described in [RFC8231]. By
[I-D.ietf-pce-stateful-pce]. By setting the D flag to zero in the setting the D flag to zero in the OPEN message, a PCEP speaker can
OPEN message, a PCEP speaker can skip the incremental synchronization skip the incremental synchronization optimization, resulting in a
optimization, resulting in a full LSP DB synchronization. full LSP-DB synchronization.
+-+-+ +-+-+ +-+-+ +-+-+
|PCC| |PCE| |PCC| |PCE|
+-+-+ +-+-+ +-+-+ +-+-+
| | | |
|--Open--, | |--Open--, |
| DBv=46 \ ,---Open--| | DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 | | S=1 \ / DBv=42 |
| D=1 \/ S=1 | | D=1 \/ S=1 |
| /\ D=1 | | /\ D=1 |
| / \ | | / \ |
| / `-------->| (Expect Delta sync) | / `-------->| (Expect delta sync)
(Do sync)|<--------` | (DONOT Purge LSP (Do sync)|<--------` | (DO NOT purge LSP
(Delta) | | State) (Delta) | | state)
| | | |
(Delta Sync starts) |--PCRpt,DBv=46,SYNC=1-->| (Delta sync starts) |--PCRpt,DBv=46,SYNC=1-->|
| . | | . |
| . | | . |
| . | | . |
| . | | . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done, |--PCRpt,DBv=46,SYNC=0-->| (Sync done,
| | PLSP-ID=0) | | PLSP-ID=0)
| | | |
|--PCRpt,DBv=47,SYNC=0-->| (Regular |--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular |--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report) | | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->| |--PCRpt,DBv=49,SYNC=0-->|
| | | |
Figure 7: Incremental Synchronization Procedure Figure 7: Incremental Synchronization Procedure
As per Section 3, the LSP State Database Version Number is As per Section 3, the LSP-DB Version Number is incremented each time
incremented each time a change is made to the PCC's local LSP State a change is made to the PCC's local LSP-DB. Each LSP is associated
Database. Each LSP is associated with the DB version at the time of with the DB version at the time of its state change. This is needed
its state change. This is needed to determine which LSP and what to determine which LSP and what information needs to be synchronized
information needs to be synchronized in incremental state in incremental State Synchronization. The incremental state sync is
synchronization. The incremental state sync is done from the last done from the last LSP-DB version received by the PCE to the latest
LSP DB version received by the PCE to the latest DB version at the DB version at the PCC. Note that the LSP-DB Version Number can wrap
PCC. Note that the LSP State Database Version Number can wrap around, in which case the incremental state sync would also wrap till
around, and in which case the incremental state sync would also wrap the latest LSP-DB Version Number at the PCC.
till the latest DB version number at the PCC.
In order to carry out incremental state synchronization, it is not In order to carry out incremental State Synchronization, it is not
necessary for a PCC to store a complete history of LSP Database necessary for a PCC to store a complete history of LSP-DB change for
change for all time, but remember the LSP state changes (including all time, but remember the LSP state changes (including LSP
LSP modification, setup and deletion), that the PCE did not get to modification, setup, and deletion) that the PCE did not get to
process during the session down. Note that, a PCC would be unaware process during the session down. Note that, a PCC would be unaware
that a particular LSP report has been processed by the PCE before the that a particular LSP report has been processed by the PCE before the
session to PCE went down. So a PCC implementation MAY choose to session to the PCE went down. So a PCC implementation MAY choose to
store the LSP State Database Version Number with each LSP at the time store the LSP-DB Version Number with each LSP at the time its status
its status changed, so that when a session is re-established an changed, so that when a session is re-established, an incremental
incremental synchronization can be attempted based on the PCE's last synchronization can be attempted based on the PCE's last LSP-DB
LSP State Database Version Number. For an LSP that is deleted at the Version Number. For an LSP that is deleted at the PCC, the PCC
PCC, the PCC implementation would need to remember the deleted LSP in implementation would need to remember the deleted LSP in some way to
some way to make sure this could be reported as part of incremental make sure this could be reported as part of incremental
synchronization later. The PCC would discard this information based synchronization later. The PCC would discard this information based
on a local policy, or when it determines that this information is no on a local policy or when it determines that this information is no
longer needed with sufficient confidence. In the example shown in longer needed with sufficient confidence. In the example shown in
Figure 7, the PCC needs to store the LSP state changes that happened Figure 7, the PCC needs to store the LSP state changes that happened
between DB Version 43 to 46 and synchronizes these changes, when between DB Versions 43 to 46 and synchronize these changes, when
performing incremental LSP state update. performing incremental LSP state update.
If a PCC finds out it does not have sufficient information to If a PCC finds out it does not have sufficient information to
complete incremental synchronization after advertising incremental complete incremental synchronization after advertising incremental
LSP state synchronization capability, it MUST send a PCErr with LSP State Synchronization capability, it MUST send a PCErr with
Error-Type 20 and Error-Value 5 'A PCC indicates to a PCE that it can Error-type=20 and Error-value=5 'A PCC indicates to a PCE that it can
not complete the state synchronization' (defined in not complete the State Synchronization' (defined in [RFC8231]), and
[I-D.ietf-pce-stateful-pce]) and terminate the session. The PCC terminate the session. The PCC SHOULD re-establish the session with
SHOULD re-establish the session with the D bit set to 0 in the OPEN the D bit set to 0 in the OPEN message.
message.
The other procedures and error checks remain unchanged from the full The other procedures and error checks remain unchanged from the full
state synchronization ([I-D.ietf-pce-stateful-pce]). State Synchronization [RFC8231].
5. PCE-triggered Initial Synchronization 5. PCE-Triggered Initial Synchronization
5.1. Motivation 5.1. Motivation
In networks such as optical transport networks, the control channel In networks such as optical transport networks, the control channel
between network nodes can be realized through in-band overhead thus between network nodes can be realized through in-band overhead, thus
has limited bandwidth. With a stateful PCE connected to the network it has limited bandwidth. With a stateful PCE connected to the
via one network node, it is desirable to control the timing of PCC network via one network node, it is desirable to control the timing
state synchronization so as not to overload the low communication of PCC State Synchronization so as not to overload the low
channel available in the network during the initial synchronization communication channel available in the network during the initial
(be it incremental or full) when the session restarts , when there is synchronization (be it incremental or full) when the session
comparatively large amount of control information needing to be restarts, when there is a comparatively large amount of control
synchronized between the stateful PCE and the network. The method information needing to be synchronized between the stateful PCE and
proposed, i.e., allowing PCE to trigger the state synchronization, is the network. The method proposed, i.e., allowing PCE to trigger the
similar to the function proposed in Section 6 but is used in State Synchronization, is similar to the function proposed in
different scenarios and for different purposes. Section 6 but is used in different scenarios and for different
purposes.
5.2. PCE-triggered Initial State Synchronization Procedure 5.2. PCE-Triggered Initial State Synchronization Procedure
Support of PCE-triggered initial state synchronization is advertised Support of PCE-triggered initial State Synchronization is advertised
during session startup using the TRIGGERED-INITIAL-SYNC (F) bit in during session startup using the TRIGGERED-INITIAL-SYNC (F) bit in
the STATEFUL-PCE-CAPABILITY TLV (see Section 7). the STATEFUL-PCE-CAPABILITY TLV (see Section 7).
In order to allow a stateful PCE to control the LSP-DB In order to allow a stateful PCE to control the LSP-DB
synchronization after establishing a PCEP session, both PCEP speakers synchronization after establishing a PCEP session, both PCEP speakers
MUST set F bit to 1 in the OPEN message. If the LSP-DB-VERSION TLV MUST set the F bit to 1 in the OPEN message. If the LSP-DB-VERSION
is included by both PCEP speakers and the TLV value matches, the TLV is included by both PCEP speakers and the TLV value matches, the
state synchronization can be skipped as described in Section 3.2. If State Synchronization can be skipped as described in Section 3.2. If
the TLV is not included or the LSP-DB Version is mis-matched, the PCE the TLV is not included or the LSP-DB Version is mismatched, the PCE
can trigger the state synchronization process by sending a PCUpd can trigger the State Synchronization process by sending a PCUpd
message with PLSP-ID = 0 and SYNC = 1. The PCUpd message SHOULD message with PLSP-ID = 0 and SYNC = 1. The PCUpd message SHOULD
include an empty ERO (with no ERO sub-object and object length of 4) include an empty Explicit Route Object (ERO) (with no ERO sub-object
as its intended path and SHOULD NOT include the optional objects for and object length of 4) as its intended path and SHOULD NOT include
its attributes for any parameter update. The PCC MUST ignore such an the optional objects for its attributes for any parameter update.
update when the SYNC flag is set. If the TRIGGERED-INITIAL-SYNC The PCC MUST ignore such an update when the SYNC flag is set. If the
capability is not advertised by a PCE and the PCC receives a PCUpd TRIGGERED-INITIAL-SYNC capability is not advertised by a PCE and the
with the SYNC flag set to 1, the PCC MUST send a PCErr with the SRP- PCC receives a PCUpd with the SYNC flag set to 1, the PCC MUST send a
ID-number of the PCUpd, Error-Type 20 and Error-Value TBD4 (suggested PCErr with the SRP-ID-number of the PCUpd, Error-type=20, and
value - 4) 'Attempt to trigger synchronization when the TRIGGERED- Error-value=4 'Attempt to trigger a synchronization when the PCE
SYNC capability has not been advertised' (see Section 8.1). If the triggered synchronization capability has not been advertised' (see
TRIGGERED-INITIAL-SYNC capability is advertised by a PCE and the PCC, Section 8.1). If the TRIGGERED-INITIAL-SYNC capability is advertised
the PCC MUST NOT trigger state synchronization on its own. If the by a PCE and the PCC, the PCC MUST NOT trigger State Synchronization
PCE receives a PCRpt message before the PCE has triggered the state on its own. If the PCE receives a PCRpt message before the PCE has
synchronization, the PCE MUST send a PCErr with Error-Type 20 and triggered the State Synchronization, the PCE MUST send a PCErr with
Error-Value TBD3 (suggested value - 3) 'Attempt to trigger Error-type=20 and Error-value=3 'Attempt to trigger synchronization
synchronization before PCE trigger' (see Section 8.1). before PCE trigger' (see Section 8.1).
In this way, the PCE can control the sequence of LSP synchronization In this way, the PCE can control the sequence of LSP synchronization
among all the PCCs that are re-establishing PCEP sessions with it. among all the PCCs that are re-establishing PCEP sessions with it.
When the capability of PCE control is enabled, only after a PCC When the capability of PCE control is enabled, only after a PCC
receives this message, it will start sending information to the PCE. receives this message, it will start sending information to the PCE.
This PCE-triggering capability can be applied to both full and This PCE-triggering capability can be applied to both full and
incremental state synchronization. If applied to the latter, the incremental State Synchronization. If applied to the latter, the
PCCs only send information that PCE does not possess, which is PCCs only send information that PCE does not possess, which is
inferred from the LSP-DB version information exchanged in the OPEN inferred from the LSP-DB version information exchanged in the OPEN
message (see Section 4.2 for detailed procedure). message (see Section 4.2 for a detailed procedure).
Once the initial state synchronization is triggered by the PCE, the Once the initial State Synchronization is triggered by the PCE, the
procedures and error checks remain unchanged procedures and error checks remain unchanged [RFC8231].
([I-D.ietf-pce-stateful-pce]).
If a PCC implementation that does not implement this extension should If a PCC implementation that does not implement this extension should
not receive a PCUpd message to trigger state synchronization as per not receive a PCUpd message to trigger State Synchronization as per
the capability advertisement, but if it were to receive it, it will the capability advertisement, but if it were to receive it, it will
behave as per [I-D.ietf-pce-stateful-pce]. behave as per [RFC8231].
6. PCE-triggered Re-synchronization 6. PCE-Triggered Resynchronization
6.1. Motivation 6.1. Motivation
The accuracy of the computations performed by the PCE is tied to the The accuracy of the computations performed by the PCE is tied to the
accuracy of the view the PCE has on the state of the LSPs. accuracy of the view the PCE has on the state of the LSPs.
Therefore, it can be beneficial to be able to re-synchronize this Therefore, it can be beneficial to be able to resynchronize this
state even after the session has been established. The PCE may use state even after the session has been established. The PCE may use
this approach to continuously sanity check its state against the this approach to continuously sanity check its state against the
network, or to recover from error conditions without having to tear network or to recover from error conditions without having to tear
down sessions. down sessions.
6.2. PCE-triggered State Re-synchronization Procedure 6.2. PCE-Triggered State Resynchronization Procedure
Support of PCE-triggered state re-synchronization is advertised by Support of PCE-triggered state resynchronization is advertised by
both PCEP speakers during session startup using the TRIGGERED-RESYNC both PCEP speakers during session startup using the TRIGGERED-RESYNC
(T) bit in the STATEFUL-PCE-CAPABILITY TLV (see Section 7). The PCE (T) bit in the STATEFUL-PCE-CAPABILITY TLV (see Section 7). The PCE
can choose to re-synchronize its entire LSP database or a single LSP. can choose to resynchronize its entire LSP-DB or a single LSP.
To trigger re-synchronization for an LSP, the PCE sends a Path To trigger resynchronization for an LSP, the PCE sends a Path
Computation State Update (PCUpd) for the LSP, with the SYNC flag in Computation State Update (PCUpd) for the LSP, with the SYNC flag in
the LSP object set to 1. The PCE SHOULD NOT include any parameter the LSP object set to 1. The PCE SHOULD NOT include any parameter
updates for the LSP, and the PCC MUST ignore such an update when the updates for the LSP, and the PCC MUST ignore such an update when the
SYNC flag is set. The PCC MUST respond with a PCRpt message with the SYNC flag is set. The PCC MUST respond with a PCRpt message with the
LSP state, SYNC Flag set to 0 and MUST include the SRP-ID-number of LSP state, SYNC flag set to 0 and MUST include the SRP-ID-number of
the PCUpd message that triggered the resynchronization. If the PCC the PCUpd message that triggered the resynchronization. If the PCC
cannot find the LSP in its database, PCC MUST also set the R (remove) cannot find the LSP in its database, PCC MUST also set the R (remove)
flag [I-D.ietf-pce-stateful-pce] in the LSP object in the PCRpt flag [RFC8231] in the LSP object in the PCRpt message.
message.
The PCE can also trigger re-synchronization of the entire LSP The PCE can also trigger resynchronization of the entire LSP-DB. The
database. The PCE MUST first mark all LSPs in the LSP database that PCE MUST first mark all LSPs in the LSP-DB that were previously
were previously reported by the PCC as stale and then send a PCUpd reported by the PCC as stale, and then send a PCUpd with an LSP
with an LSP object containing a PLSP-ID of 0 and with the SYNC flag object containing a PLSP-ID of 0 and with the SYNC flag set to 1.
set to 1. The PCUpd message MUST include an empty ERO (with no ERO The PCUpd message MUST include an empty ERO (with no ERO sub-object
sub-object and object length of 4) as its intended path and SHOULD and object length of 4) as its intended path and SHOULD NOT include
NOT include the optional objects for its attributes for any parameter the optional objects for its attributes for any parameter update.
update. The PCC MUST ignore such update if the SYNC flag is set. The PCC MUST ignore such update if the SYNC flag is set. This PCUpd
This PCUpd message is the trigger for the PCC to enter the message is the trigger for the PCC to enter the synchronization phase
synchronization phase as described in [I-D.ietf-pce-stateful-pce] and as described in [RFC8231] and start sending PCRpt messages. After
start sending PCRpt messages. After the receipt of the end-of- the receipt of the end-of-synchronization marker, the PCE will purge
synchronization marker, the PCE will purge LSPs which were not LSPs that were not refreshed. The SRP-ID-number of the PCUpd that
refreshed. The SRP-ID-number of the PCUpd that triggered the re- triggered the resynchronization SHOULD be included in each of the
synchronization SHOULD be included in each of the PCRpt messages. If PCRpt messages. If the PCC cannot resynchronize the entire LSP-DB,
the PCC cannot re-synchronize the entire LSP database, the PCC MUST the PCC MUST respond with a PCErr message with Error-type=20 and
respond with PCErr message with Error-type 20 Error-value 5 'cannot Error-value=5 'cannot complete the State Synchronization' [RFC8231],
complete the state synchronization' [I-D.ietf-pce-stateful-pce], and and it MAY terminate the session. The PCE MUST remove the stale mark
MAY terminate the session. The PCE MUST remove the stale mark for for the LSPs that were previously reported by the PCC. Based on the
the LSP that were previously reported by the PCC. Based on the local local policy, the PCE MAY reattempt synchronization at a later time.
policy, the PCE MAY reattempt synchronization at a later time.
If the TRIGGERED-RESYNC capability is not advertised by a PCE and the If the TRIGGERED-RESYNC capability is not advertised by a PCE and the
PCC receives a PCUpd with the SYNC flag set to 1, it MUST send a PCC receives a PCUpd with the SYNC flag set to 1, it MUST send a
PCErr with the SRP-ID-number of the PCUpd, Error-Type 20 and Error- PCErr with the SRP-ID-number of the PCUpd, Error-type=20, and
Value TBD4 (suggested value - 4) 'Attempt to trigger synchronization Error-value=4 'Attempt to trigger a synchronization when the PCE
when the TRIGGERED-SYNC capability has not been advertised' (see triggered synchronization capability has not been advertised' (see
Section 8.1). Section 8.1).
Once the state re-synchronization is triggered by the PCE, the Once the state resynchronization is triggered by the PCE, the
procedures and error checks remain unchanged from the full state procedures and error checks remain unchanged from the full state
synchronization ([I-D.ietf-pce-stateful-pce]). This would also synchronization [RFC8231]. This would also include the PCE
include PCE triggering multiple state re-synchronization requests triggering multiple state resynchronization requests while
while synchronization is in progress. synchronization is in progress.
If a PCC implementation that does not implement this extension should If a PCC implementation that does not implement this extension should
not receive a PCUpd message to trigger re-synchronization as per the not receive a PCUpd message to trigger resynchronization as per the
capability advertisement, but if it were to receive it, it will capability advertisement, but if it were to receive it, it will
behave as per [I-D.ietf-pce-stateful-pce]. behave as per [RFC8231].
7. Advertising Support of Synchronization Optimizations 7. Advertising Support of Synchronization Optimizations
Support for each of the optimizations described in this document Support for each of the optimizations described in this document
requires advertising the corresponding capabilities during session requires advertising the corresponding capabilities during session
establishment time. establishment time.
The STATEFUL-PCE-CAPABILITY TLV is defined in The STATEFUL-PCE-CAPABILITY TLV is defined in [RFC8231]. This
[I-D.ietf-pce-stateful-pce]. This document defines following new document defines the following new flags in the
flags in the STATEFUL-PCE-CAPABILITY TLV: STATEFUL-PCE-CAPABILITY TLV:
Bit Description Bit Description
TBD9 (suggested value 30) S bit (INCLUDE-DB-VERSION) ------------------------- ---------------------------------
TBD10 (suggested value 27) D bit (DELTA-LSP-SYNC-CAPABILITY) 30 S bit (INCLUDE-DB-VERSION)
TBD11 (suggested value 26) F bit (TRIGGERED-INITIAL-SYNC) 27 D bit (DELTA-LSP-SYNC-CAPABILITY)
TBD12 (suggested value 28) T bit (TRIGGERED-RESYNC) 26 F bit (TRIGGERED-INITIAL-SYNC)
28 T bit (TRIGGERED-RESYNC)
If the S (INCLUDE-DB-VERSION) bit is set to 1 by both PCEP Speakers, If the S bit (INCLUDE-DB-VERSION) is set to 1 by both PCEP speakers,
the PCC will include the LSP-DB-VERSION TLV in each LSP Object. See the PCC will include the LSP-DB-VERSION TLV in each LSP object. See
Section 3.2 for details. Section 3.2 for details.
If the D (DELTA-LSP-SYNC-CAPABILITY) bit is set to 1 by a PCEP If the D bit (DELTA-LSP-SYNC-CAPABILITY) is set to 1 by a PCEP
speaker, it indicates that the PCEP speaker allows incremental speaker, it indicates that the PCEP speaker allows incremental
(delta) state synchronization. See Section 4.2 for details. (delta) State Synchronization. See Section 4.2 for details.
If the F (TRIGGERED-INITIAL-SYNC) bit is set to 1 by both PCEP If the F bit (TRIGGERED-INITIAL-SYNC) is set to 1 by both PCEP
Speakers, the PCE SHOULD trigger initial (first) state speakers, the PCE SHOULD trigger initial (first) State
synchronization. See Section 5.2 for details. Synchronization. See Section 5.2 for details.
If the T (TRIGGERED-RESYNC) bit is set to 1 by both PCEP Speakers, If the T bit (TRIGGERED-RESYNC) is set to 1 by both PCEP speakers,
the PCE can trigger re-synchronization of LSPs at any point in the the PCE can trigger resynchronization of LSPs at any point in the
life of the session. See Section 6.2 for details. life of the session. See Section 6.2 for details.
See Section 8.3 for IANA allocations. See Section 8.3 for IANA allocations.
8. IANA Considerations 8. IANA Considerations
This document requests IANA actions to allocate code points for the IANA has allocated code points for the protocol elements defined in
protocol elements defined in this document. this document.
8.1. PCEP-Error Object 8.1. PCEP-Error Object
IANA is requested to make the following allocation in the "PCEP-ERROR IANA has allocated the following values in the "PCEP-ERROR Object
Object Error Types and Values" registry. Error Types and Values" registry.
Error-Type Meaning Reference Error-Type Meaning Reference
6 Mandatory Object missing [RFC5440] ------------------------------------------------------------
Error-Value= TBD1(suggested This document 6 Mandatory Object missing [RFC5440]
value 12): LSP-DB-VERSION TLV
missing Error-value
20 LSP State synchronization [I-D.ietf-pce-stateful-pce] 12: LSP-DB-VERSION TLV missing This document
error
Error-Value= TBD2(suggested This document 20 LSP State Synchronization Error [RFC8231]
value 2): LSP Database version
mismatch. Error-value
Error-Value=TBD3(suggested This document 2: LSP-DB version mismatch. This document
value 3): Attempt to trigger
synchronization before PCE 3: Attempt to trigger This document
trigger. synchronization before PCE
Error-Value=TBD4(suggested This document trigger.
value 4): Attempt to trigger a
synchronization when the 4: Attempt to trigger a This document
PCE triggered synchronization synchronization when the
capability has not been PCE triggered synchronization
advertised. capability has not been
Error-Value=TBD6(suggested This document advertised.
value 6): Received an invalid
LSP DB Version Number. 6: Received an invalid This document
Error-Value=TBD7(suggested This document LSP-DB Version Number.
value 7): Received an invalid
Speaker Entity Identifier. 7: Received an invalid This document
Speaker Entity Identifier.
8.2. PCEP TLV Type Indicators 8.2. PCEP TLV Type Indicators
IANA is requested to make the following allocation in the "PCEP TLV IANA has allocated the following values in the "PCEP TLV Type
Type Indicators" registry. Indicators" registry.
Value Meaning Reference Value Meaning Reference
TBD5(suggested value 23) LSP-DB-VERSION This document ------------------------- ----------------- -------------
TBD13(suggested value 24) SPEAKER-ENTITY-ID This document 23 LSP-DB-VERSION This document
24 SPEAKER-ENTITY-ID This document
8.3. STATEFUL-PCE-CAPABILITY TLV 8.3. STATEFUL-PCE-CAPABILITY TLV
The STATEFUL-PCE-CAPABILITY TLV is defined in The STATEFUL-PCE-CAPABILITY TLV is defined in [RFC8231]. The
[I-D.ietf-pce-stateful-pce] and a registry is requested to be "STATEFUL-PCE-CAPABILITY TLV Flag Field" registry has been created to
created to manage the flags in the TLV. IANA is requested to make manage the flags in the TLV. IANA has allocated the following values
the following allocation in the aforementioned registry. in this registry.
Bit Description Reference Bit Description Reference
TBD11 (suggested value 26) TRIGGERED-INITIAL-SYNC This document -------------------------- -------------------------- -------------
TBD10 (suggested value 27) DELTA-LSP-SYNC-CAPABILITY This document 26 TRIGGERED-INITIAL-SYNC This document
TBD12 (suggested value 28) TRIGGERED-RESYNC This document 27 DELTA-LSP-SYNC-CAPABILITY This document
TBD9 (suggested value 30) INCLUDE-DB-VERSION This document 28 TRIGGERED-RESYNC This document
30 INCLUDE-DB-VERSION This document
9. Manageability Considerations 9. Manageability Considerations
All manageability requirements and considerations listed in [RFC5440] All manageability requirements and considerations listed in [RFC5440]
and [I-D.ietf-pce-stateful-pce] apply to PCEP protocol extensions and [RFC8231] apply to PCEP protocol extensions defined in this
defined in this document. In addition, requirements and document. In addition, requirements and considerations listed in
considerations listed in this section apply. this section apply.
9.1. Control of Function and Policy 9.1. Control of Function and Policy
A PCE or PCC implementation MUST allow configuring the state A PCE or PCC implementation MUST allow configuring the State
synchronization optimization capabilities as described in this Synchronization optimization capabilities as described in this
document. The implementation SHOULD also allow the operator to document. The implementation SHOULD also allow the operator to
configure the Speaker Entity Identifier ( Section 3.3.2). Further, configure the Speaker Entity Identifier (Section 3.3.2). Further,
the operator SHOULD be to be allowed to trigger the re- the operator SHOULD be to be allowed to trigger the resynchronization
synchronization procedures as per Section 6.2. procedures as per Section 6.2.
9.2. Information and Data Models 9.2. Information and Data Models
An implementation SHOULD allow the operator to view the stateful An implementation SHOULD allow the operator to view the stateful
capabilities advertised by each peer, and the current synchronization capabilities advertised by each peer and the current synchronization
status with each peer. To serve this purpose, the PCEP YANG module status with each peer. To serve this purpose, the PCEP YANG module
[I-D.ietf-pce-pcep-yang] can be extended to include advertised [PCEP-YANG] can be extended to include advertised stateful
stateful capabilities, and synchronization status. capabilities and synchronization status.
9.3. Liveness Detection and Monitoring 9.3. Liveness Detection and Monitoring
Mechanisms defined in this document do not imply any new liveness Mechanisms defined in this document do not imply any new liveness
detection and monitoring requirements in addition to those already detection and monitoring requirements in addition to those already
listed in [RFC5440]. listed in [RFC5440].
9.4. Verify Correct Operations 9.4. Verify Correct Operations
Mechanisms defined in this document do not imply any new operation Mechanisms defined in this document do not imply any new operation
verification requirements in addition to those already listed in verification requirements in addition to those already listed in
[RFC5440] and [I-D.ietf-pce-stateful-pce]. [RFC5440] and [RFC8231].
9.5. Requirements On Other Protocols 9.5. Requirements on Other Protocols
Mechanisms defined in this document do not imply any new requirements Mechanisms defined in this document do not imply any new requirements
on other protocols. on other protocols.
9.6. Impact On Network Operations 9.6. Impact on Network Operations
Mechanisms defined in [RFC5440] and [I-D.ietf-pce-stateful-pce] also Mechanisms defined in [RFC5440] and [RFC8231] also apply to PCEP
apply to PCEP extensions defined in this document. extensions defined in this document.
The state synchronization optimizations described in this document The State Synchronization optimizations described in this document
can result in a reduction of the amount of data exchanged and the can result in a reduction of the amount of data exchanged and the
time taken for a stateful PCE to be fully operational when a PCEP time taken for a stateful PCE to be fully operational when a PCEP
session is re-established. The ability to trigger re-synchronization session is re-established. The ability to trigger resynchronization
by the PCE can be utilized by the operator to sanity check its state by the PCE can be utilized by the operator to sanity check its state
and recover from any mismatch in state without tearing down the and recover from any mismatch in state without tearing down the
session. session.
10. Security Considerations 10. Security Considerations
The security considerations listed in [I-D.ietf-pce-stateful-pce] The security considerations listed in [RFC8231] apply to this
apply to this document as well. However, this document also document as well. However, this document also introduces some new
introduces some new attack vectors. An attacker could spoof the attack vectors. An attacker could spoof the SPEAKER-ENTITY-ID and
SPEAKER-ENTITY-ID and pretend to be another PCEP speaker. An pretend to be another PCEP speaker. An attacker may flood the PCC
attacker may flood the PCC with triggered re-synchronization request with triggered resynchronization requests at a rate that exceeds the
at a rate which exceeds the PCC's ability to process them, either by PCC's ability to process them by either spoofing messages or
spoofing messages or by compromising the PCE itself. The PCC can compromising the PCE itself. The PCC can respond with a PCErr
respond with PCErr message as described in Section 6.2 and terminate message as described in Section 6.2 and terminate the session. Thus,
the session. Thus securing the PCEP session using Transport Layer securing the PCEP session using Transport Layer Security (TLS)
Security (TLS) [I-D.ietf-pce-pceps], as per the recommendations and [PCEPS], as per the recommendations and best current practices in
best current practices in [RFC7525], is RECOMMENDED. An [RFC7525], is RECOMMENDED. An administrator could also expose the
administrator could also expose the speaker entity id as part of the Speaker Entity Identifier as part of the certificate, for the peer
certificate, for the peer identity verification. identity verification.
11. Acknowledgments
We would like to thank Young Lee, Sergio Belotti and Cyril Margaria
for their comments and discussions.
Thanks to Jonathan Hardwick for being the document shepherd and
provide comments and guidance.
Thanks to Tomonori Takeda for Routing Area Directorate review.
Thanks to Adrian Farrel for TSVART review and providing detailed
comments and suggestions.
Thanks to Daniel Franke for SECDIR review.
Thanks to Alvaro Retana, Kathleen Moriarty, and Stephen Farrell for
comments during the IESG evaluation.
Thanks to Deborah Brungard for being the responsible AD and guiding
the authors as needed.
12. Contributors
Gang Xie
Huawei Technologies
F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District
Shenzhen, Guangdong, 518129
P.R. China
Email: xiegang09@huawei.com
13. References
13.1. Normative References 11. References
[I-D.ietf-pce-stateful-pce] 11.1. Normative References
Crabbe, E., Minei, I., Medved, J., and R. Varga, "PCEP
Extensions for Stateful PCE", draft-ietf-pce-stateful-
pce-18 (work in progress), December 2016.
[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>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation [RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation
Element (PCE) Communication Protocol (PCEP)", RFC 5440, Element (PCE) Communication Protocol (PCEP)", RFC 5440,
DOI 10.17487/RFC5440, March 2009, DOI 10.17487/RFC5440, March 2009,
<http://www.rfc-editor.org/info/rfc5440>. <https://www.rfc-editor.org/info/rfc5440>.
13.2. 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, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8231] Crabbe, E., Minei, I., Medved, J., and R. Varga, "Path
Computation Element Communication Protocol (PCEP)
Extensions for Stateful PCE", RFC 8231,
DOI 10.17487/RFC8231, September 2017,
<http://www.rfc-editor.org/info/rfc8231>.
11.2. Informative References
[PCEP-YANG]
Dhody, D., Hardwick, J., Beeram, V., and j.
jefftant@gmail.com, "A YANG Data Model for Path
Computation Element Communications Protocol (PCEP)", Work
in Progress, draft-ietf-pce-pcep-yang-05, July 2017.
[PCEPS] Lopez, D., Dios, O., Wu, Q., and D. Dhody, "Secure
Transport for PCEP", Work in Progress,
draft-ietf-pce-pceps-18, September 2017.
[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, May
2015, <http://www.rfc-editor.org/info/rfc7525>. 2015, <https://www.rfc-editor.org/info/rfc7525>.
[RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a [RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a
Stateful Path Computation Element (PCE)", RFC 8051, Stateful Path Computation Element (PCE)", RFC 8051,
DOI 10.17487/RFC8051, January 2017, DOI 10.17487/RFC8051, January 2017,
<http://www.rfc-editor.org/info/rfc8051>. <https://www.rfc-editor.org/info/rfc8051>.
[I-D.ietf-pce-pcep-yang] Acknowledgments
Dhody, D., Hardwick, J., Beeram, V., and j.
jefftant@gmail.com, "A YANG Data Model for Path
Computation Element Communications Protocol (PCEP)",
draft-ietf-pce-pcep-yang-02 (work in progress), March
2017.
[I-D.ietf-pce-pceps] We would like to thank Young Lee, Sergio Belotti, and Cyril Margaria
Lopez, D., Dios, O., Wu, W., and D. Dhody, "Secure for their comments and discussions.
Transport for PCEP", draft-ietf-pce-pceps-11 (work in
progress), January 2017. Thanks to Jonathan Hardwick for being the document shepherd and
providing comments and guidance.
Thanks to Tomonori Takeda for the Routing Area Directorate review.
Thanks to Adrian Farrel for the TSVART review and providing detailed
comments and suggestions.
Thanks to Daniel Franke for the SECDIR review.
Thanks to Alvaro Retana, Kathleen Moriarty, and Stephen Farrell for
comments during the IESG evaluation.
Thanks to Deborah Brungard for being the responsible AD and guiding
the authors as needed.
Contributors
Gang Xie
Huawei Technologies
F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District
Shenzhen, Guangdong, 518129
China
Email: xiegang09@huawei.com
Authors' Addresses Authors' Addresses
Edward Crabbe Edward Crabbe
Oracle Oracle
Email: edward.crabbe@gmail.com
EMail: edward.crabbe@gmail.com
Ina Minei Ina Minei
Google, Inc. Google, Inc.
1600 Amphitheatre Parkway 1600 Amphitheatre Parkway
Mountain View, CA 94043 Mountain View, CA 94043
US United States of America
Email: inaminei@google.com
EMail: inaminei@google.com
Jan Medved Jan Medved
Cisco Systems, Inc. Cisco Systems, Inc.
170 West Tasman Dr. 170 West Tasman Dr.
San Jose, CA 95134 San Jose, CA 95134
US United States of America
Email: jmedved@cisco.com
EMail: jmedved@cisco.com
Robert Varga Robert Varga
Pantheon Technologies SRO Pantheon Technologies SRO
Mlynske Nivy 56 Mlynske Nivy 56
Bratislava 821 05 Bratislava 821 05
Slovakia Slovakia
Email: robert.varga@pantheon.tech
EMail: robert.varga@pantheon.tech
Xian Zhang Xian Zhang
Huawei Technologies Huawei Technologies
F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District
Shenzhen, Guangdong 518129 Shenzhen, Guangdong 518129
P.R.China China
Email: zhang.xian@huawei.com
EMail: zhang.xian@huawei.com
Dhruv Dhody Dhruv Dhody
Huawei Technologies Huawei Technologies
Divyashree Techno Park, Whitefield Divyashree Techno Park, Whitefield
Bangalore, Karnataka 560066 Bangalore, Karnataka 560066
India India
Email: dhruv.ietf@gmail.com
EMail: dhruv.ietf@gmail.com
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