Internet Engineering Task Force (IETF)                     J. Brzozowski
Request for Comments: 8354                                      J. Leddy
Category: Informational                                          Comcast
ISSN: 2070-1721                                              C. Filsfils
                                                        R. Maglione, Ed.
                                                             M. Townsley
                                                           Cisco Systems
                                                              March 2018

Use Cases for IPv6 Source Packet Routing in Networking (SPRING)




The Source Packet Routing in Networking (SPRING) architecture describes how Segment Routing can be used to steer packets through an IPv6 or MPLS network using the source routing paradigm. This document illustrates some use cases for Segment Routing in an IPv6-only environment.


Status of This Memo


This document is not an Internet Standards Track specification; it is published for informational purposes.

このドキュメントはInternet Standards Trackの仕様ではありません。情報提供を目的として公開されています。

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). Not all documents approved by the IESG are candidates for any level of Internet Standard; see Section 2 of RFC 7841.

このドキュメントは、IETF(Internet Engineering Task Force)の製品です。これは、IETFコミュニティのコンセンサスを表しています。公開レビューを受け、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)による公開が承認されました。 IESGによって承認されたすべてのドキュメントが、あらゆるレベルのインターネット標準の候補であるとは限りません。 RFC 7841のセクション2をご覧ください。

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) 2018 IETF Trust and the persons identified as the document authors. All rights reserved.

Copyright(c)2018 IETF Trustおよびドキュメントの作成者として識別された人物。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 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.

この文書は、BCP 78およびIETF文書に関するIETFトラストの法的規定(の対象であり、この文書の発行日に有効です。これらのドキュメントは、このドキュメントに関するあなたの権利と制限を説明しているため、注意深く確認してください。このドキュメントから抽出されたコードコンポーネントには、Trust Legal Provisionsのセクション4.eに記載されているSimplified BSD Licenseのテキストが含まれている必要があり、Simplified BSD Licenseに記載されているように保証なしで提供されます。

Table of Contents


   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   3
   2.  IPv6 SPRING Use Cases . . . . . . . . . . . . . . . . . . . .   3
     2.1.  SPRING in the Small Office  . . . . . . . . . . . . . . .   3
     2.2.  SPRING in the Access Network  . . . . . . . . . . . . . .   4
     2.3.  SPRING in Data Center . . . . . . . . . . . . . . . . . .   5
     2.4.  SPRING in Content Delivery Networks . . . . . . . . . . .   5
     2.5.  SPRING in Core Networks . . . . . . . . . . . . . . . . .   6
   3.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   5.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     5.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     5.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   8
   Contributors  . . . . . . . . . . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   9
1. Introduction
1. はじめに

Source Packet Routing in Networking (SPRING) architecture leverages the source routing paradigm. An ingress node steers a packet by including a controlled set of instructions, called segments, in the SPRING header. The SPRING architecture is described in [SEGMENT-ROUTING]. This document illustrates some use cases for SPRING / Segment Routing in an IPv6-only environment.

ネットワーキングのソースパケットルーティング(SPRING)アーキテクチャは、ソースルーティングパラダイムを活用しています。入力ノードは、セグメントと呼ばれる制御された命令セットをSPRINGヘッダーに含めることにより、パケットを操作します。 SPRINGアーキテクチャは[SEGMENT-ROUTING]で説明されています。このドキュメントでは、IPv6のみの環境でのSPRING /セグメントルーティングのいくつかの使用例を示します。

2. IPv6 SPRING Use Cases
2. IPv6 SPRINGの使用例

The use cases described in this section do not constitute an exhaustive list of all the possible scenarios: this section only includes some of the most common envisioned deployment models for Segment Routing over IPv6 (SRv6).


In addition to the use cases described in this document, all the SPRING use cases [RFC7855] are also applicable to the SRv6 data plane.


2.1. SPRING in the Small Office
2.1. 小規模オフィスでのSPRING

An IPv6-enabled Small Office, Home Office (SOHO) provides ample globally routed IP addresses for all devices in the SOHO. An IPv6 small office with multiple egress points and associated provider-assigned prefixes will, in turn, provide multiple IPv6 addresses to hosts. A small office performing source and destination routing [PA-MULTIHOMING] will ensure that packets exit the SOHO at the appropriate egress based on the associated delegated prefix for that link.


A SPRING-enabled SOHO provides the ability to steer traffic into a specific path from end hosts in the SOHO or from a customer edge router in the SOHO. If the selection of the source-routed path is enabled at the customer edge router, that router is responsible for classifying traffic and steering it into the correct path. If hosts in the SOHO have explicit source selection rules, classification can be based on the source address or associated network egress point, thus avoiding the need for implicit classification techniques based on Deep Packet Inspection (DPI). If the traffic is steered into a specific path by the host itself, it is important to know which networks can interpret the SPRING header. This information can be provided as part of the host configuration as a property of the configured IP address.

SPRING対応のSOHOは、SOHOのエンドホストまたはSOHOのカスタマーエッジルーターから特定のパスにトラフィックを誘導する機能を提供します。ソースルーティングされたパスの選択がカスタマーエッジルーターで有効になっている場合、そのルーターはトラフィックを分類し、正しいパスにステアリングする責任があります。 SOHOのホストに明示的な送信元選択ルールがある場合、分類は送信元アドレスまたは関連するネットワーク出力ポイントに基づくことができるため、ディープパケットインスペクション(DPI)に基づく暗黙の分類手法の必要性を回避できます。トラフィックがホスト自体によって特定のパスに誘導される場合、どのネットワークがSPRINGヘッダーを解釈できるかを知ることが重要です。この情報は、構成済みIPアドレスのプロパティとしてホスト構成の一部として提供できます。

The ability to steer traffic to an appropriate egress or utilize a specific type of media (e.g., low power, Wi-Fi, wired, femtocell, Bluetooth, Multimedia over Coax Alliance (MoCA), HomePlug, etc.) within the home itself are obvious cases that may be of interest to an application running within a SOHO.

家庭内でトラフィックを適切な出口に誘導したり、特定のタイプのメディア(低電力、Wi-Fi、有線、フェムトセル、Bluetooth、Multimedia over Coax Alliance(MoCA)、HomePlugなど)を利用したりする機能は、 SOHO内で実行されているアプリケーションに関連する明らかなケース。

Steering to a specific egress point may be useful for a number of scenarios, including:


o regulatory compliance;

o 企業コンプライアンス;

o performance of a particular service associated with a particular link;

o 特定のリンクに関連付けられた特定のサービスのパフォーマンス。

o cost imposed due to data caps or per-byte charges;

o データの上限またはバイトごとの料金により課せられるコスト。

o distinguishing between personal vs. work traffic in homes with one or more teleworkers; and

o 1人以上の在宅勤務者がいる家庭での個人用トラフィックと仕事用トラフィックを区別する。そして

o provision of specific services by one ISP vs. another.

o ISPごとの特定のサービスの提供。

Information included in the SPRING header, whether imposed by the end host itself, a customer edge router, or within the access network of the ISP, may be of use at the far ends of the data communication as well. For example, an application running on an end host with application support in a data center can utilize the SPRING header as a channel to include information that affects its treatment within the data center itself, which allows for application-level steering and load balancing without relying upon implicit application-classification techniques at the edge of the data center. Further, as more and more application traffic is encrypted, the ability to extract (and include in the SPRING header) just enough information to enable the network and data center to load balance and steer traffic appropriately becomes more and more important.


2.2. SPRING in the Access Network
2.2. アクセスネットワークでのSPRING

Access networks deliver a variety of types of traffic from the service provider's network to the home environment and from the home towards the service provider's network.


For bandwidth management or related purposes, the service provider may want to associate certain types of traffic to specific physical or logical downstream capacity pipes.


This mapping is not the same thing as classification and scheduling. In the cable access network, these pipes are represented at the Data-Over-Cable Service Interface Specification [DOCSIS] layer as

このマッピングは、分類やスケジューリングと同じではありません。ケーブルアクセスネットワークでは、これらのパイプは、Data-Over-Cable Service Interface Specification [DOCSIS]レイヤーで次のように表されます。

different service flows, which are better identified as distinct data links. As such, creating this separation allows an operator to differentiate between different types of content and perform a variety of differing functions on these pipes, such as byte capping, regulatory compliance functions, and billing.


In a cable operator's environment, these downstream pipes could be a DOCSIS [DOCSIS] service flow, a service group, or a specific Quadrature Amplitude Modulation (QAM) as in Annex B of [ITU.J83].

ケーブル事業者の環境では、これらのダウンストリームパイプは、DOCSIS [DOCSIS]サービスフロー、サービスグル​​ープ、または[ITU.J83]の付録Bにあるような特定の直交振幅変調(QAM)です。

Similarly, the operator may want to map traffic from the home sent towards the service provider's network to specific upstream capacity pipes. Information carried in a packet's SPRING header could provide the target pipe for this specific packet. The access device would not need to know specific details about the packet to perform this mapping; instead, the access device would only need to know the interpretation of the SPRING header and how to map it to the target pipe.


2.3. SPRING in Data Center
2.3. データセンターの春

Some data center operators are transitioning their data center infrastructure from IPv4 to native IPv6 only, in order to cope with IPv4 address depletion and to achieve larger scale. In such an environment, source routing (as enabled by SRv6) can be used to steer traffic across specific paths through the network. The specific path may also include a given function that one or more nodes in the path are requested to perform.


Additionally, one of the fundamental requirements for data center architecture is to provide scalable, isolated tenant networks. In such scenarios, Segment Routing can be used to build a construct to steer the traffic across that specific path and to identify specific nodes, tenants, and functions.


2.4. SPRING in Content Delivery Networks
2.4. コンテンツ配信ネットワークでのSPRING

The rise of online video applications and new, video-capable IP devices has led to an explosion of video traffic traversing network operator infrastructures. In the drive to reduce the capital and operational impact of the massive influx of online video traffic, as well as to extend traditional TV services to new devices and screens, network operators are increasingly turning to Content Delivery Networks (CDNs).


Several studies showed the benefits of connecting caches in a hierarchical structure following the hierarchical nature of the Internet. In a cache hierarchy, one cache establishes peering relationships with its neighbor caches. There are two types of relationships: parent and sibling. A parent cache is essentially one level up in a cache hierarchy. A sibling cache is on the same level. Multiple levels of hierarchy are commonly used in order to build an efficient cache architecture.


In an environment where each single cache system can be uniquely identified by its own IPv6 address, a list containing a sequence of the caches in a hierarchy can be built. At each node (cache) in the list, the presence of the requested content is checked. If the requested content is found at the cache (a cache hits scenario), the sequence ends even if there are more nodes in the list; otherwise, the next element in the list (the next node/cache) is examined.


2.5. SPRING in Core Networks
2.5. コアネットワークでのSPRING

While the overall amount of traffic offered to the network continues to grow, and considering that multiple types of traffic with different characteristics and requirements are quickly converging over a single network architecture, the network operators are starting to face new challenges.


Some operators are currently building, or plan to build in the near future, an IPv6-only native infrastructure for their core network. These operators are also looking at the possibility to set up an explicit path based on the IPv6 source address for specific types of traffic in order to efficiently use their network infrastructure. In the case of IPv6, some operators are currently assigning or plan to assign IPv6 prefix(es) to their IPv6 customers based on regions/ geography, thus the subscriber's IPv6 prefix could be used to identify the region where the customer is located. In such an environment, the IPv6 source address could be used by the edge nodes of the network to steer traffic and forward it through a specific path other than the optimal path.

一部の事業者は現在、コアネットワーク用のIPv6のみのネイティブインフラストラクチャを構築しているか、近い将来構築する予定です。これらの事業者は、ネットワークインフラストラクチャを効率的に使用するために、特定のタイプのトラフィックのIPv6送信元アドレスに基づいて明示的なパスを設定する可能性も検討しています。 IPv6の場合、一部の事業者は現在、地域/地理に基づいてIPv6プレフィックスをIPv6顧客に割り当てている、または割り当てる予定です。したがって、加入者のIPv6プレフィックスを使用して、顧客が存在する地域を特定できます。このような環境では、ネットワークのエッジノードがIPv6送信元アドレスを使用してトラフィックを誘導し、最適なパス以外の特定のパスを介してトラフィックを転送できます。

The need to set up a source-based path that goes through some specific middle/intermediate points in the network may be related to different requirements:


o The operator may want to be able to use some high-bandwidth links for a specific type of traffic (like video) and thus avoid the need for overdimensioning all the links of the network;

o オペレーターは、特定のタイプのトラフィック(ビデオなど)にいくつかの高帯域幅リンクを使用できるようにして、ネットワークのすべてのリンクの寸法を大きくしなくても済むようにしたい場合があります。

o The operator may want to be able to set up a specific path for delay-sensitive applications;

o オペレーターは、遅延の影響を受けやすいアプリケーション用に特定のパスをセットアップできるようにしたい場合があります。

o The operator may have the need to be able to select one (or multiple) specific exit point(s) at peering points when different peering points are available;

o 異なるピアリングポイントが使用可能な場合、オペレーターはピアリングポイントで1つ(または複数)の特定の出口ポイントを選択できる必要がある場合があります。

o The operator may have the need to be able to set up a source-based path for specific services in order to be able to reach some servers hosted in some facilities that are not always reachable through the optimal path; or

o オペレーターは、特定のサービスのソースベースのパスを設定して、常に最適なパスでは到達できない施設でホストされているサーバーに到達できるようにする必要がある場合があります。または

o The operator may need to be able to provision guaranteed disjoint paths (a so-called "dual-plane network") for diversity purposes.

o 事業者は、ダイバーシティの目的で、保証されたばらばらのパス(いわゆる「デュアルプレーンネットワーク」)をプロビジョニングできる必要がある場合があります。

All these scenarios would require a form of traffic engineering capabilities in an IPv6-only network environment.


3. IANA Considerations
3. IANAに関する考慮事項

This document has no IANA actions.


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

This document presents use cases to be considered by the SPRING architecture and potential IPv6 extensions. As such, it does not introduce any security considerations. However, there are a number of security concerns with source routing at the IP layer [RFC5095]. It is expected that any solution that addresses these use cases also addresses any security concerns.


5. References
5. 参考文献
5.1. Normative References
5.1. 引用文献

[RFC7855] Previdi, S., Ed., Filsfils, C., Ed., Decraene, B., Litkowski, S., Horneffer, M., and R. Shakir, "Source Packet Routing in Networking (SPRING) Problem Statement and Requirements", RFC 7855, DOI 10.17487/RFC7855, May 2016, <>.

[RFC7855] Previdi、S.、Ed。、Filsfils、C.、Ed。、Decraene、B.、Litkowski、S.、Horneffer、M.、and R. Shakir、 "Source Packet Routing in Networking(SPRING)Problem Statementおよび要件」、RFC 7855、DOI 10.17487 / RFC7855、2016年5月、<>。

5.2. Informative References
5.2. 参考引用

[DOCSIS] CableLabs, "New Generation of DOCSIS Technology", October 2013, < new-generation-of-docsis-technology/>.

[DOCSIS] CableLabs、「新世代のDOCSISテクノロジー」、2013年10月、<>。

[ITU.J83] ITU-T, "Digital multi-programme systems for television, sound and data services or cable distribution", ITU-T Recommendation J.83, December 2007, <>.

[ITU.J83] ITU-T、「テレビ、音声およびデータサービスまたはケーブル配信用のデジタルマルチプログラムシステム」、ITU-T勧告J.83、2007年12月、< /T-REC-J.83/en>。

[PA-MULTIHOMING] Baker, F., Bowers, C., and J. Linkova, "Enterprise Multihoming using Provider-Assigned Addresses without Network Prefix Translation: Requirements and Solution", Work in Progress, draft-ietf-rtgwg-enterprise-pa-multihoming-03, February 2018.

[PA-MULTIHOMING] Baker、F.、Bowers、C。、およびJ. Linkova、「ネットワークプレフィックス変換なしでプロバイダーが割り当てたアドレスを使用したエンタープライズマルチホーミング:要件とソリューション」、Work in Progress、draft-ietf-rtgwg-enterprise- pa-multihoming-03、2018年2月。

[RFC5095] Abley, J., Savola, P., and G. Neville-Neil, "Deprecation of Type 0 Routing Headers in IPv6", RFC 5095, DOI 10.17487/RFC5095, December 2007, <>.

[RFC5095] Abley、J.、Savola、P。、およびG. Neville-Neil、「Deprecation of Type 0 Routing Headers in IPv6」、RFC 5095、DOI 10.17487 / RFC5095、2007年12月、<https://www.rfc>。

[SEGMENT-ROUTING] Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", Work in Progress, draft-ietf-spring-segment-routing-15, January 2018.

[セグメントルーティング] Filsfils、C.、Previdi、S.、Ginsberg、L.、Decraene、B.、Litkowski、S。、およびR. Shakir、「Segment Routing Architecture」、Work in Progress、draft-ietf-spring -segment-routing-15、2018年1月。



The authors would like to thank Brian Field, Robert Raszuk, Wes George, Eric Vyncke, Fred Baker, John G. Scudder, Adrian Farrel, Alvaro Retana, Bruno Decraene, and Yakov Rekhter for their valuable comments and inputs to this document.




Many people contributed to this document. The authors of this document would like to thank and recognize them and their contributions. These contributors provided invaluable concepts and content for this document's creation.


Ida Leung Independent Email:

Ida Leung独立メール

Stefano Previdi Cisco Systems Via Del Serafico, 200 Rome 00142 Italy Email:

Stefano Previdi Cisco Systems Via Del Serafico、200 Rome 00142 Italyメール

Christian Martin Arista Networks Email:


Authors' Addresses


John Brzozowski Comcast



John Leddy Comcast



Clarence Filsfils Cisco Systems Brussels Belgium

Clarence Filsfils Cisco Systemsブリュッセルベルギー


Roberta Maglione (editor) Cisco Systems Via Torri Bianche 8 Vimercate 20871 Italy

Roberta Maglione(編集者)Cisco Systems Via Torri Bianche 8 Vimercate 20871イタリア


Mark Townsley Cisco Systems

Mark Townsley Cisco Systems