Network Working Group E. Weilandt
Request for Comments: 3807 N. Khanchandani
Updates: 3057 S. Rao
Category: Standards Track Nortel Networks
June 2004
Network Working Group E. Weilandt
Request for Comments: 3807 N. Khanchandani
Updates: 3057 S. Rao
Category: Standards Track Nortel Networks
June 2004
V5.2-User Adaptation Layer (V5UA)
V5.2-用户适配层（V5UA）
Status of this Memo
本备忘录的状况
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 (2004).
版权所有（C）互联网协会（2004年）。
Abstract
摘要
This document defines a mechanism for the backhauling of V5.2 messages over IP using the Stream Control Transmission Protocol (SCTP). This protocol may be used between a Signaling Gateway (SG) and a Media Gateway controller (MGC). It is assumed that the SG receives V5.2 signaling over a standard V5.2 interface.
本文档定义了使用流控制传输协议（SCTP）通过IP回传V5.2消息的机制。该协议可在信令网关（SG）和媒体网关控制器（MGC）之间使用。假定SG通过标准V5.2接口接收V5.2信令。
This document builds on the ISDN User Adaptation Layer Protocol (RFC 3057). It defines all necessary extensions to the IUA Protocol needed for the V5UA protocol implementation.
本文件以ISDN用户适配层协议（RFC3057）为基础。它定义了V5UA协议实现所需的IUA协议的所有必要扩展。
Table of Contents
目录
1. Introduction ................................................. 2
1.1. Scope .................................................. 3
1.2. Terminology ............................................ 3
1.3. V5.2 Overview .......................................... 5
1.4. Distribution of responsibilities between MGC and SG .... 7
1.5. Client/Server Model .................................... 7
1.6. Addition to boundary primitives ........................ 7
1.6.1. V5 specific boundary primitives ................ 7
2. Conventions .................................................. 9
3. SCTP Stream Management ....................................... 10
4. Proposed V5.2 Backhaul Architecture .......................... 10
4.1. V5UA Message Header .................................... 11
4.2. V5 Naming Conventions for Interface Identifier ......... 12
4.3. V5 Additions to IUA Boundary Primitives ................ 13
4.4. Link Status Messages ................................... 14
4.5. Sa-Bit Messages ........................................ 16
4.6. Error Indication Message ............................... 17
5. Procedures ................................................... 18
5.1. V5 Layer 1 failure ..................................... 18
5.2. Loss of V5UA peer ...................................... 19
5.3. C-channel overload on SG ............................... 19
6. Examples ..................................................... 20
6.1. Link Identification Procedure (successful) ............. 20
7. Security Considerations ...................................... 21
8. IANA Considerations .......................................... 21
8.1. SCTP Payload Protocol Identifier ....................... 21
8.2. V5UA Port Number ....................................... 22
9. Acknowledgements ............................................. 22
10. References ................................................... 22
10.1. Normative References ................................... 22
10.2. Informative References ................................. 23
11. Authors' Addresses ........................................... 23
12. Full Copyright Statement ..................................... 24
1. Introduction ................................................. 2
1.1. Scope .................................................. 3
1.2. Terminology ............................................ 3
1.3. V5.2 Overview .......................................... 5
1.4. Distribution of responsibilities between MGC and SG .... 7
1.5. Client/Server Model .................................... 7
1.6. Addition to boundary primitives ........................ 7
1.6.1. V5 specific boundary primitives ................ 7
2. Conventions .................................................. 9
3. SCTP Stream Management ....................................... 10
4. Proposed V5.2 Backhaul Architecture .......................... 10
4.1. V5UA Message Header .................................... 11
4.2. V5 Naming Conventions for Interface Identifier ......... 12
4.3. V5 Additions to IUA Boundary Primitives ................ 13
4.4. Link Status Messages ................................... 14
4.5. Sa-Bit Messages ........................................ 16
4.6. Error Indication Message ............................... 17
5. Procedures ................................................... 18
5.1. V5 Layer 1 failure ..................................... 18
5.2. Loss of V5UA peer ...................................... 19
5.3. C-channel overload on SG ............................... 19
6. Examples ..................................................... 20
6.1. Link Identification Procedure (successful) ............. 20
7. Security Considerations ...................................... 21
8. IANA Considerations .......................................... 21
8.1. SCTP Payload Protocol Identifier ....................... 21
8.2. V5UA Port Number ....................................... 22
9. Acknowledgements ............................................. 22
10. References ................................................... 22
10.1. Normative References ................................... 22
10.2. Informative References ................................. 23
11. Authors' Addresses ........................................... 23
12. Full Copyright Statement ..................................... 24
This document describes a method of implementing V5.2 backhaul messaging over IP using a modified version of the ISDN User Adaptation Layer Protocol (IUAP) [1]. V5UA builds on top of IUA, defining the necessary extensions to IUA for a V5.2 implementation.
本文档描述了使用改进版ISDN用户适配层协议（IUAP）[1]通过IP实现V5.2回程消息传递的方法。V5UA构建在IUA之上，为V5.2实现定义了对IUA的必要扩展。
Since V5UA is meant to be an extension to IUAP, everything defined in [1] is also valid for V5UA unless otherwise specified in this document.
由于V5UA是IUAP的扩展，因此[1]中定义的所有内容也适用于V5UA，除非本文档中另有规定。
This document does not describe the V5 standard itself. The V5 protocol is defined by ETSI standards [2,3]. Any description of the V5 protocol in this document is meant to make the text easier to understand.
本文档不描述V5标准本身。V5协议由ETSI标准定义[2,3]。本文档中对V5协议的任何描述都旨在使文本更易于理解。
There is a need for Switched Circuit Network (SCN) signaling protocol delivery from a V5.2 Signaling Gateway (SG) to a Media Gateway Controller (MGC), analogous to the implementation of the ISDN Q.921 User Adaptation Layer (IUA) as described in [1].
需要将交换电路网络（SCN）信令协议从V5.2信令网关（SG）传送到媒体网关控制器（MGC），类似于[1]中所述的ISDN Q.921用户适配层（IUA）的实现。
This document supports analog telephone access, ISDN basic rate access and ISDN Primary rate access over a V5.2 interface.
本文档支持V5.2接口上的模拟电话接入、ISDN基本速率接入和ISDN主要速率接入。
Since the V5.2 Layer 2, and especially Layer 3, differs from the Q.921 [4] and Q.931 Adaptation layer, the IUA standard must be extended to fulfil the needs for supporting V5.2.
由于V5.2第2层，特别是第3层与Q.921[4]和Q.931适配层不同，因此必须扩展IUA标准以满足支持V5.2的需要。
Bearer Channel Connection (BCC) protocol - A protocol which allows the Local Exchange (LE) to instruct the Access Network (AN) to allocate bearer channels, either singularly or in multiples, on demand.
承载信道连接（BCC）协议-一种允许本地交换机（LE）指示接入网络（AN）按需分配承载信道的协议，可以是单条或多条。
Communication channel (C-channel) - A 64 kbit/s time slot on a V5.2 interface provisioned to carry communication paths.
通信信道（C信道）-V5.2接口上的64 kbit/s时隙，用于传输通信路径。
Communication path (C-path) - Any one of the following information types:
通信路径（C路径）-以下任何一种信息类型：
- The layer 2 data link carrying the Control protocol
- 承载控制协议的第2层数据链路
- The layer 2 data link carrying the Link Control protocol
- 承载链路控制协议的第2层数据链路
- The layer 2 data link carrying the PSTN signaling
- 承载PSTN信令的第二层数据链路
- Each of the layer 2 data links carrying the protection protocol
- 承载保护协议的每个第2层数据链路
- The layer 2 data link carrying the BCC protocol
- 承载BCC协议的第2层数据链路
- All the ISDN Ds-type data from one or more user ports
- 来自一个或多个用户端口的所有ISDN Ds类型数据
- All the ISDN p-type data from one or more user ports
- 来自一个或多个用户端口的所有ISDN p型数据
- All the ISDN t-type data from one or more user ports
- 来自一个或多个用户端口的所有ISDN t型数据
Note: This definition includes the possibility that there may be more than one C-path of the same information type, each allocated to a different logical C-channel.
注：此定义包括可能存在多个相同信息类型的C路径，每个路径分配给不同的逻辑C通道。
Envelope Function Address (EFA) - 13 bit number, ranging from 0 to 8191 (decimal). An EFA uniquely identifies one of the five V5.2 protocols, or an ISDN agent attached to an AN. The following list contains the possible values for the EFA:
信封函数地址（EFA）-13位数字，范围从0到8191（十进制）。EFA唯一标识五个V5.2协议之一，或连接到An的ISDN代理。以下列表包含EFA的可能值：
Definition Value
---------- ------
ISDN_PROTOCOL 0 - 8175
PSTN_PROTOCOL 8176
CONTROL_PROTOCOL 8177
BCC_PROTOCOL 8178
PROT_PROTOCOL 8179
LINK_CONTROL_PROTOCOL 8180
RESERVED 8181 - 8191
Definition Value
---------- ------
ISDN_PROTOCOL 0 - 8175
PSTN_PROTOCOL 8176
CONTROL_PROTOCOL 8177
BCC_PROTOCOL 8178
PROT_PROTOCOL 8179
LINK_CONTROL_PROTOCOL 8180
RESERVED 8181 - 8191
Layer 1 Functional State Machine (L1 FSM) - Functional State Machine in V5 System Management that tracks and controls the states of the physical E1 links on the interface.
第1层功能状态机（L1 FSM）-V5系统管理中的功能状态机，用于跟踪和控制接口上物理E1链路的状态。
Logical Communication channel (Logical C-channel) - A group of one or more C-paths, all of different types, but excluding the C-path for the protection protocol.
逻辑通信信道（逻辑C信道）-一组或多个C路径，所有类型都不同，但不包括保护协议的C路径。
Multi-link - A collection of more than one 2048 kbit/s link which together make up a V5.2 interface.
多链路-一个以上2048 kbit/s链路的集合，共同构成V5.2接口。
Multi-Slot - A group of more than one 64kbit/s channels providing 8Khz and time slot sequence integrity, generally used together within an ISDN Primary Rate Access (ISDN-PRA) user port, in order to supply a higher bit-rate service.
多时隙-一组多个64kbit/s信道，提供8Khz和时隙序列完整性，通常在ISDN主速率访问（ISDN-PRA）用户端口内一起使用，以提供更高的比特率服务。
Physical Communication Channel (Physical C-channel) - A 64kbit/s time slot on a V5.2 interface which has been assigned for carrying logical C-channels. A physical C-channel may not be used for carrying bearer channels.
物理通信信道（物理C信道）-V5.2接口上的64kbit/s时隙，已分配用于承载逻辑C信道。物理C信道不能用于承载承载信道。
Primary Link - A 2048 kbit/s (E1) link in a multi-link V5.2 interface whose physical C-channel in time slot 16 carries a C-path for the protection protocol and, on V5.2 initialization, also the C-path for the control protocol, link control protocol, and the BCC protocol. Other C-paths may also be carried in the time slot 16.
主链路—多链路V5.2接口中的2048 kbit/s（E1）链路，其时隙16中的物理C通道承载保护协议的C路径，在V5.2初始化时，还承载控制协议、链路控制协议和BCC协议的C路径。其他C路径也可以在时隙16中承载。
Secondary Link - A 2048 kbit/s (E1) link in a multi-link V5.2 interface whose time slot 16 carries a C-path for the protection protocol, and, on V5.2 initialization, acts as the standby C-channel for the control protocol, link control protocol, and BCC protocol and any other C-paths initially carried in time slot 16 of the primary link.
辅助链路-多链路V5.2接口中的2048 kbit/s（E1）链路，其时隙16带有保护协议的C路径，并且在V5.2初始化时，充当控制协议、链路控制协议和BCC协议以及初始在主链路的时隙16中携带的任何其他C路径的备用C信道。
V5 Link - A 2048 kbits/s E1 (PCM30) link used on a V5 interface. A V5 interface may use up to 16 V5 links.
V5链路—V5接口上使用的2048 kbits/s E1（PCM30）链路。V5接口最多可使用16个V5链路。
V5.2 is an industry standard ETSI interface (reference ETS 300 347-1 [3]) defined between a Local Exchange (LE) and an Access Network (AN) providing access to the following types:
V5.2是一个行业标准ETSI接口（参考ETS 300 347-1[3]），定义在本地交换机（LE）和接入网络（an）之间，提供对以下类型的访问：
- Analog telephone access
- 模拟电话接入
- ISDN Basic rate access
- ISDN基本速率接入
- ISDN Primary Rate access
- ISDN主速率接入
- Other analog or digital accesses for semi-permanent connections without associated outband signaling information
- 无相关带外信令信息的半永久连接的其他模拟或数字访问
The original V5 specification (V5.1 [2]) uses 2048 kbps links in a non-concentrating fashion. In contrast, V5.2 may use up to 16 such interface links and supports concentration.
原始V5规范（V5.1[2]）以非集中式方式使用2048 kbps链路。相比之下，V5.2最多可以使用16个这样的接口链接并支持集中。
---------- ---------- o--o
| | E1 | |------- /
| |--------------| | --
| LE | E1 | AN |
| |--------------| | o--o
| | | |------- /
---------- ---------- --
---------- ---------- o--o
| | E1 | |------- /
| |--------------| | --
| LE | E1 | AN |
| |--------------| | o--o
| | | |------- /
---------- ---------- --
The LE and AN are connected with up to 16 E1 (PCM30) links. Channels 16, 15 and 31 on any E1 link can be reserved for data communication between LE and AN. The channels reserved for data are called "Communication Channels" or "C-channels."
LE和AN最多通过16条E1（PCM30）链路连接。任何E1链路上的信道16、15和31可保留用于LE和AN之间的数据通信。为数据保留的通道称为“通信通道”或“C通道”
The C-channels are the physical media that exchange data between the V5.2 protocol peer entities, as well as transfer the ISDN BRI D-channel messages between the terminals and the LE. A logical communication path between two peer entities for one protocol is called a "C-path".
C通道是物理介质，用于在V5.2协议对等实体之间交换数据，以及在终端和LE之间传输ISDN BRI D通道消息。一个协议的两个对等实体之间的逻辑通信路径称为“C路径”。
The signaling information in V5.2 are defined as:
V5.2中的信令信息定义为：
- Analog signals are carried by means of the V5 PSTN protocol (L3)
- 模拟信号通过V5 PSTN协议（L3）传输
- ISDN/analog ports are controlled by the V5 Control protocol (L3)
- ISDN/模拟端口由V5控制协议（L3）控制
- ISDN protocol messages are mapped to LAPD frames, which are carried by means of LAPV5-EF sublayer (L2)
- ISDN协议消息映射到LAPD帧，LAPD帧通过LAPV5-EF子层（L2）承载
- V5 protocol messages are mapped to LAPV5-DL frames, which are carried by means of LAPV5-EF sublayer (L2)
- V5协议消息映射到LAPV5-DL帧，这些帧通过LAPV5-EF子层（L2）承载
In order to support more traffic and dynamic allocation of bearer channels, the V5.2 protocol has several additions:
为了支持更多的通信量和承载信道的动态分配，V5.2协议增加了几个功能：
- A bearer channel connection protocol establishes and disestablishes bearer connections on demand, as determined by the signaling information, under the control of the Local Exchange.
- 承载信道连接协议在本地交换机的控制下根据信令信息确定的需求建立和解除承载连接。
- A link control protocol is defined for multi-link management to control link identification, link blocking and link failure conditions.
- 定义了用于多链路管理的链路控制协议，以控制链路标识、链路阻塞和链路故障情况。
- A protection protocol, operating on two separate V5 data links is defined to manage the protection switching of communication channels in case of link failures.
- 定义了在两个单独的V5数据链路上运行的保护协议，以在链路故障时管理通信信道的保护切换。
The following protocols are defined for the various protocol layers:
为各个协议层定义了以下协议：
Layer 2: - LAPV5-EF - LAPV5-DL
第2层：-LAPV5-EF-LAPV5-DL
Layer 3: - V5-Link Control - V5-BCC - V5-PSTN - V5-Control - V5-Protection
第3层：-V5链路控制-V5-BCC-V5-PSTN-V5控制-V5保护
In the V5UA backhaul architecture, the V5 protocol entities SHALL be distributed over SG and MGC as shown below.
在V5UA回程架构中，V5协议实体应分布在SG和MGC上，如下所示。
MGC SG
+------------+ +-------+-------+
| Lnk Cntrl | | | |
+------------+ | | |
| Cntrl | | | |
+------------+ V5UA | | | V5 +------+
| BCC | <--------> | LAPV5 | LAPV5 | <----> | AN |
+------------+ | -DL | -EF | +------+
| PSTN | | | |
+------------+ | | |
| Protection | | | |
+------------+ +-------+-------+
MGC SG
+------------+ +-------+-------+
| Lnk Cntrl | | | |
+------------+ | | |
| Cntrl | | | |
+------------+ V5UA | | | V5 +------+
| BCC | <--------> | LAPV5 | LAPV5 | <----> | AN |
+------------+ | -DL | -EF | +------+
| PSTN | | | |
+------------+ | | |
| Protection | | | |
+------------+ +-------+-------+
V5 System Management SHALL be located on the MGC. The V5 L1 Functional State Machine (FSM) SHALL be located on the SG.
V5系统管理应位于MGC上。V5 L1功能状态机（FSM）应位于SG上。
Dynamic TEI Management for V5 BRI over V5UA SHALL be located on the MGC.
V5UA上V5 BRI的动态TEI管理应位于MGC上。
The Client/Server Model for V5UA shall follow the model as defined for IUAP.
V5UA的客户机/服务器模型应遵循IUAP定义的模型。
The SCTP [6] (and UDP/TCP) registered User Port Number Assignment for V5UA is 5675.
V5UA的SCTP[6]（和UDP/TCP）注册用户端口号分配为5675。
Extending IUAP to V5UA to support V5.2 backhaul requires the introduction of new boundary primitives for the Q.921/Q.931 boundary, in accordance with the definitions in the V5 standards.
根据V5标准中的定义，将IUAP扩展到V5UA以支持V5.2回程需要为Q.921/Q.931边界引入新的边界原语。
V5UA reuses some IUA primitives from the Q.921/Q.931 boundary: the DL-DATA primitive and the DL-UNIT DATA primitive. The DL-DATA primitive is used for the transportation of both V5 Layer 3 messages and V5 ISDN Layer 3 messages. The DL-UNIT DATA primitive is only used for V5 ISDN messages and is used and defined as described for IUAP.
V5UA重用来自Q.921/Q.931边界的一些IUA原语：DL-DATA原语和DL-UNIT原语。DL-DATA原语用于传输V5第3层消息和V5 ISDN第3层消息。DL-UNIT数据原语仅用于V5 ISDN消息，并按照IUAP的说明使用和定义。
In the V5 standards, V5 system management is responsible for establishing and releasing data links. Therefore, for V5UA the DL-Establish and DL-Release primitives defined in IUAP are replaced by new primitives between system management and the data link layer in accordance with the definitions in [2]:
在V5标准中，V5系统管理负责建立和发布数据链路。因此，对于V5UA，根据[2]中的定义，IUAP中定义的DL建立和DL发布原语由系统管理层和数据链路层之间的新原语替换：
MDL-ESTABLISH
MDL-ESTABLE
The MDL-Establish primitives are used to request, indicate and confirm the outcome of the procedures for establishing multiple frame operation.
MDL建立原语用于请求、指示和确认建立多帧操作的过程的结果。
MDL-RELEASE
MDL-释放
The MDL-Release primitive is used to indicate the outcome of the procedures for terminating multiple frame operation.
MDL Release原语用于指示终止多帧操作的过程的结果。
In contrast to ISDN, the V5 standards demand that V5.2 system management interacts directly with V5.2 layer 1. Since V5.2 Layer 1 (including the L1 FSM) and parts of V5 system management are physically separated in a V5 backhaul scenario, V5UA must support some services for the communication between these two entities. Specifically, these services include an indication of the status of a specific link, and messages to support the link identification procedure defined by the V5 standards.
与ISDN不同，V5标准要求V5.2系统管理直接与V5.2第1层交互。由于V5.2第1层（包括L1 FSM）和V5系统管理的部分在V5回程场景中物理上是分开的，V5UA必须支持这两个实体之间通信的一些服务。具体而言，这些服务包括特定链路的状态指示，以及支持V5标准定义的链路识别过程的消息。
The new primitive are defined as shown below:
新原语的定义如下所示：
MPH-LINK STATUS START REPORTING
MPH-LINK状态开始报告
The MPH-LINK STATUS START REPORTING primitive is used by V5 system management to request that a link be brought into service for use in a V5 interface. On reception of this message, the L1 FSM on the SG SHALL start reporting the status of the V5 link to the MGC. This primitive is used similarly to the MPH-proceed primitive defined by V5.2, but it has a more extended meaning than MPH-proceed.
MPH-LINK STATUS START START REPORTING原语由V5系统管理用于请求链路投入使用，以便在V5接口中使用。收到此消息后，SG上的L1 FSM应开始向MGC报告V5链路的状态。此原语的使用方式与V5.2定义的MPH继续原语类似，但其含义比MPH继续原语更广泛。
MPH-LINK STATUS STOP REPORTING
MPH-LINK状态停止报告
The MPH-LINK STATUS STOP REPORTING primitive is used by V5 system management to request that a link be taken out of service on a V5 interface. On reception of this message, L1 FSM on the SG SHALL stop reporting the status of the V5 link to the GWC. This primitive is used similarly to the MPH-stop primitive defined by V5.2, but it has a more extended meaning than MPH-stop.
MPH-LINK STATUS STOP REPORTING（MPH-LINK状态停止报告）原语由V5系统管理用于请求在V5接口上使链路停止服务。收到此消息后，SG上的L1 FSM应停止向GWC报告V5链路的状态。此原语的使用方式与V5.2定义的MPH stop原语类似，但其含义比MPH stop更广泛。
MPH-LINK STATUS INDICATION
MPH-LINK状态指示
The MPH-LINK STATUS INDICATION primitive is used by L1 FSM on the Signaling Gateway to report the status (operational/non-operational) of a V5 link to V5 system management. This primitive is equivalent to the MPH-AI and MPH-DI primitives in V5.2.
信令网关上的L1 FSM使用MPH-LINK状态指示原语向V5系统管理报告V5链路的状态（运行/非运行）。此原语相当于V5.2中的MPH-AI和MPH-DI原语。
MPH-SA-BIT SET
MPH-SA位设置
The MPH-SA-BIT SET primitive is used by system management to request that the L1 FSM in the SG sets or resets the value of a specified Sa bit on the requested link. The SG uses it to report the successful setting or resetting of this bit back to system management. For V5, this message is used for the V5 specific Link Identification procedure to set/reset the value of the Sa7 bit, or to confirm the successful setting of the Sa bit. The MPH-SA BIT SET REQUEST is equivalent to the MPH-ID and MPH-NOR primitives in V5.2.
系统管理使用MPH-SA-BIT SET原语请求SG中的L1 FSM设置或重置请求链路上指定SA位的值。SG使用它将该位的成功设置或重置报告给系统管理。对于V5，此消息用于V5特定链路识别程序，以设置/重置Sa7位的值，或确认Sa位的成功设置。MPH-SA位设置请求相当于V5.2中的MPH-ID和MPH-NOR原语。
MPH-SA-BIT STATUS
MPH-SA-BIT状态
The MPH-SA-BIT STATUS primitives are used by system management in the MGC to request that the L1 FSM in the SG reports the status of a specified Sa bit on the requested link. The SG uses it to report (indicate) the status of this bit back to system management. For V5, these messages are used for the V5 specific Link identification procedure to request or report the status of the Sa7 bit. This is equivalent to the MPH-IDR, MPH-IDI or MPH-Elg primitives in V5.2.
MGC中的系统管理使用MPH-SA-BIT状态原语请求SG中的L1 FSM报告所请求链路上指定SA位的状态。SG使用它向系统管理层报告（指示）该位的状态。对于V5，这些消息用于V5特定链路识别过程，以请求或报告Sa7位的状态。这相当于V5.2中的MPH-IDR、MPH-IDI或MPH Elg原语。
Due to the separation of V5 System Management and V5 Layer1/Layer2 in the V5UA backhaul architecture, it may be necessary to report error conditions of the SG's V5 stack to V5 System Management. For this purpose, a new primitive is defined:
由于V5UA回程体系结构中V5系统管理和V5 Layer1/Layer2的分离，可能需要向V5系统管理报告SG的V5堆栈的错误情况。为此，定义了一个新的原语：
MDL-ERROR INDICATION
MDL错误指示
The MDL-ERROR INDICATION primitive is used to indicate an error condition to V5 System Management. The only valid reason for this primitive is 'Overload', indicating an overload condition of the C-channel on the SG. This reason is not defined in the V5/Q.921 standards.
MDL-ERROR指示原语用于向V5系统管理层指示错误情况。此原语的唯一有效原因是“过载”，表示SG上C通道的过载情况。V5/Q.921标准中未定义此原因。
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when they appear in this document, are to be interpreted as described in [7].
本文件中出现的关键词必须、不得、必需、应、不应、应、不应、推荐、不推荐、可和可选时，应按照[7]中所述进行解释。
A single SCTP stream SHOULD be used for grouping all of the following protocols together: BCC, Link Control, Control and PSTN protocol on a specific C-channel. A separate SCTP stream SHOULD be used for the Protection protocol on a specific C-channel. One SCTP stream SHOULD be used for all ISDN user ports on a specific C-channel. One single stream SHOULD NOT be used to carry data of more than one C-channel.
应使用单个SCTP流将以下所有协议分组在一起：特定C通道上的BCC、链路控制、控制和PSTN协议。特定C通道上的保护协议应使用单独的SCTP流。一个SCTP流应用于特定C通道上的所有ISDN用户端口。单个流不应用于承载多个C通道的数据。
In addition, one separate SCTP stream SHOULD be used for all MPH (link related) messages.
此外，应为所有MPH（链路相关）消息使用一个单独的SCTP流。
****** V5.2 ****** IP *******
* AN *---------------* SG *--------------* MGC *
****** ****** *******
****** V5.2 ****** IP *******
* AN *---------------* SG *--------------* MGC *
****** ****** *******
+-----+ +-----+
|V5.2 | (NIF) |V5.2 |
+-----+ +----------+ +-----+
| | | |V5UA| |V5UA |
| | | +----+ +-----+
|LAPV5| |LAPV5|SCTP| |SCTP |
| | | +----+ +-----+
| | | | IP + | IP |
+-----+ +-----+----+ +-----+
+-----+ +-----+
|V5.2 | (NIF) |V5.2 |
+-----+ +----------+ +-----+
| | | |V5UA| |V5UA |
| | | +----+ +-----+
|LAPV5| |LAPV5|SCTP| |SCTP |
| | | +----+ +-----+
| | | | IP + | IP |
+-----+ +-----+----+ +-----+
Figure 1: V5.2 Backhaul Architecture
图1:V5.2回程架构
AN - Access Network NIF - Nodal Interworking Function SCTP - Stream Control Transmission Protocol
接入网NIF节点互通功能SCTP流控制传输协议
The original IUA message header must be modified for V5UA. The original header for the integer formatted Interface Identifier is shown below:
V5UA必须修改原始IUA消息头。整数格式接口标识符的原始标头如下所示：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifier (integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x5) | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DLCI | Spare |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifier (integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x5) | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DLCI | Spare |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Original IUA Message Header
图2：原始IUA消息头
V5UA extends the IUA Message Header by including the Envelope Function Address (EFA) in the Spare field. The V5UA format for the integer formatted Interface Identifier is shown below:
V5UA通过在备用字段中包含信封功能地址（EFA）来扩展IUA消息头。整数格式接口标识符的V5UA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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifier (integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x81) | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DLCI | EFA |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifier (integer) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x81) | Length=8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| DLCI | EFA |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: V5UA Message Header (Integer-based Interface identifier)
图3:V5UA消息头（基于整数的接口标识符）
The EFA is defined by the V5 standard. It identifies a C-path, which is a 13-bit number, ranging from 0 to 8191 (decimal). An EFA uniquely identifies one of the five V5.2 protocols, or an ISDN agent attached to an AN. The following list contains the possible values for the EFA as defined by V5:
全民教育由V5标准定义。它标识一个C路径，它是一个13位的数字，范围从0到8191（十进制）。EFA唯一标识五个V5.2协议之一，或连接到An的ISDN代理。以下列表包含V5定义的EFA的可能值：
Definition Value
---------- ------
ISDN_PROTOCOL 0 - 8175
PSTN_PROTOCOL 8176
CONTROL_PROTOCOL 8177
BCC_PROTOCOL 8178
PROT_PROTOCOL 8179
LINK_CONTROL_PROTOCOL 8180
RESERVED 8181 - 8191
Definition Value
---------- ------
ISDN_PROTOCOL 0 - 8175
PSTN_PROTOCOL 8176
CONTROL_PROTOCOL 8177
BCC_PROTOCOL 8178
PROT_PROTOCOL 8179
LINK_CONTROL_PROTOCOL 8180
RESERVED 8181 - 8191
For MPH messages which do not use DLCI and EFA, SAPI, TEI and EFA SHALL be set to ZERO and SHALL be ignored by the receiver. For all other messages, the DLCI SHALL be set as defined in the V5.2 standard [2].
对于不使用DLCI和EFA的MPH消息，SAPI、TEI和EFA应设置为零，且接收器应忽略。对于所有其他消息，应按照V5.2标准[2]中的定义设置DLCI。
The Interface Identifier SHALL follow the naming conventions for the Interface Identifier as defined below.
接口标识符应遵循以下定义的接口标识符命名约定。
The V5 standard demands that V5 System Management keep track of the states of all links on a V5 interface. To perform tasks like protection switching and bearer channel allocation on the V5 links, it is necessary that system management has the full picture of the signaling and bearer channels located on each link.
V5标准要求V5系统管理跟踪V5接口上所有链路的状态。为了在V5链路上执行保护切换和承载信道分配等任务，系统管理必须全面了解每个链路上的信令和承载信道。
The IUA protocol identifies C-channels by endpoints without a defined association with a specific link. Since no naming convention exists, there is no guarantee that a C-channel is actually located at the link it claims to be. Furthermore the V5 standard requires that the MGC receives reports of the status of all links, and it defines a link identification procedure to ensure that AN and LE are referencing the same link when they address a link with a Link Control Protocol message.
IUA协议通过端点识别C通道，而不需要定义与特定链路的关联。由于不存在命名约定，因此无法保证C通道实际位于其声称的链路上。此外，V5标准要求MGC接收所有链路状态的报告，并定义链路识别程序，以确保AN和LE在使用链路控制协议消息寻址链路时引用同一链路。
It would clearly be against the concept of V5.2 if there was no clear association between E1 links and channels. To solve this problem, a naming convention MUST be used for V5UA.
如果E1链路和信道之间没有明确的关联，这显然违背了V5.2的概念。为了解决这个问题，V5UA必须使用命名约定。
The format of the integer formatted Interface Identifier is shown below:
整数格式接口标识符的格式如下所示：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifier | Chnl ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Identifier | Chnl ID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Link Identifier - Identifier for an E1 link on the SG (27 bits). MUST be unique on the SG. This Link Identifier MUST match the Link Identifier used in the Link Management Messages defined later in this document.
链路标识符-SG上E1链路的标识符（27位）。在SG上必须是唯一的。此链接标识符必须与本文档后面定义的链接管理消息中使用的链接标识符匹配。
Chnl ID - Channel Identifier (5 bits). This is equal to the time-slot number of the addressed time slot. Possible values are 15, 16 and 31 representing the possible time slots for C-channels on a V5 interface. For Link Management Messages, the Chnl ID MUST be set to 0. All other values are reserved for future use.
Chnl ID-通道标识符（5位）。这等于已寻址时隙的时隙号。可能的值为15、16和31，表示V5接口上C通道的可能时隙。对于链接管理消息，Chnl ID必须设置为0。所有其他值保留供将来使用。
If used, the text formatted interface identifier SHALL be coded as the hex representation of the integer formatted interface identifier, written as a variable length string.
如果使用，文本格式的接口标识符应编码为整数格式接口标识符的十六进制表示，以可变长度字符串的形式写入。
Some primitives for the V5 interface boundaries are similar to the Q.921/Q.931 boundary primitive messages defined in IUA, but they need to be handled in a different way. Therefore it is neccessary to distinguish between these two message types by means of the Message Class parameter.
V5接口边界的一些原语类似于IUA中定义的Q.921/Q.931边界原语消息，但它们需要以不同的方式处理。因此，有必要通过消息类参数来区分这两种消息类型。
For all V5 interface boundary primitives, a new Message Class is introduced:
对于所有V5接口边界原语，引入了一个新的消息类：
14 V5 Boundary Primitives Transport Messages (V5PTM)
14 V5边界原语传输消息（V5PTM）
Other valid message classes for V5UA, which are also used by IUA, are:
IUA也使用的V5UA的其他有效消息类包括：
0 Management (MGMT) Message 3 ASP State Maintenance (ASPSM) Messages 4 ASP Traffic Maintenance (ASPTM) Messages
0管理（MGMT）消息3 ASP状态维护（ASPSM）消息4 ASP流量维护（ASPTM）消息
Q.921/Q.931 boundary primitive messages reused by V5.2 as V5PTM messages are:
被V5.2作为V5PTM消息重用的Q.921/Q.931边界原语消息如下：
1 Data Request Message (MGC -> SG)
2 Data Indication Message (SG -> MGC)
3 Unit Data Request Message (MGC -> SG)
4 Unit Data Indication Message (SG -> MGC)
5 Establish Request (MGC -> SG)
6 Establish Confirm (SG -> MGC)
7 Establish Indication (SG -> MGC)
8 Release Request (MGC -> SG)
9 Release Confirm (SG -> MGC)
10 Release Indication (SG -> MGC)
1 Data Request Message (MGC -> SG)
2 Data Indication Message (SG -> MGC)
3 Unit Data Request Message (MGC -> SG)
4 Unit Data Indication Message (SG -> MGC)
5 Establish Request (MGC -> SG)
6 Establish Confirm (SG -> MGC)
7 Establish Indication (SG -> MGC)
8 Release Request (MGC -> SG)
9 Release Confirm (SG -> MGC)
10 Release Indication (SG -> MGC)
All these messages are defined similarly to the QPTM messages. In addition, new boundary primitive messages are defined:
所有这些消息的定义与QPTM消息类似。此外，还定义了新的边界原语消息：
11 Link Status Start Reporting (MGC -> SG)
12 Link Status Stop Reporting (MGC -> SG)
13 Link Status Indication (SG -> MGC)
14 Sa-Bit Set Request (MGC -> SG)
15 Sa-Bit Set Confirm (SG -> MGC)
16 Sa-Bit Status Request (MGC -> SG)
17 Sa-Bit Status Indication (SG -> MGC)
18 Error Indication (SG -> MGC)
11 Link Status Start Reporting (MGC -> SG)
12 Link Status Stop Reporting (MGC -> SG)
13 Link Status Indication (SG -> MGC)
14 Sa-Bit Set Request (MGC -> SG)
15 Sa-Bit Set Confirm (SG -> MGC)
16 Sa-Bit Status Request (MGC -> SG)
17 Sa-Bit Status Indication (SG -> MGC)
18 Error Indication (SG -> MGC)
The Link Status Messages are used between V5 System Management on the MGC and the L1 FSM on the SG to track the status of a particular E1 link. This is required whether or not the E1 link carries C-channels.
链路状态消息用于MGC上的V5系统管理和SG上的L1 FSM之间，以跟踪特定E1链路的状态。无论E1链路是否承载C信道，这都是必需的。
All Link Status Messages contain the V5UA Message Header. The Link Identifier portion of the Interface Identifier identifies the physical link on the SG addressed by the message. For all link status messages, the Chnl ID SHALL be set to '0' and SHALL be ignored by the receiver.
所有链路状态消息都包含V5UA消息头。接口标识符的链路标识符部分标识消息寻址的SG上的物理链路。对于所有链路状态消息，Chnl ID应设置为“0”，并应被接收器忽略。
The integer value used for the Link Identifier is of local significance only, and is coordinated between the SG and MGC. It MUST be unique for every V5 link on the SG.
用于链路标识符的整数值仅具有局部意义，并在SG和MGC之间协调。它对于SG上的每个V5链路都必须是唯一的。
As defined by the V5 standards, V5 System Management must know the status of the links on all active V5 interfaces. The Link Status Start Reporting Message is used by V5 System Management on the MGC to request that the L1 FSM on the SG starts reporting the status of a particular link.
根据V5标准的定义，V5系统管理必须知道所有活动V5接口上链路的状态。MGC上的V5系统管理使用链路状态开始报告消息请求SG上的L1 FSM开始报告特定链路的状态。
V5 system management SHALL send this Message on interface activation for all links on the interface. The SG SHALL respond immediately to this request with a Link Status Indication message, and it SHALL then send a Link Status Indication message on all subsequent changes of the link status. Since the SG has no other way to determine whether a link is on an active interface or not, this message SHALL always be sent on interface startup.
V5系统管理应在接口上所有链路的接口激活时发送此消息。SG应立即用链路状态指示消息响应该请求，然后发送链路状态指示消息，说明链路状态的所有后续变化。由于SG没有其他方法来确定链路是否在活动接口上，因此该消息应始终在接口启动时发送。
If the L1 FSM in the SG receives a Link Status Start Reporting Message for a link that is already active (the link status is reported to System Management), the SG SHALL immediately report the actual status of this link by sending a Link Status Indication Message. The SG SHALL then proceed with the automatic link status reporting as described above.
如果SG中的L1 FSM收到已激活链路的链路状态开始报告消息（链路状态报告给系统管理），则SG应通过发送链路状态指示消息立即报告该链路的实际状态。然后，SG应继续进行上述自动链路状态报告。
To stop this reporting of the status of a link, e.g., at interface deactivation, System Management sends a Link Status Stop Reporting Message to the L1 FSM. The SG will then immediately stop reporting the status of the particular link and will assume the link to be out of service. It MUST NOT respond in any way to this message.
为了停止链路状态的报告，例如，在接口停用时，系统管理向L1 FSM发送链路状态停止报告消息。然后，SG将立即停止报告特定链路的状态，并假定链路已停止运行。它不得以任何方式响应此消息。
Since there is no other way for the SG to know that an interface has been deactivated, this message SHALL be sent on interface deactivation for all links on the interface. On reception of this message, the SG SHALL take L2 down on this link.
由于SG没有其他方式知道接口已停用，因此该消息应在接口上所有链路的接口停用时发送。收到此消息后，SG应在该链路上取下L2。
If the L1 FSM in the SG receives a Link Status Stop Reporting Message for a link that is not active (the link status is not reported to System Management), the SG SHALL ignore the message.
如果SG中的L1 FSM收到未激活链路的链路状态停止报告消息（链路状态未报告给系统管理），则SG应忽略该消息。
The Link Status Start/Stop Reporting Messages contain the common message header followed by the V5UA message header. They do not contain any additional parameters.
链路状态开始/停止报告消息包含公共消息头，后跟V5UA消息头。它们不包含任何附加参数。
The Link Status Indication Message is used by L1 FSM in the SG in response to a Link Status Start Reporting Message to indicate the status of the particular link. After a Link Status Start Reporting Message has been received by the L1 FSM, it SHALL automatically send a Link Status Indication Message every time the status of the particular link changes. It SHALL not stop this reporting until it receives a Link Status Stop Report Message from System Management.
链路状态指示消息由SG中的L1 FSM用于响应链路状态开始报告消息以指示特定链路的状态。L1 FSM收到链路状态开始报告消息后，每次特定链路的状态改变时，应自动发送链路状态指示消息。在收到来自系统管理的链路状态停止报告消息之前，不得停止该报告。
The Link Status Indication Message contains the common message header followed by the V5UA message header. In addition, it contains the following link status parameter:
链路状态指示消息包含公共消息头，后跟V5UA消息头。此外，它还包含以下链接状态参数：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x82) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x82) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Link Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The valid values for Link Status are shown in the following table:
链接状态的有效值如下表所示：
Define Value Description
定义值描述
OPERATIONAL 0x0 Link operational NON-OPERATIONAL 0x1 Link not operational
运行0x0链路运行非运行0x1链路不运行
4.5. Sa-Bit Messages (Set Request, Set Confirm, Status Request, Status Indication)
4.5. Sa位消息（设置请求、设置确认、状态请求、状态指示）
The Sa-Bit Messages are used between V5 System Management in the MGC and the L1 FSM in the SG to set and read the status of Sa bits on the E1 links. For V5, it is only required to set and read the status of the Sa7 bit that is used for the Link Identification procedure as described by the V5 standards [3].
Sa位消息用于MGC中的V5系统管理和SG中的L1 FSM之间，以设置和读取E1链路上Sa位的状态。对于V5，只需设置和读取用于V5标准所述链路识别过程的Sa7位的状态[3]。
All Sa-Bit Messages SHALL contain the V5UA message header. The Link Identifier portion of the Interface Identifier identifies the physical link on the SG addressed by the message. For all link status messages, the Chnl ID SHALL be set to '0' and SHALL be ignored by the receiver.
所有Sa位消息应包含V5UA消息头。接口标识符的链路标识符部分标识消息寻址的SG上的物理链路。对于所有链路状态消息，Chnl ID应设置为“0”，并应被接收器忽略。
The Link Identifier MUST be the same as used in the Interface Identifier to identify on which link a C-channel is located.
链路标识符必须与接口标识符中使用的相同，以标识C通道位于哪个链路上。
The Sa-Bit Set Request message is used to set the value of the specified Sa-Bit on the defined link. The value of the Sa7 bit in normal operation is ONE. For the Link Identification procedure, it is set to ZERO.
Sa位设置请求消息用于设置定义链接上指定Sa位的值。正常操作中Sa7位的值为1。对于链路识别程序，将其设置为零。
The Sa-Bit Set Request message for the Sa7 bit with Bit Value ZERO corresponds to the V5 defined primitive MPH-ID. The Sa-Bit Set Request message for the Sa7 bit with Bit Value ONE corresponds to the V5 defined primitive MPH-NOR.
位值为零的Sa7位的Sa位设置请求消息对应于V5定义的原语MPH-ID。位值为1的Sa7位的Sa位设置请求消息对应于V5定义的原语MPH-NOR。
The SG MUST answer a Sa-Bit Set Request message with a Sa-Bit Set Confirm message when the setting of the bit is complete. This message does not correspond to a V5 defined primitive.
当位设置完成时，SG必须用Sa位设置确认消息回答Sa位设置请求消息。此消息与V5定义的原语不对应。
The Sa-Bit Status Request message is used by system management to request the status of the specified Sa-Bit on the defined link from L1 FSM. The Sa-Bit Status Request message for the Sa7 bit corresponds to the V5 defined primitive MPH-IDR.
系统管理使用Sa位状态请求消息从L1 FSM请求定义链路上指定Sa位的状态。Sa7位的Sa位状态请求消息对应于V5定义的原语MPH-IDR。
L1 FSM answers the Sa-Bit Status request message by a Sa-Bit Status Indication message in which the current setting of the bit will be reported. The Sa-Bit Status Indication message for the Sa7 bit with Bit Value ZERO corresponds to the V5 defined primitive MPH-IDI. The Sa-Bit Status Indication message for the Sa7 bit with Bit Value ONE corresponds to the V5 defined primitive MPH-Elg.
L1 FSM通过Sa位状态指示消息回答Sa位状态请求消息，其中将报告位的当前设置。位值为零的Sa7位的Sa位状态指示消息对应于V5定义的原语MPH-IDI。位值为1的Sa7位的Sa位状态指示消息对应于V5定义的原语MPH Elg。
All Sa-Bit Messages contain the following additional parameter:
所有Sa位消息都包含以下附加参数：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x83) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BIT ID | Bit Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x83) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| BIT ID | Bit Value |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The valid values for Bit Value are shown in the following table:
位值的有效值如下表所示：
Define Value Description
定义值描述
ZERO 0x0 Bit value ZERO ONE 0x1 Bit value ONE
0 0x0位值0 1 0x1位值1
The valid value for BIT ID is shown in the following table:
位ID的有效值如下表所示：
Define Value Description
定义值描述
Sa7 0x7 Addresses the Sa7 bit
Sa7 0x7寻址Sa7位
There are no other valid values for V5UA. All other values are reserved for future use.
V5UA没有其他有效值。所有其他值保留供将来使用。
For the Sa-Bit Status Request and Set Confirm messages, the BIT Value SHALL be set to '0' by the sender and SHALL be ignored by the receiver.
对于Sa位状态请求和设置确认消息，发送方应将位值设置为“0”，接收方应忽略该值。
The Error Indication Message is used between the V5 stack on the SG and the V5 System Management in the MGC to indicate an error condition at the SG.
错误指示消息用于SG上的V5堆栈和MGC中的V5系统管理之间，以指示SG处的错误状况。
The only valid reason for the Error Indication Message is Overload. The SG SHOULD issue such an Error Indication with reason Overload for a C-channel if it is not able to process all Layer 3 messages on this C-channel in a timely manner (overload condition of the C-channel).
出现错误指示消息的唯一有效原因是过载。如果SG不能及时处理该C通道上的所有第3层消息（C通道过载情况），则应发出此类错误指示，并说明C通道过载的原因。
The Error Indication message SHALL contain the V5UA message header.
错误指示消息应包含V5UA消息头。
The Interface Identifier indicates the affected C-channel. SAPI, TEI and EFA SHALL be set to '0' and SHALL be ignored by the receiver.
接口标识符指示受影响的C通道。SAPI、TEI和EFA应设置为“0”，并应被接收器忽略。
The Error Indication message contains the following additional parameter:
错误指示消息包含以下附加参数：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x84) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Reason |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x84) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Reason |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The valid values for Error Reason are shown in the following table:
错误原因的有效值如下表所示：
Define Value Description
定义值描述
OVERLOAD 0x1 C-channel is in overload state
过载0x1 C通道处于过载状态
There are no other valid values for V5UA. All other values are reserved for future use.
V5UA没有其他有效值。所有其他值保留供将来使用。
The normal way to handle a V5 Layer 1 failure is described in the V5 standards[2,3] as follows:
V5标准[2,3]中描述了处理V5第1层故障的正常方法，如下所示：
- The L1 FSM detects the V5 Layer 1 failure. It reports this to V5 System management by sending a MPH-DI primitive for the affected link.
- L1 FSM检测到V5第1层故障。它通过发送受影响链路的MPH-DI原语向V5系统管理层报告此情况。
- V5 System management notifies V5 Layer 2 of the V5 Layer 1 outage by sending a MPH-Layer_1 Failure Ind primitive.
- V5系统管理通过发送MPH-Layer_1 Failure Ind原语通知V5第2层V5第1层停机。
Since V5 Layer1/2 and V5 System Management are no longer co-located in the backhaul architecture, it does not make sense to notify V5 Layer 2 about V5 Layer 1 failure via V5 system management. Instead, V5 Layer 2 SHALL be notified directly by V5 Layer 1 on the SG. V5
由于V5 Layer1/2和V5系统管理不再位于回程体系结构中，因此通过V5系统管理将V5第1层故障通知V5第2层是没有意义的。相反，SG上的V5第1层应直接通知V5第2层。V5
Layer 1 SHALL report the outage to V5 system management by sending a Link Status Indication message with status NON-OPERATIONAL, corresponding to an MPH-DI primitive as defined by the V5.2 standard. V5 system management SHALL NOT send an MPH-Layer_1 Failure Ind primitive to V5 Layer 2 in response to this message.
第1层应通过发送链路状态指示消息（状态为非运行）向V5系统管理层报告中断情况，该消息对应于V5.2标准定义的MPH-DI原语。V5系统管理不得向V5第2层发送MPH-Layer_1故障Ind原语以响应此消息。
If SCTP failure is detected or the heartbeat is lost, the following procedure SHALL be performed:
如果检测到SCTP故障或心跳信号丢失，应执行以下程序：
When loss of V5UA peer is reported to the V5UA layer, the ASP SHALL behave as if it had received a Link Status Indication (non-operational) for all links on this SG.
当向V5UA层报告V5UA对等点丢失时，ASP的行为应与收到该SG上所有链路的链路状态指示（非运行）一样。
The ASP SHALL attempt to re-establish the connection continuously. When the connection is re-established, the ASP SHALL send a Link Status Start Reporting message to the SG for all links on active V5 interfaces on the SG.
ASP应尝试连续重新建立连接。当重新建立连接时，ASP应向SG发送一条链路状态开始报告消息，用于SG上活动V5接口上的所有链路。
An example for the message flow for re-establishment of the connection is shown below for one active link on the SG:
对于SG上的一个活动链路，用于重新建立连接的消息流示例如下所示：
ASP SG
ASP SG
| |
| -------- Link Status Start Reporting ---------> |
| |
| <------ Link Status Ind (operational) --------- |
| |
| |
| -------- Link Status Start Reporting ---------> |
| |
| <------ Link Status Ind (operational) --------- |
| |
If the association can be re-established before the V5UA layer is notified, communication SHALL proceed as usual and no other action SHALL be taken by the ASP.
如果在通知V5UA层之前可以重新建立关联，则通信应照常进行，ASP不得采取其他行动。
If the SG detects an overload condition on a C-channel, it SHOULD indicate this by sending an Error Indication message, with the reason Overload to the MGC. The MGC SHOULD then take appropriate actions to clear this overload condition.
如果SG在C通道上检测到过载情况，则应通过向MGC发送错误指示消息来指示过载原因。然后，MGC应采取适当措施清除该过载情况。
The SG SHALL resend the Error Indication message with the reason Overload as long as the overload condition persists. An interval of 120 seconds for resend of this message is RECOMMENDED.
只要过载情况持续存在，SG应重新发送带有过载原因的错误指示消息。建议每隔120秒重新发送此消息。
The Link Identification Procedures themselves are described by the V5.2 standard [3].
链路识别程序本身由V5.2标准[3]描述。
A message flow example for an LE initiated Link Identification procedure over V5UA is shown below. An active association between ASP and SG is established prior to the following message flows, and the V5 interface is already in service:
V5UA上LE发起的链路标识过程的消息流示例如下所示。ASP和SG之间的活动关联在以下消息流之前建立，并且V5接口已在使用中：
ASP SG
ASP SG
| |
| ------ Data Request (LnkCtrl: FE-IDReq) ------> |
| <-- Data Indication (LnkCtrl Ack: FE-IDReq) --- |
| |
| <---- Data Indication (LnkCtrl: FE-IDAck) ----- |
| ---- Data Request (LnkCtrl Ack: FE-IDAck) ----> |
| |
| ------ Sa-Bit Status Request ( Sa7 ) ---------> |
| <--- Sa-Bit Status Indication ( Sa7, ZERO ) --- |
| |
| ------- Data Request (LnkCtrl: FE-IDRel) -----> |
| <--- Data Indication (LnkCtrl Ack: FE-IDRel) -- |
| |
| |
| ------ Data Request (LnkCtrl: FE-IDReq) ------> |
| <-- Data Indication (LnkCtrl Ack: FE-IDReq) --- |
| |
| <---- Data Indication (LnkCtrl: FE-IDAck) ----- |
| ---- Data Request (LnkCtrl Ack: FE-IDAck) ----> |
| |
| ------ Sa-Bit Status Request ( Sa7 ) ---------> |
| <--- Sa-Bit Status Indication ( Sa7, ZERO ) --- |
| |
| ------- Data Request (LnkCtrl: FE-IDRel) -----> |
| <--- Data Indication (LnkCtrl Ack: FE-IDRel) -- |
| |
The next example also shows a Link Identification procedure, but this time it is initiated by the AN. Again, the ASP association and the V5 interface are already in service:
下一个示例还显示了链路标识过程，但这次它是由AN启动的。同样，ASP关联和V5接口已经投入使用：
ASP SG
ASP SG
| |
| <---- Data Indication (LnkCtrl: FE-IDReq) ----- |
| -- Data Request (LnkCtrl Ack: FE-IDReq) ------> |
| |
| ---------- Sa-Bit Set Req ( Sa7, ZERO ) ------> |
| <--------- Sa-Bit Set Conf (Sa7) -------------- |
| |
| ------- Data Request (LnkCtrl: FE-IDAck) -----> |
| <-- Data Indication (LnkCtrl Ack: FE-IDAck) --- |
| |
| <---- Data Indication (LnkCtrl: FE-IDRel) ----- |
| ---- Data Request (LnkCtrl Ack: FE-IDRel) ----> |
| |
| ------------ Sa-Bit Set Req ( Sa7, ONE ) -----> |
| <----------- Sa-Bit Set Conf (Sa 7) ----------- |
| |
| |
| <---- Data Indication (LnkCtrl: FE-IDReq) ----- |
| -- Data Request (LnkCtrl Ack: FE-IDReq) ------> |
| |
| ---------- Sa-Bit Set Req ( Sa7, ZERO ) ------> |
| <--------- Sa-Bit Set Conf (Sa7) -------------- |
| |
| ------- Data Request (LnkCtrl: FE-IDAck) -----> |
| <-- Data Indication (LnkCtrl Ack: FE-IDAck) --- |
| |
| <---- Data Indication (LnkCtrl: FE-IDRel) ----- |
| ---- Data Request (LnkCtrl Ack: FE-IDRel) ----> |
| |
| ------------ Sa-Bit Set Req ( Sa7, ONE ) -----> |
| <----------- Sa-Bit Set Conf (Sa 7) ----------- |
| |
The security considerations discussed for the 'Security Considerations for SIGTRAN Protocols' [5] document apply to this document.
“SIGTRAN协议的安全注意事项”[5]文件中讨论的安全注意事项适用于本文件。
IANA has assigned a V5UA value for the Payload Protocol Identifier in the SCTP DATA chunk. The following SCTP Payload Protocol identifier is registered:
IANA为SCTP数据块中的有效负载协议标识符分配了V5UA值。已注册以下SCTP有效负载协议标识符：
V5UA "6"
V5UA“6”
The SCTP Payload Protocol identifier value "6" SHOULD be included in each SCTP DATA chunk to indicate that the SCTP is carrying the V5UA protocol. The value "0" (unspecified) is also allowed but any other values MUST not be used. 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值“6”应包含在每个SCTP数据块中，以指示SCTP正在承载V5UA协议。也允许使用值“0”（未指定），但不得使用任何其他值。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。
IANA has registered SCTP (and UDP/TCP) Port Number 5675 for V5UA.
IANA已为V5UA注册了SCTP（和UDP/TCP）端口号5675。
The authors would like to thank Fahir Ergincan, Milos Pujic, Graeme Currie, Berthold Jaekle, Ken Morneault and Lyndon Ong for their valuable comments and suggestions.
作者要感谢Fahir Erginga、Milos Pujic、Graeme Currie、Berthold Jaekle、Ken Morneault和Lyndon Ong提出的宝贵意见和建议。
[1] Morneault, K., Rengasami, S., Kalla, M. and G. Sidebottom, "ISDN Q.921-User Adaptation Layer", RFC 3057, February 2001.
[1] Morneault，K.，Rengasami，S.，Kalla，M.和G.Sidebottom，“ISDN Q.921-用户适配层”，RFC 3057，2001年2月。
[2] ETSI EN 300 324-1 (1999): V interfaces at the digital Local Exchange (LE); V5.1 interface for the support of Access Network (AN); Part 1: V5.1 interface specification.
[2] ETSI EN 300 324-1（1999）：数字本地交换机（LE）的V接口；支持接入网（AN）的V5.1接口；第1部分：V5.1接口规范。
[3] ETSI EN 300 347-1 (1999): V interfaces at the digital Local Exchange (LE); V5.2 interface for the support of Access Network (AN); Part 1: V5.2 interface specification.
[3] ETSI EN 300 347-1（1999）：数字本地交换机（LE）的V接口；支持接入网（AN）的V5.2接口；第1部分：V5.2接口规范。
[4] ETSI ETS 300 125 (1991) : DSS1 protocol; User-Network interface data link layer specification; (Standard is based on : ITU Q.920, Q.921).
[4] ETSI ETS 300 125（1991）：DSS1协议；用户网络接口数据链路层规范；（标准基于：ITU Q.920，Q.921）。
[5] Loughney, J., Tuexen, M., Ed. and J. Pastor-Balbas, "Security Considerations for Signaling Transport (SIGTRAN) Protocols", RFC 3788, May 2004.
[5] Loughney，J.，Tuexen，M.，Ed.和J.Pastor Balbas，“信号传输（SIGTRAN）协议的安全考虑”，RFC 3788，2004年5月。
[6] 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.
[6] 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。
[7] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997.
[7] Bradner，S.，“RFC中用于表示需求水平的关键词”，BCP 14，RFC 2119，1997年3月。
Dr. Eva Weilandt Conti Temic microelectronic GmbH An der B31 88090 Immenstaad Germany
Eva Weilandt Conti Temic microelectronic GmbH博士，德国伊曼斯塔B31 88090
Phone: +49 7545 8-2917
EMail: eva.weilandt@temic.com
Phone: +49 7545 8-2917
EMail: eva.weilandt@temic.com
Sanjay Rao Nortel Networks 35 Davis Drive Research Triangle Park, NC 27709 USA
Sanjay Rao Nortel Networks 35 Davis Drive Research Triangle Park，美国北卡罗来纳州27709
Phone: +1-919-991-2251
EMail: rsanjay@nortelnetworks.com
Phone: +1-919-991-2251
EMail: rsanjay@nortelnetworks.com
Neeraj Khanchandani Nortel Networks 35 Davis Drive Research Triangle Park, NC 27709 USA
Neeraj Khanchandani北电网络美国北卡罗来纳州戴维斯大道研究三角公园35号，邮编27709
Phone: +1-919-991-2274
EMail: neerajk@nortelnetworks.com
Phone: +1-919-991-2274
EMail: neerajk@nortelnetworks.com
Copyright (C) The Internet Society (2004). All Rights Reserved.
版权所有（C）互联网协会（2004年）。版权所有。
Copyright (C) The Internet Society (2004). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights.
版权所有（C）互联网协会（2004年）。本文件受BCP 78中包含的权利、许可和限制的约束，除其中规定外，作者保留其所有权利。
This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
本文件及其包含的信息是按“原样”提供的，贡献者、他/她所代表或赞助的组织（如有）、互联网协会和互联网工程任务组不承担任何明示或暗示的担保，包括但不限于任何保证，即使用本文中的信息不会侵犯任何权利，或对适销性或特定用途适用性的任何默示保证。
Intellectual Property
知识产权
The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.
IETF对可能声称与本文件所述技术的实施或使用有关的任何知识产权或其他权利的有效性或范围，或此类权利下的任何许可可能或可能不可用的程度，不采取任何立场；它也不表示它已作出任何独立努力来确定任何此类权利。有关RFC文件中权利的程序信息，请参见BCP 78和BCP 79。
Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr.
向IETF秘书处披露的知识产权副本和任何许可证保证，或本规范实施者或用户试图获得使用此类专有权利的一般许可证或许可的结果，可从IETF在线知识产权存储库获取，网址为http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights that may cover technology that may be required to implement this standard. Please address the information to the IETF at ietf-ipr@ietf.org.
IETF邀请任何相关方提请其注意任何版权、专利或专利申请，或其他可能涵盖实施本标准所需技术的专有权利。请将信息发送至IETF的IETF-ipr@ietf.org.
Acknowledgement
确认
Funding for the RFC Editor function is currently provided by the Internet Society.
RFC编辑功能的资金目前由互联网协会提供。