Network Working Group                                         R. Stewart
Request for Comments: 5352                                        Q. Xie
Category: Experimental                                The Resource Group
                                                             M. Stillman
                                                               M. Tuexen
                                      Muenster Univ. of Applied Sciences
                                                          September 2008
                Aggregate Server Access Protocol (ASAP)

Status of This Memo


This memo defines an Experimental Protocol for the Internet community. It does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.




Aggregate Server Access Protocol (ASAP; RFC 5352), in conjunction with the Endpoint Handlespace Redundancy Protocol (ENRP; RFC 5353), provides a high-availability data transfer mechanism over IP networks. ASAP uses a handle-based addressing model that isolates a logical communication endpoint from its IP address(es), thus effectively eliminating the binding between the communication endpoint and its physical IP address(es), which normally constitutes a single point of failure.

集計サーバアクセスプロトコル(ASAPは、RFC 5352)は、エンドポイントHandlespace冗長プロトコル(ENRP; RFC 5353)と連動して、IPネットワーク上で高可用性データ転送メカニズムを提供します。 ASAPを効果的に通信エンドポイントと通常単一障害点を構成し、その物理IPアドレス(複数可)との間の結合を排除し、そのIPアドレス(複数可)からの論理通信エンドポイントを隔離するハンドルベースのアドレッシングモデルを使用します。

In addition, ASAP defines each logical communication destination as a pool, providing full transparent support for server pooling and load sharing. It also allows dynamic system scalability -- members of a server pool can be added or removed at any time without interrupting the service.

また、できるだけ早くサーバープールと負荷分散のための完全な透明支持体を提供し、プールとして各論理通信先を定義します。また、動的システムのスケーラビリティを可能にする - サーバー・プールのメンバーは、サービスを中断することなく、いつでも追加または削除することができます。

ASAP is designed to take full advantage of the network level redundancy provided by the Stream Transmission Control Protocol (SCTP; RFC 4960). Each transport protocol, other than SCTP, MUST have an accompanying transport mapping document. It should be noted that ASAP messages passed between Pool Elements (PEs) and ENRP servers MUST use the SCTP transport protocol.

ASAPのストリーム伝送制御プロトコル(; RFC 4960 SCTP)によって提供されるネットワークレベルの冗長性を最大限に活用するように設計されています。 SCTP以外の各トランスポートプロトコルは、付属のトランスポート・マッピング・ドキュメントを持たなければなりません。プール要素(PES)とENRPサーバ間で渡さ至急メッセージがSCTPトランスポートプロトコルを使用しなければならないことに留意すべきです。

The high-availability server pooling is gained by combining two protocols, namely ASAP and ENRP, in which ASAP provides the user interface for Pool Handle to address translation, load sharing management, and fault management, while ENRP defines the high-availability Pool Handle translation service.

高可用性サーバプールは、ASAP ENRP高可用性プール・ハンドル変換を定義しながら、プールのユーザインターフェースは、翻訳、負荷分散管理、障害管理に対処するためのハンドルを提供する、すなわち、ASAPとENRP 2つのプロトコルを、組み合わせることによって得られますサービス。

Table of Contents


   1. Introduction ....................................................4
      1.1. Definitions ................................................4
      1.2. Conventions ................................................5
      1.3. Organization of This Document ..............................6
      1.4. Scope of ASAP ..............................................6
           1.4.1. Extent of the Handlespace ...........................6
   2. Message Definitions .............................................6
      2.1. ASAP Parameter Formats .....................................7
      2.2. ASAP Messages ..............................................7
           2.2.1. ASAP_REGISTRATION Message ...........................7
           2.2.2. ASAP_DEREGISTRATION Message .........................8
           2.2.3. ASAP_REGISTRATION_RESPONSE Message ..................9
           2.2.4. ASAP_DEREGISTRATION_RESPONSE Message ...............10
           2.2.5. ASAP_HANDLE_RESOLUTION Message .....................10
           2.2.6. ASAP_HANDLE_RESOLUTION_RESPONSE Message ............11
           2.2.7. ASAP_ENDPOINT_KEEP_ALIVE Message ...................13
           2.2.8. ASAP_ENDPOINT_KEEP_ALIVE_ACK Message ...............14
           2.2.9. ASAP_ENDPOINT_UNREACHABLE Message ..................14
           2.2.10. ASAP_SERVER_ANNOUNCE Message ......................15
           2.2.11. ASAP_COOKIE Message ...............................16
           2.2.12. ASAP_COOKIE_ECHO Message ..........................16
           2.2.13. ASAP_BUSINESS_CARD Message ........................17
           2.2.14. ASAP_ERROR Message ................................17
   3. Procedures .....................................................18
      3.1. Registration ..............................................18
      3.2. De-Registration ...........................................21
      3.3. Handle Resolution .........................................23
      3.4. Endpoint Keep Alive .......................................25
      3.5. Unreachable Endpoints .....................................26
      3.6. ENRP Server Hunt Procedures ...............................27
      3.7. Handling ASAP Endpoint to ENRP Server
           Communication Failures ....................................28
           3.7.1. SCTP Send Failure ..................................28
           3.7.2. T1-ENRPrequest Timer Expiration ....................29
           3.7.3. Registration Failure ...............................29
      3.8. Cookie Handling Procedures ................................29
      3.9. Business Card Handling Procedures .........................30
   4. Roles of Endpoints .............................................31
   5. SCTP Considerations ............................................31
   6. The ASAP Interfaces ............................................31
      6.1. Registration.Request Primitive ............................32
      6.2. Deregistration.Request Primitive ..........................32
      6.3. CachePopulateRequest Primitive ............................33
      6.4. CachePurgeRequest Primitive ...............................33
      6.5. DataSendRequest Primitive .................................33
           6.5.1. Sending to a Pool Handle ...........................34
           6.5.2. Pool Element Selection .............................35
         Round-Robin Policy ........................35
           6.5.3. Sending to a Pool Element Handle ...................35
           6.5.4. Send by Transport Address ..........................37
           6.5.5. Message Delivery Options ...........................37
      6.6. Data.Received Notification ................................38
      6.7. Error.Report Notification .................................39
      6.8. Examples ..................................................39
           6.8.1. Send to a New Pool .................................39
           6.8.2. Send to a Cached Pool Handle .......................40
      6.9. PE Send Failure ...........................................41
           6.9.1. Translation.Request Primitive ......................41
           6.9.2. Transport.Failure Primitive ........................42
   7. Timers, Variables, and Thresholds ..............................42
      7.1. Timers ....................................................42
      7.2. Variables .................................................42
      7.3. Thresholds ................................................43
   8. IANA Considerations ............................................43
      8.1. A New Table for ASAP Message Types ........................43
      8.2. Port Numbers ..............................................44
      8.3. SCTP Payload Protocol Identifier ..........................44
      8.4. Multicast Addresses .......................................44
   9. Security Considerations ........................................44
      9.1. Summary of RSerPool Security Threats ......................45
      9.2. Implementing Security Mechanisms ..........................46
      9.3. Chain of Trust ............................................49
   10. Acknowledgments ...............................................50
   11. References ....................................................50
      11.1. Normative References .....................................50
      11.2. Informative References ...................................51
1. Introduction
1. はじめに

The Aggregate Server Access Protocol (ASAP), when used in conjunction with Endpoint Name Resolution Protocol [RFC5353], provides a high-availability data-transfer mechanism over IP networks. ASAP uses a handle-based addressing model that isolates a logical communication endpoint from its IP address(es), thus effectively eliminating the binding between the communication endpoint and its physical IP address(es), which normally constitutes a single point of failure.

集計サーバアクセスプロトコル(できるだけ早く)、エンドポイントの名前解決プロトコルと共に使用[RFC5353]は、IPネットワーク上で高可用性データ転送機構を提供します。 ASAPを効果的に通信エンドポイントと通常単一障害点を構成し、その物理IPアドレス(複数可)との間の結合を排除し、そのIPアドレス(複数可)からの論理通信エンドポイントを隔離するハンドルベースのアドレッシングモデルを使用します。

When multiple receiver instances exist under the same handle (aka a server pool), an ASAP Endpoint will select one Pool Element (PE), based on the current load sharing policy indicated by the server pool, and deliver its message to the selected PE.


While delivering the message, ASAP can be used to monitor the reachability of the selected PE. If it is found unreachable, before notifying the message sender (an ASAP User) of the failure, ASAP can automatically select another PE (if one exists) under that pool and attempt to deliver the message to that PE. In other words, ASAP is capable of transparent failover amongst PE instances within a server pool.


ASAP depends on ENRP, which provides a high-availability Pool Handlespace. ASAP is responsible for the abstraction of the underlying transport technologies, load distribution management, fault management, as well as presentation to the upper layer (aka an ASAP User) via a unified primitive interface.


When SCTP [RFC4960] is used as the transport layer protocol, ASAP can seamlessly incorporate the link-layer redundancy provided by SCTP.

SCTP [RFC4960]は、トランスポート層プロトコルとして使用される場合、できるだけ早くシームレスSCTPによって提供されるリンク層の冗長性を組み込むことができます。

This document defines the ASAP portion of the high-availability server pool.


1.1. Definitions
1.1. 定義

This document uses the following terms:


ASAP User: Either a PE or Pool User (PU) that uses ASAP.


Business Card: When presented by a PU or PE, it specifies the pool the sender belongs to and provides a list of alternate PEs in case of failovers.


Operational Scope: The part of the network visible to pool users by a specific instance of the reliable server pooling protocols.


Pool (or Server Pool): A collection of servers providing the same application functionality.


Pool Handle: A logical pointer to a pool. Each server pool will be identifiable in the operational scope of the system by a unique Pool Handle.


Pool Element: A server entity having registered to a pool.


Pool User: A server pool user.


Pool Element Handle (or Endpoint Handle): A logical pointer to a particular Pool Element in a pool, consisting of the Pool Handle and a destination transport address of the Pool Element.


Handlespace: A cohesive structure of Pool Handles and relations that may be queried by an internal or external agent.


Home ENRP Server: The ENRP server to which a PE or PU currently sends all namespace service requests. A PE must only have one Home ENRP server at any given time, and both the PE and its Home ENRP server MUST know and keep track of this relationship. A PU should select one of the available ENRP servers as its Home ENRP server, but the collective ENRP servers may change this by the sending of an ASAP_ENDPOINT_KEEP_ALIVE message.

PEまたはPUは現在、すべての名前空間のサービス要求を送信するENRPサーバ:ホームENRPサーバ。 PEは、任意の時点で1台のホームENRPサーバを持っている必要がありますし、PEとそのホームENRPサーバの両方が知っていると、この関係を追跡する必要があります。 PUは、そのホームENRPサーバとして利用できるENRPサーバのいずれかを選択する必要がありますが、集団ENRPサーバはASAP_ENDPOINT_KEEP_ALIVEメッセージを送信することで、これを変更することがあります。

ENRP Client Channel: The communication channel through which an ASAP User sends all namespace service requests. The client channel is usually defined by the transport address of the Home ENRP server and a well-known port number. The channel MAY make use of multicast or a named list of ENRP servers.


Network Byte Order: Most significant byte first, aka Big Endian.


Transport Address: A transport address is traditionally defined by Network Layer address, Transport Layer protocol and Transport Layer port number. In the case of SCTP running over IP, a transport address is defined by the combination of an IP address and an SCTP port number (where SCTP is the Transport protocol).

トランスポートアドレス:トランスポート・アドレスは、伝統的にネットワーク層アドレス、トランスポート層プロトコルおよびトランスポート層のポート番号によって定義されます。 SCTPは、IP上で動作する場合には、トランスポートアドレスはIPアドレス及び(SCTPトランスポートプロトコルである)SCTPポート番号の組み合わせで定義されています。

1.2. Conventions
1.2. 表記

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

この文書のキーワード "MUST"、 "MUST NOT"、 "REQUIRED"、、、、 "べきではない" "べきである" "ないもの" "ものとし"、 "推奨"、 "MAY"、および "OPTIONAL" はあります[RFC2119]に記載されているように解釈されます。

1.3. Organization of This Document
1.3. この書類の構成

Section 2 details the ASAP message formats. In Section 3, we provide detailed ASAP procedures for the ASAP implementer. Section 4 summarizes which messages need to be supported by which nodes, and Section 5 describes the usage of SCTP. In Section 6, details of the ASAP interface are given, focusing on the communication primitives between ASAP, the applications above ASAP, and ASAP itself, and the communications primitives between ASAP and SCTP (or other transport layers). Also included in this discussion are relevant timers and configurable parameters, as appropriate. Section 7 provides threshold and protocol variables.


It should be noted that variables, timers, and constants are used in the text when necessary. The complete list can be found in Section 7.


1.4. Scope of ASAP
1.4. 至急の範囲

The requirements for high availability and scalability do not imply requirements on shared state and data. ASAP does not provide transaction failover. If a host or application fails during the processing of a transaction, this transaction may be lost. Some services MAY provide a way to handle the failure, but this is not guaranteed. ASAP MAY provide hooks to assist an application in building a mechanism to share state but ASAP in itself does NOT share any state.


1.4.1. Extent of the Handlespace
1.4.1. Handlespaceの範囲

The scope of ASAP/ENRP is NOT Internet-wide. The handlespace is neither hierarchical nor arbitrarily large like DNS. A flat peer-to-peer model is detailed. Pools of servers will exist in different administrative domains. For example, suppose the use of ASAP and ENRP is wanted. First, the PU may use DNS to contact an ENRP server. Suppose a PU in North America wishes to contact a server pool in Japan instead of North America. The PU would use DNS to get the list of IP addresses of the Japanese server pool; that is, the ENRP client channel in Japan. From there, the PU would query the Home ENRP server it established and then directly contact the PE(s) of interest.

至急/ ENRPの範囲は、インターネット全体ではありません。 handlespaceは、階層やDNSなどの任意の大きさでもありません。フラットピア・ツー・ピアモデルが詳細です。サーバのプールは、異なる管理ドメインに存在しています。例えば、至急の使用を想定し、ENRPが望まれます。まず、PUはENRPサーバに接続するためにDNSを使用することができます。北米のPUはなく、北米の日本におけるサーバプールに連絡したいとします。 PUは、日本のサーバー・プールのIPアドレスのリストを取得するためにDNSを使用します。それは、日本ではENRPクライアントチャンネルです。そこから、PUは、それが確立ホームENRPサーバに照会して、直接関心のPE(複数可)をご連絡します。

2. Message Definitions

All messages, as well as their fields described below, shall be in network byte order during transmission. For fields with a length bigger than 4 bytes, a number in a pair of parentheses may follow the field name to indicate the length of the field in number of bytes.

以下で説明するすべてのメッセージ、ならびにこれらのフィールドは、送信中にネットワークバイトオーダーにしなければなりません。 4バイトより大きい長さのフィールドでは、括弧のペアの数は、バイト数のフィールドの長さを示すために、フィールド名に従うことができます。

2.1. ASAP Parameter Formats
2.1. できるだけ早くパラメータのフォーマット

The basic message format and all parameter formats can be found in [RFC5354]. Note also that *all* ASAP messages exchanged between an ENRP server and a PE MUST use SCTP as transport, while ASAP messages exchanged between an ENRP server and a PU MUST use either SCTP or TCP as transport. PE to PU data traffic MAY use any transport protocol specified by the PE during registration.

基本的なメッセージ形式およびすべてのパラメータのフォーマットは、[RFC5354]に見出すことができます。 ASAPのメッセージがトランスポートとしてSCTPまたはTCPを使用しなければならないENRPサーバとPUとの間で交換しながら、ノートはまた、*全て* ASAPのメッセージは、ENRPサーバとトランスポートとしてSCTPを使用しなければならないPEとの間で交換しました。 PUデータトラフィックのPEは、登録時にPEで指定された任意のトランスポートプロトコルを使用してもよいです。

2.2. ASAP Messages
2.2. 至急のメッセージ

This section details the individual messages used by ASAP. These messages are composed of a standard message format found in Section 4 of [RFC5354]. The parameter descriptions can be found in [RFC5354].


The following ASAP message types are defined in this section:


   Type       Message Name
   -----      -------------------------
   0x00       - (Reserved by IETF)
   0x01       - ASAP_REGISTRATION
   0x0a       - ASAP_SERVER_ANNOUNCE
   0x0b       - ASAP_COOKIE
   0x0c       - ASAP_COOKIE_ECHO
   0x0d       - ASAP_BUSINESS_CARD
   0x0e       - ASAP_ERROR
   others     - (Reserved by IETF)

Figure 1



The ASAP_REGISTRATION message is sent by a PE to its Home ENRP server to either create a new pool or to add itself to an existing pool. The PE sending the ASAP_REGISTRATION message MUST fill in the Pool Handle parameter and the Pool Element parameter. The Pool Handle parameter specifies the name to be registered. The Pool Element parameter MUST be filled in by the registrant, as outlined in Section 3.1. Note that the PE sending the registration message MUST

ASAP_REGISTRATIONメッセージが新しいプールを作成するか、または既存のプールに自分自身を追加するためにそのホームENRPサーバにPEによって送信されます。 ASAP_REGISTRATIONメッセージを送信するPEは、プール・ハンドルパラメータとプール要素パラメータに記入しなければなりません。プール・ハンドルパラメータが登録する名前を指定します。 3.1節で概説したようプール要素パラメータは、登録者が記入しなければなりません。 PEは、登録メッセージを送信しなければならないことに注意してください

send the message using an SCTP association. Furthermore, the IP address(es) of the PE that is registered within the Pool Element parameter MUST be a subset of the IP address(es) used in the SCTP association, regardless of the registered transport protocol.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x01 |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                     Pool Element Parameter                    :

Pool Handle Parameter:


See [RFC5354].


Pool Element Parameter:


See [RFC5354].



The ASAP_DEREGISTRATION message is sent by a PE to its Home ENRP server to remove itself from a pool to which it registered.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x02 |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                    PE Identifier Parameter                    :

Pool Handle Parameter:


See [RFC5354].


PE Identifier Parameter:


See [RFC5354].


The PE sending the ASAP_DEREGISTRATION MUST fill in the Pool Handle and the PE identifier parameter in order to allow the ENRP server to verify the identity of the endpoint. Note that de-registration is NOT allowed by proxy; in other words, a PE may only de-register itself.



The ASAP_REGISTRATION_RESPONSE message is sent in response by the Home ENRP server to the PE that sent an ASAP_REGISTRATION message.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x03 |0|0|0|0|0|0|0|R|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                    PE Identifier Parameter                    :
   :                   Operational Error (optional)                :

R (Reject) Flag:


When set to '1', this flag indicates that the ENRP server sending this message has rejected the registration. Otherwise, when this flag is set to '0', this indicates the registration has been granted.


Pool Handle Parameter:


See [RFC5354].


PE Identifier Parameter:


See [RFC5354].


Operational Error Parameter (optional):


See [RFC5354].


This parameter is included if an error or some atypical events occurred during the registration process. When the R flag is set to '1', this parameter, if present, indicates the cause of the rejection. When the R flag is set to '0', this parameter, if present, serves as a warning to the registering PE, informing it that some of its registration values may have been modified by the ENRP server. If the registration was successful and there is no warning, this parameter is not included.

エラーまたは一部の非定型のイベントは、登録プロセス中に発生した場合、このパラメータは含まれています。 Rフラグが「1」に設定されている場合、このパラメータは、存在する場合に、拒絶の原因を示しています。 Rフラグが「0」に設定されている場合に存在する場合、このパラメータは、その登録値のいくつかはENRPサーバによって変更された可能性があることを通知する、登録PEへの警告として働きます。登録が成功したと警告がない場合は、このパラメータが含まれていません。


The ASAP_DEREGISTRATION_RESPONSE message is returned by the Home ENRP server to a PE in response to an ASAP_DEREGISTRATION message or due to the expiration of the registration life of the PE in the pool.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x04 |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                    PE Identifier Parameter                    :
   :                   Operational Error (optional)                :

Pool Handle Parameter:


See [RFC5354].


PE Identifier Parameter:


See [RFC5354].


Operational Error:


See [RFC5354].


This parameter is included if an error or some atypical events occurred during the de-registration process. If the de-registration was successful this parameter is not included.



The ASAP_HANDLE_RESOLUTION message is sent by either a PE or PU to its Home ENRP server to resolve a Pool Handle into a list of Pool Elements that are members of the pool indicated by the Pool Handle.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x05 |0|0|0|0|0|0|0|S|        Message Length         |
   :                     Pool Handle Parameter                     :

The 'S' bit:


The 'S' bit, if set to '1', requests the Home ENRP server to send updates to this Pool dynamically when the Pool changes for the lifetime of the SCTP association. Dynamic updates to the pool will consist of additional ASAP_HANDLE_RESOLUTION_RESPONSE messages, without the user needing to send in an ASAP_HANDLE_RESOLUTION.


If the 'S' bit is set to '0', no Dynamic updates are requested.


Note that if a new Home ENRP server is adopted, any 'dynamic update request' will need to be re-sent to the new Home ENPR server if the endpoint would like to continue to receive updates. In other words, the ENRP servers do NOT share state regarding which of its PU's are requesting automatic update of state. Thus, upon change of Home ENRP server, the PU will need to re-send an ASAP_HANDLE_RESOLUTION message with the 'S' bit set to '1'. Note also, that the 'S' bit will only cause Dynamic update of a Pool when the Pool exists. If a negative response is returned, no further updates to the Pool (when it is created) will occur.


Pool Handle Parameter:


See [RFC5354].



The ASAP_HANDLE_RESOLUTION_RESPONSE message is sent in response by the Home ENRP server of the PU or PE that sent an ASAP_HANDLE_RESOLUTION message or is sent periodically upon Pool changes if the PU has requested Dynamic updates.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x06 |0|0|0|0|0|0|0|A|        Message Length         |
   :                     Pool Handle Parameter                     :
   :             Overall PE Selection Policy (optional)            :
   :               Pool Element Parameter 1 (optional)             :
   :                              ...                              :
   :                                                               :
   :               Pool Element Parameter N (optional)             :
   :                   Operational Error (optional)                :

'A' bit:


This bit is set to '1' if the ENRP server accepts the request to send automatic updates (i.e., the 'S' bit was set on the request). If this bit is set to '0', either the ENRP server does NOT support automatic updates, it has resource issues and cannot supply this feature, or the user did not request it.


Pool Handle Parameter:


See [RFC5354].


Overall PE Selection Policy (optional):


See [RFC5354].


This parameter can be present when the response is positive. If present, it indicates the overall pool member selection policy of the pool. If not present, a Round-Robin overall pool member selection policy is assumed. This parameter is not present when the response is negative.


Note, any load policy parameter within a Pool Element parameter (if present) MUST be ignored, and MUST NOT be used to determine the overall pool member selection policy.


Pool Element Parameters (optional):


See [RFC5354].


When the response is positive, an array of PE parameters are included, indicating the current information about the PEs in the named pool. At least one PE parameter MUST be present. When the response is negative, no PE parameters are included.


Operational Error (optional):


See [RFC5354].


The presence of this parameter indicates that the response is negative (the handle resolution request was rejected by the ENRP server). The cause code in this parameter (if present) will indicate the reason the handle resolution request was rejected (e.g., the requested Pool Handle was not found). The absence of this parameter indicates that the response is positive.



The ASAP_ENDPOINT_KEEP_ALIVE message is sent by an ENRP server to a PE. The ASAP_ENDPOINT_KEEP_ALIVE message is used to verify that the PE is reachable and requires the PE to adopt the sending server as its new Home ENRP server if the 'H' bit is set to '1'. Regardless of the setting of the 'H' bit, an ASAP Endpoint MUST respond with an ASAP_ENDPOINT_KEEP_ALIVE_ACK to any ASAP_ENDPOINT_KEEP_ALIVE messages that arrive.

ASAP_ENDPOINT_KEEP_ALIVEメッセージはPEにENRPサーバによって送信されます。 ASAP_ENDPOINT_KEEP_ALIVEメッセージは、PEが到達可能であることを確認するために使用され、「H」ビットが「1」に設定されている場合、その新しいホームENRPサーバとして送信サーバを採用するPEを必要とします。かかわらず、「H」ビットの設定に、できるだけ早くエンドポイントは、到着したあらゆるASAP_ENDPOINT_KEEP_ALIVEメッセージにASAP_ENDPOINT_KEEP_ALIVE_ACKで応じなければなりません。

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x07 |0|0|0|0|0|0|0|H|        Message Length         |
   |                       Server Identifier                       |
   :                     Pool Handle Parameter                     :

H (Home ENRP server) Flag:


When set to '1', indicates that the ENRP server that sends this message wants to be the Home ENRP server of the receiver of this message.


Server Identifier: 32 bits (unsigned integer)


This is the ID of the ENRP server, as discussed in [RFC5353].


Pool Handle Parameter:


See [RFC5354].



The ASAP_ENDPOINT_KEEP_ALIVE_ACK message is sent by a PE in response to an ASAP_ENDPOINT_KEEP_ALIVE message sent by an ENRP server.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x08 |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                    PE Identifier Parameter                    :

Pool Handle Parameter:


See [RFC5354].


PE Identifier Parameter:


See [RFC5354].



The ASAP_ENDPOINT_UNREACHABLE message is sent by either a PE or PU to its Home ENRP server to report an unreachable PE.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x09 |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                    PE Identifier Parameter                    :

Pool Handle Parameter:


See [RFC5354].


PE Identifier Parameter:


See [RFC5354].



The ASAP_SERVER_ANNOUNCE message is sent by an ENRP server such that PUs and PEs know the transport information necessary to connect to the ENRP server.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x0a |0|0|0|0|0|0|0|0|        Message Length         |
   |                       Server Identifier                       |
   :                       Transport Param #1                      :
   :                       Transport Param #2                      :
   :                                                               :
   :                             .....                             :
   :                                                               :
   :                       Transport Param #n                      :

Server Identifier: 32 bits (unsigned integer)


This is the ID of the ENRP server, as discussed in [RFC5353].


Transport Parameters (optional):


See [RFC5354] for the SCTP and TCP Transport parameters.


Only SCTP and TCP Transport parameters are allowed for use within the SERVER_ANNOUNCE message.


2.2.11. ASAP_COOKIE Message
2.2.11. ASAP_COOKIEメッセージ

The ASAP_COOKIE message is sent by a PE to a PU, allowing the PE to convey information it wishes to share using a control channel.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x0b |0|0|0|0|0|0|0|0|        Message Length         |
   :                         Cookie Parameter                      :

Cookie Parameter :


See [RFC5354].


2.2.12. ASAP_COOKIE_ECHO Message
2.2.12. ASAP_COOKIE_ECHOメッセージ

The ASAP_COOKIE_ECHO message is sent by a PU to a new PE when it detects a failure with the current PE to aid in failover. The Cookie Parameter sent by the PE is the latest one received from the failed PE.

それは、フェイルオーバーを助けるために、現在のPEとの故障を検出した場合ASAP_COOKIE_ECHOメッセージが新しいPEにPUによって送信されます。 PEによって送信されたクッキーパラメータが失敗したPEから受信した最新のものです。

    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x0c |0|0|0|0|0|0|0|0|        Message Length         |
   :                         Cookie Parameter                      :

Cookie Parameter:


See [RFC5354].


2.2.13. ASAP_BUSINESS_CARD Message

The ASAP_BUSINESS_CARD message is sent by a PU to a PE or from a PE to a PU using a control channel to convey the pool handle and a preferred failover ordering.


    0                   1                   2                   3
    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x0d |0|0|0|0|0|0|0|0|        Message Length         |
   :                     Pool Handle Parameter                     :
   :                   Pool Element Parameter-1                    :
   :                              ..                               :
   :                   Pool Element Parameter-N                    :

Pool Handle Parameter:


See [RFC5354].


Pool Element Parameters:


See [RFC5354].


2.2.14. ASAP_ERROR Message
2.2.14. ASAP_ERRORメッセージ

The ASAP_ERROR message is sent in response by an ASAP Endpoint receiving an unknown message or an unknown parameter to the sending ASAP Endpoint to report the problem or issue.


   0                   1                   2                   3
   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
   |   Type = 0x0e |0|0|0|0|0|0|0|0|        Message Length         |
   :                 Operational Error Parameter                   :

Operational Error Parameter:


See [RFC5354].


When an ASAP Endpoint receives an ASAP message with an unknown message type or a message of known type that contains an unknown parameter, it SHOULD handle the unknown message or the unknown parameter according to the unrecognized message and parameter handling rules, defined in Section 3.


According to the rules, if an error report to the message sender is needed, the ASAP endpoint that discovered the error SHOULD send back an ASAP_ERROR message that includes an Operational Error parameter with the proper cause code, cause length, and case-specific information.


3. Procedures

This section will focus on the methods and procedures used by an internal ASAP Endpoint. Appropriate timers and recovery actions for failure detection and management are also discussed. Also, please note that ASAP messages sent between a PE and PU are identified by an SCTP Payload Protocol Identifier (PPID).


3.1. Registration
3.1. 登録

When a PE wishes to initiate or join a server pool, it MUST use the procedures outlined in this section for registration. Often, the registration will be triggered by a user request primitive (discussed in Section 6.1). The PE MUST register using an SCTP association established between itself and the Home ENRP server. If the PE has not established its Home ENRP server, it MUST follow the procedures specified in Section 3.6.

PEは、サーバー・プールを開始または参加することを望む場合は、登録のために、このセクションで概説した手順を使用しなければなりません。多くの場合、登録は(セクション6.1で説明する)プリミティブユーザ要求によってトリガされます。 PEは、それ自体とホームENRPサーバとの間で確立されたSCTPアソシエーションを使用して登録しなければなりません。 PEは、そのホームENRPサーバを確立していない場合は、セクション3.6で指定された手順に従わなければなりません。

Once the PE's ASAP Endpoint has established its Home ENRP server, the following procedures MUST be followed to register:


R1) The PE's SCTP endpoint used to communicate with the Home ENRP server MUST be bound to all IP addresses that will be used by the PE (regardless of which transport protocol will be used to service user requests to the PE).


R2) The PE's ASAP Endpoint MUST formulate an ASAP_REGISTRATION message, as defined in Section 2.2.1. In formulating the message, the PE MUST:


R2.1) Fill in the Pool Handle parameter to specify which server pool the ASAP Endpoint wishes to join.


R2.2) Fill in the PE identifier using a good-quality randomly generated number ([RFC4086] provides some information on randomness guidelines).


R2.3) Fill in the Registration Lifetime parameter with the number of seconds that this registration is valid for. Note that a PE that wishes to continue service MUST re-register before the registration expires.


R2.4) Fill in a User Transport parameter to specify the type of transport and the data/control channel usage the PE is willing to support. Note, in joining an existing server pool, the PE MUST follow the overall transport type and overall data/control channel usage of the pool. Otherwise, the registration may be rejected by the ENRP server.


R2.5) Fill in the preferred Pool Member Selection Policy parameter.


R3) Send the ASAP_REGISTRATION message to the Home ENRP server using SCTP.


R4) Start a T2-registration timer.


Note: the PE does not need to fill in the optional ASAP transport parameter. The ASAP transport parameter will be filled in and used by the Home ENRP server.


If the T2-registration timer expires before receiving an ASAP_REGISTRATION_RESPONSE message, or a SEND.FAILURE notification is received from the SCTP layer, the PE shall start the Server Hunt procedure (see Section 3.6) in an attempt to get service from a different ENRP server. After establishing a new Home ENRP server, the PE SHOULD restart the registration procedure.

T2-登録タイマは、SCTP層から受信されたASAP_REGISTRATION_RESPONSEメッセージ、またはSEND.FAILURE通知を受信する前に満了する場合、PEは、サーバーのハントの手順を開始するものと異なるENRPサーバからサービスを取得しようとする試みで(セクション3.6を参照してください) 。新しいホームENRPサーバを確立した後、PEは、登録手順を再起動する必要があります。

At the reception of the registration response, the PE MUST stop the T2-registration timer. If the response indicates success, the PE is registered and will be considered an available member of the server pool. If the registration response indicates a failure, the PE must either re-attempt registration after correcting the error or return a failure indication to the PE's upper layer. The PE MUST NOT re-attempt registration without correcting the error condition.

登録応答の受信時に、PEは、T2-登録タイマを停止する必要があります。応答が成功を示す場合、PEが登録され、サーバー・プールの使用可能なメンバーとみなされます。登録応答が失敗を示す場合、PEは、誤差を補正した後、またはPEの上位層に失敗の表示を返すのいずれかの再試行登録しなければなりません。 PEは、エラー条件を修正せずに登録を再試行してはなりません。

At any time, a registered PE MAY wish to re-register to either update its member selection Policy Value or registration expiration time. When re-registering, the PE MUST use the same PE identifier.


After successful registration, the PE MUST start a T4-reregistration timer. At its expiration, a re-registration SHOULD be made starting at step R1, including (at completion) restarting the T4- reregistration timer.


Note that an implementation SHOULD keep a record of the number of registration (and re-registration) attempts it makes in a local variable that gets set to zero before the initial registration attempt to the Home ENRP server or after a successful re-registration. If repeated registration timeouts or failures occurs and the local count exceeds the Threshold 'MAX-REG-ATTEMPT', the implementation SHOULD report the error to its upper layer and stop attempting registration.


The ENRP server handles the ASAP_REGISTRATION message according to the following rules:


1. If the named pool does not exist in the handlespace, the ENRP server MUST create a new pool with that handle in the handlespace and add the PE to the pool as its first PE.


       When a new pool is created, the overall member selection policy
       of the pool MUST be set to the policy type indicated by the first
       PE, the overall pool transport type MUST be set to the transport
       type indicated by the PE, and the overall pool data/control
       channel configuration MUST be set to what is indicated in the
       Transport Use field of the User Transport parameter by the
       registering PE.

2. If the named pool already exists in the handlespace, but the requesting PE is not currently a member of the pool, the ENRP server will add the PE as a new member to the pool.


       However, before adding the PE to the pool, the server MUST check
       if the policy type, transport type, and transport usage indicated
       by the registering PE is consistent with those of the pool.  If
       different, the ENRP server MUST reject the registration.

3. If the named pool already exists in the handlespace *and* the requesting PE is already a member of the pool, the ENRP server SHOULD consider this as a re-registration case. The ENRP server MUST perform the same tests on policy, transport type, and transport use, as described above. If the re-registration is accepted after the test, the ENRP server SHOULD replace the attributes of the existing PE with the information carried in the received ASAP_REGISTRATION message.

3.名前のプールがすでに要求してPEが既にプールのメンバーである* handlespaceに存在し、*場合は、ENRPサーバは、再登録のケースとしてこれを考慮する必要があります。上記のようにENRPサーバは、ポリシー、トランスポート・タイプ、および輸送用途に同じテストを実行しなければなりません。再登録は、試験後に受理された場合、ENRPサーバは、受信したASAP_REGISTRATIONメッセージで運ばれる情報を既存のPEの属性を置き換えてください。

4. After accepting the registration, the ENRP server MUST assign itself the owner of this PE. If this is a re-registration, the ENRP server MUST take over ownership of this PE, regardless of whether the PE was previously owned by this server or by another server. The ENRP server MUST also record the SCTP transport address from which it received the ASAP_REGISTRATION in the ASAP Transport parameter TLV inside the PE parameter of this PE.

4.登録を受け付けた後、ENRPサーバは、このPEの所有者自体を割り当てる必要があります。これは、再登録の場合は、ENRPサーバは関係なく、PEが以前にこのサーバまたは別のサーバが所有していたかどうかの、このPEの所有権を引き継ぐ必要があります。 ENRPサーバはまた、このPEのPEパラメータの内部に、ASAP交通パラメータTLVにASAP_REGISTRATIONを受信し、そこからSCTPトランスポートアドレスを記録しなければなりません。

5. The ENRP server may reject the registration due to other reasons such as invalid values, lack of resource, authentication failure, etc.

5. ENRPサーバは、そのような等無効な値、リソースの不足、認証失敗などの他の理由で登録を拒否することができます

In all above cases, the ENRP server MUST reply to the requesting PE with an ASAP_REGISTRATION_RESPONSE message. If the registration is accepted, the ENRP server MUST set the R flag in the ASAP_REGISTRATION_RESPONSE to '0'. If the registration is rejected, the ENRP server MUST indicate the rejection by setting the R flag in the ASAP_REGISTRATION_RESPONSE to '1'.


If the registration is rejected, the ENRP server SHOULD include the proper error cause(s) in the ASAP_REGISTRATION_RESPONSE message.


If the registration is granted (either a new registration or a re-registration case), the ENRP server MUST assign itself to be the Home ENRP server of the PE, i.e., to "own" the PE.


Implementation note: For better performance, the ENRP server may find it both efficient and convenient to internally maintain two separate PE lists or tables -- one is for the PEs that are owned by the ENRP server and the other is for all the PEs owned by their peer(s).

実装上の注意:より良いパフォーマンスを得るために、ENRPサーバは内部的に効率的で便利なの両方それを見つけることが二つの別々のPEのリストまたはテーブルを維持する - 1はENRPサーバによって所有されているのPE用で、もう一方が所有するすべてのPEのためでありますそのピア(複数可)。

Moreover, if the registration is granted, the ENRP server MUST take the handlespace update action to inform its peers about the change just made. If the registration is denied, no message will be sent to its peers.


3.2. De-Registration
3.2. 登録解除

In the event a PE wishes to de-register from its server pool (normally, via an upper-layer request, see Section 6.2), it SHOULD use the following procedure. It should be noted that an alternate method of de-registration is to NOT re-register and to allow the registration life of the PE to expire. In this case, an ASAP_DEREGISTRATION_RESPONSE message is sent to the PE's ASAP Endpoint to indicate the removal of the PE from the pool it registered.


When de-registering, the PE SHOULD use the SCTP association that was used for registration with its Home ENRP server. To de-register, the PE's ASAP Endpoint MUST take the following actions:


D1) Fill in the Pool Handle parameter of the ASAP_DEREGISTRATION message (Section 2.2.2) using the same Pool Handle parameter sent during registration.


D2) Fill in the PE Identifier parameter of the ASAP_DEREGISTRATION message. The identifier MUST be the same as used during registration. The use of the same Pool Handle and Pool Identifier parameters used in registration allows the identity of the PE ASAP Endpoint to be verified before de-registration can occur.

D2)ASAP_DEREGISTRATIONメッセージのPE識別子パラメータを入力します。登録時に使用される識別子は同じでなければなりません。登録に使用したのと同じプール・ハンドルとプール識別子パラメータの使用は、登録抹消が発生する前に、ASAP PEエンドポイントのアイデンティティを検証することを可能にします。

D3) Send the ASAP_DEREGISTRATION message to the Home ENRP server using the PE's SCTP association.


D4) Start a T3-Deregistration timer.


If the T3-Deregistration timer expires before receiving either an ASAP_REGISTRATION_RESPONSE message, or a SEND.FAILURE notification from the PE's SCTP endpoint, the PE's ASAP Endpoint shall start the ENRP Server Hunt procedure (see Section 3.6) in an attempt to get service from another ENRP server. After establishing a new Home ENRP server, the ASAP Endpoint SHOULD restart the de-registration procedure.

T3-登録解除タイマーがASAP_REGISTRATION_RESPONSEメッセージ、またはPEのSCTPエンドポイントからSEND.FAILURE通知のいずれかを受信する前に満了した場合、PEの至急エンドポイントは、ENRPサーバハント手順を開始するものと別からサービスを取得しようとする試みで(セクション3.6を参照してください) ENRPサーバ。新しいホームENRPサーバを確立した後、できるだけ早くエンドポイントは、登録解除の手続きを再起動する必要があります。

At the reception of the ASAP_DEREGISTRATION_RESPONSE, the PE's ASAP endpoint MUST stop the T3-Deregistration timer.


It should be noted that after a successful de-registration, the PE MAY still receive requests for some period of time. The PE MAY wish to remain active and service these requests or to exit and ignore these requests.

成功した登録解除した後、PEはまだ一定の時間のための要求を受信することができることに留意すべきです。 PEはアクティブのままとこれらの要求にサービスを提供するか、終了し、これらの要求を無視するようにすることもできます。

Upon receiving the message, the ENRP server SHALL remove the PE from its handlespace. Moreover, if the PE is the last one of the named pool, the ENRP server will remove the pool from the handlespace as well.

メッセージを受信すると、ENRPサーバはhandlespaceからPEを除去SHALL。 PEは、名前付きプールの最後のものであればまた、ENRPサーバは、同様handlespaceからプールを削除します。

If the ENRP server fails to find any record of the PE in its handlespace, it SHOULD consider the de-registration granted and completed, and send an ASAP_DEREGISTRATION_RESPONSE message to the PE.


The ENRP server may reject the de-registration request for various reasons, such as invalid parameters, authentication failure, etc.


In response, the ENRP server MUST send an ASAP_DEREGISTRATION_RESPONSE message to the PE. If the de-registration is rejected, the ENRP server MUST indicate the rejection by including the proper Operational Error parameter.


It should be noted that de-registration does not stop the PE from sending or receiving application messages.


Once the de-registration request is granted *and* the PE removed from its local copy of the handlespace, the ENRP server MUST take the handlespace update action to inform its peers about the change just made. Otherwise, the ENRP server MUST NOT inform its peers.

登録解除要求は*と* PEはhandlespaceのローカルコピーから削除付与されると、ENRPサーバは、ちょうど行われた変更について同輩に知らせるためにhandlespaceアップデート行動を取る必要があります。それ以外の場合は、ENRPサーバはそのピアに通知してはなりません。

3.3. Handle Resolution
3.3. ハンドルの解像度

At any time, a PE or PU may wish to resolve a handle. This usually will occur when an ASAP Endpoint sends a Pool Handle (Section 6.5.1) to its Home ENRP server or requests a cache population (Section 6.3). It may also occur for other reasons (e.g., the internal ASAP PE wishes to know its peers to send a message to all of them). When an ASAP Endpoint (PE or PU) wishes to resolve a pool handle to a list of accessible transport addresses of the member PEs of the pool, it MUST take the following actions:

いつでも、PEまたはPUは、ハンドルを解決することを望むかもしれません。できるだけ早くエンドポイントは、そのホームENRPサーバにプール・ハンドル(6.5.1項)を送信またはキャッシュ人口(6.3節)を要求したときにこれは通常発生します。また、(例えば、内部のASAP PEは、それらのすべてにメッセージを送信するために、そのピアを知りたい)他の理由のために起こり得ます。できるだけ早くエンドポイント(PEまたはPU)は、プールのメンバーPEのアクセストランスポート・アドレスのリストにプールハンドルを解決しようとするとき、次のことを行う必要があります。

NR1) Fill in an ASAP_HANDLE_RESOLUTION message (Section 2.2.5) with the Pool Handle to be resolved.


NR2) If the endpoint does not have a Home ENRP server, start the ENRP Server Hunt procedures specified in Section 3.6 to obtain one. Otherwise, proceed to step NR3.


NR3) If a PE, send the ASAP_HANDLE_RESOLUTION message to the Home ENRP server using SCTP; if a PU, send the ASAP_HANDLE_RESOLUTION message to the Home ENRP server using either TCP or SCTP. If sent from a PE, the SCTP association used for registration SHOULD be used.

NR3)PEた場合は、SCTPを使用して、ホームENRPサーバへASAP_HANDLE_RESOLUTIONメッセージを送ります。 PU場合、TCPまたはSCTPのいずれかを使用してホームENRPサーバへASAP_HANDLE_RESOLUTIONメッセージを送信します。 PEから送信された場合は、登録のために使用されるSCTPアソシエーションを使用すべきです。

NR4) Start a T1-ENRPrequest timer.


If the T1-ENRPrequest timer expires before receiving a response message, the ASAP Endpoint SHOULD take the steps described in Section 3.7.2. If a SEND.FAILURE notification is received from the SCTP or TCP layer, the ASAP Endpoint SHOULD start the Server Hunt procedure (see Section 3.6) in an attempt to get service from a different ENRP server. After establishing a new Home ENRP server, the ASAP Endpoint SHOULD restart the handle resolution procedure.

T1-ENRPrequestタイマーが応答メッセージを受信する前に満了した場合は、できるだけ早くエンドポイントは、セクション3.7.2で説明する手順を取る必要があります。 SEND.FAILURE通知がSCTPまたはTCPレイヤから受信された場合は、できるだけ早くエンドポイントは、別のENRPサーバからサービスを取得しようとする試みで(セクション3.6を参照)サーバーハントの手順を開始する必要があります。新しいホームENRPサーバを確立した後、できるだけ早くエンドポイントは、ハンドル解決手順を再起動する必要があります。

At the reception of the ASAP_HANDLE_RESOLUTION_RESPONSE message, the ASAP Endpoint MUST stop its T1-ENRPrequest timer. After stopping the T1-ENRPrequest timer, the ASAP Endpoint SHOULD process the message as appropriate (e.g., populate a local cache, give the response to the ASAP User, and/or use the response to send the ASAP User's message).

ASAP_HANDLE_RESOLUTION_RESPONSEメッセージの受信時に、ASAPのエンドポイントは、T1-ENRPrequestタイマーを停止する必要があります。 T1-ENRPrequestタイマを停止した後、できるだけ早くエンドポイント(例えば、ローカルキャッシュを移植できるだけ早くユーザーに応答を与え、及び/又は、ASAPユーザメッセージを送信するために応答を使用して)必要に応じてメッセージを処理しなければなりません。

Note that some ASAP Endpoints MAY use a cache to minimize the number of handle resolutions sent. If a cache is used, it SHOULD:


C1) Be consulted before sending a handle resolution.


C2) Have a stale timeout timer associated with each cache entry. If the cache entry is determined to be stale upon a cache hit, a handle resolution message SHOULD be sent so the cache can be updated.


C3) In the case of a stale cache entry, the implementation may, in parallel, update the cache and answer the request, or it may block the user and wait for an updated cache before proceeding with the users request.


C4) If the cache entry is NOT stale, the endpoint SHOULD NOT send a handle resolution request but instead SHOULD use the entry from the cache.


It should be noted that the impact of using a cache depends on the policy and the requirements of the application. For some applications, cache-usage can increase the performance of the system; for some, it can decrease it.


An ENRP server SHOULD be prepared to receive ASAP_HANDLE_RESOLUTION requests from PUs, either over an SCTP association on the well-known SCTP port, or over a TCP connection on the well-known TCP port.


Upon reception of the ASAP_HANDLE_RESOLUTION message, the ENRP server MUST first look up the pool handle in its handlespace. If the pool exists, the Home ENRP server MUST compose and send back an ASAP_HANDLE_RESOLUTION_RESPONSE message to the requesting PU.


In the response message, the ENRP server SHOULD list all the PEs currently registered in this pool, in a list of PE parameters. The ENRP server MUST also include a pool member selection policy parameter to indicate the overall member selection policy for the pool, if the current pool member selection policy is not Round-Robin.

応答メッセージに、ENRPサーバはPEパラメータのリストに、現在このプールに登録されているすべてのPEをリストする必要があります。 ENRPサーバは、現在のプールメンバー選択ポリシーがラウンドロビンでない場合は、プールの全体的なメンバー選択方針を示すために、プールメンバー選択方針パラメータを含まなければなりません。

If the named pool does not exist in the handlespace, the ENRP server MUST reject the handle resolution request by responding with an ASAP_HANDLE_RESOLUTION_RESPONSE message carrying an Unknown Pool Handle error.


3.4. Endpoint Keep Alive
3.4. エンドポイントは、キープアライブ

The ASAP_ENDPOINT_KEEP_ALIVE message is sent by an ENRP server to a PE in order to verify it is reachable. If the transport level heartbeat mechanism is insufficient, this message can be used in a heartbeat mechanism for the ASAP level whose goal is determining the health status of the ASAP level in a timely fashion. (The transport level heartbeat mechanism may be insufficient due to either the timeouts or the heartbeat interval being set too long, or, that the transport level heartbeat mechanism's coverage is limited only to the transport level at the two ends.) Additionally, the ASAP_ENDPOINT_KEEP_ALIVE message has value in the reliability of fault detection if the SCTP stack is in the kernel. In such a case, while the SCTP-level heartbeat monitors the end-to-end connectivity between the two SCTP stacks, the ASAP-level heartbeat monitors the end-to-end liveliness of the ASAP layer above it.

ASAP_ENDPOINT_KEEP_ALIVEメッセージが到達可能であることを確認するためにPEにENRPサーバによって送信されます。トランスポート・レベルのハートビートメカニズムが不十分である場合、このメッセージは、目標タイムリーにできるだけ早くレベルの健康状態を決定することですできるだけ早くレベルのハートビート・メカニズムで使用することができます。 (トランスポートレベルのハートビート機構は、トランスポートレベルのハートビート機構のカバレッジのみ両端のトランスポートレベルに限定されることは、タイムアウトにより又は長すぎる設定されているハートビート間隔のいずれかに不十分であること、又はもよい。)また、ASAP_ENDPOINT_KEEP_ALIVEメッセージSCTPスタックがカーネルにある場合は、故障検出の信頼性の値を持っています。 SCTPレベルのハートビートは、2つのSCTPスタック間のエンドツーエンドの接続性を監視しながら、このような場合には、できるだけ早くレベルのハートビートは、その上のASAP層のエンドツーエンドの活気を監視します。

The use of the ASAP_ENDPOINT_KEEP_ALIVE message (Section 2.2.7) and the ASAP_ENDPOINT_KEEP_ALIVE_ACK (Section 2.2.8) is described below. Upon reception of an ASAP_ENDPOINT_KEEP_ALIVE message, the following actions MUST be taken:

ASAP_ENDPOINT_KEEP_ALIVEメッセージ(セクション2.2.7)とASAP_ENDPOINT_KEEP_ALIVE_ACK(セクション2.2.8)の使用について説明します。 ASAP_ENDPOINT_KEEP_ALIVEメッセージを受信すると、以下のアクションを取らなければなりません。

KA1) The PE must verify that the Pool Handle is correct and matches the Pool Handle sent in its earlier ASAP_REGISTRATION message. If the Pool Handle does not match, the PE MUST silently discard the message.


KA2) Send an ASAP_ENDPOINT_KEEP_ALIVE_ACK (Section 2.2.8) as follows:


KA2.1) Fill in the Pool Handle parameter with the PE's Pool Handle.


KA2.2) Fill in the PE Identifier parameter using the PE identifier used by this PE for registration.


KA2.3) Send the ASAP_ENDPOINT_KEEP_ALIVE_ACK message via the appropriate SCTP association for the ENRP server that sent the ASAP_ENDPOINT_KEEP_ALIVE message.


KA2.4) If the H flag in the received ASAP_ENDPOINT_KEEP_ALIVE message is set, and the Server Identifier in the message is NOT the identity of your Home ENRP server (or it is not set, e.g., you have a no Home ENRP server) adopt the sender of the ASAP_ENDPOINT_KEEP_ALIVE message as the new Home ENRP server.


3.5. Unreachable Endpoints
3.5. 到達不能エンドポイント

Occasionally, an ASAP Endpoint may realize a PE is unreachable. This may occur by a specific SCTP error realized by the ASAP endpoint or via an ASAP User report via the Transport.Failure Primitive (Section 6.9.2). In either case, the ASAP Endpoint SHOULD report the unavailability of the PE by sending an ASAP_ENDPOINT_UNREACHABLE message to any ENRP server. Before sending the ASAP_ENDPOINT_UNREACHABLE message, the ASAP Endpoint should fill in the Pool Handle parameter and PE Identifier parameter of the unreachable endpoint. If the sender is a PE, the message MUST be sent via SCTP. It should be noted that an ASAP Endpoint MUST report no more than once each time it encounters such an event. Additionally, when processing a Transport.Failure Primitive (Section 6.9.2), the ASAP Endpoint MUST NOT send an ASAP_ENDPOINT_UNREACHABLE message unless the user has made a previous request to send data to the PE specified by the primitive.

時々、ASAPのエンドポイントは、PEが到達不能であると認識することができます。これは、ASAPエンドポイントによって、またはTransport.Failureプリミティブ(項6.9.2)を介して、ASAPユーザレポートを介して実現特定SCTPエラーによって起こり得ます。いずれの場合においても、できるだけ早くエンドポイントは、任意のENRPサーバにASAP_ENDPOINT_UNREACHABLEメッセージを送信することにより、PEの使用不能を報告すべきです。 ASAP_ENDPOINT_UNREACHABLEメッセージを送信する前に、ASAPのエンドポイントは、プール・ハンドルをパラメータと到達不能エンドポイントのPE識別子パラメータを記入すべきです。送信者がPEである場合、メッセージは、SCTPを介して送信されなければなりません。できるだけ早くエンドポイントは、それがこのようなイベントに遭遇するたびに一回以下で報告しなければならないことに留意すべきです。 Transport.Failureプリミティブ(節6.9.2)を処理するとき、ユーザはプリミティブで指定されたPEにデータを送信する前の要求をしていない限り、また、ASAPのエンドポイントはASAP_ENDPOINT_UNREACHABLEメッセージを送ってはいけません。

Upon the reception of an ASAP_ENDPOINT_UNREACHABLE message, an ENRP server MUST immediately send a point-to-point ASAP_ENDPOINT_KEEP_ALIVE message to the PE in question (the H flag in the message SHOULD be set to '0', in this case). If this ASAP_ENDPOINT_KEEP_ALIVE fails (e.g., it results in an SCTP SEND.FAILURE notification), the ENRP server MUST consider the PE as truly unreachable and MUST remove the PE from its handlespace.

ASAP_ENDPOINT_UNREACHABLEメッセージを受信すると、ENRPサーバは直ちに問題のPEへのポイントツーポイントASAP_ENDPOINT_KEEP_ALIVEメッセージを送らなければなりません(メッセージにおけるHフラグは、この場合には、「0」に設定されるべきです)。このASAP_ENDPOINT_KEEP_ALIVEが失敗した場合は、ENRPサーバが真に到達不能としてPEを考慮する必要があり、そのhandlespaceからPEを除去しなければならない(例えば、それは、SCTP SEND.FAILURE通知をもたらします)。

If the ASAP_ENDPOINT_KEEP_ALIVE message is transmitted successfully to the PE, the ENRP server MUST retain the PE in its handlespace. Moreover, the server SHOULD keep a counter to record how many ASAP_ENDPOINT_UNREACHABLE messages it has received reporting reachability problem relating to this PE. If the counter exceeds the protocol threshold MAX-BAD-PE-REPORT, the ENRP server SHOULD remove the PE from its handlespace.


Optionally, an ENRP server may also periodically send point-to-point ASAP_ENDPOINT_KEEP_ALIVE (with the H flag set to '0') messages to each of the PEs owned by the ENRP server in order to check their reachability status. If the sending of ASAP_ENDPOINT_KEEP_ALIVE to a PE fails, the ENRP server MUST consider the PE as unreachable and MUST remove the PE from its handlespace. Note, if an ENRP server owns a large number of PEs, the implementation should pay attention not to flood the network with bursts of ASAP_ENDPOINT_KEEP_ALIVE messages. Instead, the implementation MUST distribute the ASAP_ENDPOINT_KEEP_ALIVE message traffic over a time period. This can be achieved by varying the time between two ASAP_ENDPOINT_KEEP_ALIVE messages to the same PE randomly by plus/ minus 50 percent.

必要に応じて、ENRPサーバはまた、定期的に到達可能状態を確認するために、ENRPサーバが所有するPEのそれぞれにメッセージ(H「0」に設定されたフラグで)ポイントツーポイントASAP_ENDPOINT_KEEP_ALIVEを送信することができます。 PEにASAP_ENDPOINT_KEEP_ALIVEの送信が失敗した場合は、ENRPサーバが到達不能としてPEを考慮する必要があり、そのhandlespaceからPEを削除する必要があります。 ENRPサーバはPEの多数を所有している場合、実装はASAP_ENDPOINT_KEEP_ALIVEメッセージのバーストでネットワークを溢れさせないようにする注意を払う必要があり、注意してください。その代わり、実装は、時間をかけてASAP_ENDPOINT_KEEP_ALIVEメッセージトラフィックを配布する必要があります。これは、プラス/マイナス50%ランダムに同一のPEへの2つのASAP_ENDPOINT_KEEP_ALIVEメッセージ間の時間を変化させることによって達成することができます。

3.6. ENRP Server Hunt Procedures
3.6. ENRPサーバハント手順

Each PU and PE manages a list of transport addresses of ENRP servers it knows about.


If multicast capabilities are used within the operational scope, an ENRP server MUST send periodically every (N+1)*T6-Serverannounce an ASAP_SERVER_ANNOUNCE message (Section 2.2.10), which includes all the transport addresses available for ASAP communication on the multicast ENRP client channel, where N is the number of ENRP servers the server has found via receiving ASAP_SERVER_ANNOUNCE messages. This should result in a message rate of approximately 1 ASAP_SERVER_ANNOUNCE per T6-Serverannounce.

マルチキャスト機能が動作範囲内で使用される場合、ENRPサーバは、定期的にマルチキャストENRPに、ASAPの通信のために利用可能なすべてのトランスポート・アドレスを含むすべての(N + 1)* T6-Serverannounce ASAP_SERVER_ANNOUNCEメッセージ(セクション2.2.10)を送らなければなりませんNは、サーバがASAP_SERVER_ANNOUNCEメッセージを受信を通じて発見したENRPサーバの数あるクライアントチャネル、。これは、T6-Serverannounceあたり約1 ASAP_SERVER_ANNOUNCEのメッセージレートをもたらすべきです。

If an ASAP_SERVER_ANNOUNCE message is received by a PU or PE, it SHOULD insert all new included transport addresses into its list of ENRP server addresses and start a T7-ENRPoutdate timer for each address. For all already-known, included transport addresses, the T7-ENRPoutdate timer MUST be restarted for each address. If no transport parameters are included in the ASAP_SERVER_ANNOUNCE message, the SCTP transport protocol is assumed to be used and the source IP address and the IANA-registered ASAP port number is used for communication with the ENRP server. If a T7-ENRPoutdate timer for a transport address expires, the corresponding address is deleted from the managed list of transport addresses of the PU or PE.

ASAP_SERVER_ANNOUNCEメッセージはPUまたはPEによって受信された場合、それはENRPサーバアドレスのリストにすべての新しい含まトランスポートアドレスを挿入し、各アドレスのT7-ENRPoutdateタイマーを開始する必要があります。すべての既知の場合は、トランスポート・アドレスを含め、T7-ENRPoutdateタイマーは、各アドレスのために再起動する必要があります。いかなる輸送パラメータがASAP_SERVER_ANNOUNCEメッセージに含まれていない場合は、SCTPトランスポートプロトコルが使用されると仮定され、ソースIPアドレスと、ASAP IANA登録ポート番号はENRPサーバとの通信に使用されます。トランスポート・アドレスのためのT7-ENRPoutdateタイマーが満了した場合は、対応するアドレスは、PUまたはPEのトランスポート・アドレスの管理リストから削除されます。

If multicast capabilities are not used within the operational scope, each PU and PE MUST have a configured list of transport addresses of ENRP servers.


At its startup, or when it fails to communicate with its Home ENRP server (i.e., timed out on an ENRP request), a PE or PU MUST establish a new Home ENRP server (i.e., set up a TCP connection or SCTP association with a different ENRP server).


To establish a Home ENRP server, the following rules MUST be followed:


SH1) The PE or PU SHOULD try to establish an association or connection, with no more than three ENRP servers. An ASAP Endpoint MUST NOT establish more than three associations or connections.

PEまたはPU SH1)は、3つ以下のENRPサーバと、結合または接続を確立しようとする必要があります。できるだけ早くエンドポイントは、以上の3つの団体または接続を確立してはなりません。

SH2) The ASAP Endpoint shall start a T5-Serverhunt timer.


SH3) If the ASAP Endpoint establishes an association or connection it MUST stop its T5-Serverhunt timer. The ASAP Endpoint SHOULD also reset the T5-Serverhunt timer to its initial value and then proceed to step SH6.


SH4) If an association or connection establishment fails, the ASAP Endpoint SHOULD try to establish an association or connection using a different transport address.


SH5) If the T5-Serverhunt timer expires, the following should be performed:


SH5.1) The ASAP Endpoint MUST double the value of the T5- Serverhunt timer. Note that this doubling is capped at the value RETRAN.max.

SH5.1)できるだけ早くエンドポイントはT5- Serverhuntタイマーの値を倍にしなければなりません。この倍増は値RETRAN.maxで制限されることに注意してください。

SH5.2) The ASAP Endpoint SHOULD stop the establishment of associations and connections with the transport addresses selected in step SH1.


SH5.2) The ASAP Endpoint SHOULD repeat trying to establish an association or connection by proceeding to step SH1. It SHOULD attempt to select a different set of transport addresses with which to connect.


SH6) The PE or PU shall pick one of the ENRP servers with which it was able to establish an association or connection, and send all subsequent ENRP request messages to this new Home ENRP server.

PEまたはPU SH6)は、結合または接続を確立することであったとENRPサーバのいずれかを選択し、この新しいホームENRPサーバへの後続のすべてのENRP要求メッセージを送信しなければなりません。

3.7. Handling ASAP Endpoint to ENRP Server Communication Failures
3.7. エンドポイントENRPサーバの通信障害にできるだけ早く取り扱い

Three types of failure may occur when the ASAP Endpoint at either the PE or PU tries to communicate with an ENRP server:


A) SCTP send failure


B) T1-ENRPrequest timer expiration


C) Registration failure


3.7.1. SCTP Send Failure
3.7.1. SCTPは、失敗を送信します

This communication failure indicates that the SCTP layer was unable to deliver a message sent to an ENRP server. In other words, the ENRP server is unreachable.


In such a case, the ASAP Endpoint MUST NOT re-send the undeliverable message. Instead, it SHOULD discard the message and start the ENRP Server Hunt procedure as described in Section 3.6. After finding a new Home ENRP server, the ASAP Endpoint should re-send the request.


Note that an ASAP Endpoint MAY also choose to NOT discard the message, but to queue it for retransmission after a new Home ENRP server is found. If an ASAP Endpoint does choose to discard the message, after a new Home ENRP server is found, the ASAP Endpoint MUST be capable of reconstructing the original request.


3.7.2. T1-ENRPrequest Timer Expiration
3.7.2. T1-ENRPrequestタイマ満了

When the T1-ENRPrequest timer expires, the ASAP Endpoint should re-send the original request to the ENRP server and restart the T1- ENRPrequest timer. In parallel, the ASAP Endpoint should begin the ENRP server hunt procedures described in Section 3.6.


This should be repeated up to MAX-REQUEST-RETRANSMIT times. After that, an Error.Report notification should be generated to inform the ASAP User, and the ENRP request message associated with the T1- ENRPrequest timer should be discarded. It should be noted that if an alternate ENRP server responds, the ASAP Endpoint SHOULD adopt the responding ENRP server as its new Home ENRP server and re-send the request to the new Home ENRP server.


3.7.3. Registration Failure
3.7.3. 登録失敗

Registration failure is discussed in Section 3.1.


3.8. Cookie Handling Procedures
3.8. Cookieの取り扱い手順

Whenever a PE wants, and a control channel exists, it can send an ASAP_COOKIE message to a PU via the control channel. The PU's ASAP endpoint stores the Cookie parameter and discards an older cookie if it is previously stored.

PEが望んで、制御チャネルが存在するときはいつでも、それは、制御チャネルを介してPUにASAP_COOKIEメッセージを送信することができます。 PUのASAPのエンドポイントは、クッキーのパラメータを格納し、それが以前に格納されている場合、古いクッキーを破棄します。

Note: A control channel is a communication channel between a PU and PE that does not carry data passed to the user. This is accomplished with SCTP by using a PPID to separate the ASAP messages (Cookie and Business Card) from normal data messages.


If the PU's ASAP Endpoint detects a failure and initiates a failover to a different PE, it SHOULD send the latest received cookie parameter in an ASAP_COOKIE_ECHO message to the new PE as the first message on the control channel. Upper layers may be involved in the failover procedure.


The cookie handling procedure can be used for state sharing. Therefore, a cookie should be signed by the sending PE ASAP Endpoint and the cookie should be verified by the receiving PE's ASAP Endpoint. The details of the verification procedure are out of scope for this document. It is only important that the PU always stores the last received Cookie parameter and sends that back unmodified in case of a PE failure.

Cookie処理手順は、状態を共有するために使用することができます。したがって、送信PEのASAPエンドポイントとクッキーによって署名されなければならないクッキーは、受信PEのASAPのエンドポイントによって検証されるべきです。検証手順の詳細は、このドキュメントの範囲外です。 PUは、常に最後のクッキーパラメータを受信し、PEに障害が発生した場合には変更されていないことを送り返す保存することだけが重要です。

3.9. Business Card Handling Procedures
3.9. ビジネスカード取り扱い手順

When communication begins between a PU and a PE, either of which could be part of a PU/PE combination (i.e., a message is sent between the entities), a PE should always send an ASAP_BUSINESS_CARD message to a PU. A PU should send an ASAP_BUSINESS_CARD message to a PE only if it is part of a PU/PE combination. An ASAP_BUSINESS_CARD message MUST ONLY be sent if a control channel exists between a PU and PE. After communication has been established between a PE and PU, a new ASAP_BUSINESS_CARD message may be sent at any time by either entity to update its failover order.

通信はPU及びPU / PEの組合せの一部とすることができるいずれものPE(すなわち、メッセージが、エンティティ間で送信される)との間で開始されると、PEは常にPUにASAP_BUSINESS_CARDメッセージを送信すべきです。 PUは、PU / PEの組み合わせの一部である場合にのみ、PEにASAP_BUSINESS_CARDメッセージを送信すべきです。制御チャネルはPUとPEとの間に存在する場合ASAP_BUSINESS_CARDメッセージのみが送信されなければなりません。通信は、PEとPUとの間に確立された後、新しいASAP_BUSINESS_CARDメッセージは、フェイルオーバー順序を更新するために、いずれかのエンティティによっていつでも送信することができます。

The ASAP_BUSINESS_CARD message serves two purposes. First, it lists the pool handle. For a PU that is part of a PU/PE combination that is contacting a PE, this is essential so that the PE learns the pool handle of the PU/PE combination requesting service. Secondly, the ASAP_BUSINESS_CARD message tells the receiving entity a failover order that is recommended to follow. This should facilitate rendezvous between entities that have been working together, as well as to control the load redistribution upon the failure of any PE.

ASAP_BUSINESS_CARDメッセージは2つの目的を果たします。まず、プール・ハンドルを示しています。 PEは、サービスを要求PU / PEの組み合わせのプール・ハンドルを学習するようにPEを接触さPU / PEの組み合わせの一部であるPUの場合、これは必須です。第二に、ASAP_BUSINESS_CARDメッセージは、受信エンティティ従うことを推奨されるフェイルオーバー順序を伝えます。これは、一緒に働いているだけでなく、任意のPEの故障時に負荷の再配分を制御するエンティティ間のランデブーを促進すべきです。

Upon receipt of an ASAP_BUSINESS_CARD message (see Section 2.2.13), the receiving ASAP Endpoint SHOULD:

ASAP_BUSINESS_CARDメッセージを受信すると、エンドポイントは、ASAP SHOULD受信、(セクション2.2.13を参照のこと)。

BC1) Unpack the message, and if no entry exists in the translation cache of the receiving ASAP Endpoint for the pool handle listed within the ASAP_BUSINESS_CARD message, perform an ASAP_HANDLE_RESOLUTION for that pool handle. If the translation cache does hold an entry for the pool handle, then it may be necessary to update the peer endpoint.


BC2) Unpack the message and populate a preferred list for failover order. If the peer's PE should fail, this preferred list will be used to guide the ASAP Endpoint in the selection of an alternate PE.


4. Roles of Endpoints

A PU MUST implement the handling of ASAP_HANDLE_RESOLUTION and ASAP_HANDLE_RESOLUTION_RESPONSE messages. Furthermore, it MUST support the handling of ASAP_ERROR messages. It MAY implement the handling of ASAP_COOKIE, ASAP_COOKIE_ECHO, and ASAP_BUSINESS_CARD messages. It MAY also implement the handling of ASAP_SERVER_ANNOUNCE messages.






If a node acts as a PU and a PE, it MUST fulfill both roles.


5. SCTP Considerations
5. SCTPに関する注意事項

Each ASAP message is considered as an SCTP user message. The PPID registered for ASAP SHOULD be used. The SCTP port used at the ENRP server might be preconfigured or announced in the ASAP_SERVER_ANNOUNCE message or the well-known ASAP port.

各至急メッセージはSCTPユーザメッセージとして考えられています。至急のために登録されたPPIDを使用する必要があります。 ENRPサーバで使用SCTPポートは、事前設定やASAP_SERVER_ANNOUNCEメッセージや、よく知られた、ASAPポートに発表される可能性があります。

ASAP messages belonging to the control channel MUST be sent using the PPID registered for ASAP. Messages belonging to the data channel MUST NOT use the PPID registered for ASAP.


6. The ASAP Interfaces

This chapter will focus primarily on the primitives and notifications that form the interface between the ASAP User and ASAP and that between ASAP and its lower-layer transport protocol (e.g., SCTP).

この章では、主に、ASAPとその下層のトランスポートプロトコル(例えば、SCTP)との間のASAP ASAPはユーザとの間の界面を形成するプリミティブと通知にその焦点を当てます。

Note, the following primitive and notification descriptions are shown for illustrative purposes. We believe that including these descriptions in this document is important to the understanding of the operation of many aspects of ASAP; but an ASAP implementation is not required to use the exact syntax described in this section.


An ASAP User passes primitives to the ASAP sub-layer to request certain actions. Upon the completion of those actions or upon the detection of certain events, the ASAP layer will notify the ASAP User.


6.1. Registration.Request Primitive
6.1. Registration.Requestプリミティブ
         Format: registration.request(Pool Handle,
                                      User Transport parameter(s))

The Pool Handle parameter contains a NULL terminated ASCII string of fixed length. The optional User Transport parameter(s) indicates specific transport parameters and types with which to register. If this optional parameter is left off, then the SCTP endpoint used to communicate with the ENRP server is used as the default User Transport parameter. Note that any IP address contained within a User Transport parameter MUST be a bound IP address in the SCTP endpoint used to communicate with the ENRP server.


The ASAP User invokes this primitive to add itself to the handlespace, thus becoming a Pool Element of a pool. The ASAP User must register itself with the ENRP server by using this primitive before other ASAP Users using the handlespace can send message(s) to this ASAP User by Pool Handle or by PE handle (see Sections 6.5.1 and 6.5.3).


In response to the registration primitive, the ASAP Endpoint will send an ASAP_REGISTRATION message to the Home ENRP server (see Sections 2.2.1 and 3.1), and start a T2-registration timer.


6.2. Deregistration.Request Primitive
6.2. Deregistration.Requestプリミティブ

Format: deregistration.request(Pool Handle)


The ASAP PE invokes this primitive to remove itself from the Server Pool. This should be used as a part of the graceful shutdown process by the application.


An ASAP_DEREGISTRATION message will be sent by the ASAP Endpoint to the Home ENRP server (see Sections 2.2.2 and 3.2).


6.3. CachePopulateRequest Primitive
6.3. プリミティブCachePopulateRequest
          Format: cache_populate_request([Pool-Handle |

If the address type is a Pool Handle and a local handle translation cache exists, the ASAP Endpoint should initiate a mapping information query by sending an ASAP_HANDLE_RESOLUTION message on the Pool handle and updating its local cache when the response comes back from the ENRP server.


If a Pool-Element-Handle is passed, then the Pool Handle is unpacked from the Pool-Element-Handle and the ASAP_HANDLE_RESOLUTION message is sent to the ENRP server for resolution. When the response message returns from the ENRP server, the local cache is updated.


Note that if the ASAP service does NOT support a local cache, this primitive performs NO action.


6.4. CachePurgeRequest Primitive
6.4. プリミティブCachePurgeRequest

Format: cache_purge_request([Pool-Handle | Pool-Element-Handle])


If the user passes a Pool Handle and local handle translation cache exists, the ASAP Endpoint should remove the mapping information on the Pool Handle from its local cache. If the user passes a Pool-Element-Handle, then the Pool Handle within is used for the cache_purge_request.


Note that if the ASAP service does NOT support a local cache, this primitive performs NO action.


6.5. DataSendRequest Primitive
6.5. DataSendRequestプリミティブ
         Format: data_send_request(destinationAddress, typeOfAddress,
                                   message, sizeOfMessage, Options);

This primitive requests ASAP to send a message to some specified Pool or Pool Element within the current Operational scope.


Depending on the address type used for the send request, the sender's ASAP Endpoint may perform address translation and Pool Element selection before sending the message out. This MAY also dictate the creation of a local transport endpoint in order to meet the required transport type.


The data_send_request primitive can take different forms of address types, as described in the following sections.


6.5.1. Sending to a Pool Handle
6.5.1. プール・ハンドルに送信します

In this case, the destinationAddress and typeOfAddress together indicate a pool handle.


This is the simplest form of send_data_request primitive. By default, this directs ASAP to send the message to one of the Pool Elements in the specified pool.


Before sending the message out to the pool, the sender's ASAP endpoint MUST first perform a pool handle to address translation. It may also need to perform Pool Element selection if multiple Pool Elements exist in the pool.


If the sender's ASAP implementation does not support a local cache of the mapping information, or if it does not have the mapping information on the pool in its local cache, it will transmit an ASAP_HANDLE_RESOLUTION message (see Sections 2.2.5 and 3.3) to the current Home ENRP server and MUST hold the outbound message in queue while awaiting the response from the ENRP server (any further send request to this pool before the ENRP server responds SHOULD also be queued).


Once the necessary mapping information arrives from the ENRP server, the sender's ASAP will:


A) map the pool handle into a list of transport addresses of the destination PE(s);


B) if multiple PEs exist in the pool, choose one of them and transmit the message to it. In that case, the choice of the PE is made by the ASAP Endpoint of the sender based on the server pooling policy, as discussed in Section 6.5.2;


C) optionally create any transport endpoint that may be needed to communicate with the PE selected;


D) if no transport association or connection exists towards the destination PE, establish any needed transport state;


E) send out the queued message(s) to the appropriate transport connection using the appropriate send mechanism (e.g., for SCTP, the SEND primitive in [RFC4960] would be used); and,


F) if the local cache is implemented, append/update the local cache with the mapping information received in the ENRP server's response. Also, record the local transport information (e.g., the SCTP association id) if any new transport state was created.


For more on the ENRP server request procedures see [RFC5353].


Optionally, the ASAP Endpoint of the sender may return a Pool Element handle of the selected PE to the application after sending the message. This PE handle can then be used for future transmissions to that same PE (see Section 6.5.3).


Section 3.7 defines the failover procedures for cases where the selected PE is found unreachable.


6.5.2. Pool Element Selection
6.5.2. プールの要素の選択

Each time an ASAP User sends a message to a pool that contains more than one PE, the sender's ASAP Endpoint must select one of the PEs in the pool as the receiver of the current message. The selection is made according to the current server pooling policy of the pool to which the message is sent.


Note, no selection is needed if the ASAP_SEND_TOALL option is set (see Section 6.5.5).


Together with the server pooling policy, each PE can also specify a Policy Value for itself at the registration time. The meaning of the Policy Value depends on the current server pooling policy of the group. A PE can also change its Policy Value whenever it desires, by re-registering itself with the handlespace with a new Policy Value. Re-registration shall be done by simply sending another ASAP_REGISTRATION to its Home ENRP server (see Section 2.2.1).


One basic policy is defined in this document; others can be found in [RFC5356]

一つの基本方針は、このドキュメントで定義されています。他の人は[RFC5356]で見つけることができます Round-Robin Policy。ラウンドロビンポリシー

When an ASAP Endpoint sends messages by Pool Handle and Round-Robin is the current policy of that Pool, the ASAP Endpoint of the sender will select the receiver for each outbound message by Round-Robining through all the registered PEs in that Pool, in an attempt to achieve an even distribution of outbound messages. Note that in a large server pool, the ENRP server might not send back all PEs to the ASAP client. In this case, the client or PU will be performing a Round-Robin policy on a subset of the entire Pool.


6.5.3. Sending to a Pool Element Handle
6.5.3. プール要素ハンドルに送信します

In this case, the destinationAddress and typeOfAddress together indicate an ASAP Pool Element handle.


This requests that the ASAP Endpoint deliver the message to the PE identified by the Pool Element handle.


The Pool Element handle should contain the Pool Handle and a destination transport address of the destination PE or the Pool Handle and the transport type. Other implementation dependent elements may also be cached in a Pool Element handle.


The ASAP Endpoint shall use the transport address and transport type to identify the endpoint with which to communicate. If no communication state exists with the peer endpoint (and is required by the transport protocol), the ASAP Endpoint MAY set up the needed state and then invoke the SEND primitive for the particular transport protocol to send the message to the PE.


In addition, if a local translation cache is supported, the endpoint will:


A) send out the message to the transport address (or association id) designated by the PE handle.


B) determine if the Pool Handle is in the local cache.


If it is *not*, the endpoint will:

それは* *でない場合、エンドポイントは以下となります。

i) ask the Home ENRP server for handle resolution on the pool handle by sending an ASAP_HANDLE_RESOLUTION message (see Section 2.2.5), and


ii) use the response to update the local cache.


If the pool handle is in the cache, the endpoint will only update the pool handle if the cache is stale. A stale cache is indicated by it being older than the protocol parameter 'stale.cache.value' (see Section 7.2).


Sections 3.5 and 6.9 define the failover procedures for cases where the PE pointed to by the Pool Element handle is found to be unreachable.


Optionally, the ASAP Endpoint may return the actual Pool Element handle to which the message was sent (this may be different from the Pool Element handle specified when the primitive is invoked, due to the possibility of automatic failover).


6.5.4. Send by Transport Address
6.5.4. トランスポートアドレスで送信

In this case, the destinationAddress and typeOfAddress together indicate a transport address and transport type.


This directs the sender's ASAP Endpoint to send the message out to the specified transport address.


No endpoint failover is supported when this form of send request is used. This form of send request effectively bypasses the ASAP endpoint.


6.5.5. Message Delivery Options
6.5.5. メッセージ配信オプション

The Options parameter passed in the various forms of the above data_send_request primitive gives directions to the sender's ASAP endpoint on special handling of the message delivery.


The value of the Options parameter is generated by bit-wise "OR"ing of the following pre-defined constants:


ASAP_USE_DEFAULT: 0x0000 Use default setting.


ASAP_SEND_FAILOVER: 0x0001 Enables PE failover on this message. In the case where the first selected PE or the PE pointed to by the PE handle is found unreachable, the sender's ASAP Endpoint SHOULD re-select an alternate PE from the same pool if one exists, and silently re-send the message to this newly selected endpoint.


Note that this is a best-effort service. Applications should be aware that messages can be lost during the failover process, even if the underlying transport supports retrieval of unacknowledged data (e.g., SCTP). (Example: messages acknowledged by the SCTP layer at a PE, but not yet read by the PE when a PE failure occurs.) In the case where the underlying transport does not support such retrieval (e.g., TCP), any data already submitted by ASAP to the transport layer may be lost upon failover.

これはベストエフォート型のサービスであることに注意してください。アプリケーションは、基礎となるトランスポートが未確認のデータ(例えば、SCTP)の検索をサポートしている場合でも、メッセージは、フェールオーバープロセス中に失われる可能性があることに注意する必要があります。 (例:メッセージがPEでSCTP層によって承認が、PEの障害が発生したときにまだPEによって読み出されない。)、基礎となるトランスポートは、検索(例えば、TCP)をサポートしていない場合には、既にによって提出されたすべてのデータをできるだけ早くトランスポート層へのフェイルオーバー時に失われることがあります。

ASAP_SEND_NO_FAILOVER: 0x0002 This option prohibits the sender's ASAP Endpoint from re-sending the message to any alternate PE in case that the first selected PE, or the PE pointed to by the PE handle, is found to be unreachable. Instead, the sender's ASAP Endpoint shall notify its upper layer about the unreachability with an Error.Report and return any unsent data.


ASAP_SEND_TO_LAST: 0x0004 This option requests that the sender's ASAP Endpoint send the message to the same PE in the pool to which the previous message destined to this pool was sent.


ASAP_SEND_TO_ALL: 0x0008 When sending by Pool Handle, this option directs the sender's ASAP endpoint to send a copy of the message to all the PEs, except for the sender itself if the sender is a PE in that pool.


ASAP_SEND_TO_SELF: 0x0010 This option only applies in combination with the ASAP_SEND_TO_ALL option. It permits the sender's ASAP Endpoint to also deliver a copy of the message to itself if the sender is a PE of the pool (i.e., loop-back).


ASAP_SCTP_UNORDER: 0x1000 This option requests that the transport layer send the current message using un-ordered delivery (note the underlying transport must support un-ordered delivery for this option to be effective).


6.6. Data.Received Notification
6.6. Data.Received通知
         Format: data.received(messageReceived, sizeOfMessage,
                               senderAddress, typeOfAddress)

When a new user message is received, the ASAP Endpoint of the receiver uses this notification to pass the message to its upper layer.


Along with the message being passed, the ASAP Endpoint of the receiver should also indicate to its upper layer the message senders address. The sender's address can be in the form of either an SCTP association id, TCP transport address, UDP transport address, or an ASAP Pool Element handle.


A) If the handle translation local cache is implemented at the receiver's ASAP Endpoint, a reverse mapping from the sender's IP address to the pool handle should be performed, and if the mapping is successful, the sender's ASAP Pool Element handle should be constructed and passed in the senderAddress field.


B) If there is no local cache or the reverse mapping is not successful, the SCTP association id or other transport specific identification (if SCTP is not being used) should be passed in the senderAddress field.


6.7. Error.Report Notification
6.7. Error.Report通知
         Format:, typeOfAddress,
                              failedMessage, sizeOfMessage)

An should be generated to notify the ASAP User about failed message delivery as well as other abnormalities.


The destinationAddress and typeOfAddress together indicate to whom the message was originally sent. The address type can be either an ASAP Pool Element handle, association id, or a transport address.


The original message (or the first portion of it if the message is too big) and its size should be passed in the failedMessage and sizeOfMessage fields, respectively.


6.8. Examples
6.8. 例

These examples assume an underlying SCTP transport between the PE and PU. Other transports are possible, but SCTP is utilized in the examples for illustrative purposes. Note that all communication between the PU and ENRP server and the PE and ENRP servers would be using SCTP.

これらの実施例は、PEとPUとの間の根本的なSCTP輸送を想定します。他のトランスポートが可能であるが、SCTPは、例示の目的のために実施例において利用されています。 PUとENRPサーバとPEとENRPサーバの間のすべての通信は、SCTPを使用するであろうことに留意されたいです。

6.8.1. Send to a New Pool
6.8.1. 新しいプールに送ります

This example shows the event sequence when a Pool User sends the message "hello" to a pool that is not in the local translation cache (assuming local caching is supported).


ENRP Server PU new-handle:PEx


       |                                |                 |
       |                              +---+               |
       |                              | 1 |               |
       |2. ASAP_HANDLE_RESOLUTION     +---+               |
       |<-------------------------------|                 |
       |                              +---+               |
       |                              | 3 |               |
       |4. ASAP_HANDLE_RESOLUTION_RSP +---+               |
       |------------------------------->|                 |
       |                              +---+               |
       |                              | 5 |               |
       |                              +---+  6. "hello1"  |
       |                                |---------------->|
       |                                |                 |

1) The user at PU invokes:


data_send_request("new-handle", handle-type, "hello1", 6, 0);

data_send_request( "新しいハンドル"、 "hello1"、6型ハンドル、0);

The ASAP Endpoint, in response, looks up the pool "new-handle" in its local cache, but fails to find it.


2) The ASAP Endpoint of the PU queues the message and sends an ASAP_HANDLE_RESOLUTION request to the ENRP server asking for all information about pool "new-handle".


3) A T1-ENRPrequest timer is started while the ASAP Endpoint is waiting for the response from the ENRP server.


4) The ENRP server responds to the query with an ASAP_HANDLE_RESOLUTION_RESPONSE message that contains all the information about pool "new-handle".


5) ASAP at PU cancels the T1-ENRPrequest timer and populate its local cache with information on pool "new-handle".


6) Based on the server pooling policy of pool "new-handle", ASAP at PU selects the destination PE (PEx), sets up, if necessary, an SCTP association towards PEx (explicitly or implicitly), and sends out the queued "hello1" user message.

6)PUは、宛先PE(PEX)を選択し、ASAPに、プール「新しいハンドル」のポリシーをプールサーバに基づいて、「必要に応じて、PEX(明示的または暗黙的に)向かっSCTPアソシエーションを設定し、キューを送出しますhello1" ユーザメッセージ。

6.8.2. Send to a Cached Pool Handle
6.8.2. キャッシュされたプール・ハンドルに送ります

This shows the event sequence when the ASAP User PU sends another message to the pool "new-handle" after what happened in Section 6.8.1.


ENRP Server PU new-handle:PEx


       |                                |                 |
       |                              +---+               |
       |                              | 1 |               |
       |                              +---+  2. "hello2"  |
       |                                |---------------->|
       |                                |                 |

1) The user at PU invokes:


data_send_request("new-handle", handle-type, "hello2", 6, 0);

data_send_request( "新しいハンドル"、 "hello2"、6型ハンドル、0);

The ASAP Endpoint, in response, looks up the pool "new-handle" in its local cache and finds the mapping information.


2) Based on the server pooling policy of "new-handle", ASAP at PU selects the PE (assuming EPx is selected again), and sends out "hello2" message (assuming the SCTP association is already set up).


6.9. PE Send Failure
6.9. PEは、失敗を送信します

When the ASAP Endpoint in a PE or PU attempts to send a message to a PE and fails, the failed sender will report the event as described in Section 3.5.


Additional primitives are also defined in this section to support those user applications that do not wish to use ASAP as the actual transport.


6.9.1. Translation.Request Primitive
6.9.1. Translation.Requestプリミティブ

Format: translation.request(Pool-Handle)


If the address type is a Pool Handle and a local handle translation cache exists, the ASAP Endpoint should look within its translation cache and return the current known transport types, ports, and addresses to the caller.


If the Pool Handle does not exist in the local handle cache or no handle cache exists, the ASAP Endpoint will send an ASAP_HANDLE_RESOLUTION request using the Pool Handle. Upon completion of the handle resolution, the ASAP Endpoint should populate the local handle cache (if a local handle cache is supported) and return the transport types, ports, and addresses to the caller.

プール・ハンドルがローカルハンドルキャッシュに存在しないか、まったくハンドルキャッシュが存在しない場合は、できるだけ早くエンドポイントは、プール・ハンドルを使用してASAP_HANDLE_RESOLUTION要求を送信します。 (ローカルハンドルキャッシュがサポートされている場合)は、ハンドル解像度が完了すると、ASAPのエンドポイントは、ローカルハンドルキャッシュを投入する必要があり、呼び出し元に転送タイプ、ポート、およびアドレスを返します。

6.9.2. Transport.Failure Primitive
6.9.2. プリミティブTransport.Failure

Format: transport.failure(Pool-Handle, Transport-address)


If an external user encounters a failure in sending to a PE and is *not* using ASAP, it can use this primitive to report the failure to the ASAP endpoint. ASAP will send an ASAP_ENDPOINT_UNREACHABLE to the "Home" ENRP server in response to this primitive. Note ASAP SHOULD NOT send an ASAP_ENDPOINT_UNREACHABLE *unless* the user has actually made a previous request to send data to the PE.

外部ユーザーは、できるだけ早く使用して*いない* PEへの送信に失敗に遭遇している場合、それはできるだけ早くエンドポイントに失敗したことを報告するには、このプリミティブを使用することができます。できるだけ早くこのプリミティブに応じて、「ホーム」ENRPサーバにASAP_ENDPOINT_UNREACHABLEを送信します。ユーザが実際にPEにデータを送信する前の要求をした*しない限り、* ASAP_ENDPOINT_UNREACHABLEを送るべきではありませんできるだけ早く注意してください。

7. Timers, Variables, and Thresholds

The following is a summary of the timers, variables, and pre-set protocol constants used in ASAP.


7.1. Timers
7.1. タイマー

T1-ENRPrequest - A timer started when a request is sent by ASAP to the ENRP server (providing application information is queued). Normally set to 15 seconds.

T1-ENRPrequest - 要求は(情報がキューイングされたアプリケーションを提供する)ENRPサーバにできるだけ早くによって送信されたときにタイマーをスタート。通常は15秒に設定。

T2-registration - A timer started when sending an ASAP_REGISTRATION request to the Home ENRP server, normally set to 30 seconds.

T2-登録 - 通常は30秒に設定ホームENRPサーバへASAP_REGISTRATION要求を、送信するときにタイマーがスタート。

T3-deregistration - A timer started when sending a de-registration request to the Home ENRP server, normally set to 30 seconds.

T3-登録解除 - 通常は30秒に設定ホームENRPサーバへの登録解除要求を、送信するときにタイマーがスタート。

T4-reregistration - This timer is started after successful registration into the ENRP handlespace and is used to cause a re-registration at a periodic interval. This timer is normally set to 10 minutes or 20 seconds less than the Lifetime parameter used in the registration request (whichever is less).

T4-再登録 - このタイマはENRPのhandlespaceに登録が成功した後に開始され、定期的な間隔で再登録を引き起こすために使用されます。このタイマーは、通常10分(いずれか小さい方)登録要求に使用される寿命パラメータ未満の20秒に設定されています。

T5-Serverhunt - This timer is used during the ENRP Server Hunt procedure and is normally set to 10 seconds.

T5-Serverhunt - このタイマは、ENRPサーバハントの手続きの際に使用され、通常は10秒に設定されています。

T6-Serverannounce - This timer gives the time between the sending of consecutive ASAP_SERVER_ANNOUNCE messages. It is normally set to 1 second.

T6-Serverannounce - このタイマは、連続したASAP_SERVER_ANNOUNCEメッセージの送信間の時間を与えます。これは、通常は1秒に設定されています。

T7-ENRPoutdate - This timer gives the time a server announcement is valid. It is normally set to 5 seconds.

T7-ENRPoutdate - このタイマーは、サーバーのアナウンスが有効な時間を与えます。これは、通常は5秒に設定されています。

7.2. Variables
7.2. 変数

stale_cache_value - A threshold variable that indicates how long a cache entry is valid for.

stale_cache_value - キャッシュエントリが有効ですどのくらいの期間を示すしきい値変数。

7.3. Thresholds
7.3. しきい値

MAX-REG-ATTEMPT - The maximum number of registration attempts to be made before a server hunt is issued. The default value of this is set to 2.

MAX-REG-ATTEMPT - 登録の最大数は、サーバ狩りが発行される前に行うことを試みます。これのデフォルト値は2に設定されています。

MAX-REQUEST-RETRANSMIT - The maximum number of attempts to be made when requesting information from the local ENRP server before a server hunt is issued. The default value for this is 2.

MAX-REQUEST-RETRANSMIT - サーバ・ハントが発行される前にローカルENRPサーバから情報を要求するときに行われるべき試みの最大数。このため、デフォルト値は2です。

RETRAN-MAX - This value represents the maximum time between registration attempts and puts a ceiling on how far the registration timer will back off. The default value for this is normally set to 60 seconds.

RETRAN-MAX - この値は、登録試行間の最大時間を表し、登録タイマーがオフにバックアップする方法をはるかに上の天井を置きます。このデフォルト値は、通常は60秒に設定されています。

8. IANA Considerations
8. IANAの考慮事項

This document (RFC 5352) is the reference for all registrations described in this section. All registrations have been listed on the Reliable Server Pooling (RSerPool) Parameters page.

この文書(RFC 5352)は、このセクションで説明するすべての登録のための基準です。すべての登録は(RSerPool)パラメータページをプーリング信頼性の高いサーバーに上場されています。

8.1. A New Table for ASAP Message Types
8.1. 至急メッセージタイプのための新しい表

ASAP Message Types are maintained by IANA. Fourteen initial values have been assigned by IANA as described in Figure 1. IANA created a new table, "ASAP Message Types":

至急メッセージタイプはIANAによって維持されています。 IANAは新しいテーブル、「できるだけ早くメッセージタイプ」を作成し、図1で説明したようにフォーティーンの初期値は、IANAによって割り当てられています:

   Type       Message Name                     Reference
   -----      -------------------------        ---------
   0x00       (Reserved by IETF)               RFC 5352
   0x01       ASAP_REGISTRATION                RFC 5352
   0x02       ASAP_DEREGISTRATION              RFC 5352
   0x03       ASAP_REGISTRATION_RESPONSE       RFC 5352
   0x05       ASAP_HANDLE_RESOLUTION           RFC 5352
   0x07       ASAP_ENDPOINT_KEEP_ALIVE         RFC 5352
   0x08       ASAP_ENDPOINT_KEEP_ALIVE_ACK     RFC 5352
   0x09       ASAP_ENDPOINT_UNREACHABLE        RFC 5352
   0x0a       ASAP_SERVER_ANNOUNCE             RFC 5352
   0x0b       ASAP_COOKIE                      RFC 5352
   0x0c       ASAP_COOKIE_ECHO                 RFC 5352
   0x0d       ASAP_BUSINESS_CARD               RFC 5352
   0x0e       ASAP_ERROR                       RFC 5352
   0x0b-0xff  (Available for Assignment)       RFC 5352

Requests to register an ASAP Message Type in this table should be sent to IANA. The number must be unique. The "Specification Required" policy of [RFC5226] MUST be applied.

この表にできるだけ早くメッセージタイプを登録するための要求はIANAに送られるべきです。番号は一意である必要があります。 [RFC5226]の「仕様が必要である」というポリシーが適用されなければなりません。

8.2. Port Numbers
8.2. ポート番号

The references for the already assigned port numbers


asap-tcp 3863/tcp

できるだけ早く-TCP 3863 / TCP

asap-udp 3863/udp

できるだけ早く-UDP 3863 / UDP

asap-sctp 3863/sctp

煙-SCTP 3863 / SCTP

asap-tcp-tls 3864/tcp

できるだけ早く-TCP-TLS 3864 / TCP

asap-sctp-tls 3864/sctp

できるだけ早く-SCTP-TLS 3864 / SCTP

have been updated to RFC 5352.

RFC 5352に更新されました。

8.3. SCTP Payload Protocol Identifier
8.3. SCTPペイロードプロトコル識別子

The reference for the already assigned ASAP payload protocol identifier 11 has been updated to RFC 5352.

既に割り当てられたできるだけ早くペイロードプロトコル識別子11のための基準は、RFC 5352にアップデートされています。

8.4. Multicast Addresses
8.4. マルチキャストアドレス

IANA has assigned an IPv4 multicast address ( and an IPv6 multicast address (FF0X:0:0:0:0:0:0:133). The IPv4 address is part of the Internetwork Control Block (224.0.1/24).

(133:0:0:0:0:0:0 FF0X)IANAは、IPv4マルチキャストアドレス(とIPv6マルチキャストアドレスが割り当てられています。 IPv4アドレスは、インターネットワークコントロールブロック(224.0.1 / 24)の一部です。

9. Security Considerations

We present a summary of the of the threats to the RSerPool architecture and describe security requirements in response in order to mitigate the threats. Next, we present the security mechanisms, based on TLS, that are implementation requirements in response to the threats. Finally, we present a chain-of-trust argument that examines critical data paths in RSerPool and shows how these paths are protected by the TLS implementation.


9.1. Summary of RSerPool Security Threats
9.1. RSerPoolセキュリティの脅威の概要

"Threats Introduced by Reliable Server Pooling (RSerPool) and Requirements for Security in Response to Threats" [RFC5355] describes the threats to the RSerPool architecture in detail and lists the security requirements in response to each threat. From the threats described in this document, the security services required for the RSerPool protocol are enumerated below.


   Threat 1) PE registration/de-registration flooding or spoofing.
   Security mechanism in response: ENRP server authenticates the PE.
   Threat 2) PE registers with a malicious ENRP server.
   Security mechanism in response: PE authenticates the ENRP server.

Threats 1 and 2, taken together, result in mutual authentication of the ENRP server and the PE.


   Threat 3) Malicious ENRP server joins the ENRP server pool.
   Security mechanism in response: ENRP servers mutually authenticate.
   Threat 4) A PU communicates with a malicious ENRP server for handle
   Security mechanism in response: The PU authenticates the ENRP server.
   Threat 5) Replay attack.
   Security mechanism in response: Security protocol that has protection
   from replay attacks.
   Threat 6) Corrupted data that causes a PU to have misinformation
   concerning a pool handle resolution.
   Security mechanism in response: Security protocol that supports
   integrity protection.
   Threat 7) Eavesdropper snooping on handlespace information.
   Security mechanism in response: Security protocol that supports data
   Threat 8) Flood of ASAP_ENDPOINT_UNREACHABLE messages from the PU to
   ENRP server.
   Security mechanism in response: ASAP must control the number of ASAP
   Endpoint unreachable messages transmitted from the PU to the ENRP
   Threat 9) Flood of ASAP_ENDPOINT_KEEP_ALIVE messages to the PE from
   the ENRP server.
   Security mechanism in response: ENRP server must control the number
   of ASAP_ENDPOINT_KEEP_ALIVE messages to the PE.

To summarize, the threats 1-7 require security mechanisms that support authentication, integrity, data confidentiality, and protection from replay attacks.


For RSerPool we need to authenticate the following:


      PU <----  ENRP server (PU authenticates the ENRP server)
      PE <----> ENRP server (mutual authentication)
      ENRP server <-----> ENRP server (mutual authentication)
9.2. Implementing Security Mechanisms
9.2. セキュリティメカニズムを実装

We do not define any new security mechanisms specifically for responding to threats 1-7. Rather, we use an existing IETF security protocol, specifically [RFC3237], to provide the security services required. TLS supports all these requirements and MUST be implemented. The TLS_RSA_WITH_AES_128_CBC_SHA ciphersuite MUST be supported, at a minimum, by implementers of TLS for RSerPool. For purposes of backwards compatibility, ENRP SHOULD support TLS_RSA_WITH_3DES_EDE_CBC_SHA. Implementers MAY also support any other IETF-approved ciphersuites.

我々は、具体的な脅威1-7に対応するため、新たなセキュリティ・メカニズムを定義していません。むしろ、我々は必要なセキュリティサービスを提供するために、既存のIETFセキュリティプロトコル、特に[RFC3237]を使用します。 TLSは、これらすべての要件をサポートし、実装しなければなりません。 TLS_RSA_WITH_AES_128_CBC_SHAの暗号スイートはRSerPoolのためのTLSの実装によって、最低限、サポートしなければなりません。後方互換性の目的のために、ENRPはTLS_RSA_WITH_3DES_EDE_CBC_SHAをサポートする必要があります。実装者はまた、他のIETF承認の暗号スイートをサポートするかもしれません。

ENRP servers, PEs, and PUs MUST implement TLS. ENRP servers and PEs MUST support mutual authentication using PSK (pre-shared-key). ENRP servers MUST support mutual authentication among themselves using PSK. PUs MUST authenticate ENRP servers using certificates.

ENRPサーバは、PEを、とのPUは、TLSを実装しなければなりません。 ENRPサーバとPEはPSK(事前共有キー)を使用して相互認証をサポートしなければなりません。 ENRPサーバは、PSKを使用してそれらの間で相互認証をサポートしなければなりません。 PUが証明書を使用してENRPサーバを認証する必要があります。

TLS with PSK is mandatory to implement as the authentication mechanism for ENRP to ENRP authentication and PE to ENRP authentication. For PSK, having a pre-shared-key constitutes authorization. The network administrators of a pool need to decide which nodes are authorized to participate in the pool. The justification for PSK is that we assume that one administrative domain will control and manage the server pool. This allows for PSK to be implemented and managed by a central security administrator.

PSKとTLS認証をENRPする認証およびPEをENRPするENRPの認証機構として実装することが必須です。 PSKのために、事前共有キーを有する許可を構成しています。プールのネットワーク管理者は、プールに参加することを許可されているノードを決定する必要があります。 PSKのための正当化は、我々は1つの管理ドメインは、サーバー・プールを制御し、管理することを前提としていることです。 PSKが実装され、中央のセキュリティ管理者によって管理されるためこれができます。

TLS with certificates is mandatory to implement as the authentication mechanism for PUs to the ENRP server. PUs MUST authenticate ENRP servers using certificates. ENRP servers MUST possess a site certificate whose subject corresponds to their canonical hostname. PUs MAY have certificates of their own for mutual authentication with TLS, but no provisions are set forth in this document for their use. All RSerPool Elements that support TLS MUST have a mechanism for validating certificates received during TLS negotiation; this entails possession of one or more root certificates issued by certificate authorities (preferably, well-known distributors of site certificates comparable to those that issue root certificates for web browsers).

証明書とTLSはENRPサーバへのPUのための認証機構として実装するために必須です。 PUが証明書を使用してENRPサーバを認証する必要があります。 ENRPサーバは、その対象と彼らの正規のホスト名に対応して、サイトの証明書を持っている必要があります。 PUは、TLSとの相互認証のために自分自身の証明書を持っているかもしれませんが、何の規定は、その使用については、このドキュメントに記載されていません。 TLSは、TLSネゴシエーション中に受信した証明書を検証するためのメカニズムを持っていなければならサポートするすべての要素RSerPool。これは、認証局によって発行された一つ以上のルート証明書の所持を伴う(好ましくは、Webブラウザ用のルート証明書を発行するものと同等のサイト証明書のよく知られた代理店)。

In order to prevent man-in-the-middle attacks, the client MUST verify the server's identity (as presented in the server's Certificate message). The client's understanding of the server's identity (typically, the identity used to establish the transport connection) is called the "reference identity". The client determines the type (e.g., DNS name or IP address) of the reference identity and performs a comparison between the reference identity and each subjectAltName value of the corresponding type until a match is produced. Once a match is produced, the server's identity has been verified, and the server identity check is complete. Different subjectAltName types are matched in different ways. The client may map the reference identity to a different type prior to performing a comparison. Mappings may be performed for all available subjectAltName types to which the reference identity can be mapped; however, the reference identity should only be mapped to types for which the mapping is either inherently secure (e.g., extracting the DNS name from a URI to compare with a subjectAltName of type dNSName) or for which the mapping is performed in a secure manner (e.g., using DNS Security (DNSSEC), or using user- or admin-configured host-to-address/ address-to-host lookup tables).


If the server identity check fails, user-oriented clients SHOULD either notify the user or close the transport connection and indicate that the server's identity is suspect. Automated clients SHOULD close the transport connection and then return or log an error indicating that the server's identity is suspect, or both. Beyond the server identity check described in this section, clients should be prepared to do further checking to ensure that the server is authorized to provide the service it is requested to provide. The client may need to make use of local policy information in making this determination.


If the reference identity is an internationalized domain name, conforming implementations MUST convert it to the ASCII Compatible Encoding (ACE) format, as specified in Section 4 of [RFC3490], before comparison with subjectAltName values of type dNSName. Specifically, conforming implementations MUST perform the conversion operation specified in Section 4 of [RFC3490] as follows: * in step 1, the domain name SHALL be considered a "stored string"; * in step 3, set the flag called "UseSTD3ASCIIRules"; * in step 4, process each label with the "ToASCII" operation; and * in step 5, change all label separators to U+002E (full stop).

基準IDは国際化ドメイン名である場合型のdNSNameののsubjectAltName値と比較する前に、[RFC3490]のセクション4で指定されるように、適合実装は、ASCII互換エンコーディング(ACE)形式に変換しなければなりません。具体的には、以下のよう適合実装は、[RFC3490]のセクション4で指定された変換操作を実行しなければなりません:*ステップ1で、ドメイン名が「記憶された文字列」と見なさなければなりません。 *ステップ3で、「UseSTD3ASCIIRules」と呼ばれるフラグを設定します。 *工程4、工程「もしToASCII」操作で各ラベルにおいて、そして*ステップ5で、U + 002E(フルストップ)に、すべてのラベルの区切りを変更します。

After performing the "to-ASCII" conversion, the DNS labels and names MUST be compared for equality, according to the rules specified in Section 3 of RFC 3490. The '*' (ASCII 42) wildcard character is allowed in subjectAltName values of type dNSName, and then, only as the left-most (least significant) DNS label in that value. This wildcard matches any left-most DNS label in the server name. That is, the subject * matches the server names and, but does not match or

「へ-ASCII」変換を行った後、DNSラベルと名前が「*」(ASCII 42)ワイルドカード文字がタイプののsubjectAltName値で許可されているRFC 3490のセクション3で指定された規則に従って、等しいかどうかを比較しなければなりませんdNSName、その後、その値だけでは、一番左の(最下位)DNSラベルとして。このワイルドカードは、サーバー名に任意の一番左のDNSラベルと一致します。つまり、対象* .example.comとは、サーバー名a.example.comとb.example.comと一致しますが、example.comまたはa.b.example.comと一致していないです。

When the reference identity is an IP address, the identity MUST be converted to the "network byte order" octet string representation in [RFC0791] and [RFC2460]. For IP version 4, as specified in RFC 791, the octet string will contain exactly four octets. For IP version 6, as specified in RFC 2460, the octet string will contain exactly sixteen octets. This octet string is then compared against subjectAltName values of type iPAddress. A match occurs if the reference identity octet string and value octet strings are identical.

基準IDはIPアドレスである場合、同一性は、[RFC0791]の「ネットワークバイト順」オクテットストリング表現と[RFC2460]に変換されなければなりません。 IPバージョン4の場合、RFC 791で指定されているように、オクテット文字列は正確に4オクテットを含んでいます。 IPバージョン6の場合は、RFC 2460で指定されているように、オクテット文字列は、正確に16オクテットを含んでいます。このオクテット文字列は、その後のタイプIPアドレスののsubjectAltName値と比較されます。参照アイデンティティオクテット文字列と値のオクテット文字列が同一である場合、一致が発生します。

After a TLS layer is established in a session, both parties are to independently decide whether or not to continue based on local policy and the security level achieved. If either party decides that the security level is inadequate for it to continue, it SHOULD remove the TLS layer immediately after the TLS (re)negotiation has completed (see RFC 4511)[RFC4511]. Implementations may re-evaluate the security level at any time and, upon finding it inadequate, should remove the TLS layer.

TLS層はセッション中に確立された後、両当事者は独立して、ローカルポリシーと達成セキュリティレベルに基づいて継続するかどうかを決定することです。いずれかの当事者がそれを継続するために、セキュリティレベルが不十分であると判断した場合は、すぐにTLS(再)交渉の後にTLS層を削除する必要があります(RFC 4511を参照してください)[RFC4511]を完了しました。実装はTLS層を除去する必要があり、それが不十分な発見時に、任意の時点でセキュリティレベルを再評価します。

Implementations MUST support TLS with SCTP, as described in [RFC3436] or TLS over TCP, as described in [RFC5246]. When using TLS/SCTP we must ensure that RSerPool does not use any features of SCTP that are not available to a TLS/SCTP user. This is not a difficult technical problem, but simply a requirement. When describing an API of the RSerPool lower layer, we also have to take into account the differences between TLS and SCTP.

TCP上に[RFC3436]またはTLSに記載されているように[RFC5246]で説明されるような実装は、SCTPとTLSをサポートしなければなりません。 TLS / SCTPを使用した場合、我々はRSerPoolは、TLS / SCTPユーザに利用できないSCTPのすべての機能を使用していないことを確認する必要があります。これは困難な技術的問題ではなく、単に必要条件ではありません。 RSerPool下層のAPIを説明するとき、我々も考慮にTLSおよびSCTPの違いを取らなければなりません。

Threat 8 requires the ASAP protocol to limit the number of ASAP_ENDPOINT_UNREACHABLE messages (see Section 3.5) to the ENRP server.


Threat 9 requires the ENRP protocol to limit the number of ASAP_ENDPOINT_KEEP_ALIVE messages from the ENRP server to the PE (see [RFC5353]).


There is no security mechanism defined for the multicast announcements. Therefore, a receiver of such an announcement cannot consider the source address of such a message to be a trustworthy address of an ENRP server. A receiver must also be prepared to receive a large number of multicast announcements from attackers.


9.3. Chain of Trust
9.3. 信頼の連鎖

Security is mandatory to implement in RSerPool and is based on TLS implementation in all three architecture components that comprise RSerPool -- namely PU, PE, and ENRP server. We define an ENRP server that uses TLS for all communication and authenticates ENRP peers and PE registrants to be a secured ENRP server.

セキュリティはRSerPoolに実装するために必須であり、すべての3つのRSerPoolを含むアーキテクチャコンポーネントでTLSの実装に基づいている - すなわち、PU、PE、およびENRPサーバ。我々は、すべての通信のためにTLSを使用してピアとPEの登録は、保護されたENRPサーバであることがENRP認証ENRPサーバを定義します。

Here is a description of all possible data paths and a description of the security.


   PU <---> secured ENRP server (authentication of ENRP server;
            queries over TLS)
   PE <---> secured ENRP server (mutual authentication;
            registration/de-registration over TLS)
   secured ENRP server <---> secured ENRP server (mutual authentication;
            database updates using TLS)

If all components of the system authenticate and communicate using TLS, the chain of trust is sound. The root of the trust chain is the ENRP server. If that is secured using TLS, then security will be enforced for all ENRP and PE components that try to connect to it.


Summary of interaction between secured and unsecured components: If the PE does not use TLS and tries to register with a secure ENRP server, it will receive an error message response indicated as an error due to security considerations and the registration will be rejected. If an ENRP server that does not use TLS tries to update the database of a secure ENRP server, then the update will be rejected. If a PU does not use TLS and communicates with a secure ENRP server, it will get a response with the understanding that the response is not secure, as the response can be tampered with in transit even if the ENRP database is secured.

固定され保護されていない構成要素間の相互作用の概要:PEは、TLSを使用して安全なENRPサーバに登録しようとしない場合は、エラーメッセージ応答を受信するによるセキュリティ問題にエラーとして示され、登録は拒否されます。 TLSを使用しないENRPサーバが安全なENRPサーバのデータベースを更新しようとする場合、更新は拒否されます。 PUは、TLSを使用し、安全なENRPサーバと通信していない場合は、応答がENRPデータベースが確保されている場合でも、中に改ざんすることができますよう、応答は、セキュリティで保護されていないことを理解した上で応答を取得します。

The final case is the PU sending a secure request to ENRP. It might be that ENRP and PEs are not secured and this is an allowable configuration. The intent is to secure the communication over the Internet between the PU and the ENRP server.




RSerPool architecture components can communicate with each other to establish a chain of trust. Secured PE and ENRP servers reject any communications with unsecured ENRP or PE servers.


If the above is enforced, then a chain of trust is established for the RSerPool user.


10. Acknowledgments

The authors wish to thank John Loughney, Lyndon Ong, Walter Johnson, Thomas Dreibholz, and many others for their invaluable comments and feedback.


11. References
11.1. Normative References
11.1. 引用規格

[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981.

[RFC0791]ポステル、J.、 "インターネットプロトコル"、STD 5、RFC 791、1981年9月。

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

[RFC2119]ブラドナーの、S.、 "要件レベルを示すためにRFCsにおける使用のためのキーワード"、BCP 14、RFC 2119、1997年3月。

[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998.

[RFC2460]デアリング、S.とR. Hindenと、 "インターネットプロトコルバージョン6(IPv6)の仕様"、RFC 2460、1998年12月。

[RFC3237] Tuexen, M., Xie, Q., Stewart, R., Shore, M., Ong, L., Loughney, J., and M. Stillman, "Requirements for Reliable Server Pooling", RFC 3237, January 2002.

[RFC3237] Tuexen、M.、謝、Q.、スチュワート、R.、ショア、M.、オング、L.、Loughney、J.、およびM.スティルマン、 "信頼できるサーバプーリングのための要件"、RFC 3237年1月2002。

[RFC3436] Jungmaier, A., Rescorla, E., and M. Tuexen, "Transport Layer Security over Stream Control Transmission Protocol", RFC 3436, December 2002.

[RFC3436] Jungmaier、A.、レスコラ、E.、およびM. Tuexen、 "ストリーム制御伝送プロトコルを介してトランスポート層セキュリティ"、RFC 3436、2002年12月。

[RFC3490] Faltstrom, P., Hoffman, P., and A. Costello, "Internationalizing Domain Names in Applications (IDNA)", RFC 3490, March 2003.

[RFC3490] Faltstrom、P.、ホフマン、P.、およびA.コステロ、 "アプリケーションにおける国際化ドメイン名(IDNA)"、RFC 3490、2003年3月。

[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, August 2008.

[RFC5246]ダークス、T.およびE.レスコラ、 "トランスポート層セキュリティ(TLS)プロトコルバージョン1.2"、RFC 5246、2008年8月。

[RFC4511] Sermersheim, J., "Lightweight Directory Access Protocol (LDAP): The Protocol", RFC 4511, June 2006.

[RFC4511] Sermersheim、J.、 "ライトウェイトディレクトリアクセスプロトコル(LDAP):プロトコル"、RFC 4511、2006年6月。

[RFC4960] Stewart, R., "Stream Control Transmission Protocol", RFC 4960, September 2007.

[RFC4960]スチュワート、R.、 "ストリーム制御伝送プロトコル"、RFC 4960、2007年9月。

[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 5226, May 2008.

[RFC5226] Narten氏、T.とH. Alvestrand、 "RFCsにIANA問題部に書くためのガイドライン"、BCP 26、RFC 5226、2008年5月。

[RFC5356] Dreibholz, T. and M. Tuexen, "Reliable Server Pooling Policies", RFC 5356, September 2008.

[RFC5356] Dreibholz、T.およびM. Tuexen、 "信頼できるサーバプーリング方針"、RFC 5356、2008年9月。

[RFC5354] Stewart, R., Xie, Q., Stillman, M., and M. Tuexen, "Aggregate Server Access Protocol (ASAP) and Endpoint Handlespace Redundancy Protocol (ENRP) Parameters", RFC 5354, September 2008.

[RFC5354]スチュワート、R.、謝、Q.、スティルマン、M.、およびM. Tuexen、 "集計サーバアクセスプロトコル(ASAP)から印刷して、エンドポイントHandlespace冗長プロトコル(ENRP)パラメータ"、RFC 5354、2008年9月。

[RFC5353] Xie, Q., Stewart, R., Stillman, M., Tuexen, M., and A. Silverton, "Endpoint Handlespace Redundancy Protocol (ENRP)", RFC 5353, September 2008.

[RFC5353]謝、Q.、スチュワート、R.、スティルマン、M.、Tuexen、M.、およびA.シルバー、 "エンドポイントHandlespace冗長プロトコル(ENRP)"、RFC 5353、2008年9月。

[RFC5355] Stillman, M., Ed., Gopal, R., Guttman, E., Holdrege, M., and S. Sengodan, "Threats Introduced by Reliable Server Pooling (RSerPool) and Requirements for Security in Response to Threats", RFC 5355, September 2008.

[RFC5355]スティルマンが、M.編、ゴパル、R.、ガットマン、E.、ホールドレッジ、M.、およびS. Sengodanは、 "脅威脅威に応答して信頼できるサーバプーリング(RSerPool)とセキュリティ要件によって導入されました" 、RFC 5355、2008年9月。

11.2. Informative References
11.2. 参考文献

[RFC4086] Eastlake, D., Schiller, J., and S. Crocker, "Randomness Requirements for Security", BCP 106, RFC 4086, June 2005.

[RFC4086]イーストレーク、D.、シラー、J.、およびS.クロッカー、 "セキュリティのためのランダム要件"、BCP 106、RFC 4086、2005年6月。

Authors' Addresses


Randall R. Stewart The Resource Group 1700 Pennsylvania Ave NW Suite 560 Washington, D.C., 20006 USA

ランドールR.スチュワートザ・リソース・グループ1700ペンシルバニアアベニューNWスイート560ワシントンD.C.、20006 USA



Qiaobing Xie The Resource Group 1700 Pennsylvania Ave NW Suite 560 Washington, D.C., 20006 USA

オリンピックアイスQ私はIEにWスイート560ワシントンD.C.、20006 USA専用リソース・グループ1700年ペンシルベニア州AVをX

Phone: +1 224-465-5954 EMail:

電話:+1 224-465-5954電子メール

Maureen Stillman Nokia 1167 Peachtree Ct. Naperville, IL 60540 USA

モーリーンスティルマンノキア1167ピーチツリーのCt。ネーパーヴィル、IL 60540 USA



Michael Tuexen Muenster Univ. of Applied Sciences Stegerwaldstr. 39 48565 Steinfurt Germany

マイケルTuexenミュンスター大学。応用科学Stegerwaldstrの。 39 48565シュタインフルトドイツ



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