Internet Engineering Task Force (IETF)                    F. Le Faucheur
Request for Comments: 5945                                         Cisco
Category: Informational                                        J. Manner
ISSN: 2070-1721                                         Aalto University
                                                                 D. Wing
                                                              A. Guillou
                                                            October 2010
         Resource Reservation Protocol (RSVP) Proxy Approaches



The Resource Reservation Protocol (RSVP) can be used to make end-to-end resource reservations in an IP network in order to guarantee the quality of service required by certain flows. RSVP assumes that both the data sender and receiver of a given flow take part in RSVP signaling. Yet, there are use cases where resource reservation is required, but the receiver, the sender, or both, is not RSVP-capable. This document presents RSVP proxy behaviors allowing RSVP routers to initiate or terminate RSVP signaling on behalf of a receiver or a sender that is not RSVP-capable. This allows resource reservations to be established on a critical subset of the end-to-end path. This document reviews conceptual approaches for deploying RSVP proxies and discusses how RSVP reservations can be synchronized with application requirements, despite the sender, receiver, or both not participating in RSVP. This document also points out where extensions to RSVP (or to other protocols) may be needed for deployment of a given RSVP proxy approach. However, such extensions are outside the scope of this document. Finally, practical use cases for RSVP proxy are described.

リソース予約プロトコル(RSVP)は、特定のフローによって要求されるサービスの品質を保証するために、IPネットワーク内のエンド・ツー・エンドのリソース予約を行うために使用することができます。 RSVPは、特定のフローのデータの送信側と受信側の両方がRSVPシグナリングに参加することを想定しています。まだ、リソース予約が必要とされる用途場合があるが、受信機、送信者、またはその両方は、RSVP-ことができません。この文書では、RSVPルータが受信機またはRSVP-できない送信者に代わってRSVPシグナルを開始または終了することができRSVPプロキシの動作を示しています。これは、リソースの予約は、エンドツーエンドのパスの重要なサブセットに確立することができます。この文書では、RSVPプロキシを展開するための概念的なアプローチを検討し、RSVP予約が、送信者、受信者、またはその両方がRSVPに参加していないにも関わらず、アプリケーションの要件と同期させることができる方法について説明します。この文書はまた、拡張機能は、所与のRSVPプロキシアプローチの展開のために必要とされ得る(または他のプロトコル)RSVPする場所を指摘します。しかし、そのような拡張は、この文書の範囲外です。最後に、RSVPプロキシの実用例が記載されています。

Status of This Memo


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


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 a candidate for any level of Internet Standard; see Section 2 of RFC 5741.

このドキュメント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。これは、IETFコミュニティの総意を表しています。これは、公開レビューを受けており、インターネットエンジニアリング運営グループ(IESG)によって公表のために承認されています。 IESGによって承認されていないすべての文書がインターネットStandardのどんなレベルの候補です。 RFC 5741のセクション2を参照してください。

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) 2010 IETF Trust and the persons identified as the document authors. All rights reserved.

著作権(C)2010 IETF信託とドキュメントの作成者として特定の人物。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.

この文書では、BCP 78と、この文書の発行日に有効なIETFドキュメント(に関連IETFトラストの法律の規定に従うものとします。彼らは、この文書に関してあなたの権利と制限を説明するように、慎重にこれらの文書を確認してください。コードコンポーネントは、トラスト法規定のセクションで説明4.eおよび簡体BSDライセンスで説明したように、保証なしで提供されているよう簡体BSDライセンスのテキストを含める必要があり、この文書から抽出されました。

This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English.


Table of Contents


   1. Introduction ....................................................3
   2. RSVP Proxy Behaviors ............................................6
      2.1. RSVP Receiver Proxy ........................................6
      2.2. RSVP Sender Proxy ..........................................7
   3. Terminology .....................................................7
   4. RSVP Proxy Approaches ...........................................9
      4.1. Path-Triggered Receiver Proxy ..............................9
           4.1.1. Mechanisms for Maximizing the Reservation Span .....11
      4.2. Path-Triggered Sender Proxy for Reverse Direction .........15
      4.3. Inspection-Triggered Proxy ................................18
      4.4. STUN-Triggered Proxy ......................................21
      4.5. Application_Entity-Controlled Proxy .......................23
           4.5.1. Application_Entity-Controlled Sender Proxy
                  Using "RSVP over GRE" ..............................26
           4.5.2. Application_Entity-Controlled Proxy via Co-Location 28
      4.6. Policy_Server-Controlled Proxy ............................29
      4.7. RSVP-Signaling-Triggered Proxy ............................32
      4.8. Reachability Considerations ...............................33
   5. Security Considerations ........................................34
   6. Acknowledgments ................................................36
   7. References .....................................................36
      7.1. Normative References ......................................36
      7.2. Informative References ....................................37
   Appendix A.  Use Cases for RSVP Proxies ...........................40
     A.1.  RSVP-Based VoD Admission Control in Broadband
           Aggregation Networks ......................................40
     A.2.  RSVP-Based Voice/Video Connection Admission Control
           (CAC) in Enterprise WAN ...................................43
     A.3.  RSVP Proxies for Mobile Access Networks ...................44
     A.4.  RSVP Proxies for Reservations in the Presence of IPsec
           Gateways ..................................................46
1. Introduction
1. はじめに

Guaranteed Quality of Service (QoS) for some applications with tight requirements (such as voice or video) may be achieved by reserving resources in each node on the end-to-end path. The main IETF protocol for these resource reservations is the Resource Reservation Protocol (RSVP), as specified in [RFC2205]. RSVP does not require that all intermediate nodes support RSVP; however, it assumes that both the sender and the receiver of the data flow support RSVP. There are environments where it would be useful to be able to reserve resources for a flow on at least a subset of the flow path even when the sender or the receiver (or both) is not RSVP-capable (for example, from the sender to the network edge, or from edge to edge, or from the network edge to the receiver).

(音声やビデオなど)厳しい要件を持ついくつかのアプリケーションのためのサービス(QoS)の保証の品質は、エンドツーエンドのパス上の各ノードのリソースを確保することによって達成することができます。これらの資源予約のための主要なIETFプロトコルは、[RFC2205]で指定されるように、リソース予約プロトコル(RSVP)です。 RSVPは、すべての中間ノードのサポートRSVPする必要はありません。しかし、送信者とデータフロー支持RSVPの受信機の両方と仮定しています。送信側または受信側(または両方)はRSVP-ことができない場合であっても(例えば、送信者からへの流路の少なくともサブセットのフローのためのリソースを確保できることが有用であろう環境がありますネットワークエッジ、またはエッジからエッジまで、または)受信機へのネットワークエッジから。

Since the data sender or receiver may be unaware of RSVP, there are two types of RSVP proxies. When the sender is not using RSVP, an entity in the network must operate on behalf of the data sender, and in particular, generate RSVP Path messages, and eventually receive, process, and sink Resv messages. We refer to this entity as the RSVP Sender Proxy. When the receiver is not using RSVP, an entity in the network must receive Path messages sent by a data sender (or by an RSVP Sender Proxy), sink those, and return Resv messages on behalf of the data receiver(s). We refer to this entity as the RSVP Receiver Proxy. The RSVP proxies need to be on the data path in order to establish the RSVP reservation; note, however, that some of the approaches described in this document allow the RSVP proxies to be controlled/triggered by an off-path entity.

データの送信側または受信側がRSVPを知らないかもしれないので、RSVPプロキシの2種類があります。送信者がRSVPを使用していない場合は、ネットワーク内のエンティティは、データ送信者に代わって動作しなければならず、特に、RSVPパスメッセージを生成し、最終的には、プロセスを受信し、RESVメッセージをシンクします。私たちは、RSVP送信者のプロキシとしてこの実体を参照してください。受信機は、RSVPを使用していない場合、ネットワーク内のエンティティは、データ送信側(又はRSVP送信側プロキシによって)によって送信されたPathメッセージを受信し、それらをシンク、及びデータ受信機(複数可)の代わりにRESVメッセージを返さなければなりません。私たちは、RSVPレシーバープロキシとしてこの実体を参照してください。 RSVPプロキシは、RSVP予約を確立するために、データパスにする必要があります。ただし、本書で説明する方法のいくつかは、RSVPプロキシがオフパスエンティティによってトリガ/制御することを可能にすること。

The flow sender and receiver generally have at least some (if not full) awareness of the application producing or consuming that flow. Hence, the sender and receiver are in a natural position to synchronize the establishment, maintenance, and teardown of the RSVP reservation with the application requirements. Similarly, they are in a natural position to determine the characteristics of the reservation (bandwidth, QoS service, etc.) that best match the application requirements. For example, before completing the establishment of a multimedia session, the endpoints may decide to establish RSVP reservations for the corresponding flows. Similarly, when the multimedia session is torn down, the endpoints may decide to tear down the corresponding RSVP reservations. For instance, [RFC3312] discusses how RSVP reservations can be very tightly synchronized by endpoints that uses the Session Initiation Protocol (SIP) ([RFC3261]) for session control.


When RSVP reservation establishment, maintenance, and teardown are to be handled by RSVP proxies on behalf of an RSVP sender or receiver, a key challenge for the RSVP proxy is to determine when the RSVP reservations need to be established, maintained, and torn down, and to determine what the characteristics are (bandwidth, QoS, etc.) of the required RSVP reservations matching the application requirements. We refer to this problem as the synchronization of RSVP reservations with application-level requirements.


The IETF Next Steps in Signaling (NSIS) working group has specified a new QoS signaling protocol: the QoS NSIS Signaling Layer Protocol (NSLP) ([RFC5974]). This protocol also includes the notion of proxy operation, and terminating QoS signaling on nodes that are not the actual data senders or receivers (see Section 4.8, "Proxy Mode", of [RFC5974]. This is the same concept as the proxy operation for RSVP discussed in this document. One difference, though, is that the NSIS framework does not consider multicast resource reservations, which RSVP provides today.

QoSのNSISシグナリング層プロトコル(NSLP)([RFC5974]):IETFシグナリングに次のステップ(NSIS)ワーキンググループは、シグナリングプロトコル新しいQoSを指定しています。 、「プロキシモード」、[RFC5974]このプロトコルはまた、プロキシ動作の概念を含み、実際のデータの送信者または受信機がないノード上でシグナリングを終端するQoSは(セクション4.8を参照。これは、のプロキシ動作と同じ概念でありますRSVPは、この文書で説明する。一つの違いは、しかし、NSISフレームワークが今日提供するRSVP、マルチキャストリソース予約を考慮していないということです。

Section 2 introduces the notion of RSVP Sender Proxy and RSVP Receiver Proxy. Section 3 defines useful terminology. Section 4 then presents several fundamental RSVP proxy approaches, discussing how they achieve the necessary synchronization of RSVP reservations with application-level requirements. Appendix A includes more detailed use cases for the proxies in various real-life deployment environments.


It is important to keep in mind that the strongly recommended RSVP deployment model remains end-to-end as assumed in [RFC2205] with RSVP support on the sender and the receiver. The end-to-end model allows the most effective synchronization between the reservation and application requirements. Also, when compared to the end-to-end RSVP model, the use of RSVP proxies involves additional operational burden and/or imposes some topological constraints. The additional operational burden comes in particular from additional configuration needed to activate the RSVP proxies and to help them identify for which senders/receivers a proxy behavior is required and for which senders/receivers it is not (so that an RSVP proxy does not perform establishment of reservations on behalf of devices that are capable of doing so themselves but would then be prevented -- without notification -- from doing so by the RSVP proxy). The additional topological constraints come in particular from the requirement to have one RSVP Receiver Proxy on the path from any sender to every non-RSVP-capable device (so that a non-RSVP-capable device is always taken care of by an RSVP proxy) and the objective to have only one such Receiver Proxy on the path from any sender to every non-RSVP-capable device (so that an RSVP Receiver Proxy does not short-circuit another RSVP Receiver Proxy closer to the non-RSVP-capable device, thereby reducing the span of the RSVP reservation and the associated benefits). In the case of the Path-Triggered Receiver Proxy approach, the operational burden and topological constraints can be significantly alleviated using the mechanisms discussed in Section 4.1.1.

[RFC2205]で仮定として強く推奨RSVPの展開モデルは、送信者と受信者のRSVPサポートをエンド・ツー・エンドのままであることを心に留めておくことが重要です。エンドツーエンドモデルは、予約とアプリケーション要件の間に最も効果的な同期を可能にします。エンドツーエンドのRSVPのモデルと比較しても、RSVPプロキシの使用は、追加の作業負担を伴う、および/またはいくつかの位相幾何学的制約を課します。追加の作業負担はRSVPプロキシを有効にするには、それらをプロキシ動作が必要とされた送信者/受信者のためにそれはない(RSVPプロキシが設立を実行しないようにですされている送信者/受信者のために識別しやすくするために必要な追加の設定から特に来て通知なし - - RSVPプロキシによってそうすることから)自分自身そうすることが可能であるが、その後に防止することが考えデバイスの代わりに予約を。追加のトポロジー制約が(非RSVP対応デバイスは常にRSVPプロキシによって世話をされるように)すべての非RSVP対応デバイスへの任意の送信者からの経路上の一台のRSVP受信機プロキシを有することが必要で、特に来RSVP受信プロキシは、近い非RSVP対応デバイスへの短絡、他のRSVP受信プロキシないように目的は、すべての非RSVP対応デバイス(の任意の送信者からのパスにのみこのような受信機プロキシを持っていますこれにより、RSVP予約のスパンと関連する利益を)減らします。パス・トリガレシーバプロキシアプローチの場合には、演算負担やトポロジー制約が大幅セクション4.1.1で説明したメカニズムを使用して緩和することができます。

It is also worth noting that RSVP operations on end-systems are considerably simpler than on a router, and consequently that RSVP implementations on end-systems are very lightweight (particularly considering modern end-systems' capabilities, including mobile and portable devices). For example, end-system RSVP implementations are reported to only consume low tens of kilobytes of code space. Hence, this document should not be seen as an encouragement to depart from the end-to-end RSVP model. Its purpose is only to allow RSVP deployment in special environments where RSVP just cannot be used on some senders and/or some receivers for reasons specific to the environment.


2. RSVP Proxy Behaviors
2. RSVPプロキシの行動

This section discusses the two types of proxies: the RSVP Sender Proxy operating on behalf of data senders, and the RSVP Receiver Proxy operating for data receivers. The concepts presented in this document are not meant to deprecate the traditional [RFC2205] RSVP end-to-end model: end-to-end RSVP reservations are still expected to be used whenever possible. However, RSVP proxies are intended to facilitate RSVP deployment where end-to-end RSVP signaling is not possible.

RSVP送信者プロキシは、データの送信者に代わって操作すると、RSVP受信側プロキシは、データ受信のために操作する:このセクションでは、プロキシの2種類について説明します。この文書で説明する概念は、伝統的な[RFC2205] RSVPエンドツーエンドモデルを廃止することを意味していない:エンドツーエンドのRSVP予約はまだ可能な限り使用されることが期待されています。しかし、RSVPプロキシは、エンドツーエンドのRSVPシグナリングが可能でないRSVPの展開を容易にするために意図されています。

2.1. RSVP Receiver Proxy
2.1. RSVPレシーバープロキシ

With conventional end-to-end RSVP operations, RSVP reservations are controlled by receivers of data. After a data sender has sent an RSVP Path message towards the intended recipient(s), each recipient that requires a reservation generates a Resv message. If, however, a data receiver is not running the RSVP protocol, the last-hop RSVP router will still send the Path message to the data receiver, which will silently drop this message as an IP packet with an unknown protocol number.

従来のエンドツーエンドのRSVPの動作により、RSVP予約は、データの受信機によって制御されます。データ送信側は、意図された受信者(複数可)、予約がResvメッセージを生成し、必要とする各受信者に向かってRSVP Pathメッセージを送信した後に。しかし、データの受信機はRSVPプロトコルを実行していない、場合、最終ホップRSVPルータはまだ黙っ不明なプロトコル番号を持つIPパケットとして、このメッセージをドロップしますデータ受信、にPathメッセージを送信します。

In order for reservations to be made in such a scenario, one of the RSVP routers on the data path determines that the data receiver will not be participating in the resource reservation signaling and performs RSVP Receiver Proxy functionality on behalf of the data receiver. This is illustrated in Figure 1. Various mechanisms by which the RSVP proxy router can gain the required information are discussed later in the document.


    |****|         ***          ***         |**********|          |----|
    | S  |---------*r*----------*r*---------| RSVP     |----------| R  |
    |****|         ***          ***         | Receiver |          |----|
                                            | Proxy    |



 |****| RSVP-capable     |----| non-RSVP-capable       ***
 | S  | Sender           | R  | Receiver               *r* regular RSVP
 |****|                  |----|                        *** router

***> unidirectional media flow ==> segment of flow path protected by RSVP reservation


Figure 1: RSVP Receiver Proxy


2.2. RSVP Sender Proxy
2.2. RSVP送信者のプロキシ

With conventional end-to-end RSVP operations, if a data sender is not running the RSVP protocol, a resource reservation cannot be set up; a data receiver alone cannot reserve resources without Path messages first being received. Thus, even if the data receiver is running RSVP, it still needs some node on the data path to send a Path message towards the data receiver.


In that case, an RSVP node on the data path determines that it should generate Path messages to allow the receiver to set up the resource reservation. This node is referred to as the RSVP Sender Proxy and is illustrated in Figure 2. This case presents additional challenges over the Receiver Proxy case, since the RSVP Sender Proxy must be able to generate all the information in the Path message (such as the SENDER_TSPEC object) without the benefit of having previously received any RSVP message. An RSVP Receiver Proxy, by contrast, only needs to formulate an appropriate Resv message in response to an incoming Path message. Mechanisms to operate an RSVP Sender Proxy are discussed later in this document.

その場合に、データ経路上のRSVPノードは、受信機が、リソース予約を設定できるようにするPathメッセージを生成すべきであると判断します。このノードは、RSVP送信側プロキシは、SENDER_TSPECとしてPathメッセージのすべての情報を(生成することができなければならないので、RSVP送信側プロキシと呼ばれ、図この場合は、受信プロキシケース上の追加の課題を提示2に示されています。以前に任意のRSVPメッセージを受信したことの利点なしでオブジェクト)。 RSVP受信プロキシは、対照的に、唯一の受信Pathメッセージに応答して、適切なResvメッセージを定式化する必要があります。 RSVP送信者のプロキシを操作するためのメカニズムは、このドキュメントの後半で説明されています。

    |----|         |**********|         ***          ***          |****|
    | S  |---------| RSVP     |---------*r*----------*r*----------| R  |
    |----|         | Sender   |         ***          ***          |****|
                   | Proxy    |



 |----| non-RSVP-capable     |****| RSVP-capable       ***
 | S  | Sender               | R  | Receiver           *r* regular RSVP
 |----|                      |****|                    *** router

***> unidirectional media flow


==> segment of flow path protected by RSVP reservation


Figure 2: RSVP Sender Proxy


3. Terminology

o On-Path: located on the data path of the actual flow of application data (regardless of where it is located with respect to the application-level signaling path).


o Off-Path: not On-Path.


o RSVP-capable (or RSVP-aware): supporting the RSVP protocol as per [RFC2205].


o RSVP Receiver Proxy: an RSVP-capable router performing, on behalf of a receiver, the RSVP operations that would normally be performed by an RSVP-capable receiver if end-to-end RSVP signaling were used. Note that while RSVP is used upstream of the RSVP Receiver Proxy, RSVP is not used downstream of the RSVP Receiver Proxy.

、受信機の代わりに、エンドツーエンドのRSVPシグナリングが使用された場合、通常、RSVP対応受信機によって実行されるRSVP操作を行うRSVP対応ルータ:OレシーバプロキシRSVP。 RSVPは、RSVP受信プロキシの上流で使用されている間、RSVPは、RSVP受信プロキシの下流で使用されていないことに留意されたいです。

o RSVP Sender Proxy: an RSVP-capable router performing, on behalf of a sender, the RSVP operations that would normally be performed by an RSVP-capable sender if end-to-end RSVP signaling were used. Note that while RSVP is used downstream of the RSVP Sender Proxy, RSVP is not used upstream of the RSVP Sender Proxy.

O RSVP送信者プロキシ:RSVP対応ルータが送信者に代わって、実行は、通常、RSVP-できる送信者によって実行されるRSVP操作は、エンドツーエンドのRSVPシグナリングが使用された場合。 RSVPは、RSVP送信者のプロキシの下流で使用されている間、RSVPは、RSVP送信側プロキシの上流で使用されていないことに留意されたいです。

o Regular RSVP Router: an RSVP-capable router that is not behaving as an RSVP Receiver Proxy or as an RSVP Sender Proxy.


o Application-level signaling: signaling between entities operating above the IP layer and that are aware of the QoS requirements for actual media flows. SIP ([RFC3261]) and the Real Time Streaming Protocol (RTSP) ([RFC2326]) are examples of application-level signaling protocols. The Session Description Protocol (SDP) ([RFC4566]) is an example of a protocol that can be used by the application-level signaling protocol and from which some of the RSVP reservation parameters (addresses, ports, and bandwidth) might be derived. RSVP is clearly not an application-level signaling protocol.

Oアプリケーションレベルシグナリング:IP層以上で動作するエンティティ間のシグナリングと実際のメディアフローのためのQoS要件を認識しています。 SIP([RFC3261])及びリアルタイムストリーミングプロトコル(RTSP)([RFC2326])は、アプリケーション・レベルのシグナリングプロトコルの例です。セッション記述プロトコル(SDP)([RFC4566])は、アプリケーションレベルのシグナリングプロトコルによって、およびRSVP予約パラメータ(アドレス、ポート、および帯域幅)の一部が導出されるかもしれないから、使用することができるプロトコルの一例です。 RSVPは、明らかに、アプリケーション・レベルのシグナリング・プロトコルではありません。

The roles of the RSVP Receiver Proxy, RSVP Sender Proxy, and regular RSVP router are all relative to a given unidirectional flow. A given router may act as the RSVP Receiver Proxy for a flow, as the RSVP Sender Proxy for another flow, and as a regular RSVP router for yet another flow.


Some application-level signaling protocols support negotiation of QoS reservations for a media stream. For example, with [RFC3312], resource reservation requirements are explicitly signaled during session establishment using SIP and SDP. Also, [RFC5432] defines a mechanism to negotiate which resource reservation mechanism is to be used for a particular media stream. Clearly, these reservation negotiation mechanisms can be invoked and operate effectively when both ends support RSVP (and obviously RSVP proxies are not used). When both ends do not support RSVP (and RSVP proxies are used at both ends), these mechanisms will simply not be invoked. In the case where one end supports RSVP and the other does not (and is helped by an RSVP proxy), the application-level signaling entity supporting the non-RSVP-capable end might use the reservation negotiation mechanisms in such a way that the non-RSVP-capable end (helped by an RSVP proxy) appears to the remote end as an RSVP-capable device. This will ensure that the RSVP-capable end is not discouraged from using RSVP because the remote end is not RSVP-capable. In the case of SIP, the application-level entity may achieve this by taking advantage of the "segmented" status type of [RFC3312] and/or by taking advantage of a SIP [RFC3261] Back-to-Back User Agent (B2BUA).

いくつかのアプリケーションレベルのシグナリングプロトコルは、メディアストリームのためのQoS予約のネゴシエーションをサポートしています。例えば、[RFC3312]と、リソース予約要求は、明示的にSIP及びSDPを使用してセッション確立中にシグナリングされます。また、[RFC5432]は、特定のメディア・ストリームのために使用されるべきリソース予約メカニズム交渉するためのメカニズムを定義します。明らかに、これらの予約交渉メカニズムを呼び出すことができ、両方ともサポートRSVPを終了する(そして明らかにプロキシが使用されていないRSVP)ときに効果的に動作。両端がRSVPをサポートしていない(とRSVPプロキシは、両端で使用されている)場合、これらのメカニズムは単に呼び出されません。非ように予約交渉メカニズムを使用するかもしれない非RSVP対応端部を支持するアプリケーション・レベルのシグナリングエンティティ一端がRSVPをサポートし、他にはない(とRSVPプロキシによって助けられる)場合-RSVP対応端(RSVPプロキシによって助け)RSVP対応デバイスなどの遠隔端に現れます。これは、リモートエンドがRSVP対応されていないため、RSVP対応端部がRSVPを使用することから推奨されていないことを保証します。 SIPの場合には、アプリケーションレベルのエンティティは、[RFC3312]及び/またはSIPを利用して、[RFC3261]のステータスタイプを「セグメント」バックツーバックユーザエージェント(B2BUA)を利用することによって、これを達成することができます。

4. RSVP Proxy Approaches
4. RSVPプロキシアプローチ

This section discusses fundamental RSVP proxy approaches.


4.1. Path-Triggered Receiver Proxy
4.1. パス・トリガーレシーバープロキシ

In this approach, it is assumed that the sender is RSVP-capable and takes full care of the synchronization between application requirements and RSVP reservations. With this approach, the RSVP Receiver Proxy uses the RSVP Path messages generated by the sender as the cue for establishing the RSVP reservation on behalf of the receiver. The RSVP Receiver Proxy is effectively acting as a slave making reservations (on behalf of the receiver) under the sender's control. This changes somewhat the usual RSVP reservation model where reservations are normally controlled by receivers. Such a change greatly facilitates operations in the scenario of interest here, which is where the receiver is not RSVP-capable. Indeed, it allows the RSVP Receiver Proxy to remain application-unaware by taking advantage of the application awareness and RSVP awareness of the sender.

このアプローチでは、送信者がRSVP-ことが可能であり、アプリケーションの要件とRSVP予約の間の同期をフルに世話をすることが想定されます。このアプローチでは、RSVPレシーバープロキシは、受信機に代わってRSVP予約を確立するための手がかりとして、送信者によって生成されたRSVPのPathメッセージを使用しています。 RSVPレシーバープロキシが効果的に送信者の制御下で、(受信機に代わって)スレーブ作りの予約として機能しています。これは、やや予約が正常に受信機によって制御されている通常のRSVP予約モデルを変更します。そのような変化が大きく、受信機は、RSVP-ことができない場合であり、ここで関心のあるシナリオの動作を容易にします。確かに、それはRSVPレシーバープロキシが送信元のアプリケーション認識およびRSVP意識を利用することによって、アプリケーション気づかないままにすることができます。

With the Path-Triggered RSVP Receiver Proxy approach, the RSVP router may be configured to use receipt of a regular RSVP Path message as the trigger for RSVP Receiver Proxy behavior.

パス・トリガRSVP受信プロキシアプローチで、RSVPルータはRSVP受信プロキシ動作のトリガとして正規RSVP Pathメッセージの受信を使用するように構成されてもよいです。

On receipt of the RSVP Path message, the RSVP Receiver Proxy:

RSVP Pathメッセージ、RSVPレシーバープロキシを受信します:

1. establishes the RSVP Path state as per regular RSVP processing.
2. identifies the downstream interface towards the receiver.
3. sinks the Path message.
3. Pathメッセージをシンクします。

4. behaves as if a Resv message (whose details are discussed below) was received on the downstream interface. This includes performing admission control on the downstream interface, establishing a Resv state (in case of successful admission control), and forwarding the Resv message upstream, sending periodic refreshes of the Resv message and tearing down the reservation if the Path state is torn down.


In order to build the Resv message, the RSVP Receiver Proxy can take into account information received in the Path message. For example, the RSVP Receiver Proxy may compose a FLOWSPEC object for the Resv message that mirrors the SENDER_TSPEC object in the received Path message (as an RSVP-capable receiver would typically do).


Operation of the Path-Triggered Receiver Proxy in the case of a successful reservation is illustrated in Figure 3.


    |****|         ***          ***         |**********|          |----|
    | S  |---------*r*----------*r*---------| RSVP     |----------| R  |
    |****|         ***          ***         | Receiver |          |----|
                                            | Proxy    |
         ---Path---> ----Path----> ---Path---->
         <--Resv---> <---Resv----- <--Resv----



 |****| RSVP-capable     |----| Non-RSVP-capable        ***
 | S  | Sender           | R  | Receiver                *r* regular RSVP
 |****|                  |----|                         *** router

***> media flow


==> segment of flow path protected by RSVP reservation


Figure 3: Path-Triggered RSVP Receiver Proxy


In case the reservation establishment is rejected (for example, because of an admission control failure on a regular RSVP router on the path between the RSVP-capable sender and the RSVP Receiver Proxy), a ResvErr message will be generated as per conventional RSVP operations and will travel downstream towards the RSVP Receiver Proxy. While this ensures that the RSVP Receiver Proxy is aware of the reservation failure, conventional RSVP procedures do not cater to the notification of the sender of the reservation failure. Operation of the Path-Triggered RSVP Receiver Proxy in the case of an admission control failure is illustrated in Figure 4.

場合の予約の確立を(例えばためRSVP対応の送信側とRSVP受信プロキシとの間の経路上の正規RSVPルータのアドミッション制御不良)拒否され、ResvErrメッセージは、従来のRSVP操作に従って生成され、 RSVPレシーバープロキシに向けて下流に移動します。これはRSVPレシーバープロキシが予約失敗を認識していることを保証しますが、従来のRSVP手順は、予約の失敗の送信者の通知に応えていません。アドミッション制御に失敗した場合の経路トリガRSVP受信プロキシの動作は、図4に示されています。

    |****|         ***          ***         |**********|          |----|
    | S  |---------*r*----------*r*---------| RSVP     |----------| R  |
    |****|         ***          ***         | Receiver |          |----|
                                            | Proxy    |
         ---Path---> ----Path----> ---Path---->
                    <---Resv----- <--Resv------
                    ---ResvErr---> --ResvErr--->



 |****| RSVP-capable     |----| Non-RSVP-capable       ***
 | S  | Sender           | R  | Receiver               *r* regular RSVP
 |****|                  |----|                        *** router

***> media flow


==> segment of flow path protected by RSVP reservation


Figure 4: Path-Triggered RSVP Receiver Proxy with Failure


Since, as explained above, in this scenario involving the RSVP Receiver Proxy, synchronization between an application and an RSVP reservation is generally performed by the sender, notifying the sender of reservation failure is needed. [RFC5946] specifies RSVP extensions allowing such sender notification in the case of reservation failure in the presence of a Path-Triggered RSVP Receiver Proxy.

RSVP受信プロキシが関与するこのシナリオでは、上述したように、あるので、アプリケーションおよびRSVP予約の間の同期は、一般に、予約の失敗の送信者が必要とされる通知、送信者によって行われます。 [RFC5946]はパス・トリガRSVP受信プロキシの存在下での予約に失敗した場合に、送信者の通知を可能にするRSVP拡張を指定します。

4.1.1. Mechanisms for Maximizing the Reservation Span
4.1.1. 予約スパンを最大化するための機構

The presence in the flow path of a Path-Triggered RSVP Receiver Proxy (for a given flow) that strictly behaves as described previously would cause the Path message to be terminated and a Resv message to be generated towards the sender. When the receiver is indeed not RSVP-capable and there is no other RSVP Receiver Proxy downstream on the flow path, this achieves the best achievable result of establishing an RSVP reservation as far downstream as the RSVP Receiver Proxy.


However, if the eventual receiver was in fact RSVP-capable, it would be prevented from participating in RSVP signaling, since it does not receive any Path message. As a result, the RSVP reservation would only span a subset of the path it could actually span. A similar sub-optimality would exist with multiple Receiver Proxies in the path of the flow: the first Receiver Proxy may prevent the Path message from reaching the second one and therefore prevent the reservation from extending down to the second Receiver Proxy.


It is desirable that, in the presence of Path-Triggered RSVP Receiver Proxies and of a mix of RSVP-capable and non-RSVP-capable receivers, the RSVP reservation spans as much of the flow path as possible. This can be achieved dynamically (avoiding tedious specific configuration), using the mechanisms described in Sections and

パス・トリガRSVP受信プロキシのとRSVP-可能と非RSVP対応受信機の混合物の存在下で、RSVP予約が可能な限り流路だけに及ぶ、ことが望ましいです。これは、セクション4.1.1.1および4.1.1.2に説明されたメカニズムを使用して、動的に(退屈な具体的な構成を回避する)を達成することができます。 Dynamic Discovery of Downstream RSVP Functionality。川下のRSVP機能の動的検出

When generating a proxy Resv message upstream, a Receiver Proxy may be configured to perform dynamic discovery of downstream RSVP functionality. To that end, when generating the proxy Resv message upstream, the Receiver Proxy forwards the Path message downstream instead of terminating it. This allows an RSVP-capable receiver (or a downstream Receiver Proxy) to respond to the Path with an upstream Resv message. On receipt of a Resv message, the Receiver Proxy internally converts its state from a proxied reservation to a regular midpoint RSVP behavior. From then on, everything proceeds as if the RSVP router had behaved as a regular RSVP router at reservation establishment (as opposed to having behaved as an RSVP Receiver Proxy for that flow).

上位プロキシResvメッセージを生成する際、レシーバプロキシは、下流RSVP機能の動的な発見を実行するように構成されてもよいです。上位プロキシResvメッセージを生成する際に、その端部に、受信プロキシではなく、それを終端する下流Pathメッセージを転送します。これは、RSVP対応受信機(またはダウンストリーム受信プロキシ)は、上流Resvメッセージのパスに応答することを可能にします。 Resvメッセージを受信すると、受信側プロキシは、内部的に、通常の中間点RSVPの振る舞いにプロキシ予約からその状態を変換します。 RSVPルータは(その流れのためのRSVPレシーバープロキシとして振る舞ったとは反対に)予約成立で、通常のRSVPルータとして振る舞っていたかのようにその時から、すべてが進行します。

The RSVP Receiver Proxy behavior for dynamic discovery of downstream RSVP functionality is illustrated in Figure 5 and is also discussed in Section 4.1 of [RFC5946].


      |****|         ***         |**********|   |----|
      | S  |---------*r*---------| RSVP     |---| R1 |
      |****|         ***         | Receiver |   |----|
                                 | Proxy    |
                                 |          |
                                 |          |            |****|
                                 |          |------------| R2 |
                                 |**********|            |****|
           ---Path--->  --Path--->
              (R1)        (R1)    \-------Path-->
                                  /       (R1)
           <--Resv---  <---Resv---



           ---Path--->  --Path--->
              (R2)        (R2)    \-------------Path---->
                                  /             (R2)
           <--Resv---  <---Resv---



   |****| RSVP-capable  |----| non-RSVP-capable  |****| RSVP-capable
   | S  | Sender        | R  | Receiver          | R  | Receiver
   |****|               |----|                   |****|

*** *r* regular RSVP *** router

*** * R *通常のRSVPルータ***

(R1) = Path message contains a Session object whose destination is R1

(R1)は= Pathメッセージは、その宛先R1されたセッションオブジェクトを含みます

***> media flow


==> segment of flow path protected by RSVP reservation


Figure 5: Dynamic Discovery of Downstream RSVP Functionality


This dynamic discovery mechanism has the benefit that new (or upgraded) RSVP endpoints will automatically and seamlessly be able to take advantage of end-to-end reservations, without impacting the ability of a Receiver Proxy to proxy RSVP for other, non-RSVP-capable endpoints. This mechanism also achieves the goal of automatically discovering the longest possible RSVP-supporting segment in a network with multiple Receiver Proxies along the path. This mechanism dynamically adjusts to any topology and routing change. Also, this mechanism dynamically handles the situation in which a receiver was RSVP-capable and for some reason (e.g., software downgrade) no longer is. Finally, this approach requires no new RSVP protocol extensions and no configuration changes to the Receiver Proxy as new RSVP-capable endpoints come and go.


The only identified drawbacks to this approach are:


o If admission control fails on the segment between the Receiver Proxy and the RSVP-capable receiver, the receiver will get a ResvErr and can take application-level signaling steps to terminate the call. However, the Receiver Proxy has already sent a Resv upstream for this flow, so the sender will see a "false" reservation that is not truly end-to-end. The actual admission control status will resolve itself in a short while, but the sender will need to roll back any permanent action (such as billing) that may have been taken on receipt of the phantom Resv. Note that if the second receiver is also a Receiver Proxy that is not participating in application signaling, it will convert the received ResvErr into a PathErr that will be received by the sender.


o If there is no RSVP-capable receiver (or other Receiver Proxy) downstream of the Receiver Proxy, then the Path messages sent by the Receiver Proxy every RSVP refresh interval (e.g., 30 seconds by default) will never be responded to. However, these messages consume a small amount of bandwidth, and in addition would install some RSVP state on RSVP-capable midpoint nodes downstream of the first Receiver Proxy. This is seen as a very minor sub-optimality. We also observe that such resources would be consumed anyways if the receiver was RSVP-capable. Still, if deemed necessary, to mitigate this, the Receiver Proxy can tear down any unanswered downstream Path state and stop sending Path messages for the flow (or only send them at much lower frequency) as further discussed in [RFC5946].

レシーバープロキシの下流何RSVP対応の受信機(または他のレシーバープロキシ)が存在しない場合は、O、その後、レシーバープロキシによってすべてのRSVPのリフレッシュ間隔を送ったPathメッセージは、(例えば、デフォルトでは30秒)に対応することはありません。しかしながら、これらのメッセージは、帯域幅の小さな量を消費し、加えて、第1の受信プロキシの下流RSVP対応中点のノードでいくつかのRSVP状態をインストールします。これは非常にマイナーな準最適と見られています。また、受信機がRSVP-ことができたならば、そのようなリソースがとにかく消費されることを確認します。依然として、これを緩和するために、必要と認める場合、受信機プロキシは、さらに、[RFC5946]で説明した(または唯一のそれらをはるかに低い周波数を送信する)任意の未回答の下流路状態を切断し、フローのためのPathメッセージの送信を停止することができます。 Selective Receiver Proxy and Sender Control of Receiver Proxy。レシーバープロキシの選択レシーバプロキシとSenderコントロール

An RSVP Receiver Proxy can be selective about the sessions that it terminates, based on local policy decision. For example, an edge router functioning as a Receiver Proxy may behave as a proxy only for Path messages that are actually going to exit the domain in question, and not for Path messages that are transiting through it but stay within the domain. As another example, the Receiver Proxy may be configurable to only proxy for flows addressed to a given destination address or destination address ranges (for which end devices are known to not be RSVP-capable).


The decision to proxy a Resv for a Path may also be based on information signaled from the sender in the Path message. For example, the sender may identify the type of application or flow in the Application Identity policy element ([RFC2872]) in the Path, and the Receiver Proxy may be configured to proxy for only certain types of flows. Or, if the sender knows (for example, through application signaling) that the receiver is RSVP-capable, the sender can include an indication in a policy element to any Receiver Proxy that it ought not to terminate the Path (or conversely, if the receiver is known not to support RSVP, the sender could include an indication to Receiver Proxies that they ought to generate a proxy Resv message). The Receiver Proxy Control policy element specified in Section 4.2 of [RFC5946] can be used for that purpose.

パスのプロキシのResvの決定はまた、Pathメッセージ内の送信者からのシグナリング情報に基づくことができます。例えば、送信者は、アプリケーションの種類を識別することができるか、パスのアプリケーションIDポリシーエレメント([RFC2872])に流れ、レシーバプロキシフローのみ、特定のタイプのプロキシを構成することができます。あるいは、送信側は受信側がRSVP対応である場合、送信者は、それが逆パス(または終了するべきではないことは、任意の受信プロキシにポリシー要素に指示を含むことができること(例えば、アプリケーションシグナリングを介して)知っている場合受信機は、送信者が、彼らは)プロキシResvメッセージを生成するべきであることを受信プロキシに指示を含むことができる、RSVPをサポートしないことが知られています。 [RFC5946]のセクション4.2で指定された受信側プロキシ制御ポリシーエレメントは、その目的のために使用することができます。

4.2. Path-Triggered Sender Proxy for Reverse Direction
4.2. 逆方向のパス・トリガ送信者のプロキシ

In this approach, it is assumed that one endpoint is RSVP-capable and takes full care of the synchronization between application requirements and RSVP reservations. This endpoint is the sender for one flow direction (which we refer to as the "forward" direction) and is the receiver for the flow in the opposite direction (which we refer to as the "reverse" direction).


With the Path-Triggered Sender Proxy for Reverse Direction approach, the RSVP proxy uses the RSVP signaling generated by the receiver (for the reverse direction) as the cue for initiating RSVP signaling for the reservation in the reverse direction. More precisely, the RSVP proxy can take the creation (or maintenance or teardown) of a Path state by the receiver as the cue to create (or maintain or tear down, respectively) a Path state towards the receiver. Thus, the RSVP proxy is effectively acting as a Sender Proxy for the reverse direction under the control of the receiver (for the reverse direction). Note that this assumes a degree of symmetry, for example, in terms of bandwidth for the two directions of the flow (as is currently typical for IP telephony).


The signaling flow for the Path-Triggered Sender Proxy for Reverse Direction is illustrated in Figure 6.


Path messages generated by the receiver need to transit via the RSVP Sender Proxy that is on the path from the sender to the receiver. In some topologies, this will always be the case: for example, where the sender is on a stub network hanging off the RSVP Sender Proxy or where there is no asymmetric routing (such that if an RSVP Sender Proxy is on the path from receiver to sender, then it is also on the path from sender to receiver). In some topologies (such as those involving asymmetric routing), this may not always happen naturally. Measures to ensure this does happen in these topologies are outside the scope of this document.

受信機によって生成されたPathメッセージは、送信側から受信側へのパス上にあるRSVP送信者のプロキシを経由して輸送する必要があります。一部のトポロジでは、これは常にそうであろう:例えば、送信者がRSVP送信者プロキシまたはここ全く非対称ルーティングがないオフぶら下がっスタブ・ネットワーク上にある場合(RSVP送信側プロキシが受信機からのパス上にある場合、このようなこと送信者は、それは)送信者から受信者のパスでもあります。 (例えば、非対称ルーティングを伴うものなど)いくつかのトポロジでは、これは常に自然に発生しないことがあります。これは、これらのトポロジで起こるん確保するための措置は、この文書の範囲外です。

    |****|         ***          ***         |**********|          |----|
    | R  |---------*r*----------*r*---------| RSVP     |----------| S  |
    |****|         ***          ***         | Sender   |          |----|
                                            | Proxy    |
         ---Path---> ----Path----> ---Path---->
         <--Path---> <---Path----- <--Path----
         ---Resv---> ----Resv----> ---Resv---->



 |****| RSVP-capable       |----| Non-RSVP-capable     ***
 | R  | Receiver for       | S  | Sender for           *r* regular RSVP
 |****| reverse direction  |----| reverse direction    *** router

***> media flow


==> segment of flow path protected by RSVP reservation in reverse direction


Figure 6: Path-Triggered Sender Proxy for Reverse Direction


Of course, the RSVP proxy may simultaneously (and typically will) also act as the Path-Triggered Receiver Proxy for the forward direction, as defined in Section 4.1. Such an approach is most useful in situations involving RSVP reservations in both directions for symmetric flows. This is illustrated in Figure 7.


    |****|         ***          ***         |----------|          |----|
    |S/R |---------*r*----------*r*---------| RSVP     |----------|S/R |
    |****|         ***          ***         | Receiver |          |----|
                                            | & Sender |
                                            | Proxy    |
         ---Path---> ----Path----> ---Path---->
         <--Resv---> <---Resv----- <--Resv----
         <--Path---> <---Path----- <--Path----
         ---Resv---> ----Resv----> ---Resv---->

**********************************************************> <**********************************************************

**********************************************************> <**********************************************************

 |****| RSVP-capable     |----| Non-RSVP-capable       ***
 |S/R | Sender and       |S/R | Sender and             *r* regular RSVP
 |****| Receiver         |----| Receiver               *** router

***> media flow


==> segment of flow path protected by RSVP reservation in forward and in reverse direction


Figure 7: Path Triggered Receiver and Sender Proxy


With the Path-Triggered Sender Proxy for Reverse Direction approach, the RSVP router may be configurable to use receipt of a regular RSVP Path message as the trigger for Sender Proxy for Reverse Direction behavior.

逆方向のアプローチのためのパス・トリガ送信者のプロキシで、RSVPルータは逆方向動作用送信元プロキシのためのトリガーとして、通常のRSVP Pathメッセージの受信を使用するように構成可能です。

On receipt of the RSVP Path message for the forward direction, the RSVP Sender Receiver Proxy:

順方向、RSVPセンダレシーバプロキシのRSVP Pathメッセージを受信します:

1. sinks the Path message.
1. Pathメッセージをシンクします。

2. behaves as if a Path message for the reverse direction (whose details are discussed below) had been received by the Sender Proxy. This includes establishing the corresponding Path state, forwarding the Path message downstream, sending periodic refreshes of the Path message, and tearing down the Path in the reverse direction when the Path state in the forward direction is torn down.


In order to build the Path message for the reverse direction, the RSVP Sender Proxy can take into account information in the received Path message for the forward direction. For example, the RSVP Sender Proxy may mirror the SENDER_TSPEC object in the received Path message.


We observe that this approach does not require any extensions to the existing RSVP protocol.


In the case where reservations are required in both directions (as shown in Figure 7), the RSVP-capable device simply needs to behave as a regular RSVP sender and RSVP receiver. It need not be aware that an RSVP proxy happens to be used, and the Path message it sent for the forward reservation also acts as the trigger for establishment of the reverse reservation. However, in the case where a reservation is only required in the reverse direction (as shown in Figure 6), the RSVP-capable device has to generate Path messages in order to trigger the reverse-direction reservation even if no reservation is required in the forward direction. Although this is not in violation of [RFC2205], it may not be the default behavior of an RSVP-capable device and therefore may need a behavioral change specifically to facilitate operation of the Path-Triggered Sender Proxy for Reverse Direction.


4.3. Inspection-Triggered Proxy
4.3. 検査トリガ型プロキシ

In this approach, it is assumed that the RSVP proxy is on the data path of "packets of interest", that it can inspect such packets on the fly as they transit through it, and that it can infer information from these packets of interest to determine what RSVP reservations need to be established, as well as when and with what characteristics (possibly also using some configured information).


One example of "packets of interest" could be application-level signaling. An RSVP proxy capable of inspecting SIP signaling for a multimedia session or RTSP signaling for video streaming can obtain from such signaling information about when a multimedia session is up or when a video is going to be streamed. It can also identify the addresses and ports of senders and receivers and can determine the bandwidth of the corresponding flows. It can also determine when the reservation is no longer needed and tear it down. Thus, such an RSVP proxy can determine all necessary information to synchronize RSVP reservations to application requirements. This is illustrated in Figure 8.


                              | Application |
                              | Signaling   |
                              | Entity      |
                                  /   \
                                 /     \
                                /       \
        <///////////////////////         \\\\\\\\\\\\\\\\\\\\\\\\>
    |----|        |********|      ***        |********|          |----|
    | S  |--------| RSVP   |------*r*--------| RSVP   |----------| R  |
    |----|        | Proxy  |      ***        | Proxy  |          |----|
                  |********|                 |********|


======= ======= RSVP>



 |----| Non-RSVP-capable   |----| Non-RSVP-capable      ***
 | S  | Sender             | R  | Receiver              *r* regular RSVP
 |----|                    |----|                       *** router

</\> application-level signaling

</ \>アプリケーションレベルのシグナリング

***> media flow


==> segment of flow path protected by RSVP reservation


Figure 8: Inspection-Triggered RSVP Proxy


Another example of "packets of interest" could be transport control messages (e.g., the Real-time Transport Control Protocol (RTCP) [RFC3550]) traveling alongside the application flow itself (i.e., media packets). An RSVP proxy capable of detecting the transit of packets from a particular flow can attempt to establish a reservation corresponding to that flow. Characteristics of the reservation may be derived by various methods such as from configuration, flow measurement, or a combination of those. However, these methods usually come with their respective operational drawbacks: configuration involves an operational cost and may hinder introduction of new applications, and measurement is reactive so that accurate reservation may lag actual traffic.


In the case of reservation failure, the Inspection-Triggered RSVP Proxy does not have a direct mechanism for notifying the application (since it is not participating itself actively in application signaling) so that the application is not in a position to take appropriate action (for example, terminate the corresponding session). To mitigate this problem, the Inspection-Triggered RSVP Proxy may differently mark the Differentiated Services codepoint (DSCP) ([RFC2474]) of flows for which an RSVP reservation has been successfully proxied from the flows for which a reservation is not in place. In some situations, the Inspection-Triggered Proxy might be able to modify the "packets of interest" (e.g., application signaling messages) to convey some hint to applications that the corresponding flows cannot be guaranteed by RSVP reservations.


With the Inspection-Triggered Proxy approach, the RSVP proxy is effectively required to attempt to build application awareness by traffic inspection and then is somewhat limited in the actions it can take in case of reservation failure. Depending on the "packets of interest" used by the RSVP proxy to trigger the reservation, there is a risk that the RSVP proxy will end up establishing a reservation for a media flow that actually never starts. However, this can be mitigated by the timing out and tearing down of an unnecessary reservation by the RSVP proxy when no corresponding media flow is observed. This flow observation and timeout approach can also be used to tear down reservations that were rightfully established for a flow but are no longer needed because the flow stopped.


The Inspection-Triggered approach is also subject to the general limitations associated with data inspection. This includes being impeded by encryption or tunneling, or being dependent on some topology constraints such as relying on the fact that both the packets of interest and the corresponding flow packets always transit through the same RSVP proxy.


Nonetheless, this may be a useful approach in specific environments. Note also that this approach does not require any change to the RSVP protocol.


With the Inspection-Triggered RSVP Proxy approach, the RSVP router may be configurable to use and interpret some specific packets of interest as the trigger for RSVP Receiver Proxy behavior.


When operating off signaling traffic, the Inspection-Triggered RSVP Proxy may be able to detect from the signaling that the endpoint is capable of establishing an RSVP reservation (e.g., in the case of SIP, via the inspection of the [RFC3312]/[RFC4032] precondition), in which case it would not behave as a proxy for that endpoint. Also, the Inspection-Triggered RSVP Proxy may inspect RSVP signaling, and if it sees RSVP signaling for the flow of interest, it can disable its Sender Proxy behavior for that flow (or that sender). Optionally, through RSVP signaling inspection, the Sender Proxy might also gradually "learn" (possibly with some timeout) which sender is RSVP-capable and which is not. These mechanisms can facilitate gradual and dynamic migration from the proxy model towards the end-to-end RSVP model as more and more endpoints become RSVP-capable.

シグナリングトラフィックをオフ操作する場合、検査トリガRSVPプロキシは、[RFC3312]の検査/ [RFC4032を介して、エンドポイントがSIPの場合には、例えば、(RSVP予約を確立することが可能であることをシグナリングから検出することができます]前提条件)、その場合には、そのエンドポイントのプロキシとして動作しないであろう。また、点検・トリガRSVPプロキシは、RSVPシグナリングを検査することができる、それが関心の流れのためのシグナリングRSVPを見れば、それはそのフロー(またはその送信者)のためにその送信者のプロキシの動作を無効にすることができます。必要に応じて、RSVPシグナリングの検査により、送信者のプロキシも徐々にRSVP-ことが可能であり、これはされていない送信者(おそらくいくつかのタイムアウト付き)「学習」することがあります。より多くのエンドポイントはRSVP-可能になるように、これらのメカニズムは、エンドツーエンドRSVPモデルに向かってプロキシモデルから漸進的かつ動的移行を容易にすることができます。

4.4. STUN-Triggered Proxy
4.4. STUNトリガ型プロキシ

In this approach, the RSVP proxy takes advantage of the application awareness provided by the Session Traversal Utilities for NAT (STUN) ([RFC5389]) signaling to synchronize RSVP reservations with application requirements. The STUN signaling is sent from endpoint to endpoint. This is illustrated in Figure 9. In this approach, a STUN message triggers the RSVP proxy.

このアプローチでは、RSVPプロキシは、アプリケーション要件にRSVP予約を同期させるためにシグナリングNATのためのセッショントラバーサルユーティリティ(STUN)([RFC5389])によって提供されるアプリケーションの認識を利用します。 STUNシグナリングは、エンドポイントからエンドポイントに送信されます。これは、STUNメッセージはRSVPプロキシをトリガし、この手法では、図9に示されています。

    |----|        |********|      ***        |********|          |----|
    | S  |--------| RSVP   |------*r*--------| RSVP   |----------| R  |
    |----|        | Proxy  |      ***        | Proxy  |          |----|
                  |********|                 |********|




======= ======= RSVP>



 |----| Non-RSVP-capable   |----| Non-RSVP-capable      ***
 | S  | Sender             | R  | Receiver              *r* regular RSVP
 |----|                    |----|                       *** router

^^^> STUN message flow (over same UDP ports as media flow)

(メディアフローと同じUDPポートを介して)^^^> STUNメッセージフロー

==> segment of flow path protected by RSVP reservation


***> RTP media flow

***> RTPメディアフロー

Figure 9: STUN-Triggered Proxy


For unicast flows, [RFC5245] is a widely adopted approach for Network Address Translator (NAT) traversal. For our purposes of triggering RSVP proxy behavior, we rely on the Interactive Connectivity Establishment (ICE) protocol's connectivity check, which is based on the exchange of STUN Binding Request messages between hosts to verify connectivity (see Section 2.2 of [RFC5245]). The STUN message could also include (yet to be specified) STUN attributes to indicate information such as the bandwidth and application requesting the flow, which would allow the RSVP proxy agent to create an appropriately sized reservation for each flow. Including such new STUN attributes in the ICE connectivity check messages would facilitate operation of the RSVP proxy. To ensure RSVP reservations are only established when needed, the RSVP proxy needs to distinguish, among all the STUN messages, the ones that reflect (with high likelihood) an actual upcoming media flow. This can be achieved by identifying the STUN messages associated with an ICE connectivity check. In turn, this can be achieved through (some combination of) the following checks:

ユニキャストフローについて、[RFC5245]は、ネットワークアドレス変換(NAT)トラバーサルのために広く採用されているアプローチです。 RSVPプロキシ行動を誘発する我々の目的のために、私たちは([RFC5245]のセクション2.2を参照)の接続性を確認するために、ホスト間で要求メッセージをバインディングSTUNの交換に基づいているインタラクティブ接続確立(ICE)プロトコルの接続性チェック、に依存しています。 STUNメッセージは、(まだ指定される)STUNは、RSVPプロキシエージェントは、各フローのために適切なサイズの予約を作成することを可能にする流れを、帯域要求およびアプリケーションなどの情報を示すために属性を含むことができます。 ICEの接続性チェックメッセージで、このような新しいSTUN属性を含めると、RSVPプロキシの動作を容易にするであろう。必要なときにRSVP予約が唯一の確立されていることを確認するには、RSVPプロキシは、すべてのSTUNメッセージのうち、(高い確率で)実際の今後のメディアフローを反映したものを区別する必要があります。これは、ICE接続性チェックに関連したSTUNメッセージを識別することによって達成することができます。今度は、これは以下のチェック(の組み合わせ)を介して達成することができます。

o if, as discussed above, new STUN attributes (e.g., conveying the flow bandwidth) are indeed defined in the future in view of facilitating STUN-Triggered reservations, then the presence of these attributes would reveal that the STUN message is part of an ICE connectivity check.


o the presence of the PRIORITY, USE-CANDIDATE, ICE-CONTROLLED, or ICE-CONTROLLING attributes reveals that the STUN message is part of an ICE connectivity check.


o the RSVP proxy may wait for a STUN message containing the USE-CANDIDATE attribute indicating the selected ICE "path" to trigger reservation only for the selected "path". This allows the RSVP proxy to only trigger a reservation for the "path" actually selected and therefore for the media flow that will actually be established (for example, when ICE is being used for IPv4/v6 path selection).

O RSVPプロキシは、選択された「パス」の予約をトリガするために選択されたICE「パス」を示すUSE候補属性を含むSTUNメッセージを待つことができます。これは、実際に選択され、したがって、(ICEは、IPv4 / v6の経路選択に使用されている場合など)、実際に確立されるメディアフローのための「パス」の予約をトリガするRSVPプロキシを可能にします。

o the RSVP proxy configuration could contain some information facilitating determination of when to perform RSVP proxy reservation and when not to. For example, the RSVP proxy configuration could contain the IP addresses of the STUN servers such that STUN messages to/from those addresses are known to not be part of an ICE connectivity check. As another example, the RSVP proxy configuration could contain information identifying the set of Differentiated Services codepoint (DSCP) values that the media flows requiring reservation use, so that STUN messages not using one of these DSCP values are known to not be part of an ICE connectivity check.


Despite these checks, there is always a potential risk that the RSVP proxy will end up establishing a reservation for a media flow that actually never starts. However, this is limited to situations in which the end-systems are interested enough in establishing connectivity for a flow but never transmit. Also, this can be mitigated by timing out and tear down of an unnecessary reservation by the RSVP proxy when no corresponding media flow is observed.


The RSVP proxy agent can inform endpoints of an RSVP reservation failure implicitly by dropping the ICE connectivity check message or explicitly by sending ICMP messages back to the endpoint. This allows reasonably effective synchronization between RSVP reservations handled by the RSVP proxies and the application running on non-RSVP-capable endpoints. It also has the benefits of operating through NATs.


For multicast flows (or certain kinds of unicast flows that don't or can't use ICE), a STUN Indication message [RFC5389] could be used to carry the (yet to be defined) STUN attributes mentioned earlier to indicate the flow bandwidth, thereby providing a benefit similar to the ICE connectivity check. STUN Indication messages are not acknowledged by the receiver and have the same scalability as the underlying multicast flow.

マルチキャストフロー(またはしないか、ICEを使用することができないユニキャストフローの特定の種類)のために、STUN指示メッセージ[RFC5389]は、フロー帯域幅を示すために、前述の(まだ定義される)STUN属性を運ぶために使用することができます、それによって、ICE接続性チェックに似た利益を提供します。 STUN指示メッセージは、受信機によって認め、基礎となるマルチキャストフローと同じ拡張性を持っていません。

The corresponding extensions to ICE and STUN for such a STUN-Triggered RSVP Proxy approach are beyond the scope of this document. They may be defined in the future in a separate document. As the STUN-Triggered RSVP Proxy approach uses STUN in a way (i.e., to trigger reservations) that is beyond its initial intended purpose, the potential security implications need to be considered by the operator.

このようSTUN-トリガRSVPプロキシアプローチのためのICEとSTUNに対応する拡張は、このドキュメントの範囲を超えています。彼らは別の文書で、将来的に定義されてもよいです。 STUN・トリガRSVPプロキシアプローチは、その最初の意図された目的を超えているように、STUN(すなわち、予約をトリガするために)使用されるように、潜在的なセキュリティ上の影響は、オペレータによって考慮される必要があります。

ICE connectivity checks are not always used for all flows. When the STUN-Triggered RSVP Proxy approach is used, it can establish RSVP reservations for flows for which ICE connectivity is performed. However, the STUN-Triggered RSVP Proxy will not establish a reservation for flows for which an ICE connectivity check is not performed. Those flows either will not benefit from an RSVP reservation or can benefit from an RSVP reservation established through other means (end-to-end RSVP, other forms of RSVP proxy).

ICEの接続性チェックは、常にすべてのフローのために使用されていません。 STUN・トリガRSVPプロキシアプローチが使用される場合、それはICE接続が実行されたフローのためのRSVP予約を確立することができます。しかし、STUN-トリガRSVPプロキシは、ICE接続性チェックが実行されていないフローの予約を確立しません。これらのフローは、RSVP予約恩恵を受けるないか、または他の手段を介して確立されたRSVP予約(エンドツーエンドRSVP、RSVPプロキシの他の形態)から利益を得ることができるいずれか。

The STUN-Triggered approach relies on interception and inspection of STUN messages. Thus, this approach may be impeded by encryption or tunneling.


4.5. Application_Entity-Controlled Proxy
4.5. Application_Entity制御されたプロキシ

In this approach, it is assumed that an entity involved in the application-level signaling controls an RSVP proxy that is located in the data path of the application flows (i.e., "on-path"). With this approach, the RSVP proxy does not itself attempt to determine the application reservation requirements. Instead, the RSVP proxy is instructed by the entity participating in application-level signaling to establish, maintain, and tear down reservations as needed by the application flows. In other words, with this approach, the solution for synchronizing RSVP signaling with application-level requirements is to rely on an application-level signaling entity that controls an RSVP proxy function that sits in the flow data path. This approach allows control of an RSVP Sender Proxy, an RSVP Receiver Proxy, or both.


Operation of the Application_Entity-Controlled Proxy is illustrated in Figure 10.


                        |---------|        |---------|
               /////////|  App    |////\\\\|  App    |\\\\\\\\
              /         | Entity  |        | Entity  |        \
             /          |---------|        |---------|         \
            /               //                \\                \
           /               //                  \\                \
          /               //                    \\                \
         /               //                      \\                \
        /               //                        \\                \
    |----|          |********|      ***       |*********|         |----|
    | S  |----------|        |------*r*-------|         |---------| R  |
    |----|          | RSVP   |      ***       | RSVP    |         |----|
                    | Sender |                | Receiver|
                    | Proxy  |                | Proxy   |
                    |********|                |*********|


======= ======= RSVP>



 |----| Non-RSVP-capable   |----| Non-RSVP-capable      ***
 | S  | Sender             | R  | Receiver              *r* regular RSVP
 |----|                    |----|                       *** router

***> media flow


==> segment of flow path protected by RSVP reservation


/\ Application signaling (e.g., SIP)

/ \アプリケーションシグナリング(例えば、SIP)

// RSVP proxy control interface

// RSVP代理制御インターフェース

Figure 10: Application_Entity-Controlled Proxy


As an example, the Application_Entity-Controlled Proxy may be used in the context of SIP servers ([RFC3261]) or Session Border Controllers (SBCs) (see [RFC5853] for a description of SBCs) to establish RSVP reservations for multimedia sessions. In that case, the application entity may be the signaling component of the SBC.


This RSVP proxy approach does not require any extension to the RSVP protocol. However, it relies on an RSVP proxy control interface allowing control of the RSVP proxy by an application signaling entity. This RSVP proxy control interface is beyond the scope of this document. Candidate protocols for realizing such an interface include the IETF Network Configuration (NETCONF) Protocol ([RFC4741], [RFC5277]), the Web Services protocol ([W3C]), the QoS Policy Information Model (QPIM) ([RFC3644]), and Diameter ([RFC3588]). This interface can rely on soft states or hard states. Clearly, when hard states are used, those need to be converted appropriately by the RSVP proxy entities into the corresponding RSVP soft states. As an example, [RFC5866] is intended to allow control of RSVP proxy via Diameter.

このRSVPプロキシアプローチは、RSVPプロトコルへの拡張を必要としません。しかし、それはアプリケーションシグナリングエンティティによってRSVPプロキシの制御を可能にするRSVPプロキシ制御インターフェースに依存します。このRSVP代理制御インターフェースは、このドキュメントの範囲を超えています。 IETFネットワーク設定(NETCONF)プロトコル([RFC4741]、[RFC5277])、ウェブサービスプロトコル([W3C])を含め、このようなインタフェースを実現するための候補プロトコル、QoSポリシーの情報モデル(QPIM)([RFC3644])、そして直径([RFC3588])。このインタフェースは、柔らかい状態または困難な状態に依存することができます。困難な状態が使用されている場合、明らかに、これらは対応するRSVPソフト状態にRSVPプロキシエンティティによって適切に変換する必要があります。一例として、[RFC5866]はビア径RSVPプロキシの制御を可能にするように意図されています。

In general, the application entity is not expected to maintain awareness of which RSVP Receiver Proxy is on the path to which destination. However, in the particular cases where it does so reliably, we observe that the application entity could control the RSVP Sender Proxy and Receiver Proxy so that aggregate RSVP reservations are used between those, instead of one reservation per flow. For example, these aggregate reservations could be of the RSVP-AGGREGATE type, as specified in [RFC3175], or of the GENERIC-AGGREGATE type, as specified in [RFC4860]. Such aggregate reservations could be used so that a single reservation can be used for multiple (possibly all) application flows transiting via the same RSVP Sender Proxy and the same RSVP Receiver Proxy.


For situations in which only the RSVP Sender Proxy has to be controlled by this interface, the interface may be realized through the simple use of RSVP itself, over a Generic Routing Encapsulation (GRE) tunnel from the application entity to the RSVP Sender Proxy. This particular case is further discussed in Section 4.5.1. Another particular case of interest is where the application signaling entity resides on the same device as the RSVP proxy. In that case, this interface may be trivially realized as an internal API. An example environment based on this particular case is illustrated in Section 4.5.2.


The application entity controlling the RSVP proxy (e.g., a SIP Call Agent) would often be aware of a number of endpoint capabilities, and it has to be aware of which endpoint can be best "served" by which RSVP proxy anyways. So it is reasonable to assume that such an application is aware of whether a given endpoint is RSVP-capable or not. The application may also consider the QoS preconditions and QoS mechanisms signaled by an endpoint as per [RFC3312]/[RFC4032] and [RFC5432]. The information about endpoint RSVP capability can then be used by the application to decide whether to trigger proxy behavior or not for a given endpoint. This can facilitate gradual and dynamic migration from the proxy model towards the end-to-end RSVP model as more and more endpoints become RSVP-capable.

RSVPプロキシ(例えば、SIPコールエージェント)は、多くの場合、エンドポイント機能の数を認識しているであろう、そしてそれがどのエンドポイントを知っていなければならない制御アプリケーションエンティティは最高のことができとにかくどのRSVPプロキシによって「務め」。だから、このようなアプリケーションは、特定のエンドポイントがRSVP対応であるかどうかを認識していると仮定することは合理的です。アプリケーションは、QoSの前提条件と[RFC3312] / [RFC4032]及び[RFC5432]に従って、エンドポイントによってシグナリングQoSメカニズムを考慮することができます。エンドポイントRSVP機能についての情報は、特定のエンドポイントのプロキシの動作やないをトリガするかどうかを決定するために、アプリケーションで使用することができます。より多くのエンドポイントはRSVP-可能になるので、これは、エンドツーエンドRSVPモデルに向かってプロキシモデルから漸進的かつ動的移行を容易にすることができます。

In some environments, the application entities (e.g., SIP back-to-back user agents) that need to control the RSVP proxies would already be deployed independently of the use, or not, of the Application_Entity-Controlled Proxy approach. In this case, the activation of the RSVP proxy approach should not introduce significant disruption in the application signaling path. In some environments, additional application entities may need to be deployed to control the RSVP proxies. In this case, the network operator needs to consider the associated risks of disruption to the application signaling path.


4.5.1. Application_Entity-Controlled Sender Proxy Using "RSVP over GRE"
4.5.1. 「GREオーバーRSVPの使用」を参照してApplication_Entity制御された送信者のプロキシ

This approach is simply a particular case of the more general Application_Entity-Controlled Proxy, but where only RSVP Sender Proxies need to be controlled by the application, and where RSVP is effectively used as the control protocol between the application-signaling entity and the RSVP Sender Proxy.


In this approach, the RSVP messages (e.g., RSVP Path message) are effectively generated by the application entity and logically "tunneled" to the RSVP Sender Proxy via GRE tunneling. This is to ensure that the RSVP messages follow the exact same path as the flow they protect (as required by RSVP operations) on the segment of the end-to-end path that is to be subject to RSVP reservations.

このアプローチでは、RSVPメッセージ(例えば、RSVP Pathメッセージ)を効果的にアプリケーションエンティティによって生成され、論理的にGREトンネルを介してRSVP送信側プロキシに「トンネリング」。これは、RSVPメッセージは(RSVP操作によって要求されるように)、彼らは予約をRSVPの対象となるエンドツーエンドパスのセグメントに保護フローとまったく同じ経路に従うことを保証することです。

Figure 11 illustrates such an environment.


                    ////////////| Application |\\\\\\\\\
                   /            | Entity      |         \
                  /             |-------------|          \
                 /                 /=/                    \
                /                 /=/                      \
               /                 /=/                        \
              /                 /=/                          \
             /                 /=/                            \
            /                 /=/                              \
           /                 /=/                                \
          /                 /=/                                  \
     |----|           |********|           ***                 |****|
     | S  |-----------| RSVP   |-----------*r*-----------------| R  |
     |----|           | Sender |           ***                 |****|
                      | Proxy  |



  |----| non-RSVP-capable     |----| RSVP-capable       ***
  | S  | Sender               | R  | Receiver           *r* regular RSVP
  |----|                      |----|                    *** router

***> media flow


==> segment of flow path protected by RSVP reservation


/\ Application-level signaling

/ \アプリケーションレベルのシグナリング

/=/ GRE-tunneled RSVP (Path messages)

/ = / GREトンネリングRSVP(Pathメッセージ)

         Figure 11: Application_Entity-Controlled Sender Proxy via
                              "RSVP over GRE"

With the Application_Entity-Controlled Sender Proxy using "RSVP Over GRE", the application entity:


o generates a Path message on behalf of the sender, corresponding to the reservation needed by the application, and maintains the corresponding Path state. The Path message built by the application entity is exactly the same as would be built by the actual sender (if it was RSVP-capable), with one single exception, which is that the application entity puts its own IP address as the RSVP previous hop. In particular, it is recommended that the source address of the Path message built by the application entity be set to the IP address of the sender (not of the application entity). This helps ensure that, in the presence of non-RSVP routers and of load-balancing in the network where the load-balancing algorithm takes into account the source IP address, the Path message generated by the application entity follows the exact same path as the actual stream sourced by the sender.


o encapsulates the Path message into a GRE tunnel whose destination address is the RSVP Sender Proxy, i.e., an RSVP router sitting on the data path for the flow (and upstream of the segment that requires QoS guarantees via RSVP reservation).


o processes the corresponding received RSVP messages (including Resv messages) as per regular RSVP.


o synchronizes the RSVP reservation state with application-level requirements and signaling.


Note that since the application entity encodes its own IP address as the previous RSVP hop inside the [RFC2205] RSVP_HOP object of the Path message, the RSVP router terminating the GRE tunnel naturally addresses all the RSVP messages traveling upstream hop-by-hop (such as Resv messages) to the application entity (without having to encapsulate those in a reverse-direction GRE tunnel towards the application entity).

アプリケーションエンティティは、Pathメッセージの[RFC2205] RSVP_HOPオブジェクト内の前のRSVPホップとして自身のIPアドレスを符号化するので、GREトンネルを終端RSVPルータは当然上流ホップバイホップ(例えば走行すべてのRSVPメッセージに対処することに注意してくださいアプリケーション・エンティティへRESVメッセージ)として()アプリケーションエンティティに向かって逆方向GREトンネルにそれらをカプセル化することなく。

4.5.2. Application_Entity-Controlled Proxy via Co-Location
4.5.2. コロケーション経由Application_Entity制御されたプロキシ

This approach is simply a particular case of the more general Application_Entity-Controlled Proxy, but where the application entity is co-located with the RSVP proxy. As an example, Session Border Controllers (SBCs) with on-board SIP agents could implement RSVP proxy functions and make use of such an approach to achieve session admission control over the SBC-to-SBC segment using RSVP signaling.


Figure 12 illustrates operations of the Application_Entity-Controlled RSVP Proxy via co-location.


                  |---------|               |---------|
          ////////| App     |////////\\\\\\\| App     |\\\\\\\\\
         /        | Entity  |               | Entity  |         \
        /         |         |               |         |          \
    |----|        |*********|      ***      |*********|         |----|
    | S  |--------| RSVP    |------*r*------| RSVP    |---------| R  |
    |----|        | Sender  |      ***      | Receiver|         |----|
                  | Proxy   |               | Proxy   |
                  |*********|               |*********|


======= RSVP ======>



 |----| Non-RSVP-capable   |----| Non-RSVP-capable      ***
 | S  | Sender             | R  | Receiver              *r* regular RSVP
 |----|                    |----|                       *** router

***> media flow


==> segment of flow path protected by RSVP reservation


/\ Application-level signaling

/ \アプリケーションレベルのシグナリング

Figure 12: Application_Entity-Controlled Proxy via Co-Location


This RSVP proxy approach does not require any protocol extensions. We also observe that when multiple sessions are to be established on paths sharing the same RSVP Sender Proxy and the same RSVP Receiver Proxy, the RSVP proxies have the option to establish aggregate RSVP reservations (as defined in ([RFC3175] or [RFC4860]) for a group of sessions, instead of establishing one RSVP reservation per session.


4.6. Policy_Server-Controlled Proxy
4.6. Policy_Server制御されたプロキシ

In this approach, it is assumed that a policy server, which is located in the control plane of the network, controls an RSVP proxy that is located in the data path of the application flows (i.e., "on-path"). In turn, the policy server is triggered by an entity involved in the application-level signaling. With this approach, the RSVP proxy does not itself attempt to determine the application reservation requirements, but instead is instructed by the policy server to establish, maintain, and tear down reservations as needed by the application flows. Moreover, the entity participating in application-level signaling does not attempt to understand the specific reservation mechanism (i.e., RSVP) or the topology of the network layer, but instead it simply asks the policy server to perform (or tear down) a reservation. In other words, with this approach, the solution for synchronizing RSVP signaling with application-level requirements is to rely on an application-level entity that controls a policy server that, in turn, controls an RSVP proxy function that sits in the flow data path. This approach allows control of an RSVP Sender Proxy, an RSVP Receiver Proxy, or both.


Operation of the Policy_Server-Controlled proxy is illustrated in Figure 13.


                   /////////////|  App    |\\\\\\\\\\\\\\
                  /             | Entity  |              \
                 /              |---------|               \
                /                    I                     \
               /                     I                      \
              /                 |----------|                 \
             /                  |  Policy  |                  \
            /                   |  Server  |                   \
           /                    |----------|                    \
          /                    //          \\                    \
         /                    //            \\                    \
        /                    //              \\                    \
    |----|           |********|      ***     |*********|          |----|
    | S  |-----------|        |------*r*-----|         |----------| R  |
    |----|           | RSVP   |      ***     | RSVP    |          |----|
                     | Sender |              | Receiver|
                     | Proxy  |              | Proxy   |
                     |********|              |*********|


===== RSVP ========>



 |----| Non-RSVP-capable   |----| Non-RSVP-capable      ***
 | S  | Sender             | R  | Receiver              *r* regular RSVP
 |----|                    |----|                       *** router

***> media flow


==> segment of flow path protected by RSVP reservation


/\ Application signaling (e.g., SIP)

/ \アプリケーションシグナリング(例えば、SIP)

// RSVP proxy control interface

// RSVP代理制御インターフェース

I Interface between application entity and policy server


Figure 13: Policy_Server-Controlled Proxy


This RSVP proxy approach does not require any extension to the RSVP protocol. However, as with the Application_Entity-Controlled Proxy approach presented in Figure 10, this approach relies on an RSVP proxy control interface allowing control of the RSVP proxy (by the policy server in this case). This RSVP proxy control interface is beyond the scope of this document. Considerations about candidate protocols for realizing such an interface can be found in


Section 4.5. Again, for situations in which only the RSVP Sender Proxy has to be controlled by this interface, the interface may be realized through the simple use of RSVP itself, over a GRE tunnel from the policy server to the RSVP Sender Proxy. This is similar to what is presented in Section 4.5.1, except that the "RSVP over GRE" interface is used in this case by the policy server (instead of the application entity).

4.5節。再び、唯一のRSVP送信側プロキシは、このインタフェースによって制御されなければならない状況のために、インターフェースは、RSVP送信側プロキシにポリシーサーバからGREトンネルを介して、RSVP自体の簡単な使用を介して実現されてもよいです。これは、「RSVP GRE上」インターフェースは、ポリシーサーバ(代わりのアプリケーションエンティティ)によって、この場合に使用されることを除いて、セクション4.5.1に提示されているものと同様です。

The interface between the application entity and the policy server is beyond the scope of this document.


4.7. RSVP-Signaling-Triggered Proxy
4.7. プロキシRSVP-シグナリング・トリガ

An RSVP proxy can also be triggered and controlled through extended RSVP signaling from the remote end that is RSVP-capable (and supports these RSVP extensions for proxy control). For example, an RSVP-capable sender could send a new or extended RSVP message explicitly requesting an RSVP proxy on the path towards the receiver to behave as an RSVP Receiver Proxy and also to trigger a reverse-direction reservation, thus also behaving as an RSVP Sender Proxy. The new or extended RSVP message sent by the sender could also include attributes (e.g., bandwidth) for the reservations to be signaled by the RSVP proxy.


The challenges in these explicit signaling schemes include the following:


o How can the nodes determine when a reservation request ought to be proxied and when it should not, and accordingly invoke appropriate signaling procedures?


o How does the node sending the messages explicitly triggering the proxy know where the proxy is located, e.g., determine an IP address of the proxy that should reply to the signaling?


o How is all the information needed by a Sender Proxy to generate a Path message actually communicated to the proxy?


An example of such a mechanism is presented in [QOS-MOBILE]. This scheme is primarily targeted to local access network reservations whereby an end host can request resource reservations for both incoming and outgoing flows only over the access network. This may be useful in environments where the access network is typically the bottleneck while the core is comparatively over-provisioned, as may be the case with a number of radio access technologies. In this proposal, messages targeted to the proxy are flagged with one bit in all RSVP messages. Similarly, all RSVP messages sent back by the proxy are also flagged. The use of such a flag allows differentiating between proxied and end-to-end reservations. For triggering an RSVP Receiver Proxy, the sender of the data sends a Path message that is marked with the mentioned flag. The Receiver Proxy is located on the signaling and data path, eventually gets the Path message, and replies back with a Resv message. A node triggers an RSVP Sender Proxy with a newly defined Path_Request message, which instructs the proxy to send Path messages towards the triggering node. The node then replies back with a Resv. More details can be found in [QOS-MOBILE].

そのような機構の例は、[QOS-MOBILE]に提示されています。この方式は、主にエンドホストのみアクセスネットワークを介して受信および送信の両方のフローのためのリソース予約を要求することができるローカル・アクセス・ネットワークの予約に標的化されます。これは、無線アクセス技術の数の場合であってもよいように、コアは、比較的オーバープロビジョニングされている間、アクセスネットワークは、典型的には、ボトルネックになっている環境において有用であり得ます。この提案では、プロキシを対象のメッセージは、すべてのRSVPメッセージ内の1ビットのフラグが立てられています。同様に、プロキシにより返送されたすべてのRSVPメッセージもフラグが付けられます。このようなフラグの使用は、プロキシとエンド・ツー・エンドの予約を区別することができます。 RSVP受信プロキシをトリガするため、データの送信者は、上述のフラグでマークされたPathメッセージを送信します。受信プロキシは、最終的にPathメッセージを取得し、バックResvメッセージで応答し、シグナリング及びデータ経路上に配置されています。ノードは、トリガーノードに向けてPathメッセージを送信するようにプロキシに指示し、新たに定義されたPath_RequestメッセージとRSVP送信側プロキシをトリガします。ノードは、当時のResvと返答します。詳細は[QOS-MOBILE]で見つけることができます。

Such an RSVP-Signaling-Triggered Proxy approach would require RSVP signaling extensions (that are outside the scope of this document). However, it could provide more flexibility in the control of the proxy behavior (e.g., control of reverse reservation parameters) than would the Path-Triggered approaches defined in Section 4.1 and Section 4.2.


Through potential corresponding protocol extensions, an RSVP-Signaling-Triggered Proxy approach could facilitate operation (e.g., reduce or avoid the need for associated configuration) in hybrid environments involving both reservations established end-to-end and reservations established via RSVP proxies. For example, [QOS-MOBILE] proposed a mechanism allowing an end-system to control whether a reservation can be handled by an RSVP proxy on the path, or is to be established end-to-end.


4.8. Reachability Considerations
4.8. 到達可能性に関する注意事項

There may be situations in which the RSVP Receiver Proxy is reachable by the sender, while the receiver itself is not. In such situations, it is possible that the RSVP Receiver Proxy is not always aware that the receiver is unreachable, and consequently may accept to establish an RSVP reservation on behalf of that receiver. This would result in unnecessary reservation establishment and unnecessary network resource consumption.


This is not considered a significant practical concern for a number of reasons. First, in many cases, if the receiver is not reachable from the sender, it will not be reachable for application signaling either, and so application-level session establishment will not be possible in the first place. Secondly, where the receiver is unreachable from the sender but is reachable for application-level signaling (say, because session establishment is performed through an off-path SIP agent that uses a different logical topology to communicate with the receiver), then the sender may detect that the receiver is unreachable before attempting reservation establishment. This may be achieved through mechanisms such as ICE's connectivity check ([RFC5245]). Finally, even if the sender does not detect that


the receiver is unreachable before triggering the RSVP reservation establishment, it is very likely that the application will quickly realize this lack of connectivity (e.g., the human accepting the phone call on the receiver side will not hear the human's voice on the sender side) and therefore tear down the session (e.g., hang up the phone), which in turn will trigger RSVP reservation release.


Nonetheless, it is recommended that network administrators consider the above in light of their particular environment when deploying RSVP proxies.


The mirror considerations apply for situations involving an RSVP Sender Proxy and where the sender cannot reach the destination while the RSVP Sender Proxy can.


5. Security Considerations

In the environments of concern for this document, RSVP messages are used to control resource reservations on a segment of the end-to-end path of flows. The general security considerations associated with [RFC2205] apply. To ensure the integrity of the associated reservation and admission control mechanisms, the RSVP cryptographic authentication mechanisms defined in [RFC2747] and [RFC3097] can be used. Those protect RSVP messages integrity hop-by-hop and provide node authentication, thereby protecting against corruption, spoofing of RSVP messages, and replay. [RSVP-SEC-KEY] discusses key types and key provisioning methods, as well as their respective applicability to RSVP authentication.

この文書の懸念の環境では、RSVPメッセージは、フローのエンドツーエンドパスのセグメントに資源予約を制御するために使用されます。 [RFC2205]に関連した一般的なセキュリティ上の考慮事項が適用されます。関連する予約および入場制御機構の完全性を保証するために、[RFC2747]及び[RFC3097]で定義されたRSVP暗号化認証メカニズムを使用することができます。これらの保護RSVPメッセージの完全性によってホップホップノードの認証を提供し、それによって破損、RSVPメッセージのなりすまし、リプレイに対する保護します。 [RSVP-SEC-KEY]は認証をRSVPキータイプとキープロビジョニング方法、ならびにそれらのそれぞれの適用性を論じています。

[RSVP-SEC-KEY] also discusses applicability of IPsec mechanisms ([RFC4302][RFC4303]) and associated key provisioning methods for security protection of RSVP. This discussion applies to the protection of RSVP in the presence of RSVP proxies as defined in this document.


A subset of RSVP messages are signaled with the IP router alert option ([RFC2113], [RFC2711]). Based on the current security concerns associated with the use of the IP router alert option, the applicability of RSVP (and therefore of the RSVP proxy approaches discussed in this document) is limited to controlled environments (i.e., environments where the security risks associated with the use of the IP router alert option are understood and protected against). The security aspects and common practices around the use of the current IP router alert option, and consequences of using the IP router alert option by applications such as RSVP, are discussed in detail in [RTR-ALERT].

RSVPメッセージのサブセットは、IPルータ警告オプション([RFC2113]、[RFC2711])で通知されます。 IPルータ警告オプションの使用に関連した現在のセキュリティ上の懸念に基づいて、(そのため、この文書で説明するRSVPプロキシアプローチの)RSVPの適用性は、制御された環境のセキュリティリスクは、関連付けられた(すなわち、環境に制限されていますIPルータアラートオプションの使用は)理解して保護されています。セキュリティ面および共通プラクティス現在のIPルータ警告オプションの使用の周りに、そのようなRSVPなどのアプリケーションによって、IPルータ警告オプションを使用しての結果は、[RTR-ALERT]で詳しく説明されています。

A number of additional security considerations apply to the use of RSVP proxies and are discussed below.


With some RSVP proxy approaches, the RSVP proxy operates autonomously inside an RSVP router. This is the case for the Path-Triggered Proxy approaches defined in Section 4.1 and in Section 4.2, for the Inspection-Triggered Proxy approach defined in Section 4.3, for the STUN-Triggered Proxy approach defined in Section 4.4, and for the RSVP-Signaling-Triggered approach defined in Section 4.7. Proper reservation operation assumes that the RSVP proxy can be trusted to behave correctly in order to control the RSVP reservation as required and expected by the end-systems. Since the basic RSVP operation already assumes a trust model where end-systems trust RSVP nodes to appropriately perform RSVP reservations, the use of an RSVP proxy that behaves autonomously within an RSVP router is not seen as introducing any significant additional security threat or as fundamentally modifying the RSVP trust model.


With some RSVP proxy approaches, the RSVP proxy operates under the control of another entity. This is the case for the Application_Entity-Controlled Proxy approach defined in Section 4.5 and for the Policy_Server-Controlled Proxy approach defined in Section 4.6. This introduces additional security risks since the entity controlling the RSVP proxy needs to be trusted for proper reservation operation and also introduces additional authentication and confidentiality requirements. The exact mechanisms to establish such trust, authentication, and confidentiality are beyond the scope of this document, but they may include security mechanisms inside the protocol used as the control interface between the RSVP proxy and the entity controlling it, as well as security mechanisms for all the interfaces involved in the reservation control chain (e.g., inside the application signaling protocol between the end-systems and the application entity, and, in the case of the Policy_Server-Controlled Proxy approach, in the protocol between the application entity and the policy server).

いくつかのRSVPプロキシのアプローチでは、RSVPプロキシは別のエンティティの制御下で動作します。これは、4.5節で定義されたApplication_Entity制御されたプロキシのアプローチのためとセクション4.6で定義されたPolicy_Server制御されたプロキシのアプローチのためのケースです。 RSVPプロキシを制御エンティティは、適切な予約操作に対して信頼する必要があり、また、追加の認証と機密性の要件を紹介するので、これは、追加のセキュリティリスクを紹介します。正確なメカニズムはこの文書の範囲を超えて、このような信頼、認証、機密性を確立するために、彼らはそれを制御RSVPプロキシとエンティティ間の制御インタフェースとして使用されるプロトコル内のセキュリティメカニズム、ならびにセキュリティメカニズムを含んでいてもよいです予約制御チェーンに関与するすべてのインタフェース(例えば、エンド・システムおよびアプリケーション・エンティティ間のアプリケーションシグナリングプロトコルの内側、及び、Policy_Server-制御プロキシアプローチの場合には、アプリケーション・エンティティと、ポリシー間のプロトコルでサーバ)。

In some situations, the use of RSVP proxy to control reservations on behalf of end-systems may actually reduce the security risk (at least from the network operator viewpoint). This could be the case, for example, because the routers where the RSVP proxy functionality runs are less exposed to tampering than end-systems. Such a case is further discussed in Section 4 of [RFC5946]. This could also be the case because the use of RSVP proxy allows localization of RSVP operation within the boundaries of a given administrative domain (thus easily operating as a controlled environment) while the end-to-end flow path spans multiple administrative domains.


6. Acknowledgments

This document benefited from earlier work on the concept of RSVP proxy including the one documented by Silvano Gai, Dinesh Dutt, Nitsan Elfassy, and Yoram Bernet. It also benefited from discussions with Pratik Bose, Chris Christou, and Michael Davenport. Tullio Loffredo and Massimo Sassi provided the base material for Section 4.6. Thanks to James Polk, Magnus Westerlund, Dan Romascanu, Ross Callon, Cullen Jennings, and Jari Arkko for their thorough review and comments.

この文書では、シルヴァーノガイ、ディネッシュダット、Nitsan Elfassy、およびYoram Bernetによって文書1を含むRSVPプロキシの概念上の以前の仕事の恩恵を受けました。またPratikボーズ、クリスChristouの、そしてマイケル・ダベンポートとの議論の恩恵を受けました。 TullioのLoffredoとマッシモサッシは、4.6節のための基材を提供しました。彼らの徹底的なレビューとコメントのためのジェームズ・ポーク、マグヌスウェスター、ダンRomascanu、ロスCallon、カレン・ジェニングス、とヤリArkkoに感謝します。

7. References
7.1. Normative References
7.1. 引用規格

[RFC2205] Braden, B., Zhang, L., Berson, S., Herzog, S., and S. Jamin, "Resource ReSerVation Protocol (RSVP) -- Version 1 Functional Specification", RFC 2205, September 1997.

[RFC2205]ブレーデン、B.、チャン、L.、Berson氏、S.、ハーツォグ、S.、およびS.ヤミン、 "リソース予約プロトコル(RSVP) - バージョン1機能仕様"、RFC 2205、1997年9月。

[RFC2210] Wroclawski, J., "The Use of RSVP with IETF Integrated Services", RFC 2210, September 1997.

[RFC2210] Wroclawski、J.、RFC 2210、1997年9月 "IETF統合サービスとRSVPの使用"。

[RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, December 1998.

[RFC2475]ブレイク、S.、ブラ​​ック、D.、カールソン、M.、デイヴィス、E.、王、Z.、およびW.ワイス、 "差別化サービスのためのアーキテクチャ"、RFC 2475、1998年12月。

[RFC2747] Baker, F., Lindell, B., and M. Talwar, "RSVP Cryptographic Authentication", RFC 2747, January 2000.

[RFC2747]ベーカー、F.、リンデル、B.、およびM. Talwar、 "RSVP暗号化認証"、RFC 2747、2000年1月。

[RFC3097] Braden, R. and L. Zhang, "RSVP Cryptographic Authentication -- Updated Message Type Value", RFC 3097, April 2001.

[RFC3097]ブレーデン、R.とL.チャン、 "RSVP暗号化認証 - 更新メッセージタイプ価値"、RFC 3097、2001年4月。

[RFC5245] Rosenberg, J., "Interactive Connectivity Establishment (ICE): A Protocol for Network Address Translator (NAT) Traversal for Offer/Answer Protocols", RFC 5245, April 2010.

[RFC5245]ローゼンバーグ、J.、 "インタラクティブ接続確立(ICE):オファー/回答プロトコルのためのネットワークアドレス変換(NAT)トラバーサルのための議定書"、RFC 5245、2010年4月。

[RFC5389] Rosenberg, J., Mahy, R., Matthews, P., and D. Wing, "Session Traversal Utilities for NAT (STUN)", RFC 5389, October 2008.

[RFC5389]ローゼンバーグ、J.、マーイ、R.、マシューズ、P.、およびD.翼、 "NAT(STUN)のセッショントラバーサルユーティリティ"、RFC 5389、2008年10月。

7.2. Informative References
7.2. 参考文献

[QOS-MOBILE] Manner, J., "Provision of Quality of Service in IP-based Mobile Access Networks", Doctoral dissertation, University of Helsinki, 2003, <>.

、博士論文、ヘルシンキ大学、2003年、<> [QOS-MOBILE]マナー、J.、 "IPベースのモバイルアクセスネットワークにおけるサービス品質の提供"。

[RFC1633] Braden, B., Clark, D., and S. Shenker, "Integrated Services in the Internet Architecture: an Overview", RFC 1633, June 1994.

[RFC1633]ブレーデン、B.、クラーク、D.、およびS. Shenker、 "インターネットアーキテクチャにおける統合サービス:概要"、RFC 1633、1994年6月。

[RFC2113] Katz, D., "IP Router Alert Option", RFC 2113, February 1997.

[RFC2113]カッツ、D.、 "IPルータアラートオプション"、RFC 2113、1997年2月。

[RFC2326] Schulzrinne, H., Rao, A., and R. Lanphier, "Real Time Streaming Protocol (RTSP)", RFC 2326, April 1998.

[RFC2326] SchulzrinneとH.とラオとA.、およびR. Lanphier、 "リアルタイムのストリーミングプロトコル(RTSP)"、RFC 2326、1998年4月。

[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, December 1998.

[RFC2474]ニコルズ、K.、ブレイク、S.、ベイカー、F.、およびD.黒、 "IPv4とIPv6ヘッダーとの差別化されたサービス分野(DS分野)の定義"、RFC 2474、1998年12月。

[RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", RFC 2711, October 1999.

[RFC2711]ウズラ、C.とA.ジャクソン、 "IPv6のルータアラートオプション"、RFC 2711、1999年10月。

[RFC2872] Bernet, Y. and R. Pabbati, "Application and Sub Application Identity Policy Element for Use with RSVP", RFC 2872, June 2000.

[RFC2872] Bernet、Y.およびR. Pabbati、 "RSVPで使用するアプリケーションおよびサブアプリケーションIDポリシー要素"、RFC 2872、2000年6月。

[RFC2961] Berger, L., Gan, D., Swallow, G., Pan, P., Tommasi, F., and S. Molendini, "RSVP Refresh Overhead Reduction Extensions", RFC 2961, April 2001.

[RFC2961]バーガー、L.、ガン、D.、ツバメ、G.、パン、P.、Tommasi、F.、及びS. Molendini、 "RSVPリフレッシュオーバーヘッド削減拡張"、RFC 2961、2001年4月。

[RFC3175] Baker, F., Iturralde, C., Le Faucheur, F., and B. Davie, "Aggregation of RSVP for IPv4 and IPv6 Reservations", RFC 3175, September 2001.

[RFC3175]ベーカー、F.、Iturralde、C.、ルFaucheur、F.、およびB.デイビー、 "IPv4とIPv6の予約のためのRSVPの集約"、RFC 3175、2001年9月。

[RFC3261] Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston, A., Peterson, J., Sparks, R., Handley, M., and E. Schooler, "SIP: Session Initiation Protocol", RFC 3261, June 2002.

[RFC3261]ローゼンバーグ、J.、Schulzrinneと、H.、カマリロ、G.、ジョンストン、A.、ピーターソン、J.、スパークス、R.、ハンドレー、M.、およびE.学生、 "SIP:セッション開始プロトコル" 、RFC 3261、2002年6月。

[RFC3312] Camarillo, G., Marshall, W., and J. Rosenberg, "Integration of Resource Management and Session Initiation Protocol (SIP)", RFC 3312, October 2002.

[RFC3312]キャマリロ、G.、マーシャル、W.、およびJ.ローゼンバーグ、RFC 3312、2002年10月 "資源管理とセッション開始プロトコル(SIP)の統合"。

[RFC3550] Schulzrinne, H., Casner, S., Frederick, R., and V. Jacobson, "RTP: A Transport Protocol for Real-Time Applications", STD 64, RFC 3550, July 2003.

[RFC3550] Schulzrinneと、H.、Casner、S.、フレデリック、R.、およびV.ヤコブソン、 "RTP:リアルタイムアプリケーションのためのトランスポートプロトコル"、STD 64、RFC 3550、2003年7月。

[RFC3588] Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and J. Arkko, "Diameter Base Protocol", RFC 3588, September 2003.

[RFC3588]カルフーン、P.、Loughney、J.、ガットマン、E.、ゾルン、G.、およびJ. Arkko、 "直径ベースプロトコル"、RFC 3588、2003年9月。

[RFC3644] Snir, Y., Ramberg, Y., Strassner, J., Cohen, R., and B. Moore, "Policy Quality of Service (QoS) Information Model", RFC 3644, November 2003.

[RFC3644] SNIR、Y.、Ramberg、Y.、Strassner、J.、コーエン、R.、およびB.ムーア、 "サービスの方針品質(QoS)情報モデル"、RFC 3644、2003年11月。

[RFC4032] Camarillo, G. and P. Kyzivat, "Update to the Session Initiation Protocol (SIP) Preconditions Framework", RFC 4032, March 2005.

[RFC4032]キャマリロ、G.とP. Kyzivat、 "セッション開始プロトコル(SIP)前提条件フレームワークへの更新"、RFC 4032、2005年3月。

[RFC4301] Kent, S. and K. Seo, "Security Architecture for the Internet Protocol", RFC 4301, December 2005.

[RFC4301]ケント、S.とK. Seo、 "インターネットプロトコルのためのセキュリティアーキテクチャ"、RFC 4301、2005年12月。

[RFC4302] Kent, S., "IP Authentication Header", RFC 4302, December 2005.

[RFC4302]ケント、S.、 "IP認証ヘッダー"、RFC 4302、2005年12月。

[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", RFC 4303, December 2005.

[RFC4303]ケント、S.、 "IPカプセル化セキュリティペイロード(ESP)"、RFC 4303、2005年12月。

[RFC4566] Handley, M., Jacobson, V., and C. Perkins, "SDP: Session Description Protocol", RFC 4566, July 2006.

[RFC4566]ハンドリー、M.、ヤコブソン、V.、およびC.パーキンス、 "SDP:セッション記述プロトコル"、RFC 4566、2006年7月。

[RFC4741] Enns, R., "NETCONF Configuration Protocol", RFC 4741, December 2006.

[RFC4741]エンス、R.、 "NETCONF構成プロトコル"、RFC 4741、2006年12月。

[RFC4860] Le Faucheur, F., Davie, B., Bose, P., Christou, C., and M. Davenport, "Generic Aggregate Resource ReSerVation Protocol (RSVP) Reservations", RFC 4860, May 2007.

[RFC4860]ルFaucheur、F.、デイビー、B.、ボーズ、P.、Christouの、C.、およびM.ダヴェンポート、 "汎用集計リソース予約プロトコル(RSVP)予約"、RFC 4860、2007年5月。

[RFC4923] Baker, F. and P. Bose, "Quality of Service (QoS) Signaling in a Nested Virtual Private Network", RFC 4923, August 2007.

[RFC4923]ベイカー、F.およびP.ボーズ、RFC 4923、2007年8月 "ネストされた仮想プライベートネットワークにシグナリングサービス品質(QoS)"。

[RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event Notifications", RFC 5277, July 2008.

[RFC5277]チザム、S.およびH.トレビノ、 "NETCONFイベント通知"、RFC 5277、2008年7月。

[RFC5432] Polk, J., Dhesikan, S., and G. Camarillo, "Quality of Service (QoS) Mechanism Selection in the Session Description Protocol (SDP)", RFC 5432, March 2009.

[RFC5432]ポーク、J.、Dhesikan、S.、およびG.キャマリロ、 "QoS(Quality of Service)をセッション記述プロトコル(SDP)におけるメカニズムの選択"、RFC 5432、2009年3月。

[RFC5853] Hautakorpi, J., Camarillo, G., Penfield, R., Hawrylyshen, A., and M. Bhatia, "Requirements from Session Initiation Protocol (SIP) Session Border Control (SBC) Deployments", RFC 5853, April 2010.

[RFC5853] Hautakorpi、J.、カマリロ、G.、ペンフィールド、R.、Hawrylyshen、A.、およびM. Bhatiaは、RFC 5853年4月 "セッション開始プロトコル(SIP)セッションボーダーコントロール(SBC)デプロイメントの要件" 2010。

[RFC5866] Sun, D., McCann, P., Tschofenig, H., Tsou, T., Doria, A., and G. Zorn, "Diameter Quality-of-Service Application", RFC 5866, May 2010.

[RFC5866]日、D.、マッキャン、P.、Tschofenig、H.、ツオウ、T.、ドリア、A.、およびG.ツォルン、 "直径サービス品質の応用"、RFC 5866、2010年5月。

[RFC5946] Le Faucheur, F., Manner, J., Narayanan, A., Guillou, A., and H. Malik, "Resource Reservation Protocol (RSVP) Extensions for Path-Triggered RSVP Receiver Proxy", RFC 5946, October 2010.

[RFC5946]ルFaucheur、F.、マナー、J.、ナラヤナン、A.、Guillou、A.、およびH.マリク、 "リソース予約プロトコル(RSVP)パス・トリガRSVP受信プロキシの拡張"、RFC 5946年10月2010。

[RFC5974] Manner, J., Karagiannis, G., and A. McDonald, "NSIS Signaling Layer Protocol (NSLP) for Quality-of-Service Signaling", RFC 5974, October 2010.

[RFC5974]マナー、J.、Karagiannis、G.、およびA.マクドナルド、 "NSISシグナリング層プロトコルクオリティ・オブ・サービスシグナリングのための(NSLP)"、RFC 5974、2010年10月。

[RSVP-SEC-KEY] Behringer, M. and F. Le Faucheur, "Applicability of Keying Methods for RSVP Security", Work in Progress, June 2009.

[RSVP-SEC-KEY]ベリンガー、M.とF.ルFaucheur、 "RSVPセキュリティのためのキーイング方法の適用"、進歩、2009年6月での作業。

[RTR-ALERT] Le Faucheur, F., "IP Router Alert Considerations and Usage", Work in Progress, October 2009.

[RTR-ALERT]ルFaucheur、F.、 "IPルータアラートの考慮事項および使用方法"、進歩、2009年10月に作業。

[W3C] "World Wide Web Consortium (W3C) - Web Services Architecture", <>.

[W3C] "ワールド・ワイド・ウェブ・コンソーシアム(W3C) - Webサービスのアーキテクチャ"、<>。

Appendix A. Use Cases for RSVP Proxies


A.1. RSVP-Based VoD Admission Control in Broadband Aggregation Networks


As broadband services for residential customers are becoming more and more prevalent, next-generation aggregation networks are being deployed in order to aggregate traffic from broadband users (whether attached via Digital Subscriber Line technology, aka DSL; Fiber To The Home/Curb, aka FTTx; Cable; or other broadband access technology). Video on Demand (VoD) services, which may be offered to broadband users, present significant capacity planning challenges for the aggregation network for a number of reasons. First, each VoD stream requires significant dedicated sustained bandwidth (typically 2-4 Mb/s in Standard Definition TV and 6-12 Mb/s in High Definition TV). Secondly, the VoD codec algorithms are very sensitive to packet loss. Finally, the load resulting from such services is very hard to predict (e.g., it can vary quite suddenly with blockbuster titles made available as well as with promotional offerings). As a result, transport of VoD streams on the aggregation network usually translate into a strong requirement for admission control. The admission control solution protects the quality of established VoD sessions by rejecting the additional excessive session attempts during unpredictable peaks, during link or node failures, or a combination of those factors.

住宅の顧客のためのブロードバンドサービスがますます普及しつつあるとして、次世代のアグリゲーションネットワークは、DSL別名、ブロードバンドユーザー(デジタル加入者線技術を介して結合しているかどうかからのトラフィックを集約するために展開されている、ファイバーホーム/抑制するために、別名のFTTx ;ケーブル;またはその他のブロードバンドアクセス技術)。ブロードバンドユーザー、多くの理由からアグリゲーションネットワークの存在の重要なキャパシティプランニングの課題に提供することができるオンデマンド(VOD)サービス、ビデオオン。まず、各のVoDストリームは大きな専用の持続的な帯域幅を必要とする(通常は標準画質テレビで2-4 Mb /秒と高品位テレビで6-12 Mb /秒)。第二に、VoDのコーデックアルゴリズムは、パケット損失に非常に敏感です。最後に、このようなサービスから生じる負荷が(例えば、それはかなり急に大ヒットタイトルが利用できるだけでなく、プロモーションの供物で作られたと異なります)を予測するのは非常に困難です。結果として、のVoDの輸送は、通常、アドミッション制御のための強い要求に変換アグリゲーションネットワーク上でストリーム。アドミッションコントロール溶液は、リンクまたはノードの障害時に、予測できないピーク時の追加の過度セッションの試みを拒否することによって確立されたVoDセッションの品質、またはこれらの要因の組み合わせを保護します。

RSVP can be used in the aggregation network for admission control of the VoD sessions. However, since customer premises equipment such as Set Top Boxes (STBs) (which behave as the receiver for VoD streams) often do not support RSVP, the last IP hop in the aggregation network can behave as an RSVP Receiver Proxy. This way, RSVP can be used between VoD pumps and the last IP hop in the aggregation network to perform accurate admission control of VoD streams over the resources set aside for VoD in the aggregation network (typically a certain percentage of the bandwidth of any link). As VoD streams are unidirectional, a simple Path-Triggered RSVP Receiver Proxy (as described in Section 4.1) is all that is required in this use case.

RSVPは、VODセッションのアドミッション制御のためのアグリゲーションネットワークで使用することができます。しかし、そのような(VoDのための受信機がストリームとして振る舞う)セットトップボックス(STB)などの顧客宅内機器は、多くの場合、RSVPをサポートしていないことから、アグリゲーションネットワーク内の最後のIPホップはRSVPレシーバープロキシとして動作することができます。 VoDのポンプとのVoDの正確なアドミッション制御を実行するため、集約ネットワークにおける最後のIPホップはアグリゲーションネットワーク(任意のリンクの帯域幅の、典型的には一定の割合)でのVoD用に確保されたリソース上ストリーム間でこのように、RSVPを使用することができます。 VoDストリームが単方向であるように、単純なパス・トリガRSVP受信プロキシ(セクション4.1で説明したように)このユースケースで必要とされる全てです。

Figure 14 illustrates operation of RSVP-based admission control of VoD sessions in an aggregation network involving RSVP support on the VoD pump (the senders) and the RSVP Receiver proxy on the last IP hop of the aggregation network. All the customer premises equipment remains RSVP-unaware.


                         | VoD  SRM    |
                         |             |
                 ////////|             |\\\\\\\\\\\\\\
                /        |-------------|              \
               /                                       \
              /                                         \
             /                                           \
            /                                             \
           /                                               \
      |****|   ***   ***   ***   |********|   |-----|    |---|
      |VoD |---*r*---*r*---*r*---|RSVP    |---|DSLAM|~~~~|STB|--TV
      |Pump|   ***   ***   ***   |Receiver|   |-----|    |---|
      |****|                     |Proxy   |
               <---Aggregation Net----------->




SRM Session Resource Manager


   ***                       |---|
   *r* regular RSVP          |STB| Set Top Box
   *** router                |---|

***> VoD media flow


==> segment of flow path protected by RSVP reservation


/\ VoD Application-level signaling (e.g., RTSP)

/ \のVoDアプリケーションレベルシグナリング(例えば、RTSP)

Figure 14: VoD Use Case with Receiver Proxy


In the case where the VoD pumps are not RSVP-capable, an Application_Entity-Controlled Sender Proxy via the "RSVP over GRE" approach (as described in Section 4.5.1) can also be implemented on the VoD Controller or Session Resource Manager (SRM) devices typically involved in VoD deployments. Figure 15 illustrates operation of RSVP-based admission control of VoD sessions in an aggregation network involving such an Application_Entity-Controlled Source Proxy combined with an RSVP Receiver Proxy on the last IP hop of the aggregation network. All the customer premises equipment, as well as the VoD pumps, remain RSVP-unaware.

VoDのポンプは、RSVP対応されていない、Application_Entity-制御センダプロキシを「RSVP GRE上」アプローチを介してケースに(セクション4.5.1で説明したように)もSRM(VODコントローラ又はセッション・リソース・マネージャに実装することができます)デバイスは、通常のVoDの展開に関与します。図15は、アグリゲーションネットワークの最後のIPホップでRSVP受信プロキシと組み合わせるようApplication_Entity制御型ソース・プロキシを含む集約ネットワーク内のVoDセッションのRSVPベースのアドミッション制御の動作を示します。すべての顧客宅内機器、などのVoDポンプ、RSVP-気づかないまま。

                     ////| VoD  SRM    |\\\\\\\\\\\
                    /    |             |           \
                   /     |     +       |            \
                  /      | RSVP Sender |             \
                 /       |Proxy Control|              \
                /        |-------------|               \
               /        /=/                             \
              /        /=/                               \
             /        /=/                                 \
            /        /=/                                   \
           /        /=/                                     \
      |----|  |******|    ***  ***  |********|  |-----|    |---|
      | VoD|--|RSVP  |----*r*--*r*--|RSVP    |--|DSLAM|~~~~|STB|--TV
      |Pump|  |Sender|    ***  ***  |Receiver|  |-----|    |---|
      |----|  |Proxy |              |Proxy   |
              |******|              |********|
               <---Aggregation Net------------->




SRM Systems Resource Manager


   ***                       |---|
   *r* regular RSVP          |STB| Set Top Box
   *** router                |---|

***> VoD media flow


==> segment of flow path protected by RSVP reservation


/ VoD Application-level signaling (e.g., RTSP)

/ VODアプリケーション・レベルのシグナリング(例えば、RTSP)

/=/ GRE-tunneled RSVP (Path messages)

/ = / GREトンネリングRSVP(Pathメッセージ)

                Figure 15: VoD Use Case with Receiver Proxy
                        and SRM-Based Sender Proxy

The RSVP proxy entities specified in this document play a significant role here since they allow immediate deployment of an RSVP-based admission control solution for VoD without requiring any upgrade to the huge installed base of non-RSVP-capable customer premises equipment. In one mode described above, they also avoid upgrade of non-RSVP-capable VoD pumps. In turn, this means that the benefits of on-path admission control can be offered to VoD services over broadband aggregation networks without network or VoD pump upgrade. Those include accurate bandwidth accounting regardless of topology (hub-and-spoke, ring, mesh, star, arbitrary combinations) and dynamic adjustment to any change in topology (such as failure, routing change, additional links, etc.).


A.2. RSVP-Based Voice/Video Connection Admission Control (CAC) in Enterprise WAN


More and more enterprises are migrating their telephony and videoconferencing applications onto IP. When doing so, there is a need for retaining admission control capabilities of existing TDM-based (Time-Division Multiplexing) systems to ensure the QoS of these applications is maintained even when transiting through the enterprise's Wide Area Network (WAN). Since many of the endpoints already deployed (such as IP phones or videoconferencing terminals) are not RSVP-capable, RSVP proxy approaches are very useful: they allow deployment of an RSVP-based admission control solution over the WAN without requiring upgrade of the existing terminals.

より多くの企業は、IP上に自分の電話やビデオ会議アプリケーションを移行しています。その際、企業のワイドエリアネットワーク(WAN)を介して遷移するときにも維持されているこれらのアプリケーションのQoSを保証するために、既存のTDMベース(時分割多重)システムのアドミッション制御機能を保持する必要があります。 (たとえば、IP電話やビデオ会議端末など)は、すでに展開されたエンドポイントの多くは、RSVP対応していないので、RSVPプロキシアプローチは非常に便利です:彼らは、既存の端末のアップグレードを必要とせずにWAN経由でのRSVPベースのアドミッションコントロールソリューションの展開を許可します。

A common deployment architecture for such environments relies on the Application_Entity-Controlled Proxy approach as defined in Section 4.5. Routers sitting at the edges of the WAN are naturally "on-path" for all inter-campus calls (or sessions) and behave as RSVP proxies. The RSVP proxies establish, maintain, and tear down RSVP reservations over the WAN segment for the calls (or sessions) under the control of the SIP server/proxy. The SIP server/proxy synchronizes the RSVP reservation status with the status of end-to-end calls. For example, the called IP phone will only be instructed to play a ring tone if the RSVP reservation over the corresponding WAN segment has been successfully established.

4.5節で定義されているような環境のための一般的な展開アーキテクチャはApplication_Entity制御されたプロキシアプローチに依存しています。 WANの端に座ってルータは、すべてのインターキャンパスコール(またはセッション)のための「パスに」自然であり、RSVPプロキシとして動作します。 RSVPプロキシは、SIPサーバ/プロキシの制御下で、確立、維持、および呼(またはセッション)のためのWANセグメント上RSVP予約を取り壊します。 SIPサーバ/プロキシは、エンドツーエンドのコールのステータスでRSVP予約状態を同期します。例えば、と呼ばれるIP電話は、対応するWANセグメント経由RSVP予約が正常に確立されている場合に着信音を再生するように指示されます。

This architecture allowing RSVP-based admission control of voice and video on the enterprise WAN is illustrated in Figure 16.


                   //////////////| SIP     |\\\\\\\\\\\\
                  /              | Server/ |            \
                 /               | Proxy   |             \
                /                |---------|              \
               /                //       \\                \
              /                //         \\                \
             /                //           \\                \
            /                //             \\                \
           /                //               \\                \
      |-----|      |********|   ***   ***   |********|       |-----|
      | IP  |------| Media  |---*r*---*r*---| Media  |-------|IP   |
      |Phone|      | Relay  |   ***   ***   | Relay  |       |Phone|
      |-----|      |  +     |               |    +   |       |-----|
                   | RSVP   |               | RSVP   |
                   | Proxy  |               | Proxy  |
                   |********|               |********|

<--campus--> <--campus--> network network

< - キャンパス - > < - キャンパス - >ネットワークネットワーク


<*************> <***********************> <**************>

<*************> <***********************> <**************>


*** *r* Regular RSVP router ***

*** * R *通常のRSVPルータ***

<***> media flow


<==> segment of flow path protected by RSVP reservation


/\ SIP signaling

/ \ SIPシグナリング

// control interface between the SIP server/proxy and RSVP proxy


Figure 16: CAC on Enterprise WAN Use Case


A.3. RSVP Proxies for Mobile Access Networks


Mobile access networks are increasingly based on IP technology. This implies that, on the network layer, all traffic, both traditional data and streamed data like audio or video, is transmitted as packets. Increasingly popular multimedia applications would benefit from better than best-effort service from the network, a forwarding service with strict Quality of Service (QoS) with guaranteed minimum bandwidth and bounded delay. Other applications, such as electronic commerce, network control and management, and remote-login applications, would also benefit from a differentiated treatment.


The IETF has two main models for providing differentiated treatment of packets in routers. The Integrated Services (IntServ) model [RFC1633], together with the Resource Reservation Protocol (RSVP) [RFC2205], [RFC2210], [RFC2961] provides per-flow guaranteed end-to-end transmission service. The Differentiated Services (Diffserv) framework [RFC2475] provides non-signaled flow differentiation that usually provides, but does not guarantee, proper transmission service.


However, these architectures have potential weaknesses for deployment in Mobile Access Networks. For example, RSVP requires support from both communication endpoints, and the protocol may have potential performance issues in mobile environments. Diffserv can only provide statistical guarantees and is not well suited for dynamic environments.

しかし、これらのアーキテクチャは、モバイルアクセスネットワークにおける展開のための潜在的な弱点を持っています。例えば、RSVPは、通信エンドポイントの両方からのサポートを必要とし、プロトコルは、モバイル環境における潜在的なパフォーマンスの問題を有していてもよいです。 DiffServは唯一の統計的な保証を提供し、動的な環境に適していないことができます。

Let us consider a scenario, where a fixed network correspondent node (CN) would be sending a multimedia stream to an end host behind a wireless link. If the correspondent node does not support RSVP, it cannot signal its traffic characteristics to the network and request specific forwarding services. Likewise, if the correspondent node is not able to mark its traffic with a proper Differentiated Services codepoint (DSCP) to trigger service differentiation, the multimedia stream will get only best-effort service, which may result in poor visual and audio quality in the receiving application. Even if the connecting wired network is over-provisioned, an end host would still benefit from local resource reservations, especially in wireless access networks, where the bottleneck resource is most probably the wireless link.


RSVP proxies would be a very beneficial solution to this problem. It would allow distinguishing local network reservations from the end-to-end reservations. The end host does not need to know the access network topology or the nodes that will reserve the local resources. The access network would do resource reservations for both incoming and outgoing flows based on certain criteria, e.g., filters based on application protocols. Another option is that the mobile end host makes an explicit reservation that identifies the intention, and the access network will find the correct local access network node(s) to respond to the reservation. RSVP proxies would, thus, allow resource reservation over the segment that is the most likely bottleneck, the wireless link. If the wireless access network uses a local mobility management mechanism, where the IP address of the mobile node does not change during handover, RSVP reservations would follow the mobile node movement.

RSVPプロキシは、この問題に非常に有益な解決策になります。これは、エンド・ツー・エンドの予約からローカルネットワークの予約を区別できるようになります。エンドホストは、アクセスネットワークトポロジーや地元の資源を予約しますノードを知る必要はありません。アクセスネットワークは、例えば、一定の基準に基づいて、着信と発信の流れの両方のアプリケーションプロトコルに基づいてフィルタをリソース予約を行うだろう。別のオプションは、モバイルエンドホストが意図を特定する明示的な予約を行うことで、アクセスネットワークは、予約に対応するために正しいローカルアクセス・ネットワーク・ノード(複数可)を見つけます。 RSVPプロキシは、このように、最も可能性の高いボトルネック、無線リンクであるセグメント上のリソースの予約を可能にします。無線アクセスネットワークは、モバイルノードのIPアドレスは、ハンドオーバー中に変化しないローカルモビリティ管理メカニズムを、使用している場合は、RSVP予約は、モバイルノードの動きをたどります。

A.4. RSVP Proxies for Reservations in the Presence of IPsec Gateways

A.4。 IPsecのゲートウェイの存在下での予約のためのRSVPプロキシ

[RFC4923] discusses how resource reservation can be supported end-to-end in a nested VPN environment. At each VPN level, VPN routers behave as [RFC4301] security gateways between a plaintext domain and a ciphertext domain. To achieve end-to-end resource reservation, the VPN routers process RSVP signaling on the plaintext side, perform aggregation of plaintext reservations, and maintain the corresponding aggregate RSVP reservations on the ciphertext side. Each aggregate reservation is established on behalf of multiple encrypted end-to-end sessions sharing the same ingress and egress VPN routers. These aggregate reservations can be as specified in [RFC3175] or [RFC4860].

[RFC4923]は、リソース予約は、ネストされたVPN環境におけるエンドツーエンドをサポートすることができる方法について説明します。各VPNレベルでは、VPNルータは平文と暗号文ドメインのドメイン間の[RFC4301]のセキュリティゲートウェイとして振る舞います。エンドツーエンドのリソース予約を達成するために、平文側上でシグナリングVPNルータプロセスRSVPは、平文の予約の集計を行い、暗号文側に対応する集約RSVP予約を維持します。各集計予約は同じ入力および出力のVPNルータを共有する複数の暗号化されたエンドツーエンドのセッションに代わって確立されています。 [RFC3175]または[RFC4860]で指定されるように、これらの凝集体の予約をすることができます。

Section 3 of [RFC4923] discusses the necessary data flows within a VPN router to achieve the behavior described in the previous paragraph. Two mechanisms are described to achieve such data flows. Section 3.1 presents the case where the VPN router carries data across the cryptographic boundary. Section 3.2 discusses the case where the VPN router uses a Network Guard.

[RFC4923]のセクション3は、必要なデータは、前の段落に記載された動作を達成するために、VPNルータ内を流れる説明します。二つのメカニズムは、そのようなデータフローを達成するために記載されています。 3.1節は、VPNルータは、暗号境界を越えてデータを運ぶケースを提示します。 3.2節は、VPNルータは、ネットワークのガードを使用する場合について説明します。

Where such mechanisms are not supported by the VPN routers, the approach for end-to-end reservations presented in [RFC4923] cannot be deployed. An alternative approach to support resource reservations within the ciphertext core is to use the Application_Entity-Controlled Proxy approach (as defined in Section 4.5) in the following way:


o the RSVP proxies are located inside the ciphertext domain and use aggregate RSVP reservations.

O RSVPプロキシは、暗号文ドメイン内にあり、集約RSVP予約を使用しています。

o the application entity exchange application-level signaling with the end-systems in the plaintext domain.


o the application entity controls the RSVP proxies in the ciphertext domain via an RSVP proxy control interface.


This is illustrated in Figure 17 in the case where the application is SIP-based multimedia communications.


         |-------|                                    |-------|
         |SIP    |///////////////////\\\\\\\\\\\\\\\\\|SIP    |
        /|Server/|                                    |Server/|\
       / |Proxy  |                                    |Proxy  | \
      /  |-------|                                    |-------|  \
     /      ^    \\                                  //   ^       \
    /       ^     \\                                //    ^        \
   /        ^      \\                              //     ^         \
 |***|   |------|  |********|   ***   ***   |********|  |------|   |***|
 | S |---|IPsec |--|  ARSVP |---*r*---*r*---| ARSVP  |--|IPsec |---| R |
 |***|   | GW   |  | Sender |   ***   ***   |Receiver|  | GW   |   |***|
         |------|  |  Proxy |               | Proxy  |  |------|
                   |********|               |********|

***PT*****> **********************CT****************> ****PT***>

*** PT *****> ********************** CT ****************> **** PT ***>

=====> =====> =====ARSVP======>

=====> =====> ===== ARSVP ======>

|****| RSVP-capable |****| RSVP-capable *** | S | Sender | R | Receiver *r* regular RSVP |****| |****| *** router

| **** | RSVP対応| **** | RSVP対応*** | S |送信者| R |レシーバ* R *通常のRSVP | **** | | **** | ***ルータ

 |IPsec | IPsec security gateway
 | GW   |

ARSVP Aggregate RSVP


***> media flow


==> segment of flow path protected by RSVP reservation


/ \ SIP signaling

/ \ SIPシグナリング

^ Network management interface between SIP server/proxy and IPsec security gateway


// control interface between SIP server/proxy and ARSVP proxy


PT Plaintext network


CT Ciphertext network


        Figure 17: RSVP Proxies for Reservations in the Presence of
                              IPsec Gateways

Where the sender and receiver are RSVP-capable, they may also use RSVP signaling. This achieves resource reservation on the plaintext segments of the end-to-end, i.e.,


o from the sender to the ingress IPsec gateway, and


o from the egress IPsec gateway to the receiver.


In this use case, because the VPN routers do not support any RSVP-specific mechanism, the end-to-end RSVP signaling is effectively hidden by the IPsec gateways on the ciphertext segment of the end-to-end path.


As with the Application_Entity-Controlled Proxy approach (defined in Section 4.5), the solution here for synchronizing RSVP signaling with application-level signaling is to rely on an application-level signaling device that controls an on-path RSVP proxy function. However, in this use case, the RSVP proxies are a component of a ciphertext network where all user (bearer) traffic is IPsec encrypted. This has a number of implications, including the following:


1. encrypted flows cannot be identified in the ciphertext domain so that network nodes can only classify traffic based on IP address and Differentiated Services codepoints (DSCPs). As a result, only aggregate RSVP reservations (such as those specified in [RFC3175] or [RFC4860]) can be used. This is similar to [RFC4923].


2. Determining the RSVP Sender Proxy and RSVP Receiver Proxy to be used for aggregation of a given flow from sender to receiver creates a number of challenges. Details on how this may be achieved are beyond the scope of this document. We observe that, as illustrated in Figure 17, this may be facilitated by a network management interface between the application entity and the IPsec gateways. For example, this interface may be used by the application entity to obtain information about which IPsec gateway is on the path of a given end-to-end flow. Then, the application entity may maintain awareness of which RSVP proxy is on the ciphertext path between a given pair of IPsec gateways. How such awareness is achieved is beyond the scope of this document. We simply observe that such awareness can be easily achieved through simple configuration in the particular case where a single (physical or logical) RSVP proxy is fronting a given IPsec gateway. We also observe that when awareness of the RSVP Receiver Proxy for a particular egress IPsec gateway (or end-to-end flow) is not available, the aggregate reservation may be signaled by the RSVP Sender Proxy to the destination address of the egress IPsec gateway and then proxied by the RSVP Receiver Proxy.


Different flavors of operations are possible in terms of aggregate reservation sizing. For example, the application entity can initiate an aggregate reservation of fixed size a priori and then simply keep count of the bandwidth used by sessions and reject sessions that would result in excess usage of an aggregate reservation. The application entity could also re-size the aggregate reservations on a session-by-session basis. Alternatively, the application entity could re-size the aggregate reservations in step increments typically corresponding to the bandwidth requirement of multiple sessions.


Authors' Addresses


Francois Le Faucheur Cisco Systems Greenside, 400 Avenue de Roumanille Sophia Antipolis 06410 France

フランソワ・リーパーシスコシステムズグリーンサイド、400アベニューRoumanille 06410ソフィアアンティポリスフランス

Phone: +33 4 97 23 26 19 EMail:

電話:+33 4 97 23 26 19 Eメール

Jukka Manner Aalto University Department of Communications and Networking (Comnet) P.O. Box 13000 FIN-00076 Aalto Finland

コミュニケーションのアアルト大学学部およびネットワーキング(Comnet)私書箱からユッカマナー13000 FIN-00076アアルトフィンランド箱

Phone: +358 9 470 22481 EMail: URI:

電話:+358 9 470 22481 Eメール URI:

Dan Wing Cisco Systems 170 West Tasman Drive San Jose, CA 95134 United States

ダン・ウイングシスコシステムズ170西タスマン・ドライブサンノゼ、CA 95134米国



Allan Guillou SFR 40-42 Quai du Point du Jour Boulogne-Billancourt 92659 France

アランGuillou SFR 40-42湖岸通りポイント92659ブーローニュビヤンクールフランスの日