Internet Engineering Task Force (IETF) E. Crabbe
Request for Comments: 8232 Oracle
Category: Standards Track I. Minei
ISSN: 2070-1721 Google, Inc.
J. Medved
Cisco Systems, Inc.
R. Varga
Pantheon Technologies SRO
X. Zhang
D. Dhody
Huawei Technologies
September 2017
Internet Engineering Task Force (IETF) E. Crabbe
Request for Comments: 8232 Oracle
Category: Standards Track I. Minei
ISSN: 2070-1721 Google, Inc.
J. Medved
Cisco Systems, Inc.
R. Varga
Pantheon Technologies SRO
X. Zhang
D. Dhody
Huawei Technologies
September 2017
Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE
有状态PCE标签交换路径状态同步过程的优化
Abstract
摘要
A stateful Path Computation Element (PCE) has access to not only the information disseminated by the network's Interior Gateway Protocol (IGP) but also the set of active paths and their reserved resources for its computation. The additional Label Switched Path (LSP) state information allows the PCE to compute constrained paths while considering individual LSPs and their interactions. This requires a State Synchronization mechanism between the PCE and the network, the PCE and Path Computation Clients (PCCs), and cooperating PCEs. The basic mechanism for State Synchronization is part of the stateful PCE specification. This document presents motivations for optimizations to the base State Synchronization procedure and specifies the required Path Computation Element Communication Protocol (PCEP) extensions.
有状态路径计算元素（PCE）不仅可以访问由网络内部网关协议（IGP）传播的信息，还可以访问活动路径集及其用于计算的保留资源。附加的标签交换路径（LSP）状态信息允许PCE在考虑单个LSP及其交互的同时计算受限路径。这需要PCE和网络、PCE和路径计算客户端（PCC）以及协作PCE之间的状态同步机制。状态同步的基本机制是有状态PCE规范的一部分。本文档介绍了对基本状态同步过程进行优化的动机，并指定了所需的路径计算元素通信协议（PCEP）扩展。
Status of This Memo
关于下段备忘
This is an Internet Standards Track document.
这是一份互联网标准跟踪文件。
This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Further information on Internet Standards is available in Section 2 of RFC 7841.
本文件是互联网工程任务组（IETF）的产品。它代表了IETF社区的共识。它已经接受了公众审查，并已被互联网工程指导小组（IESG）批准出版。有关互联网标准的更多信息，请参见RFC 7841第2节。
Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at https://www.rfc-editor.org/info/rfc8232.
有关本文件当前状态、任何勘误表以及如何提供反馈的信息，请访问https://www.rfc-editor.org/info/rfc8232.
Copyright Notice
版权公告
Copyright (c) 2017 IETF Trust and the persons identified as the document authors. All rights reserved.
版权所有（c）2017 IETF信托基金和确定为文件作者的人员。版权所有。
This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
本文件受BCP 78和IETF信托有关IETF文件的法律规定的约束(https://trustee.ietf.org/license-info)自本文件出版之日起生效。请仔细阅读这些文件，因为它们描述了您对本文件的权利和限制。从本文件中提取的代码组件必须包括信托法律条款第4.e节中所述的简化BSD许可证文本，并提供简化BSD许可证中所述的无担保。
Table of Contents
目录
1. Introduction ....................................................4
1.1. Requirements Language ......................................4
2. Terminology .....................................................5
3. State Synchronization Avoidance .................................5
3.1. Motivation .................................................5
3.2. State Synchronization Avoidance Procedure ..................5
3.2.1. IP Address Change during Session Re-establishment ..10
3.3. PCEP Extensions ...........................................11
3.3.1. LSP-DB Version Number TLV ..........................11
3.3.2. Speaker Entity Identifier TLV ......................12
4. Incremental State Synchronization ..............................13
4.1. Motivation ................................................13
4.2. Incremental Synchronization Procedure .....................14
5. PCE-Triggered Initial Synchronization ..........................17
5.1. Motivation ................................................17
5.2. PCE-Triggered Initial State Synchronization Procedure .....18
6. PCE-Triggered Resynchronization ................................19
6.1. Motivation ................................................19
6.2. PCE-Triggered State Resynchronization Procedure ...........19
7. Advertising Support of Synchronization Optimizations ...........20
8. IANA Considerations ............................................21
8.1. PCEP-Error Object .........................................21
8.2. PCEP TLV Type Indicators ..................................22
8.3. STATEFUL-PCE-CAPABILITY TLV ...............................22
9. Manageability Considerations ...................................22
9.1. Control of Function and Policy ............................22
9.2. Information and Data Models ...............................22
9.3. Liveness Detection and Monitoring .........................23
9.4. Verify Correct Operations .................................23
9.5. Requirements on Other Protocols ...........................23
9.6. Impact on Network Operations ..............................23
10. Security Considerations .......................................23
11. References ....................................................24
11.1. Normative References .....................................24
11.2. Informative References ...................................24
Acknowledgments ...................................................25
Contributors ......................................................25
Authors' Addresses ................................................26
1. Introduction ....................................................4
1.1. Requirements Language ......................................4
2. Terminology .....................................................5
3. State Synchronization Avoidance .................................5
3.1. Motivation .................................................5
3.2. State Synchronization Avoidance Procedure ..................5
3.2.1. IP Address Change during Session Re-establishment ..10
3.3. PCEP Extensions ...........................................11
3.3.1. LSP-DB Version Number TLV ..........................11
3.3.2. Speaker Entity Identifier TLV ......................12
4. Incremental State Synchronization ..............................13
4.1. Motivation ................................................13
4.2. Incremental Synchronization Procedure .....................14
5. PCE-Triggered Initial Synchronization ..........................17
5.1. Motivation ................................................17
5.2. PCE-Triggered Initial State Synchronization Procedure .....18
6. PCE-Triggered Resynchronization ................................19
6.1. Motivation ................................................19
6.2. PCE-Triggered State Resynchronization Procedure ...........19
7. Advertising Support of Synchronization Optimizations ...........20
8. IANA Considerations ............................................21
8.1. PCEP-Error Object .........................................21
8.2. PCEP TLV Type Indicators ..................................22
8.3. STATEFUL-PCE-CAPABILITY TLV ...............................22
9. Manageability Considerations ...................................22
9.1. Control of Function and Policy ............................22
9.2. Information and Data Models ...............................22
9.3. Liveness Detection and Monitoring .........................23
9.4. Verify Correct Operations .................................23
9.5. Requirements on Other Protocols ...........................23
9.6. Impact on Network Operations ..............................23
10. Security Considerations .......................................23
11. References ....................................................24
11.1. Normative References .....................................24
11.2. Informative References ...................................24
Acknowledgments ...................................................25
Contributors ......................................................25
Authors' Addresses ................................................26
The Path Computation Element Communication Protocol (PCEP) provides mechanisms for Path Computation Elements (PCEs) to perform path computations in response to Path Computation Client (PCC) requests.
路径计算元素通信协议（PCEP）为路径计算元素（PCE）提供响应于路径计算客户端（PCC）请求执行路径计算的机制。
[RFC8231] describes a set of extensions to PCEP to provide stateful control. A stateful PCE has access to not only the information carried by the network's Interior Gateway Protocol (IGP) but also the set of active paths and their reserved resources for its computations. The additional state allows the PCE to compute constrained paths while considering individual LSPs and their interactions. This requires a State Synchronization mechanism between the PCE and the network, the PCE and the PCC, and cooperating PCEs. [RFC8231] describes the basic mechanism for State Synchronization. This document specifies following optimizations for State Synchronization and the corresponding PCEP procedures and extensions:
[RFC8231]描述了PCEP的一组扩展，以提供有状态控制。有状态PCE不仅可以访问网络内部网关协议（IGP）携带的信息，还可以访问一组活动路径及其用于计算的保留资源。附加状态允许PCE在考虑单个LSP及其交互时计算约束路径。这需要PCE与网络、PCE与PCC以及协作PCE之间的状态同步机制。[RFC8231]描述了状态同步的基本机制。本文档规定了以下状态同步优化以及相应的PCEP过程和扩展：
o State Synchronization Avoidance: To skip State Synchronization if the state has survived and not changed during session restart. (See Section 3.)
o 状态同步避免：如果状态在会话重新启动期间仍然存在且未更改，则跳过状态同步。（见第3节。）
o Incremental State Synchronization: To do incremental (delta) State Synchronization when possible. (See Section 4.)
o 增量状态同步：尽可能进行增量（增量）状态同步。（见第4节。）
o PCE-Triggered Initial Synchronization: To let PCE control the timing of the initial State Synchronization. (See Section 5.)
o PCE触发初始同步：让PCE控制初始状态同步的定时。（见第5节。）
o PCE-Triggered Resynchronization: To let PCE resynchronize the state for sanity check. (See Section 6.)
o PCE触发的重新同步：让PCE重新同步状态以进行健全性检查。（见第6节。）
Support for each of the synchronization optimization capabilities is advertised during the PCEP initialization phase. See Section 7 for the new flags defined in this document. The handling of each flag is described in the relevant section.
在PCEP初始化阶段公布对每个同步优化功能的支持。有关本文件中定义的新标志，请参见第7节。每个标志的处理在相关章节中进行了说明。
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.
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“建议”、“不建议”、“可”和“可选”在所有大写字母出现时（如图所示）应按照BCP 14[RFC2119][RFC8174]所述进行解释。
This document uses the following terms defined in [RFC5440]: PCC, PCE, and PCEP Peer.
本文件使用[RFC5440]中定义的以下术语：PCC、PCE和PCEP对等。
This document uses the following terms defined in [RFC8051]: Stateful PCE, Delegation, and LSP State Database (LSP-DB).
本文档使用[RFC8051]中定义的以下术语：有状态PCE、委托和LSP状态数据库（LSP-DB）。
This document uses the following terms defined in [RFC8231]: Redelegation Timeout Interval, LSP State Report, and LSP Update Request.
本文档使用[RFC8231]中定义的以下术语：重新委派超时时间间隔、LSP状态报告和LSP更新请求。
Within this document, when describing PCE-PCE communications, the requesting PCE fills the role of a PCC as usual.
在本文档中，当描述PCE-PCE通信时，请求PCE通常担任PCC的角色。
The purpose of State Synchronization is to provide a checkpoint-in-time state replica of a PCC's LSP state in a stateful PCE. State Synchronization is performed immediately after the initialization phase [RFC5440]. [RFC8231] describes the basic mechanism for State Synchronization.
状态同步的目的是在有状态PCE中提供PCC LSP状态的时间状态副本中的检查点。在初始化阶段[RFC5440]之后立即执行状态同步。[RFC8231]描述了状态同步的基本机制。
State Synchronization is not always necessary following a PCEP session restart. If the state of both PCEP peers did not change, the synchronization phase may be skipped. This can result in significant savings in both control-plane data exchanges and the time it takes for the stateful PCE to become fully operational.
PCEP会话重新启动后，状态同步并不总是必需的。如果两个PCEP对等点的状态没有改变，则可以跳过同步阶段。这可以显著节省控制平面数据交换和有状态PCE完全运行所需的时间。
State Synchronization MAY be skipped following a PCEP session restart if the state of both PCEP peers did not change during the period prior to session re-initialization. To be able to make this determination, state must be exchanged and maintained by both PCE and PCC during normal operation. This is accomplished by keeping track of the changes to the LSP-DB, using a version tracking field called the LSP-DB Version Number.
如果在会话重新初始化之前，两个PCEP对等方的状态没有改变，则在PCEP会话重新启动后，可能会跳过状态同步。为了能够做出这一决定，PCE和PCC必须在正常运行期间交换和维持状态。这是通过使用名为LSP-DB版本号的版本跟踪字段跟踪LSP-DB的更改来实现的。
The INCLUDE-DB-VERSION (S) bit in the STATEFUL-PCE-CAPABILITY TLV (Section 7) is advertised on a PCEP session during session startup to indicate that the LSP-DB Version Number is to be included when the LSPs are reported to the PCE. The LSP-DB Version Number, carried in LSP-DB-VERSION TLV (see Section 3.3.1), is owned by a PCC, and it MUST be incremented by 1 for each successive change in the PCC's LSP-DB. The LSP-DB Version Number MUST start at 1 and may wrap around.
会话启动期间，在PCEP会话上公布有状态PCE-CAPABILITY TLV（第7节）中的INCLUDE-DB-VERSION（S）位，以指示向PCE报告LSP时将包括LSP-DB版本号。LSP-DB-Version TLV（见第3.3.1节）中的LSP-DB版本号归PCC所有，且必须为PCC的LSP-DB中的每个连续更改增加1。LSP-DB版本号必须从1开始，并且可以环绕。
Values 0 and 0xFFFFFFFFFFFFFFFF are reserved. If either of the two values are used during LSP State (re)Synchronization, the PCE speaker receiving this value MUST send back a PCEP Error (PCErr) with Error-type=20 and Error-value=6 'Received an invalid LSP-DB Version Number', and close the PCEP session. Operations that trigger a 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 any of the LSP attributes that would trigger a report to the PCE.
保留值0和0xFFFFFFFFFFFFFF。如果在LSP状态（重新）同步期间使用了这两个值中的任何一个，则接收该值的PCE扬声器必须发回PCEP错误（PCErr），错误类型为20，错误值为6“接收到无效的LSP-DB版本号”，并关闭PCEP会话。触发本地LSP-DB更改的操作包括LSP操作状态的更改、LSP的委派、LSP的删除或设置，或触发向PCE报告的任何LSP属性的更改。
If the include LSP-DB version capability is enabled, a PCC MUST increment its LSP-DB Version Number when the 'Redelegation Timeout Interval' timer expires (see [RFC8231] for the use of the Redelegation Timeout Interval).
如果启用了包含LSP-DB版本功能，则PCC必须在“重新传输超时间隔”计时器过期时增加其LSP-DB版本号（有关重新传输超时间隔的使用，请参阅[RFC8231]）。
If both PCEP speakers set the S flag in the OPEN object's STATEFUL-PCE-CAPABILITY TLV to 1, the PCC MUST include the LSP-DB-VERSION TLV in each LSP object of the Path Computation LSP State Report (PCRpt) message. If the LSP-DB-VERSION TLV is missing in a PCRpt message, the PCE will generate an error with Error-type=6 (Mandatory Object missing) and Error-value=12 'LSP-DB-VERSION TLV missing', and close the session. If the include LSP-DB version capability has not been enabled on a PCEP session, the PCC SHOULD NOT include the LSP-DB-VERSION TLV in the LSP Object, and the PCE MUST ignore it, were it to receive one.
如果两个PCEP扬声器将开放对象的有状态-PCE-能力TLV中的S标志设置为1，则PCC必须在路径计算LSP状态报告（PCRpt）消息的每个LSP对象中包含LSP-DB-VERSION TLV。如果PCRpt消息中缺少LSP-DB-VERSION TLV，则PCE将生成错误类型为6（强制对象缺少）且错误值为12“LSP-DB-VERSION TLV缺少”的错误，并关闭会话。如果尚未在PCEP会话上启用包含LSP-DB版本功能，则PCC不应在LSP对象中包含LSP-DB-version TLV，并且PCE必须忽略它，否则它将接收到LSP-DB-version TLV。
If a PCE's LSP-DB survived the restart of a PCEP session, the PCE will include the LSP-DB-VERSION TLV in its OPEN object, and the TLV will contain the last LSP-DB Version Number received on an LSP State Report from the PCC in the previous PCEP session. If a PCC's LSP-DB survived the restart of a PCEP session, the PCC will include the LSP-DB-VERSION TLV in its OPEN object, and the TLV will contain the latest LSP-DB Version Number. If a PCEP speaker's LSP-DB did not survive the restart of a PCEP session or at startup when the database is empty, the PCEP speaker MUST NOT include the LSP-DB-VERSION TLV in the OPEN object.
如果PCE的LSP-DB在PCEP会话重启后幸存，则PCE将在其打开的对象中包含LSP-DB版本TLV，并且TLV将包含在上一个PCEP会话中从PCC收到的LSP状态报告中收到的最后一个LSP-DB版本号。如果PCC的LSP-DB在PCEP会话重启后幸存，则PCC将在其开放对象中包含LSP-DB版本TLV，并且TLV将包含最新的LSP-DB版本号。如果PCEP扬声器的LSP-DB在PCEP会话重新启动或数据库为空时启动时无法存活，则PCEP扬声器不得在打开的对象中包含LSP-DB版本TLV。
If both PCEP speakers include the LSP-DB-VERSION TLV in the OPEN object and the TLV values match, the PCC MAY skip State Synchronization, and the PCE does not wait for the end-of-synchronization marker [RFC8231]. Otherwise, the PCC MUST perform full State Synchronization (see [RFC8231]) or incremental State Synchronization (see Section 4 if this capability is advertised) to the stateful PCE. In other words, if the incremental State Synchronization capability is not advertised by the peers, based on the LSP-DB Version Number match, either the State Synchronization is skipped or a full State Synchronization is performed. If the PCC attempts to skip State Synchronization, by setting the SYNC flag to 0 and PLSP-ID to a non-zero value on the first LSP State Report from
如果两个PCEP扬声器在开放对象中都包含LSP-DB-VERSION TLV，并且TLV值匹配，则PCC可能会跳过状态同步，并且PCE不会等待同步结束标记[RFC8231]。否则，PCC必须对有状态PCE执行完全状态同步（请参见[RFC8231]）或增量状态同步（如果公布此功能，请参见第4节）。换句话说，如果对等方未根据LSP-DB版本号匹配公布增量状态同步能力，则跳过状态同步或执行完全状态同步。如果PCC试图跳过状态同步，请在来自的第一个LSP状态报告中将同步标志设置为0，将PLSP-ID设置为非零值
the PCC as per [RFC8231], the PCE MUST send back a PCErr with Error-type=20 and Error-value=2 'LSP-DB version mismatch', and close the PCEP session.
PCC根据[RFC8231]，PCE必须发回错误类型为20且错误值为2“LSP-DB版本不匹配”的PCErr，并关闭PCEP会话。
If State Synchronization is required, then prior to completing the initialization phase, the PCE MUST mark any LSPs in the LSP-DB that were previously reported by the PCC as stale. When the PCC reports an LSP during State Synchronization, if the LSP already exists in the LSP-DB, the PCE MUST update the LSP-DB and clear the stale marker from the LSP. When it has finished State Synchronization, the PCC MUST immediately send an end-of-synchronization marker. The end-of-synchronization marker is a PCRpt message with an LSP object containing a PLSP-ID of 0 and with the SYNC flag set to 0 [RFC8231]. The LSP-DB-VERSION TLV MUST be included in this PCRpt message. On receiving this state report, the PCE MUST purge any LSPs from the LSP-DB that are still marked as stale.
如果需要状态同步，则在完成初始化阶段之前，PCE必须将LSP-DB中先前由PCC报告的任何LSP标记为过时。当PCC在状态同步期间报告LSP时，如果LSP已经存在于LSP-DB中，则PCE必须更新LSP-DB并清除LSP中的过时标记。完成状态同步后，PCC必须立即发送同步结束标记。同步结束标记是一条PCRpt消息，其LSP对象包含PLSP-ID为0且同步标志设置为0[RFC8231]。此PCRpt消息中必须包含LSP-DB-VERSION TLV。收到此状态报告后，PCE必须清除LSP-DB中仍标记为过时的任何LSP。
Note that a PCE/PCC MAY force State Synchronization by not including the LSP-DB-VERSION TLV in its OPEN object.
请注意，PCE/PCC可能会通过在其开放对象中不包括LSP-DB-VERSION TLV来强制状态同步。
Since a PCE does not make changes to the LSP-DB Version Number, a PCC should never encounter this TLV in a message from the PCE (other than the OPEN message). A PCC SHOULD ignore the LSP-DB-VERSION TLV, were it to receive one from a PCE.
由于PCE不会更改LSP-DB版本号，因此PCC在来自PCE的消息（开放消息除外）中不应遇到此TLV。PCC应该忽略LSP-DB-VERSION TLV，如果它要从PCE接收一个TLV。
Figure 1 shows an example sequence where the State Synchronization is skipped.
图1显示了跳过状态同步的示例序列。
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=42 \ ,---Open--|
| S=1 \ / DBv=42 |
| \/ S=1 |
| /\ |
| / `-------->| (OK to skip sync)
(Skip sync) |<--------` |
| . |
| . |
| . |
| |
|--PCRpt,DBv=43,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=44,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=45,SYNC=0-->|
| |
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=42 \ ,---Open--|
| S=1 \ / DBv=42 |
| \/ S=1 |
| /\ |
| / `-------->| (OK to skip sync)
(Skip sync) |<--------` |
| . |
| . |
| . |
| |
|--PCRpt,DBv=43,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=44,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=45,SYNC=0-->|
| |
Figure 1: State Synchronization Skipped
图1：跳过状态同步
Figure 2 shows an example sequence where the State Synchronization is performed due to LSP-DB version mismatch during the PCEP session setup. Note that the same State Synchronization sequence would happen if either the PCC or the PCE would not include the LSP-DB-VERSION TLV in their respective Open messages.
图2显示了在PCEP会话设置期间由于LSP-DB版本不匹配而执行状态同步的示例序列。请注意，如果PCC或PCE在各自的打开消息中不包括LSP-DB-VERSION TLV，则会发生相同的状态同步序列。
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 |
| \/ S=1 |
| /\ |
| / `-------->| (Expect sync)
(Do sync) |<--------` |
| |
|--PCRpt,DBv=46,SYNC=1-->| (Sync start)
| . |
| . |
| . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done)
| . | (Purge LSP state
| . | if applicable)
| . |
|--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->|
| |
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 |
| \/ S=1 |
| /\ |
| / `-------->| (Expect sync)
(Do sync) |<--------` |
| |
|--PCRpt,DBv=46,SYNC=1-->| (Sync start)
| . |
| . |
| . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done)
| . | (Purge LSP state
| . | if applicable)
| . |
|--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->|
| |
Figure 2: State Synchronization Performed
图2：执行的状态同步
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, the PCC does not send LSP-DB-VERSION TLVs in subsequent PCRpt messages to the PCE. If the current PCEP session restarts, the PCEP speakers will have to perform State Synchronization, since the PCE does not know the PCC's latest LSP-DB Version Number information.
图3显示了跳过状态同步的示例序列，但由于一个或两个PCEP扬声器将S标志设置为0，PCC不会在后续PCRpt消息中向PCE发送LSP-DB-VERSION TLV。如果当前PCEP会话重新启动，PCEP扬声器将必须执行状态同步，因为PCE不知道PCC的最新LSP-DB版本号信息。
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=42 \ ,---Open--|
| S=0 \ / DBv=42 |
| \/ S=0 |
| /\ |
| / `-------->| (OK to skip sync)
(Skip sync) |<--------` |
| . |
| . |
| . |
|------PCRpt,SYNC=0----->| (Regular
| | LSP State Report)
|------PCRpt,SYNC=0----->| (Regular
| | LSP State Report)
|------PCRpt,SYNC=0----->|
| |
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=42 \ ,---Open--|
| S=0 \ / DBv=42 |
| \/ S=0 |
| /\ |
| / `-------->| (OK to skip sync)
(Skip sync) |<--------` |
| . |
| . |
| . |
|------PCRpt,SYNC=0----->| (Regular
| | LSP State Report)
|------PCRpt,SYNC=0----->| (Regular
| | LSP State Report)
|------PCRpt,SYNC=0----->|
| |
Figure 3: State Synchronization Skipped; No LSP-DB-VERSION TLVs Sent from the PCC
图3：跳过状态同步；没有从PCC发送LSP-DB-VERSION TLV
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 limited to, the following cases:
在PCEP会话重新建立期间，PCC或PCE的IP地址可能会发生变化。这包括但不限于以下情况：
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 changes, then the PCEP session goes down and comes back up again, with a different IP address associated with a new line card.
o PCC可以使用物理接口IP地址连接到PCE。在这种情况下，如果PCC从中连接的线路卡发生变化，则PCEP会话将关闭并再次恢复，并使用与新线路卡关联的不同IP地址。
o The PCC or PCE may move in the network, either physically or logically, which may cause its IP address to change. For example, the PCE may be deployed as a virtual network function (VNF), and another virtualized instance of the PCE may be populated with the original PCE instance's state, but it may be given a different IP address.
o PCC或PCE可以在网络中物理地或逻辑地移动，这可能导致其IP地址改变。例如，PCE可以部署为虚拟网络功能（VNF），并且PCE的另一个虚拟化实例可以填充原始PCE实例的状态，但是可以为其提供不同的IP地址。
To ensure that a PCEP peer can recognize a previously connected peer, each PCEP peer includes the SPEAKER-ENTITY-ID TLV described in Section 3.3.2 in the OPEN message.
为确保PCEP对等方能够识别先前连接的对等方，每个PCEP对等方在开放消息中包括第3.3.2节所述的SPEAKER-ENTITY-ID TLV。
This TLV is used during the State Synchronization procedure to identify the PCEP session as a re-establishment of a previous session that went down. Then State Synchronization optimizations such as state sync avoidance can be applied to this session. Note that this usage is only applicable within the State Timeout Interval [RFC8231]. After the State Timeout Interval expires, all state associated with the PCEP session is removed, which includes the SPEAKER-ENTITY-ID received. Note that the PCEP session initialization [RFC5440] procedure remains unchanged.
此TLV在状态同步过程中用于将PCEP会话标识为先前中断会话的重新建立。然后可以将状态同步优化（如状态同步避免）应用于此会话。请注意，此用法仅适用于状态超时间隔[RFC8231]内。状态超时时间间隔到期后，将删除与PCEP会话相关的所有状态，其中包括接收到的SPEAKER-ENTITY-ID。请注意，PCEP会话初始化[RFC5440]过程保持不变。
A new INCLUDE-DB-VERSION (S) bit is added in the stateful capabilities TLV (see Section 7 for details).
在有状态功能TLV中添加了一个新的INCLUDE-DB-VERSION（S）位（有关详细信息，请参阅第7节）。
The LSP-DB Version Number (LSP-DB-VERSION) TLV is an optional TLV that MAY be included in the OPEN object and the LSP object.
LSP-DB版本号（LSP-DB-Version）TLV是可选的TLV，可包含在开放对象和LSP对象中。
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 included in other PCEP messages (Path Computation Update Request (PCUpd), Path Computation Request (PCReq), and Path Computation Reply (PCRep)) and MUST be ignored if received.
此TLV包含在PCRpt消息的LSP对象中，以指示PCC的LSP-DB版本。此TLV不应包含在其他PCEP消息（路径计算更新请求（PCUpd）、路径计算请求（PCReq）和路径计算回复（PCRep））中，并且在收到时必须忽略。
The format of the LSP-DB-VERSION TLV is shown in the following figure:
LSP-DB-VERSION TLV的格式如下图所示：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=23 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSP-DB Version Number |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=23 | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| LSP-DB Version Number |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: LSP-DB-VERSION TLV Format
图4:LSP-DB-VERSION TLV格式
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 order, representing the LSP-DB Version Number.
TLV的类型为23，固定长度为8个八位字节。该值包含一个64位无符号整数，按网络字节顺序携带，表示LSP-DB版本号。
The Speaker Entity Identifier TLV (SPEAKER-ENTITY-ID) is an optional TLV that MAY be included in the OPEN object when a PCEP speaker wishes to determine if State Synchronization can be skipped when a PCEP session is restarted. It contains a unique identifier for the 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 address is changed.
说话人实体标识符TLV（Speaker-Entity-ID）是可选的TLV，当PCEP说话人希望确定在PCEP会话重新启动时是否可以跳过状态同步时，可以将其包括在打开的对象中。它包含节点的唯一标识符，该标识符在PCEP扬声器的使用寿命期间不会更改。即使说话人的IP地址发生变化，它也会向其对等方识别PCEP说话人。
In case of a remote peer IP address change, a PCEP speaker would learn the Speaker Entity Identifier on receiving the open message, but it MAY have already sent its open message without realizing that it is a known PCEP peer. In such a case, either a full synchronization is done or the PCEP session is terminated. This may be a local policy decision. The new IP address is associated with the Speaker Entity Identifier for the future either way. In the latter case when the PCEP session is re-established, it would be correctly associated with the Speaker Entity Identifier and not be considered as an unknown peer.
在远程对等IP地址改变的情况下，PCEP演讲者将在接收开放消息时学习演讲者实体标识符，但它可能已经发送了其开放消息，而没有意识到它是已知的PCEP对等。在这种情况下，完成完全同步或终止PCEP会话。这可能是当地的政策决定。新的IP地址与未来的说话人实体标识符关联。在后一种情况下，当重新建立PCEP会话时，它将与说话人实体标识符正确关联，并且不会被视为未知对等方。
The format of the SPEAKER-ENTITY-ID TLV is shown in the following figure:
SPEAKER-ENTITY-ID TLV的格式如下图所示：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=24 | Length (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Speaker Entity Identifier //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type=24 | Length (variable) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
// Speaker Entity Identifier //
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: SPEAKER-ENTITY-ID TLV Format
图5:SPEAKER-ENTITY-ID TLV格式
The type of the TLV is 24, and it has a variable length, which MUST 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 Speaker Entity Identifier (an identifier of the PCEP speaker transmitting this TLV). This identifier is required to be unique within its scope of visibility, which is usually limited to a single domain. It MAY be configured by the operator. Alternatively, it can be derived automatically from a suitably stable unique identifier,
TLV的类型为24，其长度可变，必须大于0。该值填充为4个八位组对齐。填充不包括在长度字段中。该值包含说话人实体标识符（传输该TLV的PCEP说话人的标识符）。该标识符在其可视范围内必须是唯一的，通常仅限于单个域。它可以由操作员进行配置。或者，它可以从适当稳定的唯一标识符自动导出，
such as a Media Access Control (MAC) address, serial number, Traffic Engineering Router ID, or similar. In the case of inter-domain connections, the speaker SHOULD prefix its usual identifier with the domain identifier of its residence, such as an Autonomous System number, an IGP area identifier, or similar to make sure it remains unique.
例如媒体访问控制（MAC）地址、序列号、流量工程路由器ID或类似信息。在域间连接的情况下，说话人应在其常用标识符前加上其住所的域标识符，例如自治系统号、IGP区域标识符或类似标识符，以确保其保持唯一性。
The relationship between this identifier and entities in the Traffic Engineering database is intentionally left undefined.
故意不定义此标识符与交通工程数据库中实体之间的关系。
From a manageability point of view, a PCE or PCC implementation SHOULD allow the operator to configure this Speaker Entity Identifier.
从可管理性的角度来看，PCE或PCC实现应允许操作员配置该扬声器实体标识符。
If a PCEP speaker receives the SPEAKER-ENTITY-ID on a new PCEP session, that matches with an existing alive PCEP session, the PCEP speaker MUST send a PCErr with Error-type=20 and Error-value=7 'Received an invalid Speaker Entity Identifier', and close the PCEP session.
如果PCEP扬声器在与现有活动PCEP会话匹配的新PCEP会话上接收到speaker-ENTITY-ID，则PCEP扬声器必须发送错误类型为20且错误值为7的PCErr“接收到无效的扬声器实体标识符”，并关闭PCEP会话。
[RFC8231] describes the LSP State Synchronization mechanism between PCCs and stateful PCEs. During the State Synchronization, a PCC sends the information of all its LSPs (i.e., the full LSP-DB) to the stateful PCE. In order to reduce the State Synchronization overhead when there is a small number of LSP state changes in the network between the PCEP session restart, this section defines a mechanism for incremental (Delta) LSP-DB synchronization.
[RFC8231]描述了PCC和有状态PCE之间的LSP状态同步机制。在状态同步期间，PCC将其所有LSP（即，完整LSP-DB）的信息发送到有状态PCE。为了在PCEP会话重启之间网络中存在少量LSP状态更改时减少状态同步开销，本节定义了增量（增量）LSP-DB同步机制。
According to [RFC8231], if a PCE restarts and its LSP-DB survived, PCCs with a mismatched LSP-DB Version Number will send all their LSPs information (full LSP-DB) to the stateful PCE, even if only a small number of LSPs underwent state change. It can take a long time and consume large communication channel bandwidth.
根据[RFC8231]，如果PCE重新启动且其LSP-DB幸存，则LSP-DB版本号不匹配的PCC将向有状态PCE发送其所有LSP信息（完整LSP-DB），即使只有少量LSP发生状态更改。这可能需要很长的时间和消耗大量的通信信道带宽。
Figure 6 shows an example of LSP State Synchronization.
图6显示了LSP状态同步的示例。
+-----+
| PCE |
+-----+
/
/
/
/
+------+ +------+
| PCC1 |------------| PCC2 |
+------+ +------+
| |
| |
+------+ +------+
| PCC3 |------------| PCC4 |
+------+ +------+
+-----+
| PCE |
+-----+
/
/
/
/
+------+ +------+
| PCC1 |------------| PCC2 |
+------+ +------+
| |
| |
+------+ +------+
| PCC3 |------------| PCC4 |
+------+ +------+
Figure 6: Topology Example
图6：拓扑示例
Assume that there are 320 LSPs in the network, with each PCC having 80 LSPs. During the time when the PCEP session is down, 20 LSPs of each PCC (i.e., 80 LSPs in total), are changed. Hence, when the PCEP session restarts, the stateful PCE needs to synchronize 320 LSPs with all PCCs. But actually, 240 LSPs stay the same. If performing full 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 bandwidth communication channel is available (e.g., in-band control channel for optical transport networks), and there is a substantial number of LSPs in the network. Another disadvantage of full LSP synchronization is that it is a waste of communication bandwidth to perform full LSP synchronization given the fact that the number of LSP changes can be small during the time when the PCEP session is down.
假设网络中有320个LSP，每个PCC有80个LSP。在PCEP会话关闭期间，每个PCC的20个LSP（即总共80个LSP）被更改。因此，当PCEP会话重新启动时，有状态PCE需要将320个lsp与所有pcc同步。但实际上，240个LSP保持不变。如果执行完全LSP状态同步，则可能需要很长时间才能执行所有LSP的同步。当只有低带宽通信信道可用（例如，光传输网络的带内控制信道）且网络中存在大量LSP时，尤其如此。完全LSP同步的另一个缺点是，鉴于在PCEP会话关闭期间LSP更改的数量可能很小，因此执行完全LSP同步是对通信带宽的浪费。
An incremental (Delta) LSP-DB State Synchronization is described in this section, where only the LSPs that underwent state change are synchronized between the session restart. This may include new/modified/deleted LSPs.
本节描述了增量（增量）LSP-DB状态同步，其中在会话重启之间仅同步状态发生更改的LSP。这可能包括新的/修改的/删除的LSP。
[RFC8231] describes State Synchronization and Section 3 of this document describes State Synchronization avoidance by using LSP-DB-VERSION TLV in its OPEN object. This section extends this idea to only synchronize the delta (changes) in case of version mismatch.
[RFC8231]描述了状态同步，本文档第3节描述了通过在其开放对象中使用LSP-DB-VERSION TLV避免状态同步。本节扩展了这一思想，仅在版本不匹配的情况下同步增量（更改）。
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 State Synchronization. Otherwise, the PCC MUST perform State Synchronization. Incremental State Synchronization capability is advertised on a PCEP session during session startup using the DELTA-LSP-SYNC-CAPABILITY (D) bit in the capabilities TLV (see Section 7). Instead of dumping full LSP-DB to the stateful PCE again, the PCC synchronizes the delta (changes) as described in Figure 7 when the D and S flags are set to 1 by both the PCC and PCE. Other combinations of D and S flags set by the PCC and PCE result in full LSP-DB synchronization procedures as described in [RFC8231]. By setting the D flag to zero in the OPEN message, a PCEP speaker can skip the incremental synchronization optimization, resulting in a full LSP-DB synchronization.
如果两个PCEP扬声器在开放对象中都包含LSP-DB-VERSION TLV，并且LSP-DB-VERSION TLV值匹配，则PCC可能会跳过状态同步。否则，PCC必须执行状态同步。在会话启动期间，使用功能TLV中的DELTA-LSP-SYNC-capability（D）位在PCEP会话上公布增量状态同步功能（参见第7节）。当PCC和PCE都将D和S标志设置为1时，PCC不会再次将完整的LSP-DB转储到有状态PCE，而是如图7所示同步增量（更改）。PCC和PCE设置的D和S标志的其他组合导致完全LSP-DB同步过程，如[RFC8231]所述。通过在OPEN消息中将D标志设置为零，PCEP扬声器可以跳过增量同步优化，从而实现完全LSP-DB同步。
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 |
| D=1 \/ S=1 |
| /\ D=1 |
| / \ |
| / `-------->| (Expect delta sync)
(Do sync)|<--------` | (DO NOT purge LSP
(Delta) | | state)
| |
(Delta sync starts) |--PCRpt,DBv=46,SYNC=1-->|
| . |
| . |
| . |
| . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done,
| | PLSP-ID=0)
| |
|--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->|
| |
+-+-+ +-+-+
|PCC| |PCE|
+-+-+ +-+-+
| |
|--Open--, |
| DBv=46 \ ,---Open--|
| S=1 \ / DBv=42 |
| D=1 \/ S=1 |
| /\ D=1 |
| / \ |
| / `-------->| (Expect delta sync)
(Do sync)|<--------` | (DO NOT purge LSP
(Delta) | | state)
| |
(Delta sync starts) |--PCRpt,DBv=46,SYNC=1-->|
| . |
| . |
| . |
| . |
|--PCRpt,DBv=46,SYNC=0-->| (Sync done,
| | PLSP-ID=0)
| |
|--PCRpt,DBv=47,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=48,SYNC=0-->| (Regular
| | LSP State Report)
|--PCRpt,DBv=49,SYNC=0-->|
| |
Figure 7: Incremental Synchronization Procedure
图7：增量同步过程
As per Section 3, the LSP-DB Version Number is incremented each time a change is made to the PCC's local LSP-DB. Each LSP is associated with the DB version at the time of its state change. This is needed to determine which LSP and what information needs to be synchronized in incremental State Synchronization. The incremental state sync is done from the last LSP-DB version received by the PCE to the latest DB version at the PCC. Note that the LSP-DB Version Number can wrap around, in which case the incremental state sync would also wrap till the latest LSP-DB Version Number at the PCC.
根据第3节，每次更改PCC的本地LSP-DB时，LSP-DB版本号都会增加。每个LSP在其状态更改时都与DB版本相关联。这需要确定在增量状态同步中需要同步哪些LSP和哪些信息。增量状态同步从PCE接收的最后一个LSP-DB版本到PCC的最新DB版本。请注意，LSP-DB版本号可以环绕，在这种情况下，增量状态同步也将环绕到PCC的最新LSP-DB版本号。
In order to carry out incremental State Synchronization, it is not necessary for a PCC to store a complete history of LSP-DB change for all time, but remember the LSP state changes (including LSP modification, setup, and deletion) that the PCE did not get to 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 session to the PCE went down. So a PCC implementation MAY choose to
为了执行增量状态同步，PCC不必始终存储LSP-DB更改的完整历史记录，但要记住PCE在会话关闭期间未处理的LSP状态更改（包括LSP修改、设置和删除）。请注意，PCC可能不知道在与PCE的会话中断之前，PCE已经处理了特定的LSP报告。因此，PCC实现可以选择
store the LSP-DB Version Number with each LSP at the time its status changed, so that when a session is re-established, an incremental synchronization can be attempted based on the PCE's last LSP-DB Version Number. For an LSP that is deleted at the PCC, the PCC implementation would need to remember the deleted LSP in some way to make sure this could be reported as part of incremental synchronization later. The PCC would discard this information based on a local policy or when it determines that this information is no longer needed with sufficient confidence. In the example shown in Figure 7, the PCC needs to store the LSP state changes that happened between DB Versions 43 to 46 and synchronize these changes, when performing incremental LSP state update.
在每个LSP的状态更改时，将LSP-DB版本号与每个LSP一起存储，以便在重新建立会话时，可以根据PCE的最后一个LSP-DB版本号尝试增量同步。对于在PCC处删除的LSP，PCC实现需要以某种方式记住已删除的LSP，以确保以后可以将其作为增量同步的一部分进行报告。PCC将根据当地政策或当其确定不再需要该信息时，以足够的信心丢弃该信息。在图7所示的示例中，PCC需要存储在DB版本43到46之间发生的LSP状态更改，并在执行增量LSP状态更新时同步这些更改。
If a PCC finds out it does not have sufficient information to complete incremental synchronization after advertising incremental 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 not complete the State Synchronization' (defined in [RFC8231]), and terminate the session. The PCC SHOULD re-establish the session with the D bit set to 0 in the OPEN message.
如果PCC在公布增量LSP状态同步功能后发现其没有足够的信息来完成增量同步，则必须发送错误类型为20且错误值为5的PCErr“PCC向PCE指示其无法完成状态同步”（在[RFC8231]中定义），并终止会话。PCC应在打开消息中将D位设置为0的情况下重新建立会话。
The other procedures and error checks remain unchanged from the full State Synchronization [RFC8231].
其他过程和错误检查与完全状态同步保持不变[RFC8231]。
In networks such as optical transport networks, the control channel between network nodes can be realized through in-band overhead, thus it has limited bandwidth. With a stateful PCE connected to the network via one network node, it is desirable to control the timing of PCC State Synchronization so as not to overload the low communication channel available in the network during the initial synchronization (be it incremental or full) when the session restarts, when there is a comparatively large amount of control information needing to be synchronized between the stateful PCE and the network. The method proposed, i.e., allowing PCE to trigger the State Synchronization, is similar to the function proposed in Section 6 but is used in different scenarios and for different purposes.
在诸如光传输网络之类的网络中，网络节点之间的控制信道可以通过带内开销来实现，因此它具有有限的带宽。在有状态PCE经由一个网络节点连接到网络的情况下，希望控制PCC状态同步的定时，以便在会话重新启动时的初始同步期间（无论是增量还是完全）不会使网络中可用的低通信信道过载，当有状态PCE和网络之间需要同步相对大量的控制信息时。提出的方法，即允许PCE触发状态同步，与第6节中提出的功能类似，但用于不同的场景和目的。
Support of PCE-triggered initial State Synchronization is advertised during session startup using the TRIGGERED-INITIAL-SYNC (F) bit in the STATEFUL-PCE-CAPABILITY TLV (see Section 7).
在会话启动期间，使用STATEFUL-PCE-CAPABILITY TLV中的triggered-initial-SYNC（F）位公布对PCE触发初始状态同步的支持（参见第7节）。
In order to allow a stateful PCE to control the LSP-DB synchronization after establishing a PCEP session, both PCEP speakers MUST set the F bit to 1 in the OPEN message. If the LSP-DB-VERSION 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 the TLV is not included or the LSP-DB Version is mismatched, the PCE can trigger the State Synchronization process by sending a PCUpd message with PLSP-ID = 0 and SYNC = 1. The PCUpd message SHOULD include an empty Explicit Route Object (ERO) (with no ERO sub-object and object length of 4) as its intended path and SHOULD NOT include the optional objects for its attributes for any parameter update. The PCC MUST ignore such an update when the SYNC flag is set. If the TRIGGERED-INITIAL-SYNC capability is not advertised by a PCE and the PCC receives a PCUpd with the SYNC flag set to 1, the PCC MUST send a PCErr with the SRP-ID-number of the PCUpd, Error-type=20, and Error-value=4 'Attempt to trigger a synchronization when the PCE triggered synchronization capability has not been advertised' (see Section 8.1). If the TRIGGERED-INITIAL-SYNC capability is advertised by a PCE and the PCC, the PCC MUST NOT trigger State Synchronization on its own. If the PCE receives a PCRpt message before the PCE has triggered the State Synchronization, the PCE MUST send a PCErr with Error-type=20 and Error-value=3 'Attempt to trigger synchronization before PCE trigger' (see Section 8.1).
为了允许有状态PCE在建立PCEP会话后控制LSP-DB同步，两个PCEP扬声器必须在OPEN消息中将F位设置为1。如果两个PCEP扬声器都包括LSP-DB-VERSION TLV，并且TLV值匹配，则可以按照第3.2节所述跳过状态同步。如果未包括TLV或LSP-DB版本不匹配，则PCE可通过发送PLSP-ID=0且SYNC=1的PCUpd消息来触发状态同步过程。PCUpd消息应包括一个空的显式路由对象（ERO）（没有ERO子对象，对象长度为4）作为其预期路径，并且不应包括任何参数更新属性的可选对象。设置同步标志时，PCC必须忽略此类更新。如果PCE未公布触发的初始同步功能，且PCC接收到同步标志设置为1的PCUpd，则PCC必须发送PCErr，其SRP ID号为PCUpd，错误类型=20，错误值=4“当PCE触发的同步功能未公布时，尝试触发同步”（见第8.1节）。如果PCE和PCC公布触发的初始同步功能，PCC不得自行触发状态同步。如果PCE在PCE触发状态同步之前收到PCRpt消息，则PCE必须发送错误类型为20且错误值为3的PCErr“尝试在PCE触发前触发同步”（见第8.1节）。
In this way, the PCE can control the sequence of LSP synchronization among all the PCCs that are re-establishing PCEP sessions with it. When the capability of PCE control is enabled, only after a PCC receives this message, it will start sending information to the PCE. This PCE-triggering capability can be applied to both full and incremental State Synchronization. If applied to the latter, the PCCs only send information that PCE does not possess, which is inferred from the LSP-DB version information exchanged in the OPEN message (see Section 4.2 for a detailed procedure).
这样，PCE可以控制与其重新建立PCEP会话的所有pcc之间的LSP同步序列。当PCE控制功能启用时，只有在PCC收到此消息后，才会开始向PCE发送信息。此PCE触发功能可应用于完全和增量状态同步。如果应用于后者，PCC仅发送PCE不具备的信息，这是从开放消息中交换的LSP-DB版本信息推断出来的（详细程序见第4.2节）。
Once the initial State Synchronization is triggered by the PCE, the procedures and error checks remain unchanged [RFC8231].
PCE触发初始状态同步后，程序和错误检查保持不变[RFC8231]。
If a PCC implementation that does not implement this extension should not receive a PCUpd message to trigger State Synchronization as per the capability advertisement, but if it were to receive it, it will behave as per [RFC8231].
如果未实现此扩展的PCC实现不应接收PCUpd消息，以根据功能公告触发状态同步，但如果要接收，则将按照[RFC8231]执行。
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. Therefore, it can be beneficial to be able to resynchronize this state even after the session has been established. The PCE may use this approach to continuously sanity check its state against the network or to recover from error conditions without having to tear down sessions.
PCE执行的计算精度与PCE对LSP状态的视图精度有关。因此，即使在会话建立之后也能够重新同步该状态是有益的。PCE可以使用这种方法持续地针对网络检查其状态，或者在不必中断会话的情况下从错误条件中恢复。
Support of PCE-triggered state resynchronization is advertised by both PCEP speakers during session startup using the TRIGGERED-RESYNC (T) bit in the STATEFUL-PCE-CAPABILITY TLV (see Section 7). The PCE can choose to resynchronize its entire LSP-DB or a single LSP.
在会话启动期间，两个PCEP扬声器使用STATEFUL-PCE-CAPABILITY TLV中的TRIGGED-RESYNC（T）位公布对PCE触发状态再同步的支持（见第7节）。PCE可以选择重新同步其整个LSP-DB或单个LSP。
To trigger resynchronization for an LSP, the PCE sends a Path 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 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 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 cannot find the LSP in its database, PCC MUST also set the R (remove) flag [RFC8231] in the LSP object in the PCRpt message.
为了触发LSP的重新同步，PCE发送LSP的路径计算状态更新（PCUpd），LSP对象中的同步标志设置为1。PCE不应包括LSP的任何参数更新，并且PCC必须在设置同步标志时忽略此类更新。PCC必须使用LSP state、SYNC标志设置为0的PCRpt消息进行响应，并且必须包括触发重新同步的PCUpd消息的SRP ID号。如果PCC在其数据库中找不到LSP，PCC还必须在PCRpt消息的LSP对象中设置R（删除）标志[RFC8231]。
The PCE can also trigger resynchronization of the entire LSP-DB. The PCE MUST first mark all LSPs in the LSP-DB that were previously reported by the PCC as stale, and then send a PCUpd with an LSP object containing a PLSP-ID of 0 and with the SYNC flag set to 1. The PCUpd message MUST include an empty ERO (with no ERO sub-object and object length of 4) as its intended path and SHOULD NOT include the optional objects for its attributes for any parameter update. The PCC MUST ignore such update if the SYNC flag is set. This PCUpd message is the trigger for the PCC to enter the synchronization phase as described in [RFC8231] and start sending PCRpt messages. After the receipt of the end-of-synchronization marker, the PCE will purge LSPs that were not refreshed. The SRP-ID-number of the PCUpd that triggered the resynchronization SHOULD be included in each of the PCRpt messages. If the PCC cannot resynchronize the entire LSP-DB, the PCC MUST respond with a PCErr message with Error-type=20 and Error-value=5 'cannot complete the State Synchronization' [RFC8231], and it MAY terminate the session. The PCE MUST remove the stale mark for the LSPs that were previously reported by the PCC. Based on the local policy, the PCE MAY reattempt synchronization at a later time.
PCE还可以触发整个LSP-DB的重新同步。PCE必须首先将LSP-DB中先前由PCC报告的所有LSP标记为过时，然后发送包含PLSP-ID为0且同步标志设置为1的LSP对象的PCUpd。PCUpd消息必须包含一个空的ERO（没有ERO子对象，对象长度为4）作为其预期路径，并且不应包含任何参数更新属性的可选对象。如果设置了同步标志，则PCC必须忽略此类更新。此PCUpd消息触发PCC进入[RFC8231]中所述的同步阶段并开始发送PCRpt消息。收到同步结束标记后，PCE将清除未刷新的LSP。触发重新同步的PCUpd的SRP ID号应包含在每个PCRpt消息中。如果PCC无法重新同步整个LSP-DB，则PCC必须使用错误类型为20且错误值为5的PCErr消息响应“无法完成状态同步”[RFC8231]，并可能终止会话。PCE必须去除PCC先前报告的LSP的过期标记。基于本地策略，PCE可以稍后重新尝试同步。
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 PCErr with the SRP-ID-number of the PCUpd, Error-type=20, and Error-value=4 'Attempt to trigger a synchronization when the PCE triggered synchronization capability has not been advertised' (see Section 8.1).
如果PCE未公布触发重新同步功能，且PCC接收到一个同步标志设置为1的PCUpd，则必须发送一个PCErr，该PCErr的SRP ID号为PCUpd，错误类型为20，错误值为4‘当PCE触发的同步功能未公布时，尝试触发同步’（见第8.1节）。
Once the state resynchronization is triggered by the PCE, the procedures and error checks remain unchanged from the full state synchronization [RFC8231]. This would also include the PCE triggering multiple state resynchronization requests while synchronization is in progress.
一旦PCE触发状态重新同步，程序和错误检查与完全状态同步保持不变[RFC8231]。这还包括PCE在同步过程中触发多个状态重新同步请求。
If a PCC implementation that does not implement this extension should not receive a PCUpd message to trigger resynchronization as per the capability advertisement, but if it were to receive it, it will behave as per [RFC8231].
如果未实现此扩展的PCC实现不应接收PCUpd消息，以根据功能公告触发重新同步，但如果要接收，则将按照[RFC8231]执行。
Support for each of the optimizations described in this document requires advertising the corresponding capabilities during session establishment time.
支持本文档中描述的每个优化需要在会话建立期间公布相应的功能。
The STATEFUL-PCE-CAPABILITY TLV is defined in [RFC8231]. This document defines the following new flags in the STATEFUL-PCE-CAPABILITY TLV:
[RFC8231]中定义了有状态PCE能力TLV。本文档在有状态-PCE-CAPABILITY TLV中定义了以下新标志：
Bit Description
------------------------- ---------------------------------
30 S bit (INCLUDE-DB-VERSION)
27 D bit (DELTA-LSP-SYNC-CAPABILITY)
26 F bit (TRIGGERED-INITIAL-SYNC)
28 T bit (TRIGGERED-RESYNC)
Bit Description
------------------------- ---------------------------------
30 S bit (INCLUDE-DB-VERSION)
27 D bit (DELTA-LSP-SYNC-CAPABILITY)
26 F bit (TRIGGERED-INITIAL-SYNC)
28 T bit (TRIGGERED-RESYNC)
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 Section 3.2 for details.
如果两个PCEP扬声器将S位（INCLUDE-DB-VERSION）设置为1，则PCC将在每个LSP对象中包括LSP-DB-VERSION TLV。详见第3.2节。
If the D bit (DELTA-LSP-SYNC-CAPABILITY) is set to 1 by a PCEP speaker, it indicates that the PCEP speaker allows incremental (delta) State Synchronization. See Section 4.2 for details.
如果PCEP扬声器将D位（DELTA-LSP-SYNC-CAPABILITY）设置为1，则表示PCEP扬声器允许增量（DELTA）状态同步。详见第4.2节。
If the F bit (TRIGGERED-INITIAL-SYNC) is set to 1 by both PCEP speakers, the PCE SHOULD trigger initial (first) State Synchronization. See Section 5.2 for details.
如果两个PCEP扬声器都将F位（TRIGGERED-INITIAL-SYNC）设置为1，则PCE应触发初始（first）状态同步。详见第5.2节。
If the T bit (TRIGGERED-RESYNC) is set to 1 by both PCEP speakers, the PCE can trigger resynchronization of LSPs at any point in the life of the session. See Section 6.2 for details.
如果两个PCEP扬声器都将T位（TRIGGERED-RESYNC）设置为1，则PCE可以在会话生命周期的任何时候触发LSP的重新同步。详见第6.2节。
See Section 8.3 for IANA allocations.
IANA分配见第8.3节。
IANA has allocated code points for the protocol elements defined in this document.
IANA已为本文档中定义的协议元素分配了代码点。
IANA has allocated the following values in the "PCEP-ERROR Object Error Types and Values" registry.
IANA已在“PCEP-ERROR对象错误类型和值”注册表中分配了以下值。
Error-Type Meaning Reference
------------------------------------------------------------
6 Mandatory Object missing [RFC5440]
Error-Type Meaning Reference
------------------------------------------------------------
6 Mandatory Object missing [RFC5440]
Error-value 12: LSP-DB-VERSION TLV missing This document
错误值12:LSP-DB-VERSION TLV缺少此文档
20 LSP State Synchronization Error [RFC8231]
20 LSP状态同步错误[RFC8231]
Error-value 2: LSP-DB version mismatch. This document
错误值2:LSP-DB版本不匹配。本文件
3: Attempt to trigger This document synchronization before PCE trigger.
3:尝试在PCE触发之前触发此文档同步。
4: Attempt to trigger a This document synchronization when the PCE triggered synchronization capability has not been advertised.
4：当PCE触发的同步功能尚未公布时，尝试触发此文档同步。
6: Received an invalid This document LSP-DB Version Number.
6：收到无效的本文件LSP-DB版本号。
7: Received an invalid This document Speaker Entity Identifier.
7:收到无效的此文档说话人实体标识符。
IANA has allocated the following values in the "PCEP TLV Type Indicators" registry.
IANA已在“PCEP TLV类型指示器”注册表中分配了以下值。
Value Meaning Reference
------------------------- ----------------- -------------
23 LSP-DB-VERSION This document
24 SPEAKER-ENTITY-ID This document
Value Meaning Reference
------------------------- ----------------- -------------
23 LSP-DB-VERSION This document
24 SPEAKER-ENTITY-ID This document
The STATEFUL-PCE-CAPABILITY TLV is defined in [RFC8231]. The "STATEFUL-PCE-CAPABILITY TLV Flag Field" registry has been created to manage the flags in the TLV. IANA has allocated the following values in this registry.
[RFC8231]中定义了有状态PCE能力TLV。已创建“STATEFUL-PCE-CAPABILITY TLV标志字段”注册表来管理TLV中的标志。IANA已在此注册表中分配了以下值。
Bit Description Reference
-------------------------- -------------------------- -------------
26 TRIGGERED-INITIAL-SYNC This document
27 DELTA-LSP-SYNC-CAPABILITY This document
28 TRIGGERED-RESYNC This document
30 INCLUDE-DB-VERSION This document
Bit Description Reference
-------------------------- -------------------------- -------------
26 TRIGGERED-INITIAL-SYNC This document
27 DELTA-LSP-SYNC-CAPABILITY This document
28 TRIGGERED-RESYNC This document
30 INCLUDE-DB-VERSION This document
All manageability requirements and considerations listed in [RFC5440] and [RFC8231] apply to PCEP protocol extensions defined in this document. In addition, requirements and considerations listed in this section apply.
[RFC5440]和[RFC8231]中列出的所有可管理性要求和注意事项适用于本文件中定义的PCEP协议扩展。此外，本节中列出的要求和注意事项也适用。
A PCE or PCC implementation MUST allow configuring the State Synchronization optimization capabilities as described in this document. The implementation SHOULD also allow the operator to configure the Speaker Entity Identifier (Section 3.3.2). Further, the operator SHOULD be to be allowed to trigger the resynchronization procedures as per Section 6.2.
PCE或PCC实现必须允许配置本文档中描述的状态同步优化功能。实施还应允许操作员配置扬声器实体标识符（第3.3.2节）。此外，应允许操作员根据第6.2节触发重新同步程序。
An implementation SHOULD allow the operator to view the stateful capabilities advertised by each peer and the current synchronization status with each peer. To serve this purpose, the PCEP YANG module [PCEP-YANG] can be extended to include advertised stateful capabilities and synchronization status.
实现应允许操作员查看每个对等机公布的有状态功能以及每个对等机的当前同步状态。为了达到这一目的，可以扩展PCEP-YANG模块[PCEP-YANG]，以包括公布的有状态功能和同步状态。
Mechanisms defined in this document do not imply any new liveness detection and monitoring requirements in addition to those already listed in [RFC5440].
除了[RFC5440]中已经列出的机制外，本文件中定义的机制并不意味着任何新的活性检测和监测要求。
Mechanisms defined in this document do not imply any new operation verification requirements in addition to those already listed in [RFC5440] and [RFC8231].
除了[RFC5440]和[RFC8231]中已经列出的机制外，本文件中定义的机制并不意味着任何新的操作验证要求。
Mechanisms defined in this document do not imply any new requirements on other protocols.
本文件中定义的机制并不意味着对其他协议有任何新的要求。
Mechanisms defined in [RFC5440] and [RFC8231] also apply to PCEP extensions defined in this document.
[RFC5440]和[RFC8231]中定义的机制也适用于本文档中定义的PCEP扩展。
The State Synchronization optimizations described in this document 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 session is re-established. The ability to trigger resynchronization 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 session.
在重新建立PCEP会话时，本文档中描述的状态同步优化可减少交换的数据量和有状态PCE完全运行所需的时间。操作员可以利用PCE触发重新同步的能力来检查其状态，并在不中断会话的情况下从任何状态不匹配中恢复。
The security considerations listed in [RFC8231] apply to this document as well. However, this document also introduces some new attack vectors. An attacker could spoof the SPEAKER-ENTITY-ID and pretend to be another PCEP speaker. An attacker may flood the PCC with triggered resynchronization requests at a rate that exceeds the PCC's ability to process them by either spoofing messages or compromising the PCE itself. The PCC can respond with a PCErr message as described in Section 6.2 and terminate the session. Thus, securing the PCEP session using Transport Layer Security (TLS) [PCEPS], as per the recommendations and best current practices in [RFC7525], is RECOMMENDED. An administrator could also expose the Speaker Entity Identifier as part of the certificate, for the peer identity verification.
[RFC8231]中列出的安全注意事项也适用于本文档。但是，本文还介绍了一些新的攻击向量。攻击者可以欺骗SPEAKER-ENTITY-ID并假装是另一个PCEP扬声器。攻击者可以通过欺骗消息或破坏PCE本身，以超过PCC处理这些请求能力的速率向PCC发送触发的重新同步请求。PCC可以按照第6.2节所述使用PCErr消息进行响应，并终止会话。因此，建议按照[RFC7525]中的建议和最佳当前实践，使用传输层安全性（TLS）[PCEP]保护PCEP会话。管理员还可以公开说话人实体标识符作为证书的一部分，用于对等身份验证。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，DOI 10.17487/RFC2119，1997年3月<https://www.rfc-editor.org/info/rfc2119>.
[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, <https://www.rfc-editor.org/info/rfc5440>.
[RFC5440]Vasseur，JP.，Ed.和JL。Le Roux主编，“路径计算元件（PCE）通信协议（PCEP）”，RFC 5440，DOI 10.17487/RFC5440，2009年3月<https://www.rfc-editor.org/info/rfc5440>.
[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>.
[RFC8174]Leiba，B.，“RFC 2119关键词中大写与小写的歧义”，BCP 14，RFC 8174，DOI 10.17487/RFC8174，2017年5月<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>.
[RFC8231]Crabbe，E.，Minei，I.，Medved，J.，和R.Varga，“有状态PCE的路径计算元素通信协议（PCEP）扩展”，RFC 8231，DOI 10.17487/RFC82312017年9月<http://www.rfc-editor.org/info/rfc8231>.
[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.
[PCEP-YANG]杜迪，D.，哈德威克，J.，比拉姆，V.，和J。jefftant@gmail.com，“路径计算元件通信协议（PCEP）的YANG数据模型”，正在进行的工作，草稿-ietf-pce-PCEP-YANG-052017年7月。
[PCEPS] Lopez, D., Dios, O., Wu, Q., and D. Dhody, "Secure Transport for PCEP", Work in Progress, draft-ietf-pce-pceps-18, September 2017.
[PCEP]Lopez，D.，Dios，O.，Wu，Q.，和D.Dhody，“PCEP的安全运输”，正在进行的工作，草案-ietf-pce-PCEPS-18，2017年9月。
[RFC7525] Sheffer, Y., Holz, R., and P. Saint-Andre, "Recommendations for Secure Use of Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)", BCP 195, RFC 7525, DOI 10.17487/RFC7525, May 2015, <https://www.rfc-editor.org/info/rfc7525>.
[RFC7525]Sheffer，Y.，Holz，R.，和P.Saint Andre，“安全使用传输层安全性（TLS）和数据报传输层安全性（DTLS）的建议”，BCP 195，RFC 7525，DOI 10.17487/RFC7525，2015年5月<https://www.rfc-editor.org/info/rfc7525>.
[RFC8051] Zhang, X., Ed. and I. Minei, Ed., "Applicability of a Stateful Path Computation Element (PCE)", RFC 8051, DOI 10.17487/RFC8051, January 2017, <https://www.rfc-editor.org/info/rfc8051>.
[RFC8051]Zhang，X.，Ed.和I.Minei，Ed.“有状态路径计算元素（PCE）的适用性”，RFC 8051，DOI 10.17487/RFC8051，2017年1月<https://www.rfc-editor.org/info/rfc8051>.
Acknowledgments
致谢
We would like to thank Young Lee, Sergio Belotti, and Cyril Margaria for their comments and discussions.
我们要感谢Young Lee、Sergio Belotti和Cyril Margaria的评论和讨论。
Thanks to Jonathan Hardwick for being the document shepherd and providing comments and guidance.
感谢Jonathan Hardwick担任文档管理员并提供评论和指导。
Thanks to Tomonori Takeda for the Routing Area Directorate review.
多亏武田友野进行了路由区域董事会审查。
Thanks to Adrian Farrel for the TSVART review and providing detailed comments and suggestions.
感谢Adrian Farrel对TSVART的审查，并提供了详细的意见和建议。
Thanks to Daniel Franke for the SECDIR review.
感谢Daniel Franke的SECDIR评论。
Thanks to Alvaro Retana, Kathleen Moriarty, and Stephen Farrell for comments during the IESG evaluation.
感谢Alvaro Retana、Kathleen Moriarty和Stephen Farrell在IESG评估期间的评论。
Thanks to Deborah Brungard for being the responsible AD and guiding the authors as needed.
感谢Deborah Brungard作为负责任的广告，并根据需要指导作者。
Contributors
贡献者
Gang Xie Huawei Technologies F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District Shenzhen, Guangdong, 518129 China Email: xiegang09@huawei.com
谢刚中国广东省深圳市龙岗区坂田华为工业基地华为技术F3-5-B研发中心邮编：518129电子邮件：xiegang09@huawei.com
Authors' Addresses
作者地址
Edward Crabbe Oracle Email: edward.crabbe@gmail.com
爱德华·克拉布-甲骨文电子邮件：爱德华。crabbe@gmail.com
Ina Minei Google, Inc. 1600 Amphitheatre Parkway Mountain View, CA 94043 United States of America Email: inaminei@google.com
Ina Minei Google，Inc.1600圆形剧场公园路山景，加利福尼亚州94043美利坚合众国电子邮件：inaminei@google.com
Jan Medved Cisco Systems, Inc. 170 West Tasman Dr. San Jose, CA 95134 United States of America Email: jmedved@cisco.com
Jan Medved Cisco Systems，Inc.170 West Tasman Dr.San Jose，CA 95134美利坚合众国电子邮件：jmedved@cisco.com
Robert Varga Pantheon Technologies SRO Mlynske Nivy 56 Bratislava 821 05 Slovakia Email: robert.varga@pantheon.tech
罗伯特·瓦尔加万神殿科技公司SRO Mlynske Nivy 56布拉迪斯拉发821 05斯洛伐克电子邮件：罗伯特。varga@pantheon.tech
Xian Zhang Huawei Technologies F3-5-B R&D Center, Huawei Industrial Base, Bantian, Longgang District Shenzhen, Guangdong 518129 China Email: zhang.xian@huawei.com
中国广东省深圳市龙岗区坂田华为工业基地华为技术F3-5-B研发中心邮编：518129电子邮件：张。xian@huawei.com
Dhruv Dhody Huawei Technologies Divyashree Techno Park, Whitefield Bangalore, Karnataka 560066 India Email: dhruv.ietf@gmail.com
Dhruv Dhody华为技术部门位于卡纳塔克邦班加罗尔怀特菲尔德科技园，邮编560066，印度电子邮件：Dhruv。ietf@gmail.com