Internet Engineering Task Force (IETF)                          D. Dhody
Request for Comments: 9168                           Huawei Technologies
Category: Standards Track                                      A. Farrel
ISSN: 2070-1721                                       Old Dog Consulting
                                                                   Z. Li
                                                     Huawei Technologies
                                                            January 2022

Path Computation Element Communication Protocol (PCEP) Extension for Flow Specification




The Path Computation Element (PCE) is a functional component capable of selecting paths through a traffic engineering (TE) network. These paths may be supplied in response to requests for computation or may be unsolicited requests issued by the PCE to network elements. Both approaches use the PCE Communication Protocol (PCEP) to convey the details of the computed path.


Traffic flows may be categorized and described using "Flow Specifications". RFC 8955 defines the Flow Specification and describes how Flow Specification components are used to describe traffic flows. RFC 8955 also defines how Flow Specifications may be distributed in BGP to allow specific traffic flows to be associated with routes.

トラフィックフローは、「フロー仕様」を使用して分類および説明することができる。RFC 8955はフロー仕様を定義し、トラフィックフローを説明するためにフロー仕様コンポーネントを使用する方法を説明します。RFC 8955はまた、特定のトラフィックフローをルートに関連付けることを可能にするためにBGPでフローの仕様を分散させる方法を定義します。

This document specifies a set of extensions to PCEP to support dissemination of Flow Specifications. This allows a PCE to indicate what traffic should be placed on each path that it is aware of.


The extensions defined in this document include the creation, update, and withdrawal of Flow Specifications via PCEP and can be applied to tunnels initiated by the PCE or to tunnels where control is delegated to the PCE by the Path Computation Client (PCC). Furthermore, a PCC requesting a new path can include Flow Specifications in the request to indicate the purpose of the tunnel allowing the PCE to factor this into the path computation.


Status of This Memo


This is an Internet Standards Track document.


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.

この文書はインターネットエンジニアリングタスクフォース(IETF)の製品です。IETFコミュニティのコンセンサスを表します。それはパブリックレビューを受け、インターネットエンジニアリングステアリンググループ(IESG)による出版の承認を受けました。インターネット規格に関する詳細情報は、RFC 7841のセクション2で利用できます。

Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at


Copyright Notice


Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved.

著作権(c)2022 IETF信頼と文書の著者として識別された人。全著作権所有。

This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents ( 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 Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License.

この文書は、この文書の公開日に有効なIETF文書(に関するBCP 78およびIETF信頼の法的規定の対象となります。この文書に関してあなたの権利と制限を説明するので、これらの文書をよくレビューしてください。この文書から抽出されたコードコンポーネントには、信託法定規定のセクション4。

Table of Contents


   1.  Introduction
   2.  Terminology
   3.  Procedures for PCE Use of Flow Specifications
     3.1.  Context for PCE Use of Flow Specifications
     3.2.  Elements of the Procedure
       3.2.1.  Capability Advertisement  PCEP Open Message  IGP PCE Capabilities Advertisement
       3.2.2.  Dissemination Procedures
       3.2.3.  Flow Specification Synchronization
   4.  PCE FlowSpec Capability TLV
   5.  PCEP FLOWSPEC Object
   6.  Flow Filter TLV
   7.  Flow Specification TLVs
   8.  Detailed Procedures
     8.1.  Default Behavior and Backward Compatibility
     8.2.  Composite Flow Specifications
     8.3.  Modifying Flow Specifications
     8.4.  Multiple Flow Specifications
     8.5.  Adding and Removing Flow Specifications
     8.6.  VPN Identifiers
     8.7.  Priorities and Overlapping Flow Specifications
   9.  PCEP Messages
   10. IANA Considerations
     10.1.  PCEP Objects
       10.1.1.  PCEP FLOWSPEC Object Flag Field
     10.2.  PCEP TLV Type Indicators
     10.3.  Flow Specification TLV Type Indicators
     10.4.  PCEP Error Codes
     10.5.  PCE Capability Flag
   11. Security Considerations
   12. Manageability Considerations
     12.1.  Management of Multiple Flow Specifications
     12.2.  Control of Function through Configuration and Policy
     12.3.  Information and Data Models
     12.4.  Liveness Detection and Monitoring
     12.5.  Verifying Correct Operation
     12.6.  Requirements for Other Protocols and Functional Components
     12.7.  Impact on Network Operation
   13. References
     13.1.  Normative References
     13.2.  Informative References
   Authors' Addresses
1. Introduction
1. はじめに

[RFC4655] defines the Path Computation Element (PCE), a functional component capable of computing paths for use in traffic engineering networks. PCE was originally conceived for use in Multiprotocol Label Switching (MPLS) for traffic engineering (TE) networks to derive the routes of Label Switched Paths (LSPs). However, the scope of PCE was quickly extended to make it applicable to networks controlled by Generalized MPLS (GMPLS), and more recent work has brought other traffic engineering technologies and planning applications into scope (for example, Segment Routing (SR) [RFC8664]).

[RFC4655]トラフィックエンジニアリングネットワークで使用するためのパスを計算できる機能コンポーネントであるPATH計算要素(PCE)を定義します。PCEはもともと、トラフィックエンジニアリング(TE)ネットワークのためのマルチプロトコルラベルスイッチング(MPLS)での使用のために、ラベルスイッチパス(LSP)のルートを導出するために想定されていました。ただし、PCEの範囲は、一般化されたMPLS(GMPLS)によって制御されたネットワークに適用できるようにすばやく拡張され、最近の作業は他のトラフィック技術技術と計画アプリケーションを範囲にもたらしました(たとえば、Segment Routing(SR)[RFC8664])。

[RFC5440] describes the PCE Communication Protocol (PCEP). PCEP defines the communication between a Path Computation Client (PCC) and a PCE, or between PCE and PCE, enabling computation of the path for MPLS-TE LSPs.

[RFC5440] PCE通信プロトコル(PCE)について説明します。PCEPは、PATH計算クライアント(PCC)とPCE、またはPCEとPCEの間の通信を定義し、MPLS-TE LSPのパスの計算を可能にします。

Stateful PCE [RFC8231] specifies a set of extensions to PCEP to enable control of TE-LSPs by a PCE that retains state about the LSPs provisioned in the network (a stateful PCE). [RFC8281] describes the setup, maintenance, and teardown of LSPs initiated by a stateful PCE without the need for local configuration on the PCC, thus allowing for a dynamic network that is centrally controlled. [RFC8283] introduces the architecture for PCE as a central controller and describes how PCE can be viewed as a component that performs computation to place "flows" within the network and decide how these flows are routed.

ステートフルPCE [RFC8231]ネットワークでプロビジョニングされたLSP(ステートフルPCE)に関する状態を保持するPCEによってTE-LSPを制御できるようにするためのPCEPの一連の拡張子を指定します。[RFC8281]は、PCC上のローカル構成を必要とせずにステートフルPCEによって開始されたLSPのセットアップ、メンテナンス、および破損を説明しているため、中央制御されている動的ネットワークが可能になります。[RFC8283]は、PCEのアーキテクチャを中央コントローラとして紹介し、ネットワーク内で「フロー」を配置し、これらのフローをルーティングする方法を決定するコンポーネントとしてPCEを表示できる方法を説明します。

The description of traffic flows by the combination of multiple Flow Specification components and their dissemination as traffic flow specifications (Flow Specifications) is described for BGP in [RFC8955]. In BGP, a Flow Specification is comprised of traffic filtering rules and is associated with actions to perform on the packets that match the Flow Specification. The BGP routers that receive a Flow Specification can classify received packets according to the traffic filtering rules and can direct packets based on the associated actions.


When a PCE is used to initiate tunnels (such as TE-LSPs or SR paths) using PCEP, it is important that the head end of the tunnels understands what traffic to place on each tunnel. The data flows intended for a tunnel can be described using Flow Specification components. When PCEP is in use for tunnel initiation, it makes sense for that same protocol to be used to distribute the Flow Specification components that describe what data is to flow on those tunnels.


This document specifies a set of extensions to PCEP to support dissemination of Flow Specification components. We term the description of a traffic flow using Flow Specification components as a "Flow Specification". This term is conceptually the same as the term used in [RFC8955]; however, no mechanism is provided to distribute an action associated with the Flow Specification because there is only one action that is applicable in the PCEP context (that is, directing the matching traffic to the identified LSP).


The extensions defined in this document include the creation, update, and withdrawal of Flow Specifications via PCEP and can be applied to tunnels initiated by the PCE or to tunnels where control is delegated to the PCE by the PCC. Furthermore, a PCC requesting a new path can include Flow Specifications in the request to indicate the purpose of the tunnel allowing the PCE to factor this into the path computation.


Flow Specifications are carried in TLVs within a new object called the FLOWSPEC object defined in this document. The flow filtering rules indicated by the Flow Specifications are mainly defined by BGP Flow Specifications.


Note that PCEP-installed Flow Specifications are intended to be installed only at the head end of the LSP to which they direct traffic. It is acceptable (and potentially desirable) that other routers in the network have Flow Specifications installed that match the same traffic but direct it onto different routes or to different LSPs. Those other Flow Specifications may be installed using the PCEP extensions defined in this document, distributed using BGP per [RFC8955], or configured using manual operations. Since this document is about PCEP-installed Flow Specifications, those other Flow Specifications at other routers are out of scope. In this context, however, it is worth noting that changes to the wider routing system (such as the distribution and installation of BGP Flow Specifications, or fluctuations in the IGP link state database) might mean that traffic matching the PCEP Flow Specification never reaches the head end of the LSP at which the PCEP Flow Specification has been installed. This may or may not be desirable according to the operator's traffic engineering and routing policies and is particularly applicable at LSPs that do not have their head ends at the ingress edge of the network, but it is not an effect that this document seeks to address.

PCEPインストールされたフローの仕様は、トラフィックを直接転送するLSPの先頭にのみインストールされることを目的としています。ネットワーク内の他のルータには、同じトラフィックに一致するが異なるルートまたはさまざまなLSPに直接アクセスするフロー仕様がインストールされていることが許容される(そして潜在的に望ましい)。これらの他のフロー仕様は、この文書で定義されているPCEP拡張機能を使用してインストールされ、RFC8955]ごとにBGPを使用するか、手動操作を使用して構成されている場合があります。この文書はPCEPインストールされたフロー仕様についてのものですので、他のルータの他のフロー仕様は範囲外です。しかしながら、これに関連して、より広いルーティングシステム(BGPフローの仕様の分布とインストール、またはIGPリンク状態データベースの変動など)の変更は、PCEPフロー仕様に合ったトラフィックが届かないことを意味する可能性があることが注目に値します。 PCEPフロー仕様がインストールされているLSPの先端。これは、オペレータのトラフィックエンジニアリングおよびルーティングポリシーに従って、または望ましくない場合があり、それらのヘッドがネットワークの入力エッジで終わらないLSPで特に適用可能であるかもしれませんが、この文書が対処しようとする効果はありません。

2. Terminology
2. 用語

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.

この文書のキーワード "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", および "OPTIONAL" はBCP 14 [RFC2119] [RFC8174]で説明されているように、すべて大文字の場合にのみ解釈されます。

This document uses the following terms defined in [RFC5440]: PCC, PCE, and PCEP Peer.


The following term from [RFC8955] is used frequently throughout this document:


   |  A Flow Specification is an n-tuple consisting of several matching
   |  criteria that can be applied to IP traffic.  A given IP packet is
   |  said to match the defined Flow Specification if it matches all the
   |  specified criteria.

[RFC8955] also states that "[a] given Flow Specification may be associated with a set of attributes" and that "...attributes can be used to encode a set of predetermined actions." However, in the context of this document, no action is explicitly specified as associated with the Flow Specification since the action of forwarding all matching traffic onto the associated path is implicit.

[RFC8955] "[A]が与えられたフロー仕様が一連の属性と関連付けられている可能性があると述べています。ただし、このドキュメントのコンテキストでは、すべての一致するトラフィックを関連パスに転送するアクションが暗黙的にあるため、フロー仕様に関連付けられているとおりに明示的に指定されていません。

How an implementation decides to filter traffic that matches a Flow Specification does not form part of this specification, but a flag is provided to indicate whether the sender of a PCEP message that includes a Flow Specification intends it to be installed as a Longest Prefix Match (LPM) route or as a Flow Specification policy.


This document uses the terms "stateful PCE" and "active PCE" as advocated in [RFC7399].


3. Procedures for PCE Use of Flow Specifications
3. フロー仕様のPCE使用の手順
3.1. Context for PCE Use of Flow Specifications
3.1. PCEフロー仕様のコンテキスト

In the PCE architecture, there are five steps in the setup and use of LSPs:


1. Decide which LSPs to set up. The decision may be made by a user, by a PCC, or by the PCE. There can be a number of triggers for this, including user intervention and dynamic response to changes in traffic demands.

1. どのLSPを設定するかを決定します。決定は、ユーザ、PCCによって、またはPCEによって行われてもよい。ユーザーの介入とトラフィック要求の変化に対する動的応答など、これには多くのトリガーがあります。

2. Decide what properties to assign to an LSP. This can include bandwidth reservations, priorities, and the Differentiated Services Code Point (DSCP) (i.e., MPLS Traffic Class field). This function is also determined by user configuration or in response to predicted or observed traffic demands.

2. LSPに割り当てるプロパティを決定します。これには、帯域幅の予約、優先順位、および微分サービスコードポイント(DSCP)(すなわち、MPLSトラフィッククラスフィールド)を含めることができます。この関数は、ユーザ構成または予測または観察されたトラフィック要求に応答しても決定される。

3. Decide what traffic to put on the LSP. This is effectively determining which traffic flows to assign to which LSPs; practically, this is closely linked to the first two decisions listed above.

3. LSPにどのトラフィックをかけるかを決めます。これは、どのトラフィックがどのLSPに割り当てるかを有効に決定しています。実際には、これは上記の最初の2つの決定と密接に関連しています。

4. Cause the LSP to be set up and modified to have the right characteristics. This will usually involve the PCE advising or instructing the PCC at the head end of the LSP, and the PCC will then signal the LSP across the network.

4. LSPを設定して正しい特性を持つように変更します。これは通常、PCEがLSPの先端にPCCを指示するか、PCCがネットワークを介してLSPを通知します。

5. Tell the head end of the LSP what traffic to put on the LSP. This may happen after or at the same time as the LSP is set up. This step is the subject of this document.

5. LSPの先頭にLSPにどのトラフィックをかけるかを指示します。これは、LSPが設定されている後と同時に発生する可能性があります。このステップはこの文書の主題です。

3.2. Elements of the Procedure
3.2. 手順の要素

There are three elements in the procedure:


1. A PCE and a PCC must be able to indicate whether or not they support the use of Flow Specifications.

1. PCEとPCCは、フロー仕様の使用をサポートしているかどうかを示すことができなければなりません。

2. A PCE or PCC must be able to include Flow Specifications in PCEP messages with a clear understanding of the applicability of those Flow Specifications in each case. This includes whether the use of such information is mandatory, constrained, or optional and how overlapping Flow Specifications will be resolved.

2. PCEまたはPCCは、それぞれの場合のフロー仕様の適用性を明確に理解して、PCEPメッセージ内のフロー仕様を含めることができなければなりません。これには、そのような情報の使用が必須、制約、またはオプションであり、フロー仕様がどのように解決されるかを含みます。

3. Flow Specification information/state must be synchronized between PCEP peers so that, on recovery, the peers have the same understanding of which Flow Specifications apply just as is required in the case of stateful PCE and LSP delegation (see Section 5.6 of [RFC8231]).

3. フロー仕様情報/状態は、リカバリ時に、復旧時に同様のフロー仕様が同じ理解があるので、ステートフルPCEおよびLSPの委任の場合と同じ理解を有するように、PCEPピア間で同期させる必要があります([RFC8231]のセクション5.6を参照)。。

The following subsections describe these points.


3.2.1. Capability Advertisement
3.2.1. 機能広告

As with most PCEP capability advertisements, the ability to support Flow Specifications can be indicated in the PCEP Open message or in IGP PCE capability advertisements.

ほとんどのPCEP機能広告と同様に、フロー仕様をサポートする機能は、PCEPオープンメッセージまたはIGP PCE機能広告に表示できます。 PCEP Open Message PCEPオープンメッセージ

During PCEP session establishment, a PCC or PCE that supports the procedures described in this document announces this fact by including the PCE FlowSpec Capability TLV (described in Section 4) in the OPEN object carried in the PCEP Open message.

PCEPセッション確立中に、この文書に記載されている手順をサポートするPCCまたはPCEは、PCEのオープンメッセージで運ばれるOpenオブジェクトのPCE Flowspec Capability TLV(セクション4で説明されている)を含めることで、この事実を発表します。

The presence of the PCE FlowSpec Capability TLV in the OPEN object in a PCE's Open message indicates that the PCE can distribute FlowSpecs to PCCs and can receive FlowSpecs in messages from PCCs.

PCEの開いているメッセージ内のOpenオブジェクト内のPCE FlowSpec機能TLVの存在は、PCEがPCCSにFlowspecを配布できることを示し、PCCからのメッセージでFlowspecsを受信できます。

The presence of the PCE FlowSpec Capability TLV in the OPEN object in a PCC's Open message indicates that the PCC supports the FlowSpec functionality described in this document.

PCCのOpenメッセージ内のOpenオブジェクト内のPCE FlowSpec Capability TLVの存在は、PCCがこのドキュメントで説明されているフロースペック機能をサポートしていることを示しています。

If either one of a pair of PCEP peers does not include the PCE FlowSpec Capability TLV in the OPEN object in its Open message, then the other peer MUST NOT include a FLOWSPEC object in any PCEP message sent to the peer. If a FLOWSPEC object is received when support has not been indicated, the receiver will respond with a PCErr message reporting the objects containing the FlowSpec as described in [RFC5440]: that is, it will use "Unknown Object" if it does not support this specification and "Not supported object" if it supports this specification but has not chosen to support FLOWSPEC objects on this PCEP session.

Open Message内のOpenオブジェクト内のPCE Flowspec Capability TLVのペアのどちらにも含まれていない場合、他のピアはピアに送信されたPCEPメッセージにFlowspecオブジェクトを含めてはいけません。サポートが示されていないときにFlowSpecオブジェクトを受信した場合、受信者は[RFC5440]で説明されているようにFlowspecを含むオブジェクトを報告するPCerrメッセージで応答します。つまり、これはサポートされていない場合は「不明なオブジェクト」を使用します。この仕様をサポートするが、このPCEPセッションでFlowspecオブジェクトをサポートするように選択していない場合は指定と「サポートされていません」。 IGP PCE Capabilities Advertisement IGP PCE機能の広告

The ability to advertise support for PCEP and PCE features in IGP advertisements is provided for OSPF in [RFC5088] and for IS-IS in [RFC5089]. The mechanism uses the PCE Discovery TLV, which has a PCE-CAP-FLAGS sub-TLV containing bit flags, each of which indicates support for a different feature.

IGP広告のPCEおよびPCE機能のサポートを宣伝する機能は、[RFC5088]でOSPFの場合は[RFC5089]に記載されています。このメカニズムはPCE検出TLVを使用します。これは、PCE-CAP-FLAGS SUB-TLVを含むビットフラグを持ち、それぞれが異なる機能のサポートを示します。

This document defines a new PCE-CAP-FLAGS sub-TLV bit, the FlowSpec Capable flag (bit number 16). Setting the bit indicates that an advertising PCE supports the procedures defined in this document.

このドキュメントでは、新しいPCE-CAPフラグSUB-TLVビット、Flowspec Capacedフラグ(ビット番号16)を定義します。ビットを設定すると、広告PCEがこのドキュメントで定義されている手順をサポートすることを示します。

Note that while PCE FlowSpec capability may be advertised during discovery, PCEP speakers that wish to use Flow Specification in PCEP MUST negotiate PCE FlowSpec capability during PCEP session setup, as specified in Section A PCC MAY initiate PCE FlowSpec capability negotiation at PCEP session setup even if it did not receive any IGP PCE capability advertisement, and a PCEP peer that advertised support for FlowSpec in the IGP is not obliged to support these procedures on any given PCEP session.

PCE Flowspec機能が発見中にアドバタイズされる可能性があるが、PCEPでフロー仕様を使用したいPCEPスピーカーは、セクション3.2.1.1で規定されているように、PCEPセッション設定中にPCEフロースピーピー機能をネゴシエートする必要があります。PCCは、IGP PCE機能広告を受信しなかった場合でもPCE Flowspec機能のネゴシエーションを開始し、IGP内のFlowspecのサポートをアドバタイズしたPCEPピアは、任意の特定のPCEPセッションでこれらの手順をサポートする義務を負いません。

3.2.2. Dissemination Procedures
3.2.2. 播種手続き

This section describes the procedures to support Flow Specifications in PCEP messages.


The primary purpose of distributing Flow Specification information is to allow a PCE to indicate to a PCC what traffic it should place on a path (such as an LSP or an SR path). This means that the Flow Specification may be included in:


* PCInitiate messages so that an active PCE can indicate the traffic to place on a path at the time that the PCE instantiates the path.

* PCEがPCEがパスをインスタンス化する時点で、Active PCEがパス上に配置するトラフィックを示すことができるようにメッセージを偽装します。

* PCUpd messages so that an active PCE can indicate or change the traffic to place on a path that has already been set up.

* Active PCEが、すでに設定されているパス上で配置するトラフィックを表示または変更できるように、PCUPDメッセージ。

* PCRpt messages so that a PCC can report the traffic that the PCC will place on the path.

* PCCがPCCがパス上に配置されるトラフィックを報告できるように、PCRPTメッセージ。

* PCReq messages so that a PCC can indicate what traffic it plans to place on a path when it requests that the PCE perform a computation in case that information aids the PCE in its work.

* PCCは、PCEがPCEがPCEをAIDSにAIDSの場合、PCEが計算を実行するように、PCEが計算を実行する場合にPCCがどのトラフィックを配置するかを示すことができます。

* PCRep messages so that a PCE that has been asked to compute a path can suggest which traffic could be placed on a path that a PCC may be about to set up.

* パスを計算するように求められたPCEがPCCが設定しようとしている可能性があるパスにどのトラフィックを配置できるかを示唆しています。

* PCErr messages so that issues related to paths and the traffic they carry can be reported to the PCE by the PCC and problems with other PCEP messages that carry Flow Specifications can be reported.

* PCRESおよびトラフィックに関連する問題がPCCによってPCEに報告されるようにPCERRメッセージは、フロー仕様を搬送する他のPCEPメッセージに関する問題を報告することができます。

To carry Flow Specifications in PCEP messages, this document defines a new PCEP object called the "PCEP FLOWSPEC object". The object is OPTIONAL in the messages described above and MAY appear more than once in each message.

フロー仕様を携帯するためにPCEPメッセージでは、このドキュメントは「PCEP Flowspecオブジェクト」という新しいPCEPオブジェクトを定義します。オブジェクトは上記のメッセージでオプションであり、各メッセージに複数回表示されることがあります。

To describe a traffic flow, the PCEP FLOWSPEC object carries a Flow Filter TLV.

トラフィックフローを説明するために、PCEP FlowSpecオブジェクトはフローフィルタTLVを搬送します。

The inclusion of multiple PCEP FLOWSPEC objects allows multiple traffic flows to be placed on a single path.

複数のPCEP FlowSpecオブジェクトを含めることで、複数のトラフィックフローを単一のパスに配置できます。

Once a PCE and PCC have established that they can both support the use of Flow Specifications in PCEP messages, such information may be exchanged at any time for new or existing paths.


The application and prioritization of Flow Specifications are described in Section 8.7.


As per [RFC8231], any attributes of the path received from a PCE are subject to the PCC's local policy. This holds true for the Flow Specifications as well.


3.2.3. Flow Specification Synchronization
3.2.3. フロー仕様同期

The Flow Specifications are carried along with the LSP state information as per [RFC8231], making the Flow Specifications part of the LSP database (LSP-DB). Thus, the synchronization of the Flow Specification information is done as part of LSP-DB synchronization. This may be achieved using normal state synchronization procedures as described in [RFC8231] or enhanced state synchronization procedures as defined in [RFC8232].

フロー仕様は、LSP状態情報とともに[RFC8231]と共に運ばれ、LSPデータベース(LSP-DB)のフロー仕様部分を作成します。したがって、フロー仕様情報の同期は、LSP - DB同期の一部として行われる。[RFC8232]で説明されている[RFC8232]で定義されているような「RFC8231」または拡張状態の同期手順で説明されているように、通常の状態同期手順を使用して実現できます。

The approach selected will be implementation and deployment specific and will depend on issues such as how the databases are constructed and what level of synchronization support is needed.


4. PCE FlowSpec Capability TLV
4. PCE Flowspec機能TLV

The PCE-FLOWSPEC-CAPABILITY TLV is an optional TLV that can be carried in the OPEN object [RFC5440] to exchange the PCE FlowSpec capabilities of the PCEP speakers.

PCE-Flowspec-Capability TLVは、Open Object [RFC5440]で実行できるオプションのTLVです.PCEPスピーカーのPCE FlowSpec機能を交換します。

The format of the PCE-FLOWSPEC-CAPABILITY TLV follows the format of all PCEP TLVs as defined in [RFC5440] and is shown in Figure 1.

PCE-Flowspec-Capability TLVのフォーマットは、[RFC5440]で定義されているすべてのPCEP TLVの形式に従います。

    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=51               |          Length=2             |
   |           Value=0             |          Padding              |



The type of the PCE-FLOWSPEC-CAPABILITY TLV is 51, and it has a fixed length of 2 octets. The Value field MUST be set to 0 and MUST be ignored on receipt. The two bytes of padding MUST be set to zero and ignored on receipt.

PCE Flowspec-Capability TLVの種類は51で、固定長が2オクテットです。値フィールドは0に設定する必要があり、受信時に無視する必要があります。2バイトのパディングはゼロに設定され、受信時に無視されなければなりません。

The inclusion of this TLV in an OPEN object indicates that the sender can perform FlowSpec handling as defined in this document.


5. PCEP Flowspecオブジェクト

The PCEP FLOWSPEC object defined in this document is compliant with the PCEP object format defined in [RFC5440]. It is OPTIONAL in the PCReq, PCRep, PCErr, PCInitiate, PCRpt, and PCUpd messages and MAY be present zero, one, or more times. Each instance of the object specifies a separate traffic flow.

このドキュメントで定義されているPCEP FlowSpecオブジェクトは、[RFC5440]で定義されているPCEPオブジェクト形式に準拠しています。PCREQ、PCREP、PCERR、PCINITIATE、PCRPT、およびPCUPDメッセージではオプションです。ゼロ、1、またはもっと存在する場合があります。オブジェクトの各インスタンスは別のトラフィックフローを指定します。

The PCEP FLOWSPEC object MAY carry a FlowSpec filter rule encoded in a Flow Filter TLV as defined in Section 6.

PCEP FlowSpecオブジェクトは、セクション6で定義されているフローフィルタTLVでエンコードされたフロースペックフィルタ規則を搬送することができる。

The FLOWSPEC Object-Class is 43 (to be assigned by IANA).


The FLOWSPEC Object-Type is 1.


The format of the body of the PCEP FLOWSPEC object is shown in Figure 2.

PCEP FlowSpecオブジェクトの本体のフォーマットを図2に示します。

    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
   |                            FS-ID                              |
   |         AFI                   |  Reserved     |   Flags   |L|R|
   |                                                               |
   //                             TLVs                            //
   |                                                               |

Figure 2: PCEP FLOWSPEC Object Body Format

図2:PCEP Flowspecオブジェクト本体フォーマット

FS-ID (32 bits): A PCEP-specific identifier for the FlowSpec information. A PCE or PCC creates an FS-ID for each FlowSpec that it originates, and the value is unique within the scope of that PCE or PCC and is constant for the lifetime of a PCEP session. All subsequent PCEP messages can identify the FlowSpec using the FS-ID. The values 0 and 0xFFFFFFFF are reserved and MUST NOT be used. Note that [NUMERIC-IDS-SEC] gives advice on assigning transient numeric identifiers such as the FS-ID so as to minimize security risks.


AFI (16 bits): Address Family Identifier as used in BGP [RFC4760] (AFI=1 for IPv4 or VPNv4, AFI=2 for IPv6 and VPNv6 as per [RFC8956]).

AFI(16ビット):BGP [RFC4760]で使用されているアドレスファミリID(IPv4またはVPNV4の場合はAFI = 1、IPv6、VPNV6の場合はAFI = 2、RFC8956)。

Reserved (8 bits): MUST be set to zero on transmission and ignored on receipt.


Flags (8 bits): Two flags are currently assigned:


R bit: The Remove bit is set when a PCEP FLOWSPEC object is included in a PCEP message to indicate removal of the Flow Specification from the associated tunnel. If the bit is clear, the Flow Specification is being added or modified.

Rビット:PCEP FlowspecオブジェクトがPCEPメッセージに含まれているときに、removeビットが設定され、関連するトンネルからのフロー仕様の削除を示す。ビットがクリアされている場合、フロー仕様は追加または変更されています。

L bit: The Longest Prefix Match (LPM) bit is set to indicate that the Flow Specification is to be installed as a route subject to LPM forwarding. If the bit is clear, the Flow Specification described by the Flow Filter TLV (see Section 6) is to be installed as a Flow Specification. If the bit is set, only Flow Specifications that describe IPv4 or IPv6 destinations are meaningful in the Flow Filter TLV, and others are ignored. If the L is set and the receiver does not support the use of Flow Specifications that are present in the Flow Filter TLV for the installation of a route subject to LPM forwarding, then the PCEP peer MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 5 (Unsupported LPM Route).


Unassigned bits MUST be set to zero on transmission and ignored on receipt.


If the PCEP speaker receives a message with the R bit set in the FLOWSPEC object and the Flow Specification identified with an FS-ID does not exist, it MUST generate a PCErr with Error-Type 30 (FlowSpec Error) and Error-value 4 (Unknown FlowSpec).


If the PCEP speaker does not understand or support the AFI in the FLOWSPEC message, the PCEP peer MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 2 (Malformed FlowSpec).

PCEPスピーカーがFlowspecメッセージ内のAFIを理解していないかサポートしていない場合、PCEPピアはError-Type 30(Flowspecエラー)とエラー値2(不正なフロースピーピー)でPCERRメッセージで応答する必要があります。

The following TLVs can be used in the FLOWSPEC object:


Speaker Entity Identifier TLV: As specified in [RFC8232], the SPEAKER-ENTITY-ID TLV encodes a unique identifier for the node that does not change during the lifetime of the PCEP speaker. This is used to uniquely identify the FlowSpec originator and thus is used in conjunction with the FS-ID to uniquely identify the FlowSpec information. This TLV MUST be included. If the TLV is missing, the PCEP peer MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 2 (Malformed FlowSpec). If more than one instance of this TLV is present, the first MUST be processed, and subsequent instances MUST be ignored.

スピーカーエンティティ識別子TLV:[RFC8232]で指定されているように、Speaker-Entity-ID TLVは、PCEPスピーカーの存続期間中に変化しないノードの一意の識別子をエンコードします。これはFlowspec発信者を一意に識別するために使用され、したがってFS-IDと組み合わせて使用され、フローペック情報を一意に識別します。このTLVを含める必要があります。TLVが欠落している場合、PCEPピアは、ERROR-TYPE 30(FLOWSPECエラー)とエラー値2(不正なFlowspec)を使用してPCERRメッセージで応答する必要があります。このTLVの複数のインスタンスが存在する場合は、最初に処理する必要があり、後続のインスタンスは無視される必要があります。

Flow Filter TLV (variable): One TLV MAY be included. The Flow Filter TLV is OPTIONAL when the R bit is set.


The Flow Filter TLV MUST be present when the R bit is clear. If the TLV is missing when the R bit is clear, the PCEP peer MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 2 (Malformed FlowSpec).

RビットがクリアされているときにフローフィルタTLVが存在する必要があります。RビットがクリアされているときにTLVが見つからない場合、PCEPピアはError-Type 30(Flowspecエラー)とエラー値2(不正なフロースピーピー)でPCERRメッセージで応答する必要があります。

Filtering based on the L2 fields is out of scope of this document.


6. Flow Filter TLV
6. フローフィルタTLV

One new PCEP TLV is defined to convey Flow Specification filtering rules that specify what traffic is carried on a path. The TLV follows the format of all PCEP TLVs as defined in [RFC5440]. The Type field values come from the code point space for PCEP TLVs and has the value 52 for Flow Filter TLV.

1つの新しいPCEP TLVは、パス上でトラフィックが実行されているトラフィックを指定するフロー仕様フィルタリングルールを伝達するように定義されています。TLVは[RFC5440]で定義されているすべてのPCEP TLVの形式に従います。タイプフィールド値はPCEP TLVのコードポイントスペースから取得され、フローフィルタTLVの値52を持ちます。

The Value field of the TLV contains one or more sub-TLVs (the Flow Specification TLVs) as defined in Section 7, and they represent the complete definition of a Flow Specification for traffic to be placed on the tunnel. This tunnel is indicated by the PCEP message in which the PCEP FLOWSPEC object is carried. The set of Flow Specification TLVs in a single instance of a Flow Filter TLV is combined to indicate the specific Flow Specification. Note that the PCEP FLOWSPEC object can include just one Flow Filter TLV.

TLVの値フィールドには、セクション7で定義されている1つ以上のサブTLV(フロー仕様TLV)が含まれており、トンネルに配置されるトラフィックのフロー仕様の完全な定義を表します。このトンネルは、PCEP FlowSpecオブジェクトが搭載されているPCEPメッセージによって示されます。フローフィルタTLVの単一のインスタンス内のフロー仕様TLVのセットを組み合わせて、特定のフロー仕様を示す。PCEP FlowSpecオブジェクトは、1つのフローフィルタTLVだけを含めることができます。

Further Flow Specifications can be included in a PCEP message by including additional FLOWSPEC objects.


In the future, there may be a desire to add support for L2 Flow Specifications (such as described in [BGP-L2VPN]).


7. Flow Specification TLVs
7. フロー仕様TLVS

The Flow Filter TLV carries one or more Flow Specification TLVs. The Flow Specification TLV follows the format of all PCEP TLVs as defined in [RFC5440]. However, the Type values are selected from a separate IANA registry (see Section 10.3) rather than from the common PCEP TLV registry.

フローフィルタTLVは1つ以上のフロー仕様TLVを搬送する。フロー仕様TLVは、[RFC5440]で定義されているすべてのPCEP TLVの形式に従います。ただし、Common PCEP TLVレジストリからではなく、タイプ値は別のIANAレジストリ(セクション10.3を参照)から選択されます。

Type values are chosen so that there can be commonality with Flow Specifications defined for use with BGP [RFC8955] [RFC8956]. This is possible because the BGP Flow Spec encoding uses a single octet to encode the type, whereas PCEP uses 2 octets. Thus, the space of values for the Type field is partitioned as shown in Table 1.

タイプ値は、BGP [RFC8955] [RFC8956]で使用するために定義されたフロー仕様との共通性があるように選択されます。これは、BGP Flow Specエンコーディングがタイプをエンコードするために単一のオクテットを使用しているため、これは可能ですが、PCEPは2オクテットを使用します。したがって、Typeフィールドの値のスペースは表1に示すように分割されます。

           | Range     | Description                           |
           | 0-255     | Per BGP Flow Spec registry defined by |
           |           | [RFC8955] and [RFC8956].              |
           |           |                                       |
           |           | Not to be allocated in this registry. |
           | 256-65535 | New PCEP Flow Specifications          |
           |           | allocated according to the registry   |
           |           | defined in this document.             |

Table 1: Flow Specification TLV Type Ranges


[RFC8955] is the reference for the "Flow Spec Component Types" registry and defines the allocations it contains. [RFC8956] requested the creation of the "Flow Spec IPv6 Component Types" registry, as well as its initial allocations. If the AFI (in the FLOWSPEC object) is set to IPv4, the range 0..255 is as per "Flow Spec Component Types" [RFC8955]; if the AFI is set to IPv6, the range 0..255 is as per "Flow Spec IPv6 Component Types" [RFC8956].

[RFC8955] "Flow Spec Component Types"レジストリの参照で、それが含む割り当てを定義します。[RFC8956]「フロー仕様IPv6コンポーネントタイプ」レジストリ、および初期割り当ての作成を要求しました。AFI(FlowSpecオブジェクト内の)がIPv4に設定されている場合、0..255の範囲は「Flow Spec Component Types」(RFC8955]と同じです。AFIがIPv6に設定されている場合、0..255の範囲は「Flow Spec IPv6コンポーネントタイプ」と同じです[RFC8956]。

The content of the Value field in each TLV is specific to the type/ AFI and describes the parameters of the Flow Specification. The definition of the format of many of these Value fields is inherited from BGP specifications. Specifically, the inheritance is from [RFC8955] and [RFC8956], but it may also be inherited from future BGP specifications.

各TLVの値フィールドの内容はTYPE / AFIに固有のもので、フロー仕様のパラメータを記述します。これらの値フィールドの多くのフォーマットの定義はBGP仕様から継承されています。具体的には、継承は[RFC8955]から[RFC8956]からのものですが、将来のBGP仕様から継承することもできます。

When multiple Flow Specification TLVs are present in a single Flow Filter TLV, they are combined to produce a more detailed specification of a flow. For examples and rules about how this is achieved, see [RFC8955]. As described in [RFC8955], where it says "A given component type MAY (exactly once) be present in the Flow Specification", a Flow Filter TLV MUST NOT contain more than one Flow Specification TLV of the same type: an implementation that receives a PCEP message with a Flow Filter TLV that contains more than one Flow Specification TLV of the same type MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 2 (Malformed FlowSpec) and MUST NOT install the Flow Specification.


An implementation that receives a PCEP message carrying a Flow Specification TLV with a type value that it does not recognize or support MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 1 (Unsupported FlowSpec) and MUST NOT install the Flow Specification.

Flow Specification TLVを受信した実装は、エラータイプ30(Flowspecエラー)およびエラー値1(サポートされていないフロースピーピー)を使用してPCERRメッセージで応答する必要があります。フロー仕様をインストールしてください。

When used in other protocols (such as BGP), these Flow Specifications are also associated with actions to indicate how traffic matching the Flow Specification should be treated. In PCEP, however, the only action is to associate the traffic with a tunnel and to forward matching traffic onto that path, so no encoding of an action is needed.


Section 8.7 describes how overlapping Flow Specifications are prioritized and handled.


All Flow Specification TLVs with Types in the range 0 to 255 have values defined for use in BGP (for example, in [RFC8955] and [RFC8956]) and are set using the BGP encoding but without the type octet (the relevant information is in the Type field of the TLV). The Value field is padded with trailing zeros to achieve 4-byte alignment.


This document defines the following new types:


   | Type | Description         | Value Defined In |
   | 256  | Route Distinguisher | RFC 9168         |
   | 257  | IPv4 Multicast Flow | RFC 9168         |
   | 258  | IPv6 Multicast Flow | RFC 9168         |

Table 2: Flow Specification TLV Types Defined in this Document


To allow identification of a VPN in PCEP via a Route Distinguisher (RD) [RFC4364], a new TLV, ROUTE-DISTINGUISHER TLV, is defined in this document. A Flow Specification TLV with Type 256 (ROUTE-DISTINGUISHER TLV) carries an RD value, which is used to identify that other flow filter information (for example, an IPv4 destination prefix) is associated with a specific VPN identified by the RD. See Section 8.6 for further discussion of VPN identification.


    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=256            |           Length=8            |
   |                     Route Distinguisher                       |
   |                                                               |

Figure 3: The Format of the ROUTE-DISTINGUISHER TLV

図3:ルート識別usuisher TLVの形式

The format of the RD is as per [RFC4364].


Although it may be possible to describe a multicast Flow Specification from the combination of other Flow Specification TLVs with specific values, it is more convenient to use a dedicated Flow Specification TLV. Flow Specification TLVs with Type values 257 and 258 are used to identify a multicast flow for IPv4 and IPv6, respectively. The Value field is encoded as shown in Figure 4.


    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
   |        Reserved           |S|G|  Src Mask Len | Grp Mask Len  |
   ~                        Source Address                         ~
   ~                   Group multicast Address                     ~

Figure 4: Multicast Flow Specification TLV Encoding


The address fields and address mask lengths of the two Multicast Flow Specification TLVs contain source and group prefixes for matching against packet flows. Note that the two address fields are 32 bits for an IPv4 Multicast Flow and 128 bits for an IPv6 Multicast Flow.


The Reserved field MUST be set to zero and ignored on receipt.


Two bit flags (S and G) are defined to describe the multicast wildcarding in use. If the S bit is set, then source wildcarding is in use, and the values in the Source Mask Length and Source Address fields MUST be ignored. If the G bit is set, then group wildcarding is in use, and the values in the Group Mask Length and Group multicast Address fields MUST be ignored. The G bit MUST NOT be set unless the S bit is also set: if a Multicast Flow Specification TLV is received with S bit = 0 and G bit = 1, the receiver MUST respond with a PCErr with Error-Type 30 (FlowSpec Error) and Error-value 2 (Malformed FlowSpec).

2ビットフラグ(SとG)は、使用中のマルチキャストワイルドカードを説明するために定義されています。Sビットが設定されている場合は、ソースのワイルドカードが使用されていますが、ソースマスクの長さと送信元アドレスフィールドの値は無視される必要があります。Gビットが設定されている場合は、グループワイルドカードが使用中で、グループマスク長およびグループマルチキャストアドレスフィールドの値を無視する必要があります。Sビットも設定されていない限り、Gビットを設定してはいけません。マルチキャストフロー仕様TLVがS BIT = 0とG BIT = 1で受信された場合、受信側はエラータイプ30のPCERRで応答する必要があります(Flowspecエラー)。error-value 2(不正なフロースピーピー)。

The three multicast mappings may be achieved as follows:


(S, G) - S bit = 0, G bit = 0, the Source Address and Group multicast Address prefixes are both used to define the multicast flow.

(S、G) - S BIT = 0、G BIT = 0、送信元アドレスとグループマルチキャストアドレスプレフィックスは両方ともマルチキャストフローを定義するために使用されます。

(*, G) - S bit = 1, G bit = 0, the Group multicast Address prefix is used to define the multicast flow, but the Source Address prefix is ignored.

(*、g) - s bit = 1、gビット= 0、グループマルチキャストアドレスプレフィックスはマルチキャストフローを定義するために使用されますが、送信元アドレスプレフィックスは無視されます。

(*, *) - S bit = 1, G bit = 1, the Source Address and Group multicast Address prefixes are both ignored.

(*、*) - S bit = 1、G bit = 1、送信元アドレスとグループマルチキャストアドレスのプレフィックスはどちらも無視されます。

8. Detailed Procedures
8. 詳細な手順

This section outlines some specific detailed procedures for using the protocol extensions defined in this document.


8.1. Default Behavior and Backward Compatibility
8.1. デフォルトの動作と下位互換性

The default behavior is that no Flow Specification is applied to a tunnel. That is, the default is that the FLOWSPEC object is not used, as is the case in all systems before the implementation of this specification.


In this case, it is a local matter (such as through configuration) how tunnel head ends are instructed in terms of what traffic to place on a tunnel.


[RFC5440] describes how receivers respond when they see unknown PCEP objects.


8.2. Composite Flow Specifications
8.2. 複合フロー仕様

Flow Specifications may be represented by a single Flow Specification TLV or may require a more complex description using multiple Flow Specification TLVs. For example, a flow indicated by a source-destination pair of IPv6 addresses would be described by the combination of Destination IPv6 Prefix and Source IPv6 Prefix Flow Specification TLVs.


8.3. Modifying Flow Specifications
8.3. フロー仕様の変更

A PCE may want to modify a Flow Specification associated with a tunnel, or a PCC may want to report a change to the Flow Specification it is using with a tunnel.


It is important to identify the specific Flow Specification so it is clear that this is a modification of an existing flow and not the addition of a new flow as described in Section 8.4. The FS-ID field of the PCEP FLOWSPEC object is used to identify a specific Flow Specification in the context of the content of the Speaker Entity Identifier TLV.

特定のフロー仕様を識別することが重要ですので、これが既存のフローの修正であり、セクション8.4に記載されているような新しいフローの追加ではないことが明らかです。PCEP FlowSpecオブジェクトのFS-IDフィールドは、スピーカーエンティティ識別子TLVの内容のコンテキストで特定のフロー仕様を識別するために使用されます。

When modifying a Flow Specification, all Flow Specification TLVs for the intended specification of the flow MUST be included in the PCEP FLOWSPEC object. The FS-ID MUST be retained from the previous description of the flow, and the same Speaker Entity Identifier TLV MUST be used.

フロー仕様を変更するときは、フローの意図された指定のすべてのフロー仕様TLVをPCEP Flowspecオブジェクトに含める必要があります。FS-IDは、フローの前の説明から保持されなければならず、同じスピーカーエンティティ識別子TLVを使用する必要があります。

8.4. Multiple Flow Specifications
8.4. 複数のフロー仕様

It is possible that traffic from multiple flows will be placed on a single tunnel. In some cases, it is possible to define these within a single PCEP FLOWSPEC object by widening the scope of a Flow Specification TLV: for example, traffic to two destination IPv4 prefixes might be captured by a single Flow Specification TLV with type "Destination" with a suitably adjusted prefix. However, this is unlikely to be possible in most scenarios, and it must be recalled that it is not permitted to include two Flow Specification TLVs of the same type within one Flow Filter TLV.

複数のフローからのトラフィックが単一のトンネルに配置される可能性があります。場合によっては、フロー仕様TLVの範囲を広くすることで、単一のPCEP FlowSpecオブジェクト内でこれらを定義することが可能です。たとえば、2つの宛先IPv4プレフィックスへのトラフィックは、タイプ "宛先"タイプの単一のフロー仕様TLVによってキャプチャされる可能性があります。適切に調整された接頭辞。ただし、ほとんどのシナリオでは可能性が低くなる可能性があり、1つのフローフィルタTLV内に同じタイプの2つのフロー仕様TLVを含めることが許可されていないことを思い出す必要があります。

The normal procedure, therefore, is to carry each Flow Specification in its own PCEP FLOWSPEC object. Multiple objects may be present on a single PCEP message, or multiple PCEP messages may be used.

したがって、通常の手順は、各フロー仕様を独自のPCEP FlowSpecオブジェクトに搬送することです。複数のオブジェクトが単一のPCEPメッセージに存在している可能性があります。または複数のPCEPメッセージを使用できます。

8.5. Adding and Removing Flow Specifications
8.5. フロー仕様の追加と削除

The Remove bit in the PCEP FLOWSPEC object is left clear when a Flow Specification is being added or modified.

PCEP FlowSpecオブジェクトの除去ビットは、フロー指定が追加または変更されているときにクリアされます。

To remove a Flow Specification, a PCEP FLOWSPEC object is included with the FS-ID matching the one being removed, and the R bit is set to indicate removal. In this case, it is not necessary to include any Flow Specification TLVs.


If the R bit is set and Flow Specification TLVs are present, an implementation MAY ignore them. If the implementation checks the Flow Specification TLVs against those recorded for the FS-ID and Speaker Entity Identifier of the Flow Specification being removed and finds a mismatch, the Flow Specification matching the FS-ID MUST still be removed, and the implementation SHOULD record a local exception or log.


8.6. VPN Identifiers
8.6. VPN識別子

VPN instances are identified in BGP using RDs [RFC4364]. These values are not normally considered to have any meaning outside of the network, and they are not encoded in data packets belonging to the VPNs. However, RDs provide a useful way of identifying VPN instances and are often manually or automatically assigned to VPNs as they are provisioned.

VPNインスタンスは、RDS [RFC4364]を使用してBGPで識別されます。これらの値は、通常、ネットワークの外部に意味があると見なされ、VPNに属するデータパケットには符号化されていません。ただし、RDSはVPNインスタンスを識別するための便利な方法を提供し、プロビジョニングされているときに手動でまたは自動的にVPNに割り当てられます。

Thus, the RD provides a useful way to indicate that traffic for a particular VPN should be placed on a given tunnel. The tunnel head end will need to interpret this Flow Specification not as a filter on the fields of data packets but rather using the other mechanisms that it already uses to identify VPN traffic. These mechanisms could be based on the incoming port (for port-based VPNs) or may leverage knowledge of the VPN Routing and Forwarding (VRF) that is in use for the traffic.


8.7. Priorities and Overlapping Flow Specifications
8.7. 優先順位と重複するフロー仕様

Flow Specifications can overlap. For example, two different Flow Specifications may be identical except for the length of the prefix in the destination address. In these cases, the PCC must determine how to prioritize the Flow Specifications so as to know which path to assign packets that match both Flow Specifications. That is, the PCC must assign a precedence to the Flow Specifications so that it checks each incoming packet for a match in a predictable order.


The processing of BGP Flow Specifications is described in [RFC8955]. Section 5.1 of that document explains the order of traffic filtering rules to be executed by an implementation of that specification.


PCCs MUST apply the same ordering rules as defined in [RFC8955].


Furthermore, it is possible that Flow Specifications will be distributed by BGP as well as by PCEP as described in this document. In such cases, implementations supporting both approaches MUST apply the prioritization and ordering rules as set out in [RFC8955] regardless of which protocol distributed the Flow Specifications. However, implementations MAY provide a configuration control to allow one protocol to take precedence over the other; this may be particularly useful if the Flow Specifications make identical matches on traffic but have different actions. It is RECOMMENDED that a message be logged for the operator to understand the behavior when two Flow Specifications distributed by different protocols overlap, especially when one acts to replace another.


Section 12.1 of this document covers manageability considerations relevant to the prioritized ordering of Flow Specifications.


An implementation that receives a PCEP message carrying a Flow Specification that it cannot resolve against other Flow Specifications already installed (for example, because the new Flow Specification has irresolvable conflicts with other Flow Specifications that are already installed) MUST respond with a PCErr message with Error-Type 30 (FlowSpec Error) and Error-value 3 (Unresolvable Conflict) and MUST NOT install the Flow Specification.

既にインストールされている他のフロー仕様に対して解決できないフロー仕様を載せるPCEPメッセージを受信する実装(たとえば、新しいフロー仕様はすでにインストールされている他のフロー仕様との矛盾不可能な競合があるため)は、エラーのあるPCERRメッセージで応答する必要があります。-type 30(Flowspecエラー)とエラー値3(解除可能な競合)およびフロー仕様をインストールしてはいけません。

9. PCEP Messages
9. PCEPメッセージ

This section describes the format of messages that contain FLOWSPEC objects. The only difference from previous message formats is the inclusion of that object.


The figures in this section use the notation defined in [RFC5511].


The FLOWSPEC object is OPTIONAL and MAY be carried in the PCEP messages.


The PCInitiate message is defined in [RFC8281] and updated as below:


   <PCInitiate Message> ::= <Common Header>
      <PCE-initiated-lsp-list> ::= <PCE-initiated-lsp-request>
      <PCE-initiated-lsp-request> ::=
                                    ( <PCE-initiated-lsp-instantiation>|
                                      <PCE-initiated-lsp-deletion> )
      <PCE-initiated-lsp-instantiation> ::= <SRP>
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]

The PCUpd message is defined in [RFC8231] and updated as below:


   <PCUpd Message> ::= <Common Header>
      <update-request-list> ::= <update-request>
      <update-request> ::= <SRP>
         <path>::= <intended-path><intended-attribute-list>
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]

The PCRpt message is defined in [RFC8231] and updated as below:


   <PCRpt Message> ::= <Common Header>
      <state-report-list> ::= <state-report>[<state-report-list>]
      <state-report> ::= [<SRP>]
         <path>::= <intended-path>
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]

The PCReq message is defined in [RFC5440] and updated in [RFC8231]; it is further updated below for a Flow Specification:


   <PCReq Message>::= <Common Header>
      <svec-list>::= <SVEC>[<svec-list>]
      <request-list>::= <request>[<request-list>]
      <request>::= <RP>
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]

The PCRep message is defined in [RFC5440] and updated in [RFC8231]; it is further updated below for a Flow Specification:


   <PCRep Message> ::= <Common Header>
         <flowspec-list> ::= <FLOWSPEC> [<flowspec-list>]
10. IANA Considerations
10. IANAの考慮事項

This document requests that IANA allocate code points for the protocol elements defined in this document.


10.1. PCEP Objects
10.1. PCEPオブジェクト

IANA maintains a subregistry called "PCEP Objects" within the "Path Computation Element Protocol (PCEP) Numbers" registry. Each PCEP object has an Object-Class and an Object-Type, and IANA has allocated new code points in this subregistry as follows:


   | Object-Class Value | Name     | Object-Type           | Reference |
   | 43                 | FLOWSPEC | 0: Reserved           | RFC 9168  |
   |                    |          +-----------------------+-----------+
   |                    |          | 1: Flow               | RFC 9168  |
   |                    |          | Specification         |           |

Table 3: PCEP Objects Subregistry Additions


10.1.1. PCEP FLOWSPEC Object Flag Field
10.1.1. PCEP Flowspecオブジェクトフラグフィールド

This document requests that a new subregistry, "FLOWSPEC Object Flag Field", be created within the "Path Computation Element Protocol (PCEP) Numbers" registry to manage the Flag field of the FLOWSPEC object. New values are to be assigned by Standards Action [RFC8126]. Each bit should be tracked with the following qualities:

このドキュメントは、FlowspecオブジェクトのFlagフィールドを管理するために、「Path Computation Element Protocol(PCEP)番号」の「PCEP演算要素プロトコル(PCEP)番号」内で作成され、「Flowspec Object Flag Flagフィールド」を要求します。新しい値は標準アクション[RFC8126]によって割り当てられます。各ビットは以下の資質で追跡されるべきです。

* Bit number (counting from bit 0 as the most significant bit)

* ビット数(最上位ビットとしてビット0からのカウント)

* Capability description

* 機能の説明

* Defining RFC

* RFCを定義する

The initial population of this registry is as follows:


   | Bit | Description    | Reference |
   | 0-5 | Unassigned     |           |
   | 6   | LPM (L bit)    | RFC 9168  |
   | 7   | Remove (R bit) | RFC 9168  |

Table 4: Initial Contents of the FLOWSPEC Object Flag Field Registry


10.2. PCEP TLV Type Indicators
10.2. PCEP TLVタイプインジケータ

IANA maintains a subregistry called "PCEP TLV Type Indicators" within the "Path Computation Element Protocol (PCEP) Numbers" registry. IANA has made the following allocations in this subregistry:

IANAは、「PATH計算要素プロトコル(PCEP)番号」レジストリ内の「PCEP TLVタイプインジケータ」と呼ばれるサブレジストを管理しています。IANAはこのサブレジストに次の割り当てを行った。

   | Value | Description                 | Reference |
   | 51    | PCE-FLOWSPEC-CAPABILITY TLV | RFC 9168  |
   | 52    | FLOW FILTER TLV             | RFC 9168  |

Table 5: PCEP TLV Type Indicators Subregistry Additions

表5:PCEP TLVタイプ指標サブレジスト追加

10.3. Flow Specification TLV Type Indicators
10.3. フロー仕様TLVタイプインジケータ

IANA has created a new subregistry called "PCEP Flow Specification TLV Type Indicators" within the "Path Computation Element Protocol (PCEP) Numbers" registry.


Allocations from this registry are to be made according to the following assignment policies [RFC8126]:


   | Range       | Registration Procedures           |
   | 0-255       | Reserved - must not be allocated. |
   |             |                                   |
   |             | Usage mirrors the BGP Flow Spec   |
   |             | registry [RFC8955] [RFC8956].     |
   | 256-64506   | Specification Required            |
   | 64507-65531 | First Come First Served           |
   | 65532-65535 | Experimental Use                  |

Table 6: Registration Procedures for the PCEP Flow Specification TLV Type Indicators Subregistry


IANA has populated this registry with values defined in this document as follows, taking the new values from the range 256 to 64506:


   | Value | Meaning             |
   | 256   | Route Distinguisher |
   | 257   | IPv4 Multicast      |
   | 258   | IPv6 Multicast      |

Table 7: Initial Contents of the PCEP Flow Specification TLV Type Indicators Subregistry


10.4. PCEP Error Codes
10.4. PCEPエラーコード

IANA maintains a subregistry called "PCEP-ERROR Object Error Types and Values" within the "Path Computation Element Protocol (PCEP) Numbers" registry. Entries in this subregistry are described by Error-Type and Error-value. IANA has added the following assignment to this subregistry:


   | Error-Type | Meaning        | Error-value             | Reference |
   | 30         | FlowSpec error | 0: Unassigned           | RFC 9168  |
   |            |                +-------------------------+-----------+
   |            |                | 1: Unsupported          | RFC 9168  |
   |            |                | FlowSpec                |           |
   |            |                +-------------------------+-----------+
   |            |                | 2: Malformed            | RFC 9168  |
   |            |                | FlowSpec                |           |
   |            |                +-------------------------+-----------+
   |            |                | 3: Unresolvable         | RFC 9168  |
   |            |                | Conflict                |           |
   |            |                +-------------------------+-----------+
   |            |                | 4: Unknown              | RFC 9168  |
   |            |                | FlowSpec                |           |
   |            |                +-------------------------+-----------+
   |            |                | 5: Unsupported          | RFC 9168  |
   |            |                | LPM Route               |           |
   |            |                +-------------------------+-----------+
   |            |                | 6-255:                  | RFC 9168  |
   |            |                | Unassigned              |           |

Table 8: PCEP-ERROR Object Error Types and Values Subregistry Additions


10.5. PCE Capability Flag
10.5. PCE機能の国旗

IANA has registered a new capability bit in the OSPF Parameters "Path Computation Element (PCE) Capability Flags" registry as follows:


   | Bit | Capability Description | Reference |
   | 16  | FlowSpec               | RFC 9168  |

Table 9: Path Computation Element (PCE) Capability Flags Registry Additions


11. Security Considerations
11. セキュリティに関する考慮事項

We may assume that a system that utilizes a remote PCE is subject to a number of vulnerabilities that could allow spurious LSPs or SR paths to be established or that could result in existing paths being modified or torn down. Such systems, therefore, apply security considerations as described in [RFC5440], Section 2.5 of [RFC6952], [RFC8253], and [RFC8955].


The description of Flow Specifications associated with paths set up or controlled by a PCE adds a further detail that could be attacked without tearing down LSPs or SR paths but causes traffic to be misrouted within the network. Therefore, the use of the security mechanisms for PCEP referenced above is important.


Visibility into the information carried in PCEP does not have direct privacy concerns for end users' data; however, knowledge of how data is routed in a network may make that data more vulnerable. Of course, the ability to interfere with the way data is routed also makes the data more vulnerable. Furthermore, knowledge of the connected endpoints (such as multicast receivers or VPN sites) is usually considered private customer information. Therefore, implementations or deployments concerned with protecting privacy MUST apply the mechanisms described in the documents referenced above, in particular, to secure the PCEP session using IPsec per Sections 10.4 to 10.6 of [RFC5440] or TLS per [RFC8253]. Note that TCP-MD5 security as originally suggested in [RFC5440] does not provide sufficient security or privacy guarantees and SHOULD NOT be relied upon.


Experience with Flow Specifications in BGP systems indicates that they can become complex and that the overlap of Flow Specifications installed in different orders can lead to unexpected results. Although this is not directly a security issue per se, the confusion and unexpected forwarding behavior may be engineered or exploited by an attacker. Furthermore, this complexity might give rise to a situation where the forwarding behaviors might create gaps in the monitoring and inspection of particular traffic or provide a path that avoids expected mitigations. Therefore, implementers and operators SHOULD pay careful attention to the manageability considerations described in Section 12 and familiarize themselves with the careful explanations in [RFC8955].


12. Manageability Considerations
12. 管理性の考慮事項

The feature introduced by this document enables operational manageability of networks operated in conjunction with a PCE and using PCEP. In the case of a stateful active PCE or with PCE-initiated services, in the absence of this feature, additional manual configuration is needed to tell the head ends what traffic to place on the network services (LSPs, SR paths, etc.).


This section follows the advice and guidance of [RFC6123].


12.1. Management of Multiple Flow Specifications
12.1. 複数のフロー仕様の管理

Experience with Flow Specification in BGP suggests that there can be a lot of complexity when two or more Flow Specifications overlap. This can arise, for example, with addresses indicated using prefixes and could cause confusion about what traffic should be placed on which path. Unlike the behavior in a distributed routing system, it is not important to the routing stability and consistency of the network that each head-end implementation applies the same rules to disambiguate overlapping Flow Specifications, but it is important that:


* a network operator can easily find out what traffic is being placed on which path and why. This will facilitate analysis of the network and diagnosis of faults.

* ネットワークオペレータはどのパスとその理由にどのトラフィックが配置されているかを簡単に見つけることができます。これにより、ネットワークの分析と障害の診断が容易になります。

* a PCE be able to correctly predict the effect of instructions it gives to a PCC. This will ensure that traffic is correctly placed on the network without causing congestion or other network inefficiencies and that traffic is correctly delivered.

* PCEは、PCCに与える指示の効果を正しく予測できるようになります。これにより、輻輳やその他のネットワークの非効率性を引き起こすことなく、トラフィックが正しくネットワーク上に配置され、そのトラフィックが正しく配信されます。

To that end, a PCC MUST enable an operator to view the Flow Specifications that it has installed, and these MUST be presented in order of precedence such that when two Flow Specifications overlap, the one that will be serviced with higher precedence is presented to the operator first.


A discussion of precedence ordering for Flow Specifications is found in Section 8.7.


12.2. Control of Function through Configuration and Policy
12.2. 構成とポリシーによる機能の制御

Support for the function described in this document implies that a functional element that is capable of requesting that a PCE compute and control a path is also able to configure the specification of what traffic should be placed on that path. Where there is a human involved in this action, configuration of the Flow Specification must be available through an interface (such as a graphical user interface or a Command Line Interface). Where a distinct software component (i.e., one not co-implemented with the PCE) is used, a protocol mechanism will be required that could be PCEP itself or a data model, such as extensions to the YANG model for requesting path computation [TEAS-YANG-PATH].


Implementations MAY be constructed with a configurable switch to indicate whether they support the functions defined in this document. Otherwise, such implementations MUST indicate that they support the function as described in Section 4. If an implementation allows configurable support of this function, that support MAY be configurable per peer or once for the whole implementation.


As mentioned in Section 12.1, a PCE implementation SHOULD provide a mechanism to configure variations in the precedence ordering of Flow Specifications per PCC.


12.3. Information and Data Models
12.3. 情報とデータモデル

The YANG model in [PCE-PCEP-YANG] can be used to model and monitor PCEP states and messages. To make that YANG model useful for the extensions described in this document, it would need to be augmented to cover the new protocol elements.


Similarly, as noted in Section 12.2, the YANG model defined in [TEAS-YANG-PATH] could be extended to allow the specification of Flow Specifications.


Finally, as mentioned in Section 12.1, a PCC implementation SHOULD provide a mechanism to allow an operator to read the Flow Specifications from a PCC and to understand in what order they will be executed. This could be achieved using a new YANG model.


12.4. Liveness Detection and Monitoring
12.4. 活性の検出と監視

The extensions defined in this document do not require any additional liveness detection and monitoring support. See [RFC5440] and [RFC5886] for more information.


12.5. Verifying Correct Operation
12.5. 正しい操作を確認する

The chief element of operation that needs to be verified (in addition to the operation of the protocol elements as described in [RFC5440]) is the installation, precedence, and correct operation of the Flow Specifications at a PCC.


In addition to the YANG model, for reading Flow Specifications described in Section 12.3, tools may be needed to inject Operations and Management (OAM) traffic at the PCC that matches specific criteria so that it can be monitored while traveling along the desired path. Such tools are outside the scope of this document.


12.6. Requirements for Other Protocols and Functional Components
12.6. 他のプロトコルと機能部品の要件

This document places no requirements on other protocols or components.


12.7. Impact on Network Operation
12.7. ネットワーク事業への影響

The use of the features described in this document clearly have an important impact on network traffic since they cause traffic to be routed on specific paths in the network. However, in practice, these changes make no direct changes to the network operation because traffic is already placed on those paths using some pre-existing configuration mechanism. Thus, the significant change is the reduction in mechanisms that have to be applied rather than a change to how the traffic is passed through the network.


13. References
13. 参考文献
13.1. Normative References
13.1. 引用文献

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <>.

[RFC2119] BRADNER、S、「RFCで使用するためのキーワード」、BCP 14、RFC 2119、DOI 10.17487 / RFC2119、1997年3月、<>。

[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006, <>.

[RFC4364] Rosen、E.およびY.Rekhter、「BGP / MPLS IP仮想プライベートネットワーク(VPNS)」、RFC 4364、DOI 10.17487 / RFC4364、2006年2月、< RFC4364>。

[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, "Multiprotocol Extensions for BGP-4", RFC 4760, DOI 10.17487/RFC4760, January 2007, <>.

[RFC4760]ベイツ、T.、Chandra、R.、Katz、D.、およびY。2007年1月、<https:// www。>。

[RFC5440] Vasseur, JP., Ed. and JL. Le Roux, Ed., "Path Computation Element (PCE) Communication Protocol (PCEP)", RFC 5440, DOI 10.17487/RFC5440, March 2009, <>.

[RFC5440] Vasseur、JP。、ED。そしてJL。Le Roux、Ed。、「PATH計算要素(PCE)通信プロトコル(PCEP)」、RFC 5440、DOI 10.17487 / RFC5440、2009年3月、<>。

[RFC5511] Farrel, A., "Routing Backus-Naur Form (RBNF): A Syntax Used to Form Encoding Rules in Various Routing Protocol Specifications", RFC 5511, DOI 10.17487/RFC5511, April 2009, <>.

[RFC5511] farrel、A。、「ルーティングバックス - ナウルフォーム(RBNF):様々なルーティングプロトコル仕様の符号化規則を形成するために使用される構文、RFC 5511、DOI 10.17487 / RFC5511、2009年4月、<https:// www。>。

[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <>.

[RFC8174] Leiba、B.、RFC 2119キーワードの「大文字の曖昧さ」、BCP 14、RFC 8174、DOI 10.17487 / RFC8174、2017年5月、<>。

[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, <>.

[RFC8231] Crabbe、E.、Minei、I.、Medved、J.、およびR. Varga、ステートフルPCEの「パス計算要素通信プロトコル(PCEP)拡張子」、RFC 8231、DOI 10.17487 / RFC8231、2017年9月、<>。

[RFC8232] Crabbe, E., Minei, I., Medved, J., Varga, R., Zhang, X., and D. Dhody, "Optimizations of Label Switched Path State Synchronization Procedures for a Stateful PCE", RFC 8232, DOI 10.17487/RFC8232, September 2017, <>.

[RFC8232] Crabbe、E.、Minei、I。、Medved、J.、Varga、R.、Zhang、X.、およびD.Dhody、「ラベルスイッチド経路の最適化:ステートフルPCEの最適化」、RFC 8232、DOI 10.17487 / RFC8232、2017年9月、<>。

[RFC8253] Lopez, D., Gonzalez de Dios, O., Wu, Q., and D. Dhody, "PCEPS: Usage of TLS to Provide a Secure Transport for the Path Computation Element Communication Protocol (PCEP)", RFC 8253, DOI 10.17487/RFC8253, October 2017, <>.

[RFC8253] Lopez、D.、Gonzalez de Dios、O.、Wu、Q.、およびD.D.Dhody、 "PCEP:パス計算要素通信プロトコル(PCEP)"、RFC 8253のための安全な輸送を提供するためのTLSの使用、DOI 10.17487 / RFC8253、2017年10月、<>。

[RFC8281] Crabbe, E., Minei, I., Sivabalan, S., and R. Varga, "Path Computation Element Communication Protocol (PCEP) Extensions for PCE-Initiated LSP Setup in a Stateful PCE Model", RFC 8281, DOI 10.17487/RFC8281, December 2017, <>.

[RFC8281] Crabbe、E.、Minei、I.、Sivabalan、S.、およびR. Varga、ステートフルPCEモデルにおけるPCE開始LSPセットアップのための「PCE - 経路計算要素通信プロトコル(PCE)拡張」、RFC 8281、DOI10.17487 / RFC8281、2017年12月、<>。

[RFC8955] Loibl, C., Hares, S., Raszuk, R., McPherson, D., and M. Bacher, "Dissemination of Flow Specification Rules", RFC 8955, DOI 10.17487/RFC8955, December 2020, <>.

[RFC8955] LOIBL、C.、HARES、S.、Raszuk、R.、McPherson、D.、およびM. Bacher、「フロー仕様規則の普及」、RFC 8955、DOI 10.17487 / RFC8955、2020年12月、<>。

[RFC8956] Loibl, C., Ed., Raszuk, R., Ed., and S. Hares, Ed., "Dissemination of Flow Specification Rules for IPv6", RFC 8956, DOI 10.17487/RFC8956, December 2020, <>.

[RFC8956] LOIBL、C、ED。、RASZUK、R.、ED。、およびS.HARES、ED。、「IPv6のフロー仕様規則の普及」、RFC 8956、DOI 10.17487 / RFC8956、2020年12月、<HTTPS//>。

13.2. Informative References
13.2. 参考引用

[BGP-L2VPN] Hao, W., Eastlake, D. E., Litkowski, S., and S. Zhuang, "BGP Dissemination of L2 Flow Specification Rules", Work in Progress, Internet-Draft, draft-ietf-idr-flowspec-l2vpn-18, 24 October 2021, <>.


[NUMERIC-IDS-SEC] Gont, F. and I. Arce, "Security Considerations for Transient Numeric Identifiers Employed in Network Protocols", Work in Progress, Internet-Draft, draft-gont-numeric-ids-sec-considerations-06, 5 December 2020, <>.

[Numeric-IDS-SEC] Gont、F.およびI. Arce、「ネットワークプロトコルで採用されている一時的な数値識別子のセキュリティ上の考慮事項」、進行中の作業、インターネットドラフト、ドラフトGont-Numeric-IDS-SEC-SEC-SEC-INTICATIONS-06、2020年12月5日、<>。

[PCE-PCEP-YANG] Dhody, D., Hardwick, J., Beeram, V. P., and J. Tantsura, "A YANG Data Model for Path Computation Element Communications Protocol (PCEP)", Work in Progress, Internet-Draft, draft-ietf-pce-pcep-yang-17, 23 October 2021, <>.

[PCE-PCEP-YANG] Dhody、D.、Hardwick、J.、Bearam、VP、J.Tantantura、「パス計算要素通信プロトコル(PCEP)のYangデータモデル」、進行中、インターネットドラフト、DRAFT-IETF-PCE-PCEP-YANG-17,2021、<>。

[RFC4655] Farrel, A., Vasseur, J.-P., and J. Ash, "A Path Computation Element (PCE)-Based Architecture", RFC 4655, DOI 10.17487/RFC4655, August 2006, <>.

[RFC4655] Farrel、A.、Vasseur、J.-P.およびJ.ASH、「Aパス計算要素(PCE)ベースのアーキテクチャ」、RFC 4655、DOI 10.17487 / RFC4655、2006年8月、<>。

[RFC5088] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. Zhang, "OSPF Protocol Extensions for Path Computation Element (PCE) Discovery", RFC 5088, DOI 10.17487/RFC5088, January 2008, <>.

[RFC5088] Le Roux、JL。、JP。、Vasseur、JP。、Ed。、Ikejiri、Y.、およびR. Zhang、 "PANS計算要素のためのOSPFプロトコル拡張(PCE)発見"、RFC 5088、DOI 10.17487 /RFC5088、2008年1月、<>。

[RFC5089] Le Roux, JL., Ed., Vasseur, JP., Ed., Ikejiri, Y., and R. Zhang, "IS-IS Protocol Extensions for Path Computation Element (PCE) Discovery", RFC 5089, DOI 10.17487/RFC5089, January 2008, <>.

[RFC5089] Le Roux、Jl。、JP。、Vasseur、JP。、Ikejiri、Y.、およびR.Zhang、 "IS-ISプロトコルのパス計算要素(PCE)ディスカバリの拡張"、RFC 5089、DOI10.17487 / RFC5089、2008年1月、<>。

[RFC5886] Vasseur, JP., Ed., Le Roux, JL., and Y. Ikejiri, "A Set of Monitoring Tools for Path Computation Element (PCE)-Based Architecture", RFC 5886, DOI 10.17487/RFC5886, June 2010, <>.

[RFC5886] Vasseur、JP、Ed。、Le Roux、JL、およびY.Ikejiri、「パス計算要素の一連の監視ツール(PCE)ベースのアーキテクチャ」、RFC 5886、DOI 10.17487 / RFC5886、2010年6月<>。

[RFC6123] Farrel, A., "Inclusion of Manageability Sections in Path Computation Element (PCE) Working Group Drafts", RFC 6123, DOI 10.17487/RFC6123, February 2011, <>.

[RFC6123] Farrel、A。、「経路計算要素(PCE)ワーキンググループのドラフト」、RFC 6123、DOI 10.17487 / RFC6123、2011年2月、< RFC6123>。

[RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of BGP, LDP, PCEP, and MSDP Issues According to the Keying and Authentication for Routing Protocols (KARP) Design Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, <>.

[RFC6952] Jethanandani、M.、Patel、K。、およびL.Zheng、「ルーティングプロトコルのためのキーイング・認証(KARP)設計ガイド」、RFC 6952、DOIによるBGP、LDP、PCE、およびMSDP問題の分析10.17487 / RFC6952、2013年5月、<>。

[RFC7399] Farrel, A. and D. King, "Unanswered Questions in the Path Computation Element Architecture", RFC 7399, DOI 10.17487/RFC7399, October 2014, <>.

[RFC7399] Farrel、A.およびD. King、「パス計算要素アーキテクチャにおける未回答の質問」、RFC 7399、DOI 10.17487 / RFC7399、2014年10月、<>。

[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, <>.

[RFC8126]コットン、M.、Leiba、B.およびT.Narten、「RFCSのIANAに関する考察のためのガイドライン」、BCP 26、RFC 8126、DOI 10.17487 / RFC8126、2017年6月、<https:// / info / rfc8126>。

[RFC8283] Farrel, A., Ed., Zhao, Q., Ed., Li, Z., and C. Zhou, "An Architecture for Use of PCE and the PCE Communication Protocol (PCEP) in a Network with Central Control", RFC 8283, DOI 10.17487/RFC8283, December 2017, <>.

[RFC8283] Farrel、A.、ED。、Zhao、Q。、ED。、LI、Z.、およびC.Zhou、「PCEの使用および中央制御を備えたネットワークのPCE通信プロトコル(PCE)のアーキテクチャ"、RFC 8283、DOI 10.17487 / RFC8283、2017年12月、<>。

[RFC8664] Sivabalan, S., Filsfils, C., Tantsura, J., Henderickx, W., and J. Hardwick, "Path Computation Element Communication Protocol (PCEP) Extensions for Segment Routing", RFC 8664, DOI 10.17487/RFC8664, December 2019, <>.

[RFC8664] Sivabalan、S.、Filsfils、C、Tantura、J.、Henderickx、W.、およびJ.Hormwick、セグメントルーティング用PATH計算要素通信プロトコル(PCE)拡張(PCE)、RFC 8664、DOI 10.17487 / RFC86642019年12月、<>。

[TEAS-YANG-PATH] Busi, I., Belotti, S., Lopez, V., Sharma, A., and Y. Shi, "YANG Data Model for requesting Path Computation", Work in Progress, Internet-Draft, draft-ietf-teas-yang-path-computation-16, 6 September 2021, <>.

[ティー - ヤンパス] BUSI、I。、S.、Lopez、V.、Sharma、A.、Y。Shi、「パス計算要求のためのYangデータモデル」、進捗状況、インターネットドラフト、Draft-Ietf-Teas-Yang-Path-Computation-16,2021、<>。



Thanks to Julian Lucek, Sudhir Cheruathur, Olivier Dugeon, Jayant Agarwal, Jeffrey Zhang, Acee Lindem, Vishnu Pavan Beeram, Julien Meuric, Deborah Brungard, Éric Vyncke, Erik Kline, Benjamin Kaduk, Martin Duke, Roman Danyliw, and Alvaro Retana for useful discussions and comments.

Julian Lucek、Sudhir Cheruathur、Jayant agarwal、Jayant Agarwal、Jeffrey Zhang、Jefreen Pavan Bearam、Julien Meuric、Deborah Brungard、Erien Kiduk、Martin Duke、Roman Danyyw、Alvaro Retana、Alvaro Retana、Alvaro Retana議論とコメント



Shankara Huawei Technologies Divyashree Techno Park, Whitefield Bangalore 560066 Karnataka India

Shankara Huawei Technologies Divyashree Techno Park、Whitefield Bangalore 560066 Karnataka India


Qiandeng Liang Huawei Technologies Yuhuatai District 101 Software Avenue, Nanjing, 210012 China

Qiandeng Liang Huawei Technologies Yuhuatai District 101ソフトウェアアベニュー、南京、210012中国


Cyril Margaria Juniper Networks 200 Somerset Corporate Boulevard, Suite 4001 Bridgewater, NJ 08807 United States of America

Cyril Margaria Juniper Networks 200 Somerset Corporate Boulevard、Suite 4001 Bridgewater、NJ 08807アメリカ合衆国


Colby Barth Juniper Networks 200 Somerset Corporate Boulevard, Suite 4001 Bridgewater, NJ 08807 United States of America

Colby Barth Juniper Networks 200 Somerset Corporate Boulevard、スイート4001 Bridgewater、NJ 08807アメリカ合衆国


Xia Chen Huawei Technologies Huawei Bld., No. 156 Beiqing Rd. Beijing, 100095 China

Xia Chen Huawei Technologies Huawei Bld、No.156北緯RD。北京、100095中国


Shunwan Zhuang Huawei Technologies Huawei Bld., No. 156 Beiqing Rd. Beijing, 100095 China

Shunwan Zhuang Huawei Technologies Huawei BLD、No.156北部RD。北京、100095中国


Cheng Li Huawei Technologies Huawei Campus, No. 156 Beiqing Rd. Beijing, 100095 China

Cheng Li Huawei Technologies Huawei Campus、156北部RD。北京、100095中国


Authors' Addresses


Dhruv Dhody Huawei Technologies Divyashree Techno Park, Whitefield Bangalore 560066 Karnataka India

Dhruv Dhody Huawei Technologies Divyashree Techno Park、Whitefield Bangalore 560066 Karnataka India


Adrian Farrel Old Dog Consulting



Zhenbin Li Huawei Technologies Huawei Bldg., No. 156 Beiqing Rd. Beijing 100095 China

Zhenbin Li Huawei Technologies Huawei Bldg、No.156 Beqing RD。北京100095中国