Network Working Group T. George
Request for Comments: 4165 B. Bidulock
Category: Standards Track OpenSS7
R. Dantu
University of North Texas
H. Schwarzbauer
Siemens
K. Morneault
Cisco Systems
September 2005
Network Working Group T. George
Request for Comments: 4165 B. Bidulock
Category: Standards Track OpenSS7
R. Dantu
University of North Texas
H. Schwarzbauer
Siemens
K. Morneault
Cisco Systems
September 2005
Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) - User Peer-to-Peer Adaptation Layer (M2PA)
信令系统7（SS7）消息传输第2部分（MTP2）-用户对等适配层（M2PA）
Status of This Memo
关于下段备忘
This document specifies an Internet standards track protocol for the Internet community, and requests discussion and suggestions for improvements. Please refer to the current edition of the "Internet Official Protocol Standards" (STD 1) for the standardization state and status of this protocol. Distribution of this memo is unlimited.
本文件规定了互联网社区的互联网标准跟踪协议，并要求进行讨论和提出改进建议。有关本协议的标准化状态和状态，请参考当前版本的“互联网官方协议标准”（STD 1）。本备忘录的分发不受限制。
Copyright Notice
版权公告
Copyright (C) The Internet Society (2005).
版权所有（C）互联网协会（2005年）。
Abstract
摘要
This document defines a protocol supporting the transport of Signaling System Number 7 (SS7) Message Transfer Part (MTP) Level 3 signaling messages over Internet Protocol (IP) using the services of the Stream Control Transmission Protocol (SCTP). This protocol would be used between SS7 Signaling Points using the MTP Level 3 protocol. The SS7 Signaling Points may also use standard SS7 links using the SS7 MTP Level 2 to provide transport of MTP Level 3 signaling messages. The protocol operates in a manner similar to MTP Level 2 so as to provide peer-to-peer communication between SS7 endpoints.
本文件定义了一个协议，该协议支持使用流控制传输协议（SCTP）的服务通过互联网协议（IP）传输信令系统7号（SS7）消息传输部分（MTP）3级信令消息。该协议将使用MTP 3级协议在SS7信令点之间使用。SS7信令点还可以使用使用SS7 MTP级别2的标准SS7链路来提供MTP级别3信令消息的传输。该协议以类似于MTP级别2的方式运行，以便在SS7端点之间提供对等通信。
Table of Contents
目录
1. Introduction ....................................................3
1.1. Scope ......................................................3
1.2. Terminology ................................................3
1.3. Abbreviations ..............................................4
1.4. Conventions ................................................5
1.5. Signaling Transport Architecture ...........................5
1.6. Services Provided by M2PA ..................................7
1.7. Functions Provided by M2PA .................................9
1.8. Definition of the M2PA Boundaries .........................10
1.9. Differences Between M2PA and M2UA .........................10
2. Protocol Elements ..............................................12
2.1. Common Message Header .....................................12
2.2. M2PA Header ...............................................13
2.3. M2PA Messages .............................................14
3. State Control ..................................................17
3.1. SCTP Association State Control ............................17
3.2. M2PA Link State Control ...................................18
4. Procedures .....................................................19
4.1. Procedures to Support MTP2 Features .......................19
4.2. Procedures to Support the MTP3/MTP2 Interface .............30
4.3. SCTP Considerations .......................................33
5. Examples of M2PA Procedures ....................................34
5.1. Link Initialization (Alignment) ...........................34
5.2. Message Transmission and Reception ........................37
5.3. Link Status Indication ....................................37
5.4. Link Status Message (Processor Outage) ....................38
5.5. Level 2 Flow Control ......................................42
5.6. MTP3 Signaling Link Congestion ............................44
5.7. Link Deactivation .........................................45
5.8. Link Changeover ...........................................45
6. Security Considerations ........................................47
7. IANA Considerations ............................................47
7.1. SCTP Payload Protocol Identifier ..........................47
7.2. M2PA Protocol Extensions ..................................48
8. Acknowledgements ...............................................49
9. References .....................................................50
9.1. Normative References ......................................50
9.2. Informative References ....................................51
1. Introduction ....................................................3
1.1. Scope ......................................................3
1.2. Terminology ................................................3
1.3. Abbreviations ..............................................4
1.4. Conventions ................................................5
1.5. Signaling Transport Architecture ...........................5
1.6. Services Provided by M2PA ..................................7
1.7. Functions Provided by M2PA .................................9
1.8. Definition of the M2PA Boundaries .........................10
1.9. Differences Between M2PA and M2UA .........................10
2. Protocol Elements ..............................................12
2.1. Common Message Header .....................................12
2.2. M2PA Header ...............................................13
2.3. M2PA Messages .............................................14
3. State Control ..................................................17
3.1. SCTP Association State Control ............................17
3.2. M2PA Link State Control ...................................18
4. Procedures .....................................................19
4.1. Procedures to Support MTP2 Features .......................19
4.2. Procedures to Support the MTP3/MTP2 Interface .............30
4.3. SCTP Considerations .......................................33
5. Examples of M2PA Procedures ....................................34
5.1. Link Initialization (Alignment) ...........................34
5.2. Message Transmission and Reception ........................37
5.3. Link Status Indication ....................................37
5.4. Link Status Message (Processor Outage) ....................38
5.5. Level 2 Flow Control ......................................42
5.6. MTP3 Signaling Link Congestion ............................44
5.7. Link Deactivation .........................................45
5.8. Link Changeover ...........................................45
6. Security Considerations ........................................47
7. IANA Considerations ............................................47
7.1. SCTP Payload Protocol Identifier ..........................47
7.2. M2PA Protocol Extensions ..................................48
8. Acknowledgements ...............................................49
9. References .....................................................50
9.1. Normative References ......................................50
9.2. Informative References ....................................51
There is a need for Switched Circuit Network (SCN) signaling protocol delivery over an IP network. This includes message transfer between the following:
需要通过IP网络传送交换电路网络（SCN）信令协议。这包括以下各项之间的消息传输：
- a Signaling Gateway (SG) and a Media Gateway Controller (MGC) [RFC2719]
- 信令网关（SG）和媒体网关控制器（MGC）[RFC2719]
- a SG and an IP Signaling Point (IPSP)
- SG和IP信令点（IPSP）
- an IPSP and an IPSP
- IPSP和IPSP
This could allow for convergence of some signaling and data networks. SCN signaling nodes would have access to databases and other devices in the IP network domain that do not use SS7 signaling links. Likewise, IP telephony applications would have access to SS7 services. There may also be operational cost and performance advantages when traditional signaling links are replaced by IP network "connections".
这将允许某些信令和数据网络的融合。SCN信令节点可以访问IP网络域中不使用SS7信令链路的数据库和其他设备。同样，IP电话应用程序也可以访问SS7服务。当传统的信令链路被IP网络“连接”所取代时，也可能具有运营成本和性能优势。
The delivery mechanism described in this document allows for full MTP3 message handling and network management capabilities between any two SS7 nodes communicating over an IP network. An SS7 node equipped with an IP network connection is called an IP Signaling Point (IPSP). The IPSPs function as traditional SS7 nodes using the IP network instead of SS7 links.
本文档中描述的传递机制允许在通过IP网络通信的任何两个SS7节点之间实现完整的MTP3消息处理和网络管理功能。配备有IP网络连接的SS7节点称为IP信令点（IPSP）。IPSP作为传统的SS7节点使用IP网络而不是SS7链路。
The delivery mechanism should:
交付机制应：
- Support seamless operation of MTP3 protocol peers over an IP network connection.
- 支持通过IP网络连接无缝操作MTP3协议对等方。
- Support the MTP Level 2 / MTP Level 3 interface boundary.
- 支持MTP 2级/MTP 3级接口边界。
- Support management of SCTP transport associations and traffic instead of MTP2 Links.
- 支持管理SCTP传输关联和流量，而不是MTP2链路。
- Support asynchronous reporting of status changes to management.
- 支持向管理层异步报告状态更改。
MTP - The Message Transfer Part of the SS7 protocol [Q.700] [Q.701] [Q.702] [Q.703] [Q.704] [Q.705] [T1.111].
MTP-七号信令协议的报文传输部分[Q.700][Q.701][Q.702][Q.703][Q.704][Q.705][T1.111]。
MTP2 - MTP Level 2, the MTP signaling link layer.
MTP2-MTP级别2，MTP信令链路层。
MTP3 - MTP Level 3, the MTP signaling network layer.
MTP3-MTP级别3，MTP信令网络层。
MTP2-User - A protocol that normally uses the services of MTP Level 2. The only MTP2 user is MTP3. The MTP2 user is equivalent to the M2PA user.
MTP2用户-通常使用MTP级别2服务的协议。唯一的MTP2用户是MTP3。MTP2用户等同于M2PA用户。
Signaling End Point (SEP) - An SS7 Signaling Point that originates or terminates signaling messages. One example is a central office switch. [RFC2719]
信令端点（SEP）-发起或终止信令消息的SS7信令点。一个例子是中央局交换机。[RFC2719]
IP Signaling Point (IPSP) - An SS7 Signaling Point with an IP network connection used for SS7 over IP.
IP信令点（IPSP）-具有IP网络连接的SS7信令点，用于SS7 over IP。
Signaling Gateway (SG) - A signaling agent that receives/sends SCN native signaling at the edge of the IP network [RFC2719]. In this context, an SG is an SS7 Signaling Point that has both an IP network connection used for SS7 over IP, and a traditional (non-IP) link to an SS7 network.
信令网关（SG）-在IP网络边缘接收/发送SCN本机信令的信令代理[RFC2719]。在此上下文中，SG是具有用于SS7 over IP的IP网络连接和到SS7网络的传统（非IP）链路的SS7信令点。
Signal Transfer Point (STP) - A Signal Transfer Point as defined by MTP standards, e.g., [Q.700].
信号传输点（STP）-MTP标准定义的信号传输点，例如[Q.700]。
Signaling Point (STP) - A Signaling Point as defined by MTP standards, e.g., [Q.700].
信令点（STP）-MTP标准定义的信令点，例如[Q.700]。
Association - An association refers to an SCTP association [RFC2960]. The association provides the transport for MTP3 protocol data units and M2PA adaptation layer peer messages.
关联-关联是指SCTP关联[RFC2960]。该关联为MTP3协议数据单元和M2PA适配层对等消息提供传输。
Network Byte Order - Most significant byte first, also known as "Big Endian". See [RFC791], Appendix B "Data Transmission Order".
网络字节顺序-最高有效字节优先，也称为“Big-Endian”。参见[RFC791]，附录B“数据传输顺序”。
Stream - A stream refers to an SCTP stream [RFC2960].
流-流指SCTP流[RFC2960]。
BSNT - Backward Sequence Number to be Transmitted
BSNT-要传输的向后序列号
FSNC - Forward Sequence Number of last message accepted by remote level 2
FSNC-远程级别2接受的最后一条消息的转发序列号
LI - Length Indicator
长度指示器
MSU - Message Signal Unit
消息信号单元
SCCP - Signaling Connection Control Part
信令连接控制部分
SCN - Switched Circuit Network
交换电路网络
SCTP - Stream Control Transmission Protocol
流控制传输协议
SIF - Signaling Information Field
信令信息域
SIO - Service Information Octet
服务信息八位组
SLC - Signaling Link Code
信令链路码
SS7 - Signaling System Number 7
SS7-7号信号系统
SSN - Stream Sequence Number
SSN-流序列号
STP - Signal Transfer Point
STP-信号传输点
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].
本文件中的关键词“必须”、“不得”、“必需”、“应”、“不应”、“应”、“不应”、“建议”、“可”和“可选”应按照[RFC2119]中所述进行解释。
The architecture that has been defined [RFC2719] for Switched Circuit Network (SCN) signaling transport over IP uses multiple components, including an IP transport protocol, the Stream Control Transmission Protocol (SCTP), and an adaptation module to support the services expected by a particular SCN signaling protocol from its underlying protocol layer.
为IP上的交换电路网络（SCN）信令传输定义的体系结构[RFC2719]使用多个组件，包括IP传输协议、流控制传输协议（SCTP），以及适配模块，用于支持特定SCN信令协议从其底层协议层期望的服务。
Within this framework architecture, this document defines an SCN adaptation module that is suitable for the transport of SS7 MTP3 messages. The adaptation layer, known as the MTP2 User Peer-to-peer Adaptation Layer (M2PA), provides MTP3 with an interface and services similar to MTP2. In effect, MTP2 and lower layers of the traditional SS7 protocol stack are replaced by an IP equivalent.
在该框架架构内，本文档定义了一个SCN适配模块，该模块适用于SS7 MTP3消息的传输。被称为MTP2用户对等适配层（M2PA）的适配层为MTP3提供类似于MTP2的接口和服务。实际上，MTP2和传统SS7协议栈的较低层被IP等价物所取代。
Figure 1 shows the seamless interworking at the MTP3 layer. MTP3 is adapted to the SCTP layer using the MTP2 User Peer-to-peer Adaptation Layer (M2PA). All the primitives between MTP3 and MTP2 are supported by M2PA. The SCTP association acts as one SS7 link between the IPSPs. An IPSP may have the Signaling Connection Control Part (SCCP) and other SS7 layers above MTP3.
图1显示了MTP3层的无缝互通。MTP3使用MTP2用户对等适配层（M2PA）适配到SCTP层。M2PA支持MTP3和MTP2之间的所有原语。SCTP关联充当IPSP之间的一条SS7链路。IPSP可以在MTP3上具有信令连接控制部分（SCCP）和其他SS7层。
******** IP ********
* IPSP *--------* IPSP *
******** ********
******** IP ********
* IPSP *--------* IPSP *
******** ********
+------+ +------+
| TCAP | | TCAP |
+------+ +------+
| SCCP | | SCCP |
+------+ +------+
| MTP3 | | MTP3 |
+------+ +------+
| M2PA | | M2PA |
+------+ +------+
| SCTP | | SCTP |
+------+ +------+
| IP | | IP |
+------+ +------+
+------+ +------+
| TCAP | | TCAP |
+------+ +------+
| SCCP | | SCCP |
+------+ +------+
| MTP3 | | MTP3 |
+------+ +------+
| M2PA | | M2PA |
+------+ +------+
| SCTP | | SCTP |
+------+ +------+
| IP | | IP |
+------+ +------+
IP - Internet Protocol IPSP - IP Signaling Point SCTP - Stream Control Transmission Protocol [RFC2960]
IP-互联网协议IPSP-IP信令点SCTP-流控制传输协议[RFC2960]
Figure 1. M2PA Symmetrical Peer-to-Peer Architecture
图1。M2PA对称对等体系结构
Figure 2 shows an example of M2PA used in a Signaling Gateway (SG). The SG is an IPSP that is equipped with both traditional SS7 and IP network connections.
图2显示了信令网关（SG）中使用的M2PA示例。SG是一个配备传统SS7和IP网络连接的IPSP。
The SEP and the SG communicate through a traditional SS7 link, which follows a protocol such as [Q.702]. The SG and the IPSP communicate through an IP link using the M2PA protocol. Messages sent from the SEP to the IPSP (and vice versa) are routed by the SG.
SEP和SG通过传统的SS7链路进行通信，该链路遵循[Q.702]等协议。SG和IPSP使用M2PA协议通过IP链路进行通信。从SEP发送到IPSP的消息（反之亦然）由SG路由。
Any of the nodes in the diagram could have SCCP or other SS7 layers above MTP3. The Signaling Gateway acts as a Signal Transfer Point (STP). Other STPs MAY be present in the SS7 path between the SEP and the SG.
图中的任何节点都可以在MTP3上具有SCCP或其他SS7层。信令网关充当信号传输点（STP）。SEP和SG之间的SS7路径中可能存在其他STP。
******** SS7 *************** IP ********
* SEP *--------* SG *--------* IPSP *
******** *************** ********
******** SS7 *************** IP ********
* SEP *--------* SG *--------* IPSP *
******** *************** ********
+------+ +------+
| TCAP | | TCAP |
+------+ +------+
| SCCP | | SCCP |
+------+ +-------------+ +------+
| MTP3 | | MTP3 | | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2PA | | M2PA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
+------+ +------+
| TCAP | | TCAP |
+------+ +------+
| SCCP | | SCCP |
+------+ +-------------+ +------+
| MTP3 | | MTP3 | | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2PA | | M2PA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
SEP - SS7 Signaling Endpoint
SEP-SS7信令端点
Figure 2. M2PA in IP Signaling Gateway
图2。IP信令网关中的M2PA
Figure 2 is only an example. Other configurations are possible. In short, M2PA uses the SCTP association as an SS7 link. The M2PA/SCTP/IP stack can be used in place of an MTP2/MTP1 stack.
图2只是一个示例。其他配置也是可能的。简言之，M2PA将SCTP关联用作SS7链路。可以使用M2PA/SCTP/IP堆栈代替MTP2/MTP1堆栈。
MTP requires that each node with an MTP3 layer is identified by an SS7 point code. In particular, each IPSP MUST have its own SS7 point code.
MTP要求具有MTP3层的每个节点由SS7点代码标识。特别是，每个IPSP必须有自己的SS7点代码。
The SS7 MTP3/MTP2 (MTP2-User) interface is retained in the IPSP. The M2PA protocol layer is required to provide a set of services to its user equivalent to that provided by MTP Level 2 to MTP Level 3.
SS7 MTP3/MTP2（MTP2用户）界面保留在IPSP中。M2PA协议层需要向其用户提供一组与MTP级别2至MTP级别3提供的服务相同的服务。
These services are described in the following subsections.
这些服务将在以下小节中介绍。
This interface is the same as the MTP2/MTP3 interface described in the applicable SS7 standards [Q.703] [Q.704] [T1.111] [Q.2140], with the addition of support for the larger sequence numbers found in [T1.111] and [Q.2210].
该接口与适用SS7标准[Q.703][Q.704][T1.111][Q.2140]中描述的MTP2/MTP3接口相同，增加了对[T1.111]和[Q.2210]中较大序列号的支持。
M2PA receives the primitives sent from MTP3 to its lower layer. M2PA processes these primitives or maps them to appropriate primitives at the M2PA/SCTP interface. Likewise, M2PA sends primitives to MTP3 similar to those used in the MTP3/MTP2 interface.
M2PA接收从MTP3发送到其下层的原语。M2PA处理这些原语或将它们映射到M2PA/SCTP接口上的适当原语。同样，M2PA向MTP3发送与MTP3/MTP2接口中使用的原语类似的原语。
Because M2PA uses larger sequence numbers than MTP2, the MTP3 Changeover procedure MUST use the Extended Changeover Order and Extended Changeover Acknowledgement messages described in [Q.2210] and [T1.111].
由于M2PA使用的序列号大于MTP2，因此MTP3转换程序必须使用[Q.2210]和[T1.111]中所述的扩展转换顺序和扩展转换确认消息。
Also, the following MTP3/MTP2 primitives must use the larger sequence numbers:
此外，以下MTP3/MTP2原语必须使用较大的序列号：
- BSNT Confirmation
- BSNT确认
- Retrieval Request and FSNC
- 检索请求与FSNC
In SS7, MTP Level 2 sends three types of messages, known as signal units: Message Signal Units (MSUs), Link Status Signal Units (LSSUs), and Fill-In Signal Units (FISUs).
在SS7中，MTP级别2发送三种类型的消息，称为信号单元：消息信号单元（MSU）、链路状态信号单元（LSSU）和填充信号单元（FISU）。
MSUs originate at a higher level than MTP2, and are destined for a peer at another node. Likewise, M2PA passes these messages from MTP3 to SCTP as data for transport across a link. These are called User Data messages in M2PA.
MSU起源于比MTP2更高的级别，并且目的地是另一个节点上的对等方。同样，M2PA将这些消息作为数据从MTP3传递到SCTP，以便通过链路进行传输。这些在M2PA中称为用户数据消息。
LSSUs allow peer MTP2 layers to exchange status information. Analogous messages are needed for M2PA. The Link Status message serves this purpose.
LSSU允许对等MTP2层交换状态信息。M2PA需要类似的消息。链路状态消息用于此目的。
FISUs are transmitted continuously when no other signal units are waiting to be sent. FISUs also carry acknowledgement of messages. Since an IP network is a shared resource, it would be undesirable to have a message type that is sent continuously as is the case with FISUs. Furthermore, SCTP does not require its upper layer to continuously transmit messages. Therefore, M2PA does not provide a protocol data unit like the FISU. The M2PA User Data message is used to carry acknowledgement of messages. If M2PA needs to acknowledge a message, and it has no MTP3 message of its own to send, an empty User Data message can be sent.
当没有其他信号单元等待发送时，FISU连续发送。FISU还带有对消息的确认。由于IP网络是共享资源，因此不希望像FISU那样连续发送消息类型。此外，SCTP不需要其上层连续传输消息。因此，M2PA不提供类似FISU的协议数据单元。M2PA用户数据消息用于携带消息确认。如果M2PA需要确认一条消息，并且它自己没有MTP3消息要发送，则可以发送一条空的用户数据消息。
M2PA provides MTP2 functionality that is not provided by SCTP; thus, together M2PA and SCTP provide functionality similar to that of MTP2.
M2PA提供SCTP未提供的MTP2功能；因此，M2PA和SCTP一起提供与MTP2类似的功能。
SCTP provides reliable, sequenced delivery of messages.
SCTP提供可靠、有序的消息传递。
M2PA functionality includes:
M2PA功能包括：
- Data retrieval to support the MTP3 changeover procedure
- 数据检索以支持MTP3转换程序
- Reporting of link status changes to MTP3
- 向MTP3报告链路状态更改
- Processor outage procedure
- 处理器中断过程
- Link alignment procedure
- 链接对齐程序
The M2PA layer must maintain a map of each of its SS7 links to the corresponding SCTP association.
M2PA层必须维护其每个SS7链路到相应SCTP关联的映射。
SCTP allows a user-specified number of streams to be opened during the initialization. It is the responsibility of the M2PA layer to ensure proper management of the streams allowed within each association.
SCTP允许在初始化期间打开用户指定数量的流。M2PA层负责确保对每个关联中允许的流进行适当管理。
M2PA uses two streams in each direction for each association. Stream 0 in each direction is designated for Link Status messages. Stream 1 is designated for User Data messages, as well as Link Status messages that must remain in sequence with the User Data messages. Separating the Link Status and User Data messages into separate streams allows M2PA to prioritize the messages in a manner similar to MTP2.
M2PA在每个关联的每个方向上使用两个流。每个方向上的流0都指定用于链接状态消息。流1被指定用于用户数据消息以及必须与用户数据消息保持顺序的链路状态消息。将链路状态和用户数据消息分离为单独的流允许M2PA以类似于MTP2的方式对消息进行优先级排序。
Notifications received from SCTP are processed by M2PA or translated into an appropriate notification to be sent to the upper layer MTP3.
从SCTP接收的通知由M2PA处理或转换为适当的通知发送到上层MTP3。
M2PA allows MTP3 to perform all of its Message Handling and Network Management functions with IPSPs as it does with other SS7 nodes.
M2PA允许MTP3使用IPSP执行其所有消息处理和网络管理功能，就像它使用其他SS7节点一样。
The upper layer primitives provided by M2PA are the same as those provided by MTP2 to MTP3. These primitives are described in the applicable SS7 standards [Q.703] [Q.704] [T1.111] [Q.2140].
M2PA提供的上层原语与MTP2至MTP3提供的原语相同。这些原语在适用的SS7标准[Q.703][Q.704][T1.111][Q.2140]中有描述。
The upper layer primitives provided by SCTP are described in [RFC2960] Section 10 "Interface with Upper Layer".
[RFC2960]第10节“与上层的接口”中描述了SCTP提供的上层原语。
The MTP2 User Adaptation Layer (M2UA) [M2UA] also adapts the MTP3 layer to the SCTP/IP stack. It does so through a backhauling architecture [RFC2719]. This section is intended to clarify some of the differences between the M2PA and M2UA approaches.
MTP2用户适配层（M2UA）[M2UA]还将MTP3层适配到SCTP/IP堆栈。它通过一个回程结构[RFC2719]实现。本节旨在澄清M2PA和M2UA方法之间的一些差异。
A possible M2PA architecture is shown in Figure 3. Here the IPSP's MTP3 uses its underlying M2PA as a replacement for MTP2. Communication between the two layers MTP3/M2PA is defined by the same primitives as in SS7 MTP3/MTP2. M2PA performs functions similar to MTP2.
图3显示了一种可能的M2PA架构。此处，IPSP的MTP3使用其基础M2PA替代MTP2。两层MTP3/M2PA之间的通信由与SS7 MTP3/MTP2中相同的原语定义。M2PA执行与MTP2类似的功能。
******** SS7 *************** IP ********
* SEP *--------* SG *--------* IPSP *
******** *************** ********
******** SS7 *************** IP ********
* SEP *--------* SG *--------* IPSP *
******** *************** ********
+------+ +-------------+ +------+
| SCCP | | SCCP | | SCCP |
+------+ +-------------+ +------+
| MTP3 | | MTP3 | | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2PA | | M2PA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
+------+ +-------------+ +------+
| SCCP | | SCCP | | SCCP |
+------+ +-------------+ +------+
| MTP3 | | MTP3 | | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2PA | | M2PA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
Figure 3. M2PA in IP Signaling Gateway
图3。IP信令网关中的M2PA
A comparable architecture for M2UA is shown in Figure 4. In M2UA, the MGC's MTP3 uses the SG's MTP2 as its lower SS7 layer. Likewise, the SG's MTP2 uses the MGC's MTP3 as its upper SS7 layer. In SS7,
图4显示了M2UA的类似架构。在M2UA中，MGC的MTP3使用SG的MTP2作为其较低的SS7层。同样，SG的MTP2使用MGC的MTP3作为其上SS7层。在SS7中，
communication between the MTP3 and MTP2 layers is defined by primitives. In M2UA, the MTP3/MTP2 communication is defined as M2UA messages and sent over the IP connection.
MTP3和MTP2层之间的通信由原语定义。在M2UA中，MTP3/MTP2通信被定义为M2UA消息，并通过IP连接发送。
******** SS7 *************** IP ********
* SEP *--------* SG *--------* MGC *
******** *************** ********
******** SS7 *************** IP ********
* SEP *--------* SG *--------* MGC *
******** *************** ********
+------+ +------+
| SCCP | | SCCP |
+------+ +------+
| MTP3 | (NIF) | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2UA | | M2UA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
+------+ +------+
| SCCP | | SCCP |
+------+ +------+
| MTP3 | (NIF) | MTP3 |
+------+ +------+------+ +------+
| MTP2 | | MTP2 | M2UA | | M2UA |
| | | +------+ +------+
| | | | SCTP | | SCTP |
+------+ +------+------+ +------+
| MTP1 | | MTP1 | IP | | IP |
+------+ +------+------+ +------+
NIF - Nodal Interworking Function
NIF-节点互通函数
Figure 4. M2UA in IP Signaling Gateway
图4。IP信令网关中的M2UA
M2PA and M2UA are similar in that:
M2PA和M2UA的相似之处在于：
a. Both transport MTP3 data messages.
a. 两者都传输MTP3数据消息。
b. Both present an MTP2 upper interface to MTP3.
b. 两者都为MTP3提供了一个MTP2上接口。
Differences between M2PA and M2UA include:
M2PA和M2UA之间的差异包括：
a. M2PA: IPSP processes MTP3/MTP2 primitives. M2UA: MGC transports MTP3/MTP2 primitives between the SG's MTP2 and the MGC's MTP3 (via the NIF) for processing.
a. M2PA:IPSP处理MTP3/MTP2原语。M2UA:MGC在SG的MTP2和MGC的MTP3之间传输MTP3/MTP2原语（通过NIF）进行处理。
b. M2PA: SG-IPSP connection is an SS7 link. M2UA: SG-MGC connection is not an SS7 link. It is an extension of MTP to a remote entity.
b. M2PA:SG-IPSP连接是SS7链路。M2UA:SG-MGC连接不是SS7链路。它是MTP对远程实体的扩展。
c. M2PA: SG is an SS7 node with a point code. M2UA: SG is not an SS7 node and has no point code.
c. M2PA:SG是具有点代码的SS7节点。M2UA:SG不是SS7节点，没有点代码。
d. M2PA: SG can have upper SS7 layers, e.g., SCCP. M2UA: SG does not have upper SS7 layers since it has no MTP3.
d. M2PA:SG可以具有更高的SS7层，例如SCCP。M2UA:SG没有上层SS7层，因为它没有MTP3。
e. M2PA: relies on MTP3 for management procedures. M2UA: uses M2UA management procedures.
e. M2PA：管理程序依赖MTP3。M2UA：使用M2UA管理程序。
Potential users of M2PA and M2UA should be aware of these differences when deciding how to use them for SS7 signaling transport over IP networks.
M2PA和M2UA的潜在用户在决定如何将其用于IP网络上的SS7信令传输时，应了解这些差异。
This section describes the format of various messages used in this protocol.
本节介绍本协议中使用的各种消息的格式。
All fields in an M2PA message must be transmitted in the network byte order, i.e., most significant byte first, unless otherwise stated.
除非另有说明，M2PA消息中的所有字段必须以网络字节顺序传输，即，最高有效字节优先。
The protocol messages for M2PA require a message header structure that contains a version, message class, message type, and message length. The header structure is shown in Figure 5.
M2PA的协议消息需要包含版本、消息类、消息类型和消息长度的消息头结构。标题结构如图5所示。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Spare | Message Class | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Spare | Message Class | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5. Common Message Header
图5。公共消息头
The version field contains the version of M2PA. The supported versions are:
版本字段包含M2PA的版本。受支持的版本包括：
Value
(decimal) Version
--------- -------
1 Release 1.0 of M2PA protocol
Value
(decimal) Version
--------- -------
1 Release 1.0 of M2PA protocol
The Spare field SHOULD be set to all zeroes (0's) by the sender and ignored by the receiver. The Spare field SHOULD NOT be used for proprietary information.
发送方应将备用字段设置为全零（0），接收方应忽略该字段。备用字段不应用于专有信息。
The following List contains the valid Message Classes:
以下列表包含有效的消息类：
Value
(decimal) Message Class
--------- -------------
11 M2PA Messages
Value
(decimal) Message Class
--------- -------------
11 M2PA Messages
Other values are invalid for M2PA.
其他值对于M2PA无效。
The following list contains the message types for the defined messages.
以下列表包含已定义消息的消息类型。
Value
(decimal) Message Type
--------- -------------
1 User Data
2 Link Status
Value
(decimal) Message Type
--------- -------------
1 User Data
2 Link Status
Other values are invalid.
其他值无效。
The Message Length defines the length of the message in octets, including the Common Header.
消息长度以八位字节定义消息的长度，包括公共头。
All protocol messages for M2PA require an M2PA-specific header. The header structure is shown in Figure 6.
M2PA的所有协议消息都需要M2PA特定的报头。标题结构如图6所示。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | BSN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | FSN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | BSN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| unused | FSN |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6. M2PA-specific Message Header
图6。M2PA特定消息头
This is the FSN of the message last received from the peer.
这是上次从对等方接收的消息的FSN。
This is the M2PA sequence number of the User Data message being sent.
这是正在发送的用户数据消息的M2PA序列号。
The FSN and BSN values range from 0 to 16,777,215.
FSN和BSN值的范围为0到16777215。
The following section defines the messages and parameter contents. An M2PA message consists of a Common Message Header and M2PA Header, followed by the data appropriate to the message.
以下部分定义了消息和参数内容。M2PA消息由公共消息头和M2PA消息头组成，后跟适合该消息的数据。
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Common Message Header /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ M2PA-specific Message Header /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Message Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Common Message Header /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ M2PA-specific Message Header /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Message Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The field "Message Data" contains either:
“消息数据”字段包含以下内容之一：
- a User Data message (Section 2.3.1), or - a Link State message (Section 2.3.2)
- 用户数据消息（第2.3.1节）或-链路状态消息（第2.3.2节）
The User Data is the data sent from MTP3. The User Data is an optional field. It need not be included in an acknowledgement-only message.
用户数据是从MTP3发送的数据。用户数据是可选字段。它不需要包含在仅确认的消息中。
The format of the User Data message is as follows:
用户数据信息的格式如下：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Data /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Data field contains the following fields of the MTP Message Signal Unit (MSU):
数据字段包含MTP消息信号单元（MSU）的以下字段：
- the Message Priority field (PRI) - Service Information Octet (SIO) - Signaling Information Field (SIF)
- 消息优先级字段（PRI）-服务信息八位组（SIO）-信令信息字段（SIF）
The MTP MSU is described in Q.703 [Q.703], Section 2.2, "Signal Unit Format", and T1.111.3 [T1.111], Section 2.2, "Signal Unit Format". The Japanese TTC standard uses the PRI field as an MTP3 Message Priority field [JT-Q703] [JT-Q704]. For versions of MTP that do not use these two bits, the entire first octet of the Data field is spare.
MTP MSU在Q.703[Q.703]第2.2节“信号单元格式”和T1.111.3[T1.111]第2.2节“信号单元格式”中进行了描述。日本TTC标准使用PRI字段作为MTP3消息优先级字段[JT-Q703][JT-Q704]。对于不使用这两个位的MTP版本，数据字段的整个第一个八位字节是备用的。
The format of the first octet of the Data field is:
数据字段的第一个八位字节的格式为：
0
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|PRI| spare | (followed by SIO, SIF)
+-+-+-+-+-+-+-+-+
0
0 1 2 3 4 5 6 7
+-+-+-+-+-+-+-+-+
|PRI| spare | (followed by SIO, SIF)
+-+-+-+-+-+-+-+-+
PRI - Priority used only in national MTP defined in [JT-Q703] and [JT-Q704]. These bits are spare for other MTP versions.
PRI——仅在[JT-Q703]和[JT-Q704]中定义的国家MTP中使用的优先级。这些位是其他MTP版本的备用位。
Note that the Data field SHALL NOT contain other components of the MTP MSU format:
请注意，数据字段不应包含MTP MSU格式的其他组件：
- Flag - Backward Sequence Number (BSN) - Backward Indicator Bit (BIB) - Forward Sequence Number (FSN) - Forward Indicator Bit (FIB) - Length Indicator (LI) - Check bits (CK)
- 标志-后向序列号（BSN）-后向指示符位（BIB）-前向序列号（FSN）-前向指示符位（FIB）-长度指示符（LI）-检查位（CK）
The Data field SHALL be transmitted in the byte order as defined by MTP3.
数据字段应按照MTP3规定的字节顺序传输。
M2PA SHALL NOT add padding to the MTP3 message.
M2PA不得在MTP3消息中添加填充。
Note: In the SS7 Recommendations, the format of the messages and fields within the messages are based on bit transmission order. In these recommendations, the Least Significant Bit (LSB) of each field is positioned to the right. The received SS7 fields are populated octet by octet as received into the 4-octet word, as shown below.
注意：在SS7建议中，消息的格式和消息中的字段基于位传输顺序。在这些建议中，每个字段的最低有效位（LSB）位于右侧。接收到的SS7字段在接收到4个八位字节字时按八位字节填充，如下所示。
As an example, in the ANSI MTP protocol, the Data field format is shown below:
例如，在ANSI MTP协议中，数据字段格式如下所示：
|MSB---------------------------------------------------------LSB|
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|PRI| spare | SIO | SIF octet | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ : /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... | ... | SIF octet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|MSB---------------------------------------------------------LSB|
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|PRI| spare | SIO | SIF octet | ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ : /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| ... | ... | ... | SIF octet |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Within each octet, the Least Significant Bit (LSB) per the SS7 Recommendations is to the right (e.g., bit 15 of SIO is the LSB).
在每个八位组中，SS7建议的最低有效位（LSB）位于右侧（例如，SIO的位15是LSB）。
The MTP2 Link Status message can be sent between M2PA peers to indicate link status. This message performs a function similar to the Link Status Signal Unit in MTP2. The format of the Link Status message is as follows:
可以在M2PA对等方之间发送MTP2链路状态消息，以指示链路状态。此消息执行与MTP2中的链路状态信号单元类似的功能。链接状态消息的格式如下所示：
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The valid values for State are shown in the following table.
状态的有效值如下表所示。
Value
(decimal) Description
--------- -----------
1 Alignment
2 Proving Normal
3 Proving Emergency
4 Ready
5 Processor Outage
6 Processor Recovered
7 Busy
8 Busy Ended
9 Out of Service (OOS)
Value
(decimal) Description
--------- -----------
1 Alignment
2 Proving Normal
3 Proving Emergency
4 Ready
5 Processor Outage
6 Processor Recovered
7 Busy
8 Busy Ended
9 Out of Service (OOS)
The Link Status Proving message may optionally carry additional bytes. If the optional bytes are used, the format of the message is as follows.
链路状态证明消息可以选择性地携带附加字节。如果使用可选字节，则消息的格式如下所示。
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ filler /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ filler /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
It is RECOMMENDED that the length of the Link Status Proving message be similar to the size of the User Data messages that will be carried on the link.
建议链路状态证明消息的长度与将在链路上承载的用户数据消息的大小相似。
It is RECOMMENDED that the filler field contain a number pattern that varies among the Link Status Proving messages, and that allows the SCTP checksum [RFC3309] to be used to verify the accuracy of transmission.
建议填充字段包含在链路状态证明消息之间变化的数字模式，并允许使用SCTP校验和[RFC3309]来验证传输的准确性。
Figure 7 illustrates state changes in the M2PA management of the SCTP association, together with the causing events. Note that some of the error conditions are not shown in the state diagram.
图7说明了SCTP关联的M2PA管理中的状态变化以及导致事件的原因。请注意，状态图中未显示某些错误条件。
Following is a list of the M2PA Association States and a description of each.
以下是M2PA关联状态列表及其说明。
IDLE - State of the association during power-up initialization.
IDLE—通电初始化期间关联的状态。
ASSOCIATING - M2PA is attempting to establish an SCTP association.
关联-M2PA正在尝试建立SCTP关联。
ESTABLISHED - SCTP association is established.
已建立-SCTP协会已建立。
+-----------+
| IDLE |
+-----------+
|
| Associate
| (Issue SCTP associate)
|
| +----------------------+
| | (Issue SCTP |
V V associate) |
+-------------+ |
| ASSOCIATING |----------------->+
+-------------+ SCTP Comm Error |
| |
| |
| SCTP Comm Up |
| |
V |
+-------------+ |
| ESTABLISHED |----------------->+
+-------------+ SCTP Comm Error
OR SCTP Comm Lost
+-----------+
| IDLE |
+-----------+
|
| Associate
| (Issue SCTP associate)
|
| +----------------------+
| | (Issue SCTP |
V V associate) |
+-------------+ |
| ASSOCIATING |----------------->+
+-------------+ SCTP Comm Error |
| |
| |
| SCTP Comm Up |
| |
V |
+-------------+ |
| ESTABLISHED |----------------->+
+-------------+ SCTP Comm Error
OR SCTP Comm Lost
Figure 7. M2PA Association State Transition Diagram
图7。M2PA关联状态转换图
The M2PA link moves from one state to another in response to various events. The events that may result in a change of state include:
M2PA链路根据各种事件从一种状态移动到另一种状态。可能导致状态变化的事件包括：
- MTP3 primitive requests
- MTP3原语请求
- Receipt of messages from the peer M2PA
- 从对等M2PA接收消息
- Expiration of timers
- 计时器过期
- SCTP notifications
- SCTP通知
These events affect the M2PA link state in a manner similar to MTP2.
这些事件以类似于MTP2的方式影响M2PA链路状态。
Because M2PA provides MTP3 with an interface and functionality like MTP2, its internal functioning is similar to that of MTP2.
由于M2PA为MTP3提供了类似MTP2的接口和功能，因此其内部功能与MTP2类似。
Except as modified in this document, M2PA SHOULD follow the requirements of the applicable MTP2 specification. These may include [Q.703] or [T1.111]. The same standard MUST be followed on both ends of the M2PA link.
除本文件中的修改外，M2PA应遵循适用MTP2规范的要求。这些可能包括[Q.703]或[T1.111]。M2PA链路两端必须遵循相同的标准。
In particular, the corresponding applicable timer value defaults and ranges specified for the applicable MTP2 standard should be used for the M2PA timers.
特别是，M2PA定时器应使用适用MTP2标准规定的相应适用定时器值默认值和范围。
When referring to MTP2 terminology in this document, the terminology of [Q.703] is used. This does not imply that the requirements of [Q.703] are to be followed.
在本文件中提及MTP2术语时，使用[Q.703]中的术语。这并不意味着要遵守[Q.703]的要求。
Messages for transmission across the network must follow the format described in Section 2.
通过网络传输的消息必须遵循第2节中描述的格式。
SCTP provides reliable, in-sequence delivery of user messages. Therefore the related functionality of MTP2 is not needed. SCTP does not provide functions related to Link State Control in MTP2. These functions must be provided by M2PA.
SCTP提供可靠的、按顺序的用户消息传递。因此，不需要MTP2的相关功能。SCTP在MTP2中不提供与链路状态控制相关的功能。这些功能必须由M2PA提供。
Since SCTP provides delivery of messages, there is no need for M2PA to delimit its messages with a flag, as is done in MTP2. Furthermore, M2PA does not need to perform zero bit insertion and deletion on its messages.
由于SCTP提供消息传递，所以M2PA不需要像在MTP2中那样使用标志来分隔其消息。此外，M2PA不需要对其消息执行零位插入和删除。
Since SCTP uses a checksum to detect transmission errors, there is no need for an M2PA checksum, as is needed in MTP2. This also eliminates the need for the error rate monitors of MTP2.
由于SCTP使用校验和来检测传输错误，因此不需要像MTP2中那样使用M2PA校验和。这也消除了对MTP2错误率监视器的需要。
Since SCTP provides reliable delivery and ordered delivery, M2PA does not perform retransmissions. This eliminates the need for the forward and backward indicator bits in MTP2 signal units.
由于SCTP提供可靠的传送和有序传送，M2PA不执行重传。这消除了MTP2信号单元中向前和向后指示符位的需要。
Acceptance of a message is indicated by a successful receipt of the message from SCTP.
成功接收来自SCTP的消息表示接受消息。
This section describes how M2PA relates MTP and SCTP entities.
本节介绍M2PA如何关联MTP和SCTP实体。
Each MTP link corresponds to an SCTP association. To prevent duplicate associations from being established, it is RECOMMENDED that each endpoint know the IP address (or IP addresses, if multi-homing is used) and port number of both endpoints. SCTP prevents two associations with the same IP addresses and port numbers from being established.
每个MTP链路对应一个SCTP关联。为了防止建立重复关联，建议每个端点都知道两个端点的IP地址（或IP地址，如果使用多宿主），以及端口号。SCTP阻止建立具有相同IP地址和端口号的两个关联。
It is necessary for at least one of the endpoints to be listening on the port on which the other endpoint is trying to establish the association. Therefore, at least one of the port numbers SHOULD be the M2PA registered port.
至少有一个端点需要侦听另一个端点尝试在其上建立关联的端口。因此，至少一个端口号应该是M2PA注册的端口。
If only one association is to be established between these two IP addresses, then the association SHOULD be established using the M2PA registered port at each endpoint.
如果在这两个IP地址之间只建立一个关联，那么应该在每个端点使用M2PA注册端口建立关联。
If it is desirable to create multiple associations (for multiple links) between the two IP addresses, different port numbers can be used for each association. Nevertheless, the M2PA registered port number SHOULD be used at one end of each association.
如果希望在两个IP地址之间创建多个关联（针对多个链路），则可以为每个关联使用不同的端口号。然而，M2PA注册端口号应在每个关联的一端使用。
Each combination of IP address/port for the two endpoints (i.e., each association) MUST be mapped to the same Signaling Link Code (SLC) at each endpoint, so that each endpoint knows which link is being created at the time the SCTP association is established. However, M2PA does not do any processing based on the SLC.
两个端点（即，每个关联）的IP地址/端口的每个组合必须映射到每个端点处的相同信令链路代码（SLC），以便每个端点知道在建立SCTP关联时正在创建哪个链路。但是，M2PA不基于SLC进行任何处理。
Following are examples of the relationships between associations and links. Note that a link is an SCTP association identified by two endpoints. Each endpoint is identified by an IP address and port number. Each association is mapped to an SLC.
下面是关联和链接之间关系的示例。请注意，链接是由两个端点标识的SCTP关联。每个端点由IP地址和端口号标识。每个关联都映射到一个SLC。
Figure 8 shows a case with two IPSPs, each with two IP addresses. Two associations are the links that connect the two IPSPs. Since these links are in the same link set, they MUST have different SLCs.
图8显示了一个有两个IPSP的案例，每个IPSP有两个IP地址。两个关联是连接两个IPSP的链接。由于这些链路位于同一链路集中，因此它们必须具有不同的SLC。
Table 1 shows the relationships in tabular form. Table 1 is only conceptual. The actual method for mapping the SCTP associations to the SLCs is implementation dependent.
表1以表格形式显示了这些关系。表1只是概念性的。将SCTP关联映射到SLC的实际方法取决于实现。
IPSP X IPSP Y
IPSP X IPSP Y
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = PW +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPC | association 2 | IPD |
| port = PW +---------------+ port = PW |
| SLC = b | | SLC = b |
| | | |
| | | |
+-------------+ +-------------+
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = PW +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPC | association 2 | IPD |
| port = PW +---------------+ port = PW |
| SLC = b | | SLC = b |
| | | |
| | | |
+-------------+ +-------------+
IPx = IP address PW = Registered port number for M2PA
IPx=IP地址PW=M2PA的注册端口号
Figure 8. Two IPSPs with Two IP Addresses Each
图8。两个IPSP，每个IP地址两个
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | PW | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPC | PW | IPD | PW | b |
+-------------+------------+------+------------+------+-----+
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | PW | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPC | PW | IPD | PW | b |
+-------------+------------+------+------------+------+-----+
Table 1. Two IPSPs with Two IP Addresses Each
表1。两个IPSP，每个IP地址两个
Figure 9 and Table 2 show an example with three IPSPs. Note that in this example, the two links are in different link sets. Therefore, it is possible that the SLC values a and b MAY be equal.
图9和表2显示了三个IPSP的示例。请注意，在本例中，两个链接位于不同的链接集中。因此，SLC值a和b可能相等。
IPSP X IPSP Y
IPSP X IPSP Y
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = PW +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPC | association 2 | |
| port = PW +-------+ | |
| SLC = b | | | |
| | | | |
| | | | |
+-------------+ | +-------------+
|
|
| IPSP Z
|
| +-------------+
| | |
| | IPD |
+-------+ port = PW |
| SLC = b |
| |
| |
| |
| |
| |
| |
| |
| |
+-------------+
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = PW +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPC | association 2 | |
| port = PW +-------+ | |
| SLC = b | | | |
| | | | |
| | | | |
+-------------+ | +-------------+
|
|
| IPSP Z
|
| +-------------+
| | |
| | IPD |
+-------+ port = PW |
| SLC = b |
| |
| |
| |
| |
| |
| |
| |
| |
+-------------+
IPx = IP address PW = Registered port number for M2PA
IPx=IP地址PW=M2PA的注册端口号
Figure 9. One IPSP Connected to Two IPSPs
图9。一个IPSP连接到两个IPSP
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y/Z | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | PW | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPC | PW | IPD | PW | b |
+-------------+------------+------+------------+------+-----+
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y/Z | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | PW | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPC | PW | IPD | PW | b |
+-------------+------------+------+------------+------+-----+
Table 2. One IPSP Connected to Two IPSPs
表2。一个IPSP连接到两个IPSP
Figure 10 and Table 3 show two associations between the same IP addresses. This is accomplished by using different port numbers for each association at one endpoint.
图10和表3显示了相同IP地址之间的两个关联。这是通过在一个端点为每个关联使用不同的端口号来实现的。
IPSP X IPSP Y
IPSP X IPSP Y
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = P1 +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPA | association 2 | IPB |
| port = PW +---------------+ port = PW |
| SLC = b | | SLC = b |
| | | |
| | | |
+-------------+ +-------------+
+-------------+ +-------------+
| | SCTP | |
| IPA | association 1 | IPB |
| port = P1 +---------------+ port = PW |
| SLC = a | | SLC = a |
| | | |
| | | |
| | SCTP | |
| IPA | association 2 | IPB |
| port = PW +---------------+ port = PW |
| SLC = b | | SLC = b |
| | | |
| | | |
+-------------+ +-------------+
IPx = IP address P1 = Pre-selected port number PW = Registered port number for M2PA
IPx=IP地址P1=预选端口号PW=M2PA的注册端口号
Figure 10. Multiple Associations Between Two IP Addresses
图10。两个IP地址之间的多个关联
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | P1 | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPA | PW | IPB | PW | b |
+-------------+------------+------+------------+------+-----+
+-------------+---------------------------------------+-----+
| Association | IPSP X | IPSP Y | SLC |
| +------------+------+------------+------+ |
| | IP address | Port | IP address | Port | |
+=============+============+======+============+======+=====+
| 1 | IPA | P1 | IPB | PW | a |
+-------------+------------+------+------------+------+-----+
| 2 | IPA | PW | IPB | PW | b |
+-------------+------------+------+------------+------+-----+
Table 3. Multiple Associations Between Two IP Addresses
表3。两个IP地址之间的多个关联
The association SHALL contain two streams in each direction. Stream 0 is designated for Link Status messages. Stream 1 is designated for User Data messages, as well as Link Status messages that must remain in sequence with the User Data messages.
该组合应在每个方向上包含两条流。为链接状态消息指定了流0。流1被指定用于用户数据消息以及必须与用户数据消息保持顺序的链路状态消息。
The following Link Status messages SHALL be sent on the Link Status stream (stream 0):
应在链路状态流（流0）上发送以下链路状态消息：
- Alignment - Proving Normal - Proving Emergency - Ready (when sent during alignment) - Busy - Busy Ended - Out of Service
- 校准-证明正常-证明紧急-准备就绪（校准期间发送时）-忙-忙结束-停止服务
The following Link Status messages SHALL be sent on the User Data stream (stream 1):
应在用户数据流（流1）上发送以下链路状态消息：
- Processor Outage - Processor Recovered - Ready (when sent at the end of processor outage)
- 处理器停机-处理器已恢复-就绪（在处理器停机结束时发送）
The purposes of the alignment procedure are:
校准程序的目的是：
(1) To provide a handshaking procedure so that both endpoints are prepared to send SS7 traffic, and to prevent traffic from being sent before the other end is ready.
(1) 提供握手过程，以便两个端点都准备好发送SS7通信量，并防止在另一端准备好之前发送通信量。
(2) To verify that the SCTP association is suitable for use as an SS7 link.
(2) 验证SCTP关联是否适合用作SS7链路。
Link alignment takes place after the association is established. If SCTP fails to establish the association, and M2PA has received a Start Request from its MTP3, then M2PA SHALL report to MTP3 that the link is out of service.
链接对齐在关联建立后进行。如果SCTP未能建立关联，且M2PA已收到来自其MTP3的启动请求，则M2PA应向MTP3报告链路已停止服务。
The Link Status Out of Service message replaces the SIOS message of MTP2. Unlike MTP2, the message SHOULD NOT be transmitted continuously. After the association is established, M2PA SHALL send a Link Status Out of Service message to its peer. Prior to the beginning of alignment, M2PA MAY send additional Link Status Out of Service messages.
链路状态停用消息替换MTP2的SIOS消息。与MTP2不同，消息不应连续传输。建立关联后，M2PA应向其对等方发送链路状态停止服务消息。在校准开始之前，M2PA可能会发送额外的链路状态停用消息。
The Link Status Alignment message replaces the SIO message of MTP2. This message is sent to signal the beginning of the alignment procedure. The Link Status Alignment message SHOULD NOT be transmitted continuously. M2PA MAY send additional Link Status Alignment until it receives Link Status Alignment, Link Status Proving Normal, or Link Status Proving Emergency from the peer.
链路状态校准信息取代MTP2的SIO信息。发送此消息是为了发出校准程序开始的信号。链路状态校准消息不应连续传输。M2PA可以发送额外的链路状态校准，直到它从对等方接收到链路状态校准、链路状态证明正常或链路状态证明紧急。
The Link Status Proving Normal message replaces the SIN message of MTP2. The Link Status Proving Emergency message replaces the SIE message of MTP2.
链路状态证明正常消息取代MTP2的SIN消息。链路状态证明紧急消息取代MTP2的SIE消息。
The proving period MAY be omitted if this is allowed by the applicable MTP2 standard (e.g., [Q.2140]).
如果适用的MTP2标准（如[Q.2140]）允许，则可省略验证期。
If proving is performed, then during the proving period (i.e., after M2PA starts the proving period timer T4), M2PA SHALL send Link Status Proving messages to its peer at an interval defined by the protocol parameter Proving_Interval. It is RECOMMENDED that Proving_Interval be set so that the traffic load generated with the Link Status Proving messages during the proving period is comparable to the normal traffic load expected when the link is in service.
如果执行了验证，则在验证期间（即，在M2PA启动验证期间计时器T4之后），M2PA应按照协议参数验证间隔定义的间隔向其对等方发送链路状态验证消息。建议设置验证间隔，以便在验证期间通过链路状态验证消息生成的流量负载与链路处于服务状态时预期的正常流量负载相当。
The Link Status Ready message replaces the FISU of MTP2 that is sent at the end of the proving period. The Link Status Ready message is used to verify that both ends have completed proving. When M2PA starts timer T1, it SHALL send a Link Status Ready message to its peer in the case where MTP2 would send a FISU after proving is complete. If the Link Status Ready message is sent, then M2PA MAY send additional Link Status Ready messages while timer T1 is running. These Link Status Ready messages are sent on the Link Status stream.
链路状态就绪消息替换在验证期结束时发送的MTP2的FISU。链路状态就绪消息用于验证两端是否已完成验证。当M2PA启动定时器T1时，如果MTP2在证明完成后将发送FISU，则M2PA应向其对等方发送链路状态就绪消息。如果发送链路状态就绪消息，则M2PA可在定时器T1运行时发送额外的链路状态就绪消息。这些链路状态就绪消息在链路状态流上发送。
In the case that MTP2 sends an MSU or SIPO message at the end of proving, M2PA SHALL send (respectively) a User Data or Link Status Processor Outage message.
如果MTP2在验证结束时发送MSU或SIPO消息，M2PA应（分别）发送用户数据或链路状态处理器中断消息。
The Link Status Processor Outage message replaces the SIPO message of MTP2. Unlike MTP2, the message SHOULD NOT be transmitted continuously. M2PA SHALL send a Link Status Processor Outage message to its peer at the beginning of a processor outage condition where MTP2 would send SIPO. M2PA MAY send additional Link Status Processor Outage messages as long as that condition persists. The Link Status Processor Outage message SHALL be sent on the User Data stream.
链路状态处理器中断消息取代MTP2的SIPO消息。与MTP2不同，消息不应连续传输。M2PA应在MTP2将发送SIPO的处理器中断条件开始时，向其对等方发送链路状态处理器中断消息。只要这种情况持续存在，M2PA可能会发送额外的链路状态处理器中断消息。链路状态处理器中断消息应在用户数据流上发送。
While in a local processor outage (LPO) condition:
在本地处理器中断（LPO）情况下：
(a) Any User Data messages received from the peer MUST NOT be acknowledged and MUST be buffered.
(a) 从对等方接收的任何用户数据消息都不得被确认，必须进行缓冲。
(b) M2PA SHOULD continue to acknowledge User Data messages received and accepted by MTP3 before the local processor outage.
(b) M2PA应在本地处理器停机前继续确认MTP3接收和接受的用户数据消息。
(c) M2PA SHOULD continue to transmit messages that have been sent by its upper layer MTP3.
(c) M2PA应继续传输其上层MTP3发送的消息。
While there is a remote processor outage (RPO) condition:
存在远程处理器中断（RPO）情况时：
(a) M2PA SHOULD continue to acknowledge User Data messages received and accepted by MTP3, regardless of the remote processor outage.
(a) M2PA应继续确认MTP3接收和接受的用户数据消息，无论远程处理器是否中断。
(b) If any User Data messages received from the peer after the Link Status Processor Outage cannot be delivered to MTP3, then these messages MUST NOT be acknowledged and MUST be buffered.
(b) 如果链路状态处理器中断后从对等方接收到的任何用户数据消息无法发送到MTP3，则不得确认这些消息，必须对其进行缓冲。
If M2PA receives a Flush command from MTP3,
如果M2PA收到来自MTP3的刷新命令，
(a) M2PA SHALL discard any incoming messages that were queued and unacknowledged during the processor outage condition.
(a) M2PA应丢弃处理器停机期间排队且未确认的任何传入消息。
(b) M2PA SHALL discard messages in the transmit and retransmit queues as required by MTP2.
(b) M2PA应按照MTP2的要求丢弃传输和重传队列中的消息。
If M2PA receives a Continue command from MTP3, M2PA SHALL begin processing the incoming messages that were queued and unacknowledged during the processor outage condition.
如果M2PA收到来自MTP3的Continue命令，M2PA应开始处理在处理器停机期间排队且未确认的传入消息。
When the local processor outage condition ends, M2PA SHALL send a Link Status Processor Recovered message to its peer on the User Data stream. This message is used to signal the end of the processor outage condition, instead of an MSU or FISU, as is used in MTP2. The
当本地处理器中断条件结束时，M2PA应向其用户数据流上的对等方发送链路状态处理器恢复消息。此消息用于表示处理器中断状态结束，而不是MTP2中使用的MSU或FISU。这个
BSN in the Link Status Processor Recovered message is set to the FSN of the last User Data message received (and not discarded) from the peer M2PA. M2PA SHALL cease transmitting User Data messages after sending the Link Status Processor Recovered message, until it has received the Link Status Ready message (see below).
链路状态处理器恢复消息中的BSN设置为从对等M2PA接收（且未丢弃）的最后一条用户数据消息的FSN。M2PA应在发送链路状态处理器恢复消息后停止发送用户数据消息，直到收到链路状态就绪消息（见下文）。
Upon receiving the Link Status Processor Recovered message, the M2PA in RPO SHALL respond with a Link Status Ready message on the User Data stream. The BSN in the Link Status Ready message is set to the FSN of the last User Data message received (and not discarded) from the peer M2PA.
收到链路状态处理器恢复消息后，RPO中的M2PA应在用户数据流上响应链路状态就绪消息。链路状态就绪消息中的BSN设置为从对等M2PA接收（且未丢弃）的最后一条用户数据消息的FSN。
Upon receiving the Link Status Ready message, the M2PA formerly in LPO SHALL respond with a Link Status Ready message on the User Data stream. The BSN in the Link Status Ready message is set to the FSN of the last User Data message received (and not discarded) from the peer M2PA.
收到链路状态就绪消息后，先前处于LPO的M2PA应在用户数据流上响应链路状态就绪消息。链路状态就绪消息中的BSN设置为从对等M2PA接收（且未丢弃）的最后一条用户数据消息的FSN。
M2PA (at both the LPO and RPO ends) uses the BSN value in the received Link Status Ready message to resynchronize its sequence numbers, if this is required by MTP2. M2PA SHALL NOT resume transmitting User Data messages until it has sent the Link Status Ready message.
M2PA（在LPO和RPO端）使用接收到的链路状态就绪消息中的BSN值来重新同步其序列号（如果MTP2要求）。M2PA在发送链路状态就绪消息之前，不得恢复传输用户数据消息。
During resynchronization, M2PA SHALL NOT discard any received User Data messages that were sent after the processor outage ended.
在重新同步期间，M2PA不得丢弃处理器中断结束后发送的任何接收到的用户数据消息。
When M2PA experiences a local processor outage, it MAY put the link out of service by sending a Link Status Out of Service message, if this is allowed by the applicable MTP2 standard (e.g., [Q.2140]).
当M2PA经历本地处理器中断时，如果适用的MTP2标准（例如[Q.2140]）允许，它可以通过发送链路状态停止服务消息使链路停止服务。
In other respects, M2PA SHOULD follow the same procedures as MTP2 in processor outage.
在其他方面，M2PA在处理器中断时应遵循与MTP2相同的程序。
The Link Status Busy message replaces the SIB message of MTP2. The message SHOULD NOT be transmitted continuously. M2PA SHALL send a Link Status Busy message to its peer at the beginning of a receive congestion condition where MTP2 would send SIB. M2PA MAY send additional Link Status Busy messages as long as that condition persists. When the condition ends, M2PA SHALL send a Link Status Busy Ended message to its peer.
链路状态忙消息替换MTP2的SIB消息。该信息不应连续传输。M2PA应在MTP2将发送SIB的接收拥塞条件开始时向其对等方发送链路状态忙碌消息。只要这种情况持续存在，M2PA可能会发送额外的链路状态忙碌消息。当条件结束时，M2PA应向其对等方发送链路状态忙结束消息。
M2PA SHALL continue transmitting messages while it is in receive congestion, but MUST NOT acknowledge the message that triggered the sending of the Link Status Busy message, nor any messages received before the sending of Link Status Busy Ended.
M2PA应在接收拥塞时继续发送消息，但不得确认触发发送链路状态忙消息的消息，也不得确认在发送链路状态忙消息结束前收到的任何消息。
When the peer M2PA receives the first Link Status Busy message, it SHALL start the Remote Congestion timer T6 if there are messages in the retransmission buffer awaiting acknowledgement (i.e., T7 is running). M2PA SHALL stop the T7 timer if it is running. Additional Link Status Busy messages received while T6 is running do not cause T6 to be reset and do not cause T7 to be started. While T6 is running, T7 SHALL NOT be started.
当对等M2PA接收到第一条链路状态忙消息时，如果重传缓冲器中有消息等待确认（即T7正在运行），则其应启动远程拥塞计时器T6。如果T7定时器正在运行，M2PA应停止该定时器。T6运行时收到的其他链路状态忙碌消息不会导致T6复位，也不会导致T7启动。T6运行时，不得启动T7。
When the peer M2PA receives the Link Status Busy Ended message and T6 has not expired, it SHALL stop T6 (if T6 is running) and start T7 (if there are messages awaiting acknowledgement in the retransmission buffer).
当对等M2PA接收到链路状态忙结束消息且T6尚未过期时，它应停止T6（如果T6正在运行）并启动T7（如果重传缓冲器中有等待确认的消息）。
The peer M2PA SHOULD continue receiving and acknowledging messages while the other end is busy, but MUST NOT send User Data messages after receiving Link Status Busy and before receiving Link Status Busy Ended.
对等M2PA应在另一端忙时继续接收和确认消息，但在接收到链路状态忙后和接收到链路状态忙结束前不得发送用户数据消息。
The Link Status Out of Service message replaces the SIOS message of MTP2. Unlike MTP2, the message SHOULD NOT be transmitted continuously. M2PA SHALL send a Link Status Out of Service message to its peer at the beginning of a condition where MTP2 would send SIOS. M2PA MAY send additional Link Status Out of Service messages as long as that condition persists.
链路状态停用消息替换MTP2的SIOS消息。与MTP2不同，消息不应连续传输。M2PA应在MTP2发送SIO的条件开始时向其对等方发送链路状态停用消息。只要这种情况持续存在，M2PA可能会发送额外的链路状态停用消息。
When M2PA places a link in the OUT OF SERVICE state, M2PA SHOULD NOT terminate the SCTP association.
当M2PA将链路置于停用状态时，M2PA不应终止SCTP关联。
The SCTP association for a link may become unusable, such as when one of the following occurs:
链路的SCTP关联可能会变得不可用，例如当发生以下情况之一时：
- SCTP sends a Send Failure notification to M2PA.
- SCTP向M2PA发送发送失败通知。
- SCTP sends a Communication Lost notification to M2PA.
- SCTP向M2PA发送通信丢失通知。
- SCTP sends a Communication Error notification to M2PA.
- SCTP向M2PA发送通信错误通知。
- The SCTP association is lost.
- SCTP关联已丢失。
If the SCTP association for a link becomes unable to transmit or receive messages, M2PA SHALL report to MTP3 that the link is out of service and enter the OUT OF SERVICE state.
如果链路的SCTP关联无法发送或接收消息，M2PA应向MTP3报告链路停止服务并进入停止服务状态。
In MTP, Link Status messages have priority over User Data messages ([Q.703], Section 11.2). To achieve this in M2PA, M2PA uses separate streams in its SCTP association for Link Status messages and User Data messages.
在MTP中，链路状态消息优先于用户数据消息（[Q.703]，第11.2节）。为了在M2PA中实现这一点，M2PA在其SCTP关联中为链路状态消息和用户数据消息使用单独的流。
M2PA SHALL send all messages using the ordered delivery option of SCTP.
M2PA应使用SCTP的有序交付选项发送所有消息。
M2PA SHOULD give higher priority to messages sent on the Link Status stream than to messages sent on the User Data stream when sending messages to SCTP.
向SCTP发送消息时，M2PA应给予链路状态流上发送的消息比用户数据流上发送的消息更高的优先级。
M2PA SHOULD give higher priority to reading the Link Status stream than to reading the User Data stream.
M2PA应该给予读取链路状态流比读取用户数据流更高的优先级。
M2PA SHOULD give higher priority to receiving notifications from SCTP than to reading either the Link Status stream or the User Data stream.
M2PA应该给予从SCTP接收通知的更高优先级，而不是读取链路状态流或用户数据流。
A node upgraded to a newer version of M2PA SHOULD support the older versions used on other nodes with which it is communicating. If that is the case, then alignment can proceed normally.
升级到M2PA较新版本的节点应支持与之通信的其他节点上使用的较旧版本。如果是这种情况，则校准可以正常进行。
In particular, it is recommended that for future modifications to this protocol:
特别是，对于本协议的未来修改，建议：
- Any newer version SHOULD be able to process the messages from an older version.
- 任何较新版本都应该能够处理来自较旧版本的消息。
- A newer version of M2PA SHOULD refrain from sending messages to an older version of M2PA messages that the older version cannot process.
- 新版本的M2PA应避免向旧版本的M2PA发送旧版本无法处理的消息。
- If an older version of M2PA receives a message that it cannot process, it SHOULD discard the message.
- 如果旧版本的M2PA收到无法处理的消息，则应丢弃该消息。
- In cases where different processing is done in two versions for the same format of a message, then the newer version SHOULD contain procedures to recognize and handle this appropriately.
- 如果对同一格式的消息在两个版本中进行了不同的处理，则较新版本应包含相应的识别和处理过程。
In case a newer version of M2PA is incompatible with an older version, the newer version SHOULD recognize this and prevent the alignment of the link. If a Link Status Alignment message with an
如果M2PA的较新版本与较旧版本不兼容，较新版本应能识别这一点并防止链路对齐。如果链接状态对齐消息带有
unsupported version is received by the newer version, the receiving end's M2PA SHOULD reply with a Link Status Out of Service message and not complete the alignment procedure.
较新版本接收到不支持的版本，接收端的M2PA应回复链路状态停止服务消息，并且不完成校准过程。
When MTP3 sends a message for transmission to M2PA, M2PA passes the corresponding M2PA message to SCTP using the SEND primitive.
当MTP3向M2PA发送传输消息时，M2PA使用发送原语将相应的M2PA消息传递给SCTP。
User Data messages SHALL be sent via the User Data stream (stream 1) of the association.
用户数据消息应通过关联的用户数据流（流1）发送。
M2PA Link Status messages are passed to SCTP using the SEND primitive.
M2PA链路状态消息使用发送原语传递给SCTP。
The following Link Status messages SHALL be sent on the Link Status stream (stream 0):
应在链路状态流（流0）上发送以下链路状态消息：
- Alignment - Proving Normal - Proving Emergency - Ready (when sent during alignment) - Busy - Busy Ended - Out of Service
- 校准-证明正常-证明紧急-准备就绪（校准期间发送时）-忙-忙结束-停止服务
The following Link Status messages SHALL be sent on the User Data stream (stream 1):
应在用户数据流（流1）上发送以下链路状态消息：
- Processor Outage - Processor Recovered - Ready (when sent at the end of processor outage)
- 处理器停机-处理器已恢复-就绪（在处理器停机结束时发送）
If M2PA receives a message from SCTP with an invalid Message Class or unsupported Message Type in the Common Message Header, M2PA SHALL discard the message.
如果M2PA从SCTP接收到的消息在公共消息头中包含无效消息类或不支持的消息类型，M2PA应丢弃该消息。
For message types other than User Data, the Forward Sequence Number is set to the FSN of the last User Data message sent.
对于用户数据以外的消息类型，转发序列号设置为最后发送的用户数据消息的FSN。
If M2PA receives a User Data message with an FSN that is out of order, M2PA SHALL discard the message.
如果M2PA收到一条用户数据消息，其FSN出现故障，M2PA应丢弃该消息。
Note: In all calculations involving FSN and BSN, the programmer should be aware that the value wraps around to 0 after reaching its maximum value.
注意：在涉及FSN和BSN的所有计算中，程序员应注意，在达到其最大值后，该值将变为0。
When there is a message to acknowledge, M2PA MUST acknowledge the message with the next User Data message sent. If there is no User Data message available to be sent when there is a message to acknowledge, M2PA SHOULD generate and send a User Data message with no data payload, without delay. (In other words, in the case where MTP2 would acknowledge a message with a FISU, M2PA SHOULD acknowledge the message with an empty User Data message.) The FSN for this empty User Data message is not incremented. It MUST contain the same FSN as the most recently sent User Data message that contains data. Delaying of acknowledgements can result in poor SS7 performance.
当有消息要确认时，M2PA必须在发送下一条用户数据消息时确认该消息。如果在有需要确认的消息时没有可发送的用户数据消息，M2PA应毫不延迟地生成并发送无数据有效负载的用户数据消息。（换句话说，在MTP2将使用FISU确认消息的情况下，M2PA应使用空用户数据消息确认消息。）此空用户数据消息的FSN不增加。它必须包含与最近发送的包含数据的用户数据消息相同的FSN。延迟确认可能会导致SS7性能不佳。
If M2PA receives an empty User Data message, it SHALL NOT send an acknowledgement of that message.
如果M2PA接收到空用户数据消息，则不应发送对该消息的确认。
Note that there is no reason to place Link Status messages or empty User Data messages in the M2PA retransmit buffer, since these messages are not retrieved for changeover and timer T7 does not apply to them.
请注意，没有理由将链路状态消息或空用户数据消息放置在M2PA重传缓冲区中，因为不会检索这些消息进行切换，并且计时器T7不适用于它们。
Note that since SCTP provides reliable delivery and ordered delivery within the stream, M2PA does not perform retransmissions. Nevertheless, M2PA SHALL retain transmitted User Data messages in a retransmit queue until they are acknowledged. These messages are needed in case MTP3 performs data retrieval as part of a changeover procedure.
注意，由于SCTP在流中提供可靠的传递和有序的传递，M2PA不执行重传。然而，M2PA应将传输的用户数据消息保留在重传队列中，直到确认为止。如果MTP3在转换过程中执行数据检索，则需要这些消息。
Because propagation delays in IP networks are more variable than in traditional SS7 networks, a single T7 timer (excessive delay of acknowledgement), as in MTP2, is inadequate. If any message is unacknowledged after a period equal to the T7 value, the T7 timer SHALL expire.
由于IP网络中的传播延迟比传统SS7网络中的传播延迟变化更大，因此单个T7计时器（过度的确认延迟），如MTP2中的，是不够的。如果任何消息在等于T7值的时间段后未被确认，则T7计时器将过期。
M2PA SHALL detect transmit congestion in its buffers according to the requirements for signaling link transmit congestion in MTP3, e.g., Q.704 [Q.704], Section 3.8.
M2PA应根据MTP3中的信令链路传输拥塞要求，如Q.704[Q.704]，第3.8节，检测其缓冲器中的传输拥塞。
The objective of the changeover is to ensure that signaling traffic carried by the unavailable signaling link is diverted to the alternative signaling link(s) as quickly as possible while avoiding message loss, duplication, or mis-sequencing. For this purpose, the changeover procedure includes data retrieval, which is performed before opening the alternative signaling links to the diverted traffic. Data retrieval consists of these steps:
转换的目的是确保不可用信令链路承载的信令业务尽快转移到备用信令链路，同时避免消息丢失、重复或错误排序。为此，转换过程包括数据检索，该数据检索是在向分流业务开放替代信令链路之前执行的。数据检索包括以下步骤：
(1) buffer updating, i.e., identifying all those User Data messages in the retransmission buffer of the unavailable signaling link which have not been received by the far end M2PA, as well as untransmitted messages, and
(1) 缓冲器更新，即，识别远端M2PA未接收到的不可用信令链路的重传缓冲器中的所有那些用户数据消息以及未传输的消息，以及
(2) transferring those messages to the transmission buffers of the alternate links.
(2) 将这些消息传输到备用链路的传输缓冲区。
Note that only User Data messages containing data are retrieved and transmitted over the alternate links. Link Status messages and empty User Data messages SHALL NOT be retrieved and transmitted over the alternate links.
请注意，只有包含数据的用户数据消息才能通过备用链路检索和传输。链路状态消息和空用户数据消息不得通过备用链路检索和传输。
M2PA's Sequence Numbers are 24 bits long. MTP2's Forward and Backward Sequence Numbers are only seven bits long. Hence, it is necessary for MTP3 to accommodate the larger sequence numbers. This is done through the use of the Extended Changeover Order (XCO) and Extended Changeover Acknowledgement (XCA) messages instead of the Changeover Order (COO) and Changeover Acknowledgement (COA) messages. The XCO and XCA messages are specified in [Q.2210] Section 9.8.1 and T1.111.4 [T1.111], Section 15.4. Only the XCO and XCA messages from [Q.2210] or [T1.111] are required. The BSN is placed in the XCO/XCA message as explained in [Q.2210] and [T1.111].
M2PA的序列号为24位长。MTP2的正向和反向序列号只有7位长。因此，MTP3必须适应较大的序列号。这是通过使用扩展转换订单（XCO）和扩展转换确认（XCA）消息而不是转换订单（COO）和转换确认（COA）消息来实现的。[Q.2210]第9.8.1节和T1.111.4[T1.111]第15.4节规定了XCO和XCA消息。只需要来自[Q.2210]或[T1.111]的XCO和XCA消息。如[Q.2210]和[T1.111]所述，BSN被置于XCO/XCA消息中。
Also, the following MTP3/MTP2 primitives MUST use the larger sequence numbers:
此外，以下MTP3/MTP2原语必须使用较大的序列号：
- BSNT Confirmation
- BSNT确认
- Retrieval Request and FSNC
- 检索请求与FSNC
If M2PA receives a Retrieval Request and FSNC request from MTP3, M2PA SHALL retrieve from its buffers and deliver to MTP3 in order:
如果M2PA收到MTP3的检索请求和FSNC请求，则M2PA应从其缓冲区中检索并按以下顺序交付给MTP3：
(a) any transmitted User Data messages beginning with the first unacknowledged message with FSN greater than FSNC.
(a) 任何传输的用户数据消息，以FSN大于FSNC的第一条未确认消息开始。
(b) any untransmitted User Data messages.
(b) 任何未传输的用户数据消息。
For emergency changeover, MTP3 retrieves only the unsent messages for transmission on the alternate link(s). If M2PA receives a Retrieval Request and FSNC request with no FSNC value, or with an invalid FSNC, then M2PA SHALL retrieve from its buffers and deliver to MTP3 in order:
对于紧急切换，MTP3仅检索未发送的消息，以便在备用链路上传输。如果M2PA收到无FSNC值或FSNC无效的检索请求和FSNC请求，则M2PA应从其缓冲区中检索并按以下顺序交付给MTP3：
(a) any untransmitted User Data messages.
(a) 任何未传输的用户数据消息。
The Japanese TTC version of MTP defined in [JT-Q703] and [JT-Q704] has a Retrieval Request (as well as Retrieval Request and FSNC). The Retrieval allows MTP3 to retrieve both unsent and unacknowledged messages for transmission on the alternate link(s). In this version of MTP, if M2PA receives a Retrieval Request, then M2PA SHALL retrieve from its buffers and deliver to MTP3 in order:
[JT-Q703]和[JT-Q704]中定义的日本TTC版MTP具有检索请求（以及检索请求和FSNC）。检索允许MTP3检索未发送和未确认的消息，以便在备用链路上传输。在本版本的MTP中，如果M2PA收到检索请求，则M2PA应从其缓冲区中检索，并按以下顺序交付给MTP3：
(a) any transmitted but unacknowledged User Data messages.
(a) 任何已传输但未确认的用户数据消息。
(b) any untransmitted User Data messages.
(b) 任何未传输的用户数据消息。
The changeover procedure makes it problematic for M2PA to have multiple User Data streams in one direction for a link. Buffer updating would have to be done separately for each User Data stream to avoid duplication or loss of messages. But MTP3 provides for only one XCO/XCA message for sending the last-received sequence number.
转换过程使得M2PA在链路的一个方向上有多个用户数据流成为问题。必须为每个用户数据流分别进行缓冲区更新，以避免重复或丢失消息。但MTP3仅提供一条XCO/XCA消息，用于发送最后接收到的序列号。
Even with sequence numbering of User Data messages at the M2PA layer, it is necessary to perform buffer updating on each stream. Since the M2PA messages would be delivered over multiple streams, there could be a gap in the M2PA sequence numbers at the receiving end when the changeover procedure begins. If only the M2PA sequence number is used in the XCO/XCA message, there would be a possibility of losing the messages in the gap, or duplicating messages after the gap.
即使在M2PA层对用户数据消息进行序列编号，也需要对每个流执行缓冲区更新。由于M2PA消息将通过多个流传送，因此在转换过程开始时，接收端的M2PA序列号可能存在间隙。如果XCO/XCA消息中仅使用M2PA序列号，则可能会丢失间隙中的消息，或在间隙后复制消息。
M2PA links with multiple User Data streams would be possible if a multiple-BSNT XCO/XCA message is defined in MTP3, or if MTP3 allows multiple XCO/XCA messages (one for each User Data stream) to be sent during a changeover. This is beyond the scope of this document.
如果MTP3中定义了多个BSNT XCO/XCA消息，或者MTP3允许在转换期间发送多个XCO/XCA消息（每个用户数据流一个），则可以使用多个用户数据流建立M2PA链路。这超出了本文件的范围。
Some M2PA procedures may be affected by the use of SCTP as a transport layer. These considerations are discussed in this section.
使用SCTP作为传输层可能会影响某些M2PA程序。本节将讨论这些注意事项。
SCTP contains a slow start algorithm to control the amount of data being injected into the network. The algorithm allows SCTP to probe the network to determine the available capacity. The algorithm is invoked in these cases: when transmission begins on an association, after a sufficiently long idle period, or after repairing loss detected by the SCTP retransmission timer.
SCTP包含一个慢启动算法，用于控制注入网络的数据量。该算法允许SCTP探测网络以确定可用容量。在以下情况下调用该算法：在关联上开始传输时，在足够长的空闲时间之后，或者在修复SCTP重传计时器检测到的丢失之后。
It is possible that transmission of M2PA messages MAY be delayed by SCTP slow start under certain conditions, including the following:
在某些条件下，M2PA消息的传输可能会因SCTP慢速启动而延迟，包括以下情况：
(a) Link Alignment. Link alignment takes place after an association is established. SCTP invokes the slow start algorithm since transmission is beginning on the association.
(a) 链接对齐。链接对齐在建立关联后进行。SCTP调用慢启动算法，因为传输是在关联上开始的。
(b) Changeover. Messages are retrieved from one link (association) and transferred to another for transmission. If the second link had previously been idle, or is in the process of link alignment, SCTP may invoke the slow start algorithm.
(b) 转换。消息从一个链路（关联）检索并传输到另一个链路进行传输。如果第二条链路先前处于空闲状态，或者正在链路对齐过程中，SCTP可以调用慢启动算法。
(c) Path failure (multi-homing). If SCTP switches from a failed path to a new path, and the new path had previously been idle, SCTP may invoke the slow start algorithm.
(c) 路径故障（多归宿）。如果SCTP从故障路径切换到新路径，并且新路径以前处于空闲状态，则SCTP可能会调用慢启动算法。
(d) Reduced traffic volume. Any time that M2PA sends a low volume of traffic on a link and then the volume increases, SCTP may invoke the slow start algorithm.
(d) 交通量减少。当M2PA在链路上发送低流量，然后流量增加时，SCTP可以调用慢启动算法。
Programmers should be aware of this condition and how it may affect M2PA performance. In some cases, it may be possible to avoid the negative effects of slow start. For example, the Link Status Proving messages sent during the proving period may be used to complete slow start before the link is placed in service.
程序员应该了解这种情况以及它可能如何影响M2PA性能。在某些情况下，可以避免缓慢启动的负面影响。例如，在验证期间发送的链路状态验证消息可用于在链路投入使用之前完成慢启动。
In general, messages passed between MTP3 and M2PA are the same as those passed between MTP3 and MTP2. M2PA interprets messages from MTP3 and sends the appropriate message to SCTP. Likewise, messages from SCTP are used to generate a meaningful message to MTP3.
通常，MTP3和M2PA之间传递的消息与MTP3和MTP2之间传递的消息相同。M2PA解释来自MTP3的消息，并将适当的消息发送给SCTP。同样，来自SCTP的消息用于生成一条有意义的消息到MTP3。
Note that throughout this section, the primitives between MTP3 and M2PA are named using the MTP terminology [Q.700] [Q.701] [Q.702] [Q.703] [Q.704] [Q.705]. Communications between M2PA and SCTP are named using SCTP terminology.
请注意，在本节中，MTP3和M2PA之间的原语使用MTP术语[Q.700][Q.701][Q.702][Q.703][Q.704][Q.705]命名。M2PA和SCTP之间的通信使用SCTP术语命名。
An example of the message flow used to bring an SS7 link in service is shown in Figures 11 and 12. Alignment is done by both ends of the link. To simplify the diagram, alignment is shown on one end only. Some messages from the remote end are not shown. It is assumed in this example that SCTP has been initialized.
图11和图12显示了用于使SS7链路投入服务的消息流示例。对齐由连杆的两端完成。为了简化图表，对齐仅显示在一端。来自远程端的某些消息未显示。在此示例中，假设SCTP已初始化。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Associate . . . .
. ------------> . . .
. . . . . .
. . (SCTP Association . .
. . procedure) . .
. . . . . .
. Communication Up Communication Up .
. <------------ ------------> .
. . . . . .
. Link Status Out of Service . .
. ------------------------------------> .
. . . . . .
Emergency OR . . . .
Emergency Ceases . . . .
------------> . . . .
. . . . . .
Start . . . . .
------------> . . . .
. . . . . .
. . . . . .
. Link Status Alignment . . .
. ------------------------------------> .
. . . . . .
. Start timer T2 . . .
. . . . . .
. . . Link Status Alignment .
. <------------------------------------ .
. . . . . .
. Stop timer T2 . . .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Associate . . . .
. ------------> . . .
. . . . . .
. . (SCTP Association . .
. . procedure) . .
. . . . . .
. Communication Up Communication Up .
. <------------ ------------> .
. . . . . .
. Link Status Out of Service . .
. ------------------------------------> .
. . . . . .
Emergency OR . . . .
Emergency Ceases . . . .
------------> . . . .
. . . . . .
Start . . . . .
------------> . . . .
. . . . . .
. . . . . .
. Link Status Alignment . . .
. ------------------------------------> .
. . . . . .
. Start timer T2 . . .
. . . . . .
. . . Link Status Alignment .
. <------------------------------------ .
. . . . . .
. Stop timer T2 . . .
. . . . . .
Proving period begins.
证明期开始。
Figure 11. Example: Link Initialization - Alignment
图11。示例：链接初始化-对齐
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Start timer T3 . . .
. Link Status Proving . . .
. ------------------------------------> .
. . . . . .
. . . Link Status Proving .
. <------------------------------------ .
. . . . . .
. Stop timer T3 . . .
. . . . . .
. Start timer T4 . . .
. Link Status Proving . . .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. . . . . .
. Timer T4 expires . . .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Start timer T3 . . .
. Link Status Proving . . .
. ------------------------------------> .
. . . . . .
. . . Link Status Proving .
. <------------------------------------ .
. . . . . .
. Stop timer T3 . . .
. . . . . .
. Start timer T4 . . .
. Link Status Proving . . .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. ------------------------------------> .
. . . . . .
. Timer T4 expires . . .
. . . . . .
Send Link Status Ready (one or more) and wait for the remote end to complete its proving period.
发送链路状态就绪（一个或多个），并等待远程端完成其验证期。
. . . . . .
. Start timer T1 . . .
. . . . . .
. Link Status Ready . . .
. ------------------------------------> .
. . . . . .
. . . . . .
. . . Link Status Ready .
. <------------------------------------ .
. . . . . .
. Stop timer T1 . . .
. . . . . .
In Service . . In Service
<------------ . . ------------>
. . . . . .
. . . . . .
. Start timer T1 . . .
. . . . . .
. Link Status Ready . . .
. ------------------------------------> .
. . . . . .
. . . . . .
. . . Link Status Ready .
. <------------------------------------ .
. . . . . .
. Stop timer T1 . . .
. . . . . .
In Service . . In Service
<------------ . . ------------>
. . . . . .
MTP3 MAY begin sending data messages.
MTP3可开始发送数据消息。
Figure 12. Example: Link Initialization - Proving
图12。示例：链接初始化-验证
Messages are transmitted using the Data Request primitive from MTP3 to M2PA. Figure 13 shows the case where the Link is In Service. The message is passed from MTP3 of the source to MTP3 of the destination.
使用数据请求原语将消息从MTP3传输到M2PA。图13显示了链接正在使用的情况。消息从源的MTP3传递到目标的MTP3。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
Message for . . . .
transmission . . . .
------------> . . . .
. . . . . .
. Send . . . .
. (Data Message) . . .
. ------------> . . .
. . . . . .
. . (SCTP sends message) . .
. . . . . .
. . . Receive .
. . . ------------> .
. . . . . .
. . . . Received message
. . . . ------------>
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
Message for . . . .
transmission . . . .
------------> . . . .
. . . . . .
. Send . . . .
. (Data Message) . . .
. ------------> . . .
. . . . . .
. . (SCTP sends message) . .
. . . . . .
. . . Receive .
. . . ------------> .
. . . . . .
. . . . Received message
. . . . ------------>
. . . . . .
Figure 13. Example: Link Initialization - In Service
图13。示例：链路初始化-在用
An example of a Link Status Indication is shown in Figure 14. If SCTP sends a Communication Lost primitive to M2PA, M2PA notifies MTP3 that the link is out of service. MTP3 responds in its usual way.
链路状态指示的示例如图14所示。如果SCTP向M2PA发送通信丢失原语，M2PA将通知MTP3链路停止服务。MTP3以其通常的方式响应。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Communication Lost . . .
. <------------ . . .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Communication Lost . . .
. <------------ . . .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
Figure 14. Example: Link Status Indication
图14。示例：链路状态指示
Figure 15 shows how M2PA responds to a local processor outage. M2PA sends a Link Status message to its peer. The peer M2PA notifies MTP3 of the outage. MTP3 can then follow the processor outage procedures as in [Q.703].
图15显示了M2PA如何响应本地处理器中断。M2PA向其对等方发送链路状态消息。对等M2PA将停机通知MTP3。然后，MTP3可以遵循[Q.703]中的处理器中断程序。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. M2PA detects . . . .
. Local Processor . . . .
. Outage . . . .
. . . . . .
. Link Status . . . .
. Processor Outage . . .
. ------------------------------------> .
. . . . . .
. . . . Remote Processor
. . . . Outage .
. . . . ------------>
. . . . . .
. Link Status . . .
. Processor . . .
. Recovered . . .
. ------------------------------------> .
. . . . . .
. . . . Remote Processor
. . . . Outage Ceases
. . . . ------------>
. . . . . .
. . . Link Status Ready .
. <------------------------------------ .
. . . . . .
. Link Status Ready . . .
. ------------------------------------> .
. . . . . .
Message for . . . .
transmission . . . .
------------> . . . .
. . . . . .
. User Data . . .
. ------------------------------------> .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. M2PA detects . . . .
. Local Processor . . . .
. Outage . . . .
. . . . . .
. Link Status . . . .
. Processor Outage . . .
. ------------------------------------> .
. . . . . .
. . . . Remote Processor
. . . . Outage .
. . . . ------------>
. . . . . .
. Link Status . . .
. Processor . . .
. Recovered . . .
. ------------------------------------> .
. . . . . .
. . . . Remote Processor
. . . . Outage Ceases
. . . . ------------>
. . . . . .
. . . Link Status Ready .
. <------------------------------------ .
. . . . . .
. Link Status Ready . . .
. ------------------------------------> .
. . . . . .
Message for . . . .
transmission . . . .
------------> . . . .
. . . . . .
. User Data . . .
. ------------------------------------> .
. . . . . .
Figure 15. Example: Link Status Message - Processor Outage
图15。示例：链路状态消息-处理器中断
Figure 16 shows an example of processor outage in more detail. All M2PA messages in this example are sent on the Data stream (stream 1).
图16更详细地显示了处理器中断的示例。本例中的所有M2PA消息都在数据流（流1）上发送。
A B
---------------------------- ----------------------------
A B
---------------------------- ----------------------------
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
6 Messages for . . . .
transmission . . . .
------------> . . 6 Messages for
. . . . transmission
. . . . <------------
. User Data FSN=1 . . .
. ------------------------------------> .
. User Data FSN=2 . . .
. ------------------------------------> .
. User Data FSN=3 . . .
. ------------------------------------> .
. . . User Data FSN=11 .
. <------------------------------------ .
. . . User Data FSN=12 .
. <------------------------------------ .
. . . User Data FSN=13 .
. <------------------------------------ .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
6 Messages for . . . .
transmission . . . .
------------> . . 6 Messages for
. . . . transmission
. . . . <------------
. User Data FSN=1 . . .
. ------------------------------------> .
. User Data FSN=2 . . .
. ------------------------------------> .
. User Data FSN=3 . . .
. ------------------------------------> .
. . . User Data FSN=11 .
. <------------------------------------ .
. . . User Data FSN=12 .
. <------------------------------------ .
. . . User Data FSN=13 .
. <------------------------------------ .
Side A detects LPO.
A侧检测LPO。
. . . . . .
. . . User Data FSN=14 BSN=3 .
. <------------------------------------ .
. . . User Data FSN=15 BSN=3 .
. <------------------------------------ .
. . . User Data FSN=16 BSN=3 .
. <------------------------------------ .
. LS PO FSN=3 BSN=11 . . .
. ------------------------------------> .
. . . . Remote Processor
. . . . Outage .
. . . . ------------>
. . . . . .
. . . User Data FSN=14 BSN=3 .
. <------------------------------------ .
. . . User Data FSN=15 BSN=3 .
. <------------------------------------ .
. . . User Data FSN=16 BSN=3 .
. <------------------------------------ .
. LS PO FSN=3 BSN=11 . . .
. ------------------------------------> .
. . . . Remote Processor
. . . . Outage .
. . . . ------------>
While in LPO, A must buffer messages 14-16 without acknowledging them. A may continue transmitting messages from MTP3, and acknowledging messages that were received before LPO.
在LPO中，A必须在不确认消息的情况下缓冲消息14-16。A可以继续发送来自MTP3的消息，并确认在LPO之前接收到的消息。
. . . . . .
. User Data FSN=4 BSN=13 . . .
. ------------------------------------> .
. User Data FSN=5 BSN=13 . . .
. ------------------------------------> .
. User Data FSN=6 BSN=13 . . .
. ------------------------------------> .
. . . . . .
. . . . . .
. User Data FSN=4 BSN=13 . . .
. ------------------------------------> .
. User Data FSN=5 BSN=13 . . .
. ------------------------------------> .
. User Data FSN=6 BSN=13 . . .
. ------------------------------------> .
. . . . . .
While in RPO, B may continue acknowledging messages. Suppose that B receives message 4 and 5, but has not processed 6 yet.
在RPO中，B可以继续确认消息。假设B接收到消息4和5，但尚未处理消息6。
. . . . . .
. (empty) User Data FSN=16 BSN=4
. <------------------------------------ .
. (empty) User Data FSN=16 BSN=5
. <------------------------------------ .
. . . . . .
. (empty) User Data FSN=16 BSN=4
. <------------------------------------ .
. (empty) User Data FSN=16 BSN=5
. <------------------------------------ .
LPO ends at A. A flushes 14-16 (the messages that were buffered without acknowledgement).
LPO在A处结束。A刷新14-16条消息（在没有确认的情况下缓冲的消息）。
. . . . . .
. LS PR FSN=6 BSN=13 . . .
. ------------------------------------> .
. . . . Remote Processor
. . . . Outage Ceases
. . . . ------------>
. . . . . .
. . . . . .
. LS PR FSN=6 BSN=13 . . .
. ------------------------------------> .
. . . . Remote Processor
. . . . Outage Ceases
. . . . ------------>
. . . . . .
Suppose that B processed message 5, but never processed message 6. B flushes message 6 from its Receive Buffer. B notifies A of this using the Link Status Ready message setting BSN=5, the last message that was processed at B.
假设B处理了消息5，但从未处理过消息6。B从其接收缓冲区刷新消息6。B使用链路状态就绪消息设置BSN=5（在B处处理的最后一条消息）将此情况通知A。
. . . . . .
. . . . . .
. . . LS Ready FSN=13 BSN=5 .
. <------------------------------------ .
. . . . . .
. . . . . .
. . . . . .
. . . LS Ready FSN=13 BSN=5 .
. <------------------------------------ .
. . . . . .
B has completed synchronization of sequence numbers and has sent an LS Ready, so it is able to resume sending data at this point with the new sequence numbers (starting with FSN=14).
B已完成序列号的同步，并已发送LS Ready，因此它能够在此时使用新序列号（从FSN=14开始）恢复发送数据。
. . . . . .
. . . . . Message for
. . . . transmission
. . . . <------------
. . . User Data FSN=14 BSN=5 .
. <------------------------------------ .
. . . . . .
. . . . . .
. . . . . Message for
. . . . transmission
. . . . <------------
. . . User Data FSN=14 BSN=5 .
. <------------------------------------ .
. . . . . .
A can use the Link Status Ready information to resynchronize its sequence numbers to begin with FSN=6 in the next User Data message.
A可以使用链路状态就绪信息重新同步其序列号，以便在下一条用户数据消息中以FSN=6开头。
. . . . . .
. LS Ready FSN=5 BSN=13 . . .
. ------------------------------------> .
. . . . . .
. . . . . .
. LS Ready FSN=5 BSN=13 . . .
. ------------------------------------> .
. . . . . .
A has completed synchronization of sequence number and has both received and sent an LS Ready, so it is able to resume sending data at this point with the new sequence numbers and acknowledging data received after receiving LS Ready.
A已完成序列号的同步，并已接收和发送LS就绪，因此它能够在此时使用新序列号恢复发送数据，并在接收LS就绪后确认接收到的数据。
. . . . . .
. . . . . .
. User Data FSN=5 BSN=14 (empty) . .
. ------------------------------------> .
. . . . . .
Message for . . . Message for
transmission . . transmission
------------> . . <------------
. User Data FSN=6 BSN=14 . . .
. ------------------------------------> .
. . . User Data FSN=15 BSN=5 .
. <------------------------------------ .
. . . . . .
. . (empty) User Data FSN=15 BSN=6 .
. <------------------------------------ .
. User Data FSN=6 BSN=15 (empty) . .
. ------------------------------------> .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. User Data FSN=5 BSN=14 (empty) . .
. ------------------------------------> .
. . . . . .
Message for . . . Message for
transmission . . transmission
------------> . . <------------
. User Data FSN=6 BSN=14 . . .
. ------------------------------------> .
. . . User Data FSN=15 BSN=5 .
. <------------------------------------ .
. . . . . .
. . (empty) User Data FSN=15 BSN=6 .
. <------------------------------------ .
. User Data FSN=6 BSN=15 (empty) . .
. ------------------------------------> .
. . . . . .
. . . . . .
. . . . . .
Figure 16. Example: Processor Outage and Recovery
图16。示例：处理器中断和恢复
Figures 17 and 18 illustrate the Level 2 Flow Control procedure. In Figure 17, congestion ceases before timer T6 expires. Figure 18 shows the case where T6 expires.
图17和图18说明了2级流量控制程序。在图17中，拥塞在计时器T6到期之前停止。图18显示了T6过期的情况。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion onset . .
. . . . . .
. Link Status Busy . . .
. ------------------------------------> .
. . . . . .
. . . . Start .
. . . . Timer T6 .
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion abatement . .
. . . . . .
. Link Status Busy Ended . . .
. ------------------------------------> .
. . . . . .
. . . . Stop .
. . . . Timer T6 .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion onset . .
. . . . . .
. Link Status Busy . . .
. ------------------------------------> .
. . . . . .
. . . . Start .
. . . . Timer T6 .
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion abatement . .
. . . . . .
. Link Status Busy Ended . . .
. ------------------------------------> .
. . . . . .
. . . . Stop .
. . . . Timer T6 .
. . . . . .
Figure 17. Example: Level 2 Flow Control - Congestion Ceases
图17。示例：2级流量控制-拥塞停止
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion onset . .
. . . . . .
. Link Status Busy . . .
. ------------------------------------> .
. . . . . .
. . . . Start .
. . . . Timer T6 .
. . . . : .
. . . . : .
. . . . Timer T6 .
. . . . Expires .
. . . . . .
. . Link Status Out of Service .
. <------------------------------------ .
. . . . . .
. . . . Out of Service
. . . . ------------>
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . .
. receive congestion onset . .
. . . . . .
. Link Status Busy . . .
. ------------------------------------> .
. . . . . .
. . . . Start .
. . . . Timer T6 .
. . . . : .
. . . . : .
. . . . Timer T6 .
. . . . Expires .
. . . . . .
. . Link Status Out of Service .
. <------------------------------------ .
. . . . . .
. . . . Out of Service
. . . . ------------>
. . . . . .
Figure 18. Example: Level 2 Flow Control - Timer T6 Expires
图18。示例：2级流量控制-计时器T6过期
In Figure 19, M2PA notifies MTP3 of congestion onset and abatement. The notification includes the congestion level, if there are levels of congestion defined.
在图19中，M2PA通知MTP3拥塞开始和缓解。如果定义了拥塞级别，则通知包括拥塞级别。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . . .
. transmit congestion . . .
. onset (level) . . .
. . . . . .
Congestion Indication . . . .
(level) . . . . .
<------------ . . . .
. . . . . .
. Implementation dependent . .
. determination of M2PA . . .
. transmit congestion . . .
. abatement (level) . . .
. . . . . .
Congestion Indication . . . .
(level) . . . . .
<------------ . . . .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Implementation dependent . .
. determination of M2PA . . .
. transmit congestion . . .
. onset (level) . . .
. . . . . .
Congestion Indication . . . .
(level) . . . . .
<------------ . . . .
. . . . . .
. Implementation dependent . .
. determination of M2PA . . .
. transmit congestion . . .
. abatement (level) . . .
. . . . . .
Congestion Indication . . . .
(level) . . . . .
<------------ . . . .
. . . . . .
Figure 19. Example: MTP3 Signaling Link Congestion
图19。示例：MTP3信令链路拥塞
Figure 20 shows an example of link deactivation. MTP3 can request that a link be taken out of service.
图20显示了链路停用的示例。MTP3可以请求链路停止服务。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
Stop . . . . .
------------> . . . .
. . . . . .
. Link Status Out of Service . .
. ------------------------------------> .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
Stop . . . . .
------------> . . . .
. . . . . .
. Link Status Out of Service . .
. ------------------------------------> .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
Figure 20. Example: Link Deactivation
图20。示例：链路停用
In Figure 21, MTP3 performs a changeover because the link went out of service. MTP3 selects a different link to retransmit the unacknowledged and unsent messages.
在图21中，MTP3执行转换，因为链路停止服务。MTP3选择不同的链接以重新传输未确认和未发送的消息。
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Communication Lost . . .
. <------------ . . .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
Retrieve BSNT . . . .
------------> . . . .
. . . . . .
BSNT Confirmation . . . .
<------------ . . . .
. . . . . .
XCO (BSNT) on another link . . .
------------------------------------------------------------>
. . . . . .
. . . . Retrieve BSNT
. . . . <------------
. . . . . .
. . . . BSNT Confirmation
. . . . ------------>
. . . . . .
. . . . . XCA (BSNT)
<------------------------------------------------------------
. . . . . .
Retrieval Request . . . .
and FSNC . . . . .
------------> . . . .
. . . . . .
Retrieved Message . . . .
<------------ . . . .
. : . . . . .
. : . . . . .
<------------ . . . .
. . . . . .
Retrieval Complete . . . .
<------------ . . . .
. . . . . .
Send messages on another link.
MTP3 M2PA SCTP SCTP M2PA MTP3
---- ---- ---- ---- ---- ----
. . . . . .
. Communication Lost . . .
. <------------ . . .
. . . . . .
Out of Service . . . .
<------------ . . . .
. . . . . .
Retrieve BSNT . . . .
------------> . . . .
. . . . . .
BSNT Confirmation . . . .
<------------ . . . .
. . . . . .
XCO (BSNT) on another link . . .
------------------------------------------------------------>
. . . . . .
. . . . Retrieve BSNT
. . . . <------------
. . . . . .
. . . . BSNT Confirmation
. . . . ------------>
. . . . . .
. . . . . XCA (BSNT)
<------------------------------------------------------------
. . . . . .
Retrieval Request . . . .
and FSNC . . . . .
------------> . . . .
. . . . . .
Retrieved Message . . . .
<------------ . . . .
. : . . . . .
. : . . . . .
<------------ . . . .
. . . . . .
Retrieval Complete . . . .
<------------ . . . .
. . . . . .
Send messages on another link.
Figure 21. Example: Link Changeover
图21。示例：链路转换
M2PA is designed to carry signaling messages for telephony services. As such, M2PA MUST involve the security needs of several parties:
M2PA设计用于承载电话服务的信令消息。因此，M2PA必须涉及多方的安全需求：
- the end users of the services
- 服务的最终用户
- the network providers
- 网络供应商
- the applications involved
- 所涉及的应用程序
Additional requirements MAY come from local regulation.
其他要求可能来自当地法规。
While these parties may have some overlapping security needs, their needs may not be identical. Any security solution SHOULD fulfill all of the different parties' needs.
虽然这些当事方可能有一些重叠的安全需求，但它们的需求可能并不相同。任何安全解决方案都应满足各方的所有需求。
Consult [RFC3788] for a discussion of security requirements and for guidance on the use of security protocols. Implementers of M2PA MUST follow the guidelines in [RFC3788].
有关安全要求的讨论和安全协议的使用指南，请参阅[RFC3788]。M2PA的实施者必须遵守[RFC3788]中的指南。
The SCTP Registered User Port Number Assignment for M2PA is 3565. The TCP Registered User Port Number 3565 is also assigned to M2PA, in case a specification for M2PA over TCP is created.
M2PA的SCTP注册用户端口号分配为3565。如果创建了通过TCP的M2PA规范，TCP注册的用户端口号3565也会分配给M2PA。
The value assigned by IANA for the Payload Protocol Identifier in the SCTP Payload Data chunk is
IANA为SCTP有效负载数据块中的有效负载协议标识符分配的值为
M2PA 5
M2PA 5
The SCTP Payload Protocol Identifier is included in each SCTP Data chunk, to indicate which protocol the SCTP is carrying. This Payload Protocol Identifier is not directly used by SCTP but may be used by certain network entities to identify the type of information being carried in a Data chunk.
SCTP有效负载协议标识符包含在每个SCTP数据块中，以指示SCTP承载的协议。此有效负载协议标识符不直接由SCTP使用，但可由某些网络实体用于标识数据块中承载的信息类型。
The User Adaptation peer may use the Payload Protocol Identifier as a way of determining additional information about the data being presented to it by SCTP.
用户适配对等方可以使用有效负载协议标识符作为确定关于由SCTP呈现给它的数据的附加信息的方式。
This protocol may be extended through IANA in three ways:
本协议可通过IANA以三种方式扩展：
- through definition of additional message classes,
- 通过定义其他消息类，
- through definition of additional message types, and
- 通过定义其他消息类型，以及
- through definition of additional message parameters.
- 通过定义附加的消息参数。
The definition and use of new message classes, types, and parameters is an integral part of SIGTRAN adaptation layers. Thus, these extensions are assigned by IANA through an IETF Consensus action as defined in [RFC2434].
新消息类、类型和参数的定义和使用是SIGTRAN适配层不可分割的一部分。因此，IANA通过[RFC2434]中定义的IETF共识行动分配这些扩展。
The proposed extension must in no way adversely affect the general working of the protocol.
拟议的延期决不能对议定书的一般工作产生不利影响。
The defined values for the message classes, types, and parameters are listed in the Signaling User Adaptation Layer registry (sigtran-adapt).
消息类、类型和参数的定义值列在信令用户适配层注册表（sigtran adapt）中。
The documentation for a new message class MUST include the following information:
新消息类的文档必须包括以下信息：
(a) A long and short name for the message class.
(a) 消息类的长名称和短名称。
(b) A detailed description of the purpose of the message class.
(b) 消息类用途的详细说明。
Documentation of the message type MUST contain the following information:
消息类型的文档必须包含以下信息：
(a) A long and short name for the new message type.
(a) 新消息类型的长名称和短名称。
(b) A detailed description of the structure of the message.
(b) 对消息结构的详细描述。
(c) A detailed definition and description of the intended use of each field within the message.
(c) 消息中每个字段的预期用途的详细定义和说明。
(d) A detailed procedural description of the use of the new message type within the operation of the protocol.
(d) 协议操作中使用新消息类型的详细过程描述。
(e) A detailed description of error conditions when receiving this message type.
(e) 接收此消息类型时错误情况的详细说明。
When an implementation receives a message type that it does not support, it MUST discard the message.
当实现接收到它不支持的消息类型时，它必须丢弃该消息。
Documentation of the message parameter MUST contain the following information:
消息参数的文档必须包含以下信息：
(a) Name of the parameter type.
(a) 参数类型的名称。
(b) Detailed description of the structure of the parameter field.
(b) 参数字段结构的详细说明。
(c) Detailed definition of each component of the parameter value.
(c) 参数值的每个组件的详细定义。
(d) Detailed description of the intended use of this parameter type, and an indication of whether, and under what circumstances, multiple instances of this parameter type may be found within the same message type.
(d) 此参数类型的预期用途的详细说明，以及是否以及在何种情况下可在同一消息类型中找到此参数类型的多个实例的指示。
This section lists the values defined in this document that should be included in the Signaling User Adaptation Layer registry (sigtran-adapt).
本节列出了本文档中定义的应包含在信令用户适配层注册表（sigtran adapt）中的值。
The following values for Message Class are defined in this document:
本文档中定义了消息类的以下值：
Value
(decimal) Message Class
--------- -------------
11 M2PA Messages
Value
(decimal) Message Class
--------- -------------
11 M2PA Messages
The following values for Message Type are defined in this document:
本文档中定义了以下消息类型值：
Value
(decimal) Message Type
--------- -------------
1 User Data
2 Link Status
Value
(decimal) Message Type
--------- -------------
1 User Data
2 Link Status
The authors would like to thank the following for their valuable comments and suggestions: Brian Tatum, Wayne Davis, Cliff Thomas, Jeff Copley, Monique Bernard, Malleswar Kalla, Ian Rytina, Greg Sidebottom, Al Varney, Jeff Craig, and Andrew Booth.
作者要感谢以下人士提出的宝贵意见和建议：布赖恩·塔图姆、韦恩·戴维斯、克利夫·托马斯、杰夫·科普利、莫妮克·伯纳德、马勒斯瓦尔·卡拉、伊恩·雷蒂娜、格雷格·西德巴顿、艾尔·瓦尼、杰夫·克雷格和安德鲁·布斯。
[JT-Q703] TTC, "Message Transfer Part Signalling Link," TTC Standard JT-Q703, Telecommunication Technology Committee (TTC), version 3 (April 27, 1994).
[JT-Q703]TTC，“信息传输部分信令链路”，TTC标准JT-Q703，电信技术委员会（TTC），第3版（1994年4月27日）。
[JT-Q704] TTC, "Message Transfer Part Signalling Network Functions," TTC Standard JT-Q704, Telecommunication Technology Committee (TTC), version 4 (May 30, 2002).
[JT-Q704]TTC，“信息传输部分信令网络功能”，TTC标准JT-Q704，电信技术委员会（TTC），第4版（2002年5月30日）。
[Q.703] ITU, "Signalling System No. 7 - Signalling Link," ITU-T Recommendation Q.703, ITU-T Telecommunication Standardization Sector of ITU (July 1996).
[Q.703]ITU，“第7号信令系统-信令链路”，ITU-T建议Q.703，ITU-T电信标准化部门（1996年7月）。
[Q.704] ITU, "Message Transfer Part - Signalling Network Functions and Messages," ITU-T Recommendation Q.704, ITU-T Telecommunication Standardization Sector of ITU (July 1996).
[Q.704]ITU，“信息传输部分——信令网络功能和信息”，ITU-T建议Q.704，ITU-T电信标准化部门（1996年7月）。
[Q.2140] ITU, "B-ISDN ATM Adaptation Layer - Service Specific Coordination Function for Signalling at the Network Node Interface (SSCF at NNI)," ITU-T Recommendation Q.2140, ITU-T Telecommunication Standardization Sector of ITU (February 1995).
[Q.2140]ITU，“B-ISDN ATM适配层-网络节点接口信令的特定服务协调功能（NNI的SSCF）”，ITU-T建议Q.2140，ITU-T电信标准化部门（1995年2月）。
[Q.2210] ITU, "Message Transfer Part Level 3 Functions and Messages Using the Services of ITU-T Recommendation Q.2140," ITU-T Recommendation Q.2210, ITU-T Telecommunication Standardization Sector of ITU (July 1996).
[Q.2210]ITU，“使用ITU-T建议Q.2140服务的信息传输第3级功能和信息”，ITU-T建议Q.2210，ITU-T电信标准化部门（1996年7月）。
[RFC791] Postel, J., "Internet Protocol", STD 5, RFC 791, September 1981.
[RFC791]Postel，J.，“互联网协议”，标准5，RFC7911981年9月。
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2119]Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 2434, October 1998.
[RFC2434]Narten，T.和H.Alvestrand，“在RFCs中编写IANA注意事项部分的指南”，BCP 26，RFC 2434，1998年10月。
[RFC2960] Stewart, R., Xie, Q., Morneault, K., Sharp, C., Schwarzbauer, H., Taylor, T., Rytina, I., Kalla, M., Zhang, L., and V. Paxson, "Stream Control Transmission Protocol", RFC 2960, October 2000.
[RFC2960]Stewart，R.，Xie，Q.，Morneault，K.，Sharp，C.，Schwarzbauer，H.，Taylor，T.，Rytina，I.，Kalla，M.，Zhang，L.，和V.Paxson，“流控制传输协议”，RFC 29602000年10月。
[RFC3309] Stone, J., Stewart, R., and D. Otis, "Stream Control Transmission Protocol (SCTP) Checksum Change", RFC 3309, September 2002.
[RFC3309]Stone，J.，Stewart，R.，和D.Otis，“流控制传输协议（SCTP）校验和更改”，RFC 33092002年9月。
[RFC3788] Loughney, J., Tuexen, M., and J. Pastor-Balbas, "Security Considerations for Signaling Transport (SIGTRAN) Protocols", RFC 3788, June 2004.
[RFC3788]Loughney，J.，Tuexen，M.，和J.Pastor Balbas，“信号传输（SIGTRAN）协议的安全考虑”，RFC 3788，2004年6月。
[T1.111] ANSI, "American National Standard for Telecommunications - Signaling System Number 7 (SS7) - Message Transfer Part (MTP)," ANSI T1.111-2001, American National Standards Institute (February 2001).
[T1.111]ANSI，“美国国家电信标准-第7号信号系统（SS7）-消息传输部分（MTP）”，ANSI T1.111-2001，美国国家标准协会（2001年2月）。
[M2UA] K. Morneault, et. al., "Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) - User Adaptation Layer," RFC 3331, Internet Engineering Task Force - Signalling Transport Working Group (September, 2002).
[M2UA]K.Morneault等人，“信令系统7（SS7）消息传输第2部分（MTP2）-用户适配层”，RFC 3331，互联网工程任务组-信令传输工作组（2002年9月）。
[Q.700] ITU, "Introduction to CCITT Signalling System No. 7," ITU-T Recommendation Q.700, ITU-T Telecommunication Standardization Sector of ITU (March 1993).
[Q.700]ITU，“CCITT信令系统介绍第7号”，ITU-T建议Q.700，ITU-T电信标准化部门（1993年3月）。
[Q.701] ITU, "Functional Description of the Message Transfer Part (MTP) of Signalling System No. 7," ITU-T Recommendation Q.701, ITU-T Telecommunication Standardization Sector of ITU (March 1993).
[Q.701]ITU，“第7号信令系统消息传输部分（MTP）的功能说明”，ITU-T建议Q.701，ITU-T电信标准化部门（1993年3月）。
[Q.702] ITU, "Signalling Data Link," ITU-T Recommendation Q.702, ITU-T Telecommunication Standardization Sector of ITU (November 1988).
[Q.702]ITU，“信令数据链路”，ITU-T建议Q.702，ITU-T电信标准化部门（1988年11月）。
[Q.705] ITU, "Signalling System No. 7 - Signalling Network Structure," ITU-T Recommendation Q.705, ITU-T Telecommunication Standardization Sector of ITU (March 1993).
[Q.705]ITU，“第7号信令系统-信令网络结构”，ITU-T建议Q.705，ITU-T电信标准化部门（1993年3月）。
[RFC2719] Ong, L., Rytina, I., Garcia, M., Schwarzbauer, H., Coene, L., Lin, H., Juhasz, I., Holdrege, M., and C. Sharp, "Framework Architecture for Signaling Transport", RFC 2719, October 1999.
[RFC2719]Ong，L.，Rytina，I.，Garcia，M.，Schwarzbauer，H.，Coene，L.，Lin，H.，Juhasz，I.，Holdrege，M.，和C.Sharp，“信号传输的框架架构”，RFC 2719，1999年10月。
Authors' Addresses
作者地址
Tom George Plano, TX USA
美国德克萨斯州汤姆·乔治·普莱诺
Phone: +1-972-985-4594
EMail: tgeorge_tx@verizon.net
Phone: +1-972-985-4594
EMail: tgeorge_tx@verizon.net
Brian Bidulock OpenSS7 Corporation 1469 Jeffreys Crescent Edmonton, AB T6L 6T1 Canada
Brian Bidulock OpenSS7 Corporation 1469 Jeffreys Crescent Edmonton，AB T6L 6T1加拿大
Phone: +1-780-490-1141
EMail: bidulock@openss7.org
Phone: +1-780-490-1141
EMail: bidulock@openss7.org
Ram Dantu, Ph.D. Assistant Professor Department of Computer Science University of North Texas Denton, TX 76203 USA
拉姆·丹图博士。北得克萨斯大学计算机系副教授丹顿，TX 76203美国
Phone: +1-940-565-2822
EMail: rdantu@unt.edu
Phone: +1-940-565-2822
EMail: rdantu@unt.edu
Hanns Juergen Schwarzbauer SIEMENS AG Hofmannstr. 51 81359 Munich Germany
Hanns Juergen Schwarzbauer西门子公司Hofmannstr。5181359德国慕尼黑
Phone: +49-89-722-24236
EMail: HannsJuergen.Schwarzbauer@Siemens.com
Phone: +49-89-722-24236
EMail: HannsJuergen.Schwarzbauer@Siemens.com
Ken Morneault Cisco Systems Inc. 13615 Dulles Technology Drive Herndon, VA 20171 USA
Ken Morneault Cisco Systems Inc.美国弗吉尼亚州赫恩登市杜勒斯技术大道13615号，邮编20171
Phone: +1-703-484-3323
EMail: kmorneau@cisco.com
Phone: +1-703-484-3323
EMail: kmorneau@cisco.com
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确认
Funding for the RFC Editor function is currently provided by the Internet Society.
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