Network Working Group A. Vainshtein
Request for Comments: 5287 ECI Telecom
Category: Standards Track Y(J). Stein
RAD Data Communications
August 2008
Network Working Group A. Vainshtein
Request for Comments: 5287 ECI Telecom
Category: Standards Track Y(J). Stein
RAD Data Communications
August 2008
Control Protocol Extensions for the Setup of Time-Division Multiplexing (TDM) Pseudowires in MPLS Networks
用于在MPLS网络中设置时分复用（TDM）伪线的控制协议扩展
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。
Abstract
摘要
This document defines extension to the Pseudowire Emulation Edge-to-Edge (PWE3) control protocol RFC 4447 and PWE3 IANA allocations RFC 4446 required for the setup of Time-Division Multiplexing (TDM) pseudowires in MPLS networks.
本文档定义了在MPLS网络中设置时分复用（TDM）伪线所需的伪线仿真边到边（PWE3）控制协议RFC 4447和PWE3 IANA分配RFC 4446的扩展。
Table of Contents
目录
1. Introduction ....................................................2
2. PW FEC for Setup of TDM PWs .....................................2
3. Interface Parameters for TDM PWs ................................4
3.1. Overview ...................................................4
3.2. CEP/TDM Payload Bytes ......................................5
3.3. CEP/TDM Bit-Rate (0x07) ....................................5
3.4. Number of TDMoIP AAL1 Cells per Packet .....................6
3.5. TDMoIP AAL1 Mode ...........................................7
3.6. TDMoIP AAL2 Options ........................................7
3.7. Fragmentation Indicator ....................................8
3.8. TDM Options ................................................8
4. Extending CESoPSN Basic NxDS0 Services with CE
Application Signaling ..........................................11
5. LDP Status Codes ...............................................12
6. Using the PW Status TLV ........................................13
7. IANA Considerations ............................................13
8. Security Considerations ........................................14
9. Acknowledgements ...............................................14
10. References ....................................................14
10.1. Normative References .....................................14
10.2. Informative References ...................................14
1. Introduction ....................................................2
2. PW FEC for Setup of TDM PWs .....................................2
3. Interface Parameters for TDM PWs ................................4
3.1. Overview ...................................................4
3.2. CEP/TDM Payload Bytes ......................................5
3.3. CEP/TDM Bit-Rate (0x07) ....................................5
3.4. Number of TDMoIP AAL1 Cells per Packet .....................6
3.5. TDMoIP AAL1 Mode ...........................................7
3.6. TDMoIP AAL2 Options ........................................7
3.7. Fragmentation Indicator ....................................8
3.8. TDM Options ................................................8
4. Extending CESoPSN Basic NxDS0 Services with CE
Application Signaling ..........................................11
5. LDP Status Codes ...............................................12
6. Using the PW Status TLV ........................................13
7. IANA Considerations ............................................13
8. Security Considerations ........................................14
9. Acknowledgements ...............................................14
10. References ....................................................14
10.1. Normative References .....................................14
10.2. Informative References ...................................14
This document defines an extension to the PWE3 control protocol [RFC4447] and PWE3 IANA allocations [RFC4446] required for the setup of TDM pseudowires in MPLS networks.
本文件定义了在MPLS网络中设置TDM伪线所需的PWE3控制协议[RFC4447]和PWE3 IANA分配[RFC4446]的扩展。
Structure-agnostic TDM pseudowires have been specified in [RFC4553], and structure-aware ones have been specified in [RFC5086] and [RFC5087].
[RFC4553]中规定了与结构无关的TDM伪线，而[RFC5086]和[RFC5087]中规定了与结构相关的伪线。
[RFC4447] defines extensions to the Label Distribution Protocol (LDP) [RFC5036] that are required to exchange PW labels for PWs emulating various Layer 2 services (Ethernet, Frame Relay (FR), Asynchronous Transfer Mode (ATM), High-Level Data Link Control (HDLC), etc.). The setup of TDM PWs requires both interpretation of the existing information elements of these extensions and exchange of additional information.
[RFC4447]定义了标签分发协议（LDP）[RFC5036]的扩展，这些扩展需要为模拟各种第2层服务（以太网、帧中继（FR）、异步传输模式（ATM）、高级数据链路控制（HDLC）等）的PW交换PW标签。TDM PWs的设置既需要解释这些扩展的现有信息元素，也需要交换附加信息。
The setup of TDM PWs using L2TPv3 will be defined in a separate document.
使用L2TPv3的TDM PWs设置将在单独的文件中定义。
The status of attachment circuits of TDM PWs can be exchanged between the terminating Provider Edges (PEs) using the PW Status mechanism defined in [RFC4447] without any changes. However, usage of this mechanism is NOT RECOMMENDED for TDM PWs since the indication of the status of the TDM attachment circuits is carried in-band in the data plane.
TDM PWs的连接电路的状态可以使用[RFC4447]中定义的PW状态机制在端接提供商边缘（PE）之间交换，无需任何更改。但是，由于TDM连接电路的状态指示在数据平面的频带内进行，因此不建议对TDM PWs使用该机制。
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。
[RFC4447] uses the LDP Label Mapping message [RFC5036] for advertising the FEC-to-PW Label binding, and defines two types of PW Forwarding Equivalence Classes (FECs) that can be used for this purpose:
[RFC4447]使用LDP标签映射消息[RFC5036]公布FEC到PW标签绑定，并定义两种类型的PW转发等价类（FEC），可用于此目的：
1. PWId FEC (FEC 128). This FEC contains:
1. PWId FEC（FEC 128）。本FEC包含：
a) PW type
a) PW型
b) Control bit (indicates presence of the control word)
b) 控制位（表示控制字的存在）
c) Group ID
c) 组ID
d) PW ID
d) PW ID
e) Interface parameters Sub-TLV
e) 接口参数子TLV
2. Generalized PW FEC (FEC 129). This FEC contains only:
2. 广义PW FEC（FEC 129）。本FEC仅包含：
a) PW type
a) PW型
b) Control bit
b) 控制位
c) Attachment Group Identifier (AGI), Source Attachment Individual Identifier (SAII), and Target Attachment Individual Identifier (TAII) that replace the PW ID
c) 替换PW ID的附件组标识符（AGI）、源附件个人标识符（SAII）和目标附件个人标识符（TAII）
The Group ID and the Interface Parameters are contained in separate TLVs, called the PW Grouping TLV and the Interface Parameters TLV.
组ID和接口参数包含在单独的TLV中，称为PW分组TLV和接口参数TLV。
Either of these types of PW FEC MAY be used for the setup of TDM PWs with the appropriate selection of PW types and interface parameters.
通过适当选择PW类型和接口参数，这些类型的PW FEC均可用于TDM PWs的设置。
The PW types for TDM PWs are allocated in [RFC4446] as follows:
TDM PWs的PW类型在[RFC4446]中分配如下：
o 0x0011 Structure-agnostic E1 over Packet [RFC4553]
o 0x0012 Structure-agnostic T1 (DS1) over Packet [RFC4553]
o 0x0013 Structure-agnostic E3 over Packet [RFC4553]
o 0x0014 Structure-agnostic T3 (DS3) over Packet [RFC4553]
o 0x0015 CESoPSN basic mode [RFC5086]
o 0x0016 TDMoIP AAL1 mode [RFC5087]
o 0x0017 CESoPSN TDM with CAS [RFC5086]
o 0x0018 TDMoIP AAL2 mode [RFC5087]
o 0x0011 Structure-agnostic E1 over Packet [RFC4553]
o 0x0012 Structure-agnostic T1 (DS1) over Packet [RFC4553]
o 0x0013 Structure-agnostic E3 over Packet [RFC4553]
o 0x0014 Structure-agnostic T3 (DS3) over Packet [RFC4553]
o 0x0015 CESoPSN basic mode [RFC5086]
o 0x0016 TDMoIP AAL1 mode [RFC5087]
o 0x0017 CESoPSN TDM with CAS [RFC5086]
o 0x0018 TDMoIP AAL2 mode [RFC5087]
The two endpoints MUST agree on the PW type, as both directions of the PW are required to be of the same type.
两个端点必须在PW类型上一致，因为PW的两个方向必须是同一类型。
The Control bit MUST always be set for TDM PWs since all TDM PW encapsulations always use a control word.
必须始终为TDM PW设置控制位，因为所有TDM PW封装始终使用控制字。
PW type 0x0012 MUST also be used for the setup of structure-agnostic TDM PWs between a pair of J1 attachment circuits (see [RFC4805]).
0x0012型PW还必须用于在一对J1连接电路之间设置结构无关的TDM PW（参见[RFC4805]）。
The interface parameters that are relevant for the setup of the TDM PWs are listed below.
与TDM PWs设置相关的接口参数如下所示。
-------------------------------------------------------------
| Interface Parameter | Sub-TLV ID | Length | Description |
|-----------------------|------------|--------|-------------|
| CEP/TDM Payload Bytes | 0x04 | 4 |Section 3.2 |
|-----------------------|------------|--------|-------------|
| CEP/TDM Bit-Rate | 0x07 | 6 |Section 3.3 |
|-----------------------|------------|--------|-------------|
| Number of TDMoIP AAL1 | 0x0E | 4 |Section 3.4 |
| Cells per Packet | | | |
|-----------------------|-------=----|--------|-------------|
| TDMoIP AAL1 Mode | 0x10 | 4 |Section 3.5 |
|-----------------------|------------|--------|-------------|
| TDMoIP AAL2 Options | 0x11 | 8 or |Section 3.6 |
| | | larger | |
| | |see note| |
|-----------------------|------------|--------|-------------|
| Fragmentation | 0x09 | 4 |Section 3.7 |
| Indicator | | | |
|-----------------------|------------|--------|-------------|
| TDM Options | 0x0B | 4, 8, |Section 3.8 |
| | | or 12 | |
-------------------------------------------------------------
-------------------------------------------------------------
| Interface Parameter | Sub-TLV ID | Length | Description |
|-----------------------|------------|--------|-------------|
| CEP/TDM Payload Bytes | 0x04 | 4 |Section 3.2 |
|-----------------------|------------|--------|-------------|
| CEP/TDM Bit-Rate | 0x07 | 6 |Section 3.3 |
|-----------------------|------------|--------|-------------|
| Number of TDMoIP AAL1 | 0x0E | 4 |Section 3.4 |
| Cells per Packet | | | |
|-----------------------|-------=----|--------|-------------|
| TDMoIP AAL1 Mode | 0x10 | 4 |Section 3.5 |
|-----------------------|------------|--------|-------------|
| TDMoIP AAL2 Options | 0x11 | 8 or |Section 3.6 |
| | | larger | |
| | |see note| |
|-----------------------|------------|--------|-------------|
| Fragmentation | 0x09 | 4 |Section 3.7 |
| Indicator | | | |
|-----------------------|------------|--------|-------------|
| TDM Options | 0x0B | 4, 8, |Section 3.8 |
| | | or 12 | |
-------------------------------------------------------------
If not explicitly indicated otherwise in the appropriate description, the value of the interface parameter is interpreted as an unsigned integer of the appropriate size (16 or 32 bits).
如果在适当的描述中没有明确指出，接口参数的值将被解释为适当大小（16或32位）的无符号整数。
Note: The length of basic TDMoIP AAL2 Options interface parameter is 8 bytes, and when the optional Channel ID (CID) mapping bases field is used, there is one additional byte for each trunk transported. Thus, if 1 trunk is being supported, this message occupies 9 bytes. Since there can be no more than 248 CIDs in a given PW, this can never exceed 256 (this when each channel comes from a different trunk). 248 channels translates to less than 9 E1s, and so, for this case, the length is
注意：基本TDMoIP AAL2 Options接口参数的长度为8字节，当使用可选通道ID（CID）映射基字段时，每个传输的中继线都有一个额外的字节。因此，如果支持1个中继，则此消息将占用9个字节。由于给定PW中最多只能有248个CID，因此永远不能超过256个（当每个通道来自不同的主干时）。248个通道转换为小于9个E1，因此，在这种情况下，长度为
no more than 17 bytes. A single PE is not required to support more than 10 AAL2 PWs (i.e., up to 2480 individual channels, which is more than carried by a fully populated STM1). Thus, the memory required to store all the AAL2 mapping information is typically between 80 and 170 bytes per PE.
不超过17个字节。单个PE不需要支持10个以上的AAL2 PW（即，最多2480个单独通道，这比完全填充的STM1承载的通道多）。因此，存储所有AAL2映射信息所需的内存通常在每个PE 80到170字节之间。
This parameter is used for the setup of all SAToP and CESoPSN PWs (i.e., PW types 0x0011, 0x0012, 0x0013, 0x0014, 0x0015, and 0x0017) and employs the following semantics:
此参数用于设置所有SAToP和CESoPSN PW（即PW类型0x0011、0x0012、0x0013、0x0014、0x0015和0x0017），并采用以下语义：
1. The two endpoints of a TDM PW MUST agree on the same value of this parameter for the PW to be set up successfully.
1. TDM PW的两个端点必须在此参数的相同值上一致，才能成功设置PW。
2. Presence of this parameter in the PWId FEC or in the Interface Parameters Field TLV is OPTIONAL. If this parameter is omitted, default payload size defined for the corresponding service (see [RFC4553], [RFC5086]) MUST be assumed.
2. PWId FEC或接口参数字段TLV中是否存在此参数是可选的。如果省略此参数，则必须假定为相应服务定义的默认有效负载大小（请参阅[RFC4553]、[RFC5086]）。
3. For structure-agnostic emulation, any value consistent with the MTU of the underlying PSN MAY be specified.
3. 对于结构不可知仿真，可以指定与基础PSN的MTU一致的任何值。
4. For CESoPSN PWs:
4. 对于CESoPSN PWs：
a) The specified value P MUST be an integer multiple of N, where N is the number of timeslots in the attachment circuit.
a) 指定的值P必须是N的整数倍，其中N是连接回路中的时隙数。
b) For trunk-specific NxDS0 with CAS:
b) 对于具有CAS的中继特定NxDS0：
i) (P/N) MUST be an integer factor of the number of frames per corresponding trunk multiframe (i.e., 16 for an E1 trunk and 24 for a T1 or J1 trunk).
i) （P/N）必须是每个相应中继多帧的帧数的整数因子（即，E1中继16，T1或J1中继24）。
ii) The size of the signaling sub-structure is not accounted for in the specified value P.
ii）规定值P中未考虑信号子结构的尺寸。
5. This parameter MUST NOT be used for the setup of TDMoIP PWs (i.e., PWs with PW types 0x0016 and 0x0018).
5. 此参数不得用于设置TDMoIP PWs（即PW类型为0x0016和0x0018的PWs）。
This interface parameter represents the bit-rate of the TDM service in multiples of the "basic" 64 Kbit/s rate. Its usage for all types of TDM PWs assumes the following semantics:
此接口参数表示TDM服务的比特率，单位为“基本”64 Kbit/s速率的倍数。它对所有类型的TDM PWs的使用假设以下语义：
1. This interface parameter MAY be omitted if the attachment circuit bit-rate can be unambiguously derived from the PW type (i.e., for structure-agnostic emulation of E1, E3, and T3 circuits). If this value is omitted for the structure-agnostic emulation of T1 PW type, the basic emulation mode MUST be assumed.
1. 如果附件电路比特率可以明确地从PW类型导出（即，对于E1、E3和T3电路的结构不可知仿真），则可以省略该接口参数。如果对于T1 PW类型的结构不可知仿真忽略此值，则必须假定基本仿真模式。
2. If present, only the following values MUST be specified for structure-agnostic emulation (see [RFC4553]:
2. 如果存在，则必须仅为结构无关仿真指定以下值（请参见[RFC4553]：
a) Structure-agnostic E1 emulation - 32
a) 结构不可知E1仿真-32
b) Structure-agnostic T1 emulation:
b) 结构不可知T1仿真：
i) MUST be set to 24 in the basic emulation mode
i) 在基本仿真模式下必须设置为24
ii) MUST be set to 25 for the "Octet-aligned T1" emulation mode
ii）对于“八位字节对齐T1”仿真模式，必须设置为25
c) Structure-agnostic E3 emulation - 535
c) 结构不可知E3仿真-535
d) Structure-agnostic T3 emulation - 699
d) 结构不可知T3仿真-699
3. For all kinds of structure-aware emulation, this parameter MUST be set to N, where N is the number of DS0 channels in the corresponding attachment circuit.
3. 对于所有类型的结构感知仿真，此参数必须设置为N，其中N是相应连接电路中的DS0通道数。
Note: The value 24 does not represent the actual bit-rate of the T1 or J1 circuit (1,544 Mbit/s) in units of 64 kbit/s. The values mentioned above are used for convenience.
注：值24不代表T1或J1电路的实际比特率（1544 Mbit/s），单位为64 kbit/s。使用上述值是为了方便。
Note: A 4-byte space is reserved for this parameter for compatibility with [RFC4842].
注：为与[RFC4842]兼容，此参数保留了4字节的空间。
This parameter MAY be present for TDMoIP AAL1 mode PWs (PW type 0x0016) and specifies the number of 48-byte AAL1 PDUs per MPLS packet. Any values consistent with the MTU of the underlying PSN MAY be specified. If this parameter is not specified, it defaults to 1 PDU per packet for low bit-rates (CEP/TDM Bit-Rate less than or equal to 32), and to 5 for high bit-rates (CEP/TDM Bit-Rate of 535 or 699).
此参数可能适用于TDMoIP AAL1模式PWs（PW类型0x0016），并指定每个MPLS数据包48字节AAL1 PDU的数量。可以指定与基础PSN的MTU一致的任何值。如果未指定此参数，则对于低比特率（CEP/TDM比特率小于或等于32），默认为每个数据包1个PDU，对于高比特率（CEP/TDM比特率535或699），默认为5个PDU。
This parameter MAY be present for TDMoIP AAL1 mode PWs (PW type 0x0016) and specifies the AAL1 mode. If this parameter is not present, the AAL1 mode defaults to "structured". When specified, the values have the following significance:
此参数可能存在于TDMoIP AAL1模式PWs（PW类型0x0016）中，并指定AAL1模式。如果此参数不存在，AAL1模式默认为“结构化”。指定时，这些值具有以下意义：
0 - unstructured AAL1 2 - structured AAL1 3 - structured AAL1 with CAS
0-非结构化AAL1 2-结构化AAL1 3-带CAS的结构化AAL1
The two endpoints MUST agree on the TDMoIP AAL1 mode.
两个端点必须在TDMoIP AAL1模式上一致。
This parameter MUST be present for TDMoIP AAL2 mode PWs (PW type 0x0018) and has the following format:
对于TDMoIP AAL2模式PWs（PW类型0x0018），此参数必须存在，并且具有以下格式：
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x11 | Length | V | ENCODING |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Duration |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CID mapping bases |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x11 | Length | V | ENCODING |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Maximum Duration |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| CID mapping bases |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The fields in this parameter are defined as follows:
此参数中的字段定义如下：
V defines the Voice Activity Detection (VAD) capabilities. Its values have the following significance:
V定义了语音活动检测（VAD）功能。其值具有以下意义：
0 means that activity is only indicated by signaling. 1 means that voice activity detection is employed. 3 means this channel is always active. In particular, this channel may be used for timing recovery.
0表示活动仅通过信号指示。1表示采用语音活动检测。3表示此通道始终处于活动状态。特别地，该信道可用于定时恢复。
Encoding specifies native signal processing performed on the payload. When no native signal processing is performed (i.e., G.711 encoding), this field MUST be zero. Other specific values that can be used in this field are beyond the scope of this specification, but the two directions MUST match for the PW setup to succeed.
编码指定对有效负载执行的本机信号处理。当未执行本机信号处理（例如，711编码）时，该字段必须为零。此字段中可使用的其他特定值超出了本规范的范围，但两个方向必须匹配，PW设置才能成功。
Maximum Duration specifies the maximum time allowed for filling an AAL2 PDU, in units of 125 microseconds. For unencoded 64 kbps channels, this numerically equals the maximum number of bytes per PDU and MUST be less than 64. For other encoding parameters, larger values may be attained.
最大持续时间指定填充AAL2 PDU所允许的最大时间，单位为125微秒。对于未编码的64 kbps通道，该值在数字上等于每个PDU的最大字节数，并且必须小于64。对于其他编码参数，可以获得更大的值。
CID mapping bases is an OPTIONAL parameter; its existence and length are determined by the length field. If the mapping of AAL2 CID values to a physical interface and time slot is statically configured, or if AAL2 switching [Q.2630.1] is employed, this parameter MUST NOT appear. When it is present, and the channels belong to N physical interfaces (i.e., N E1s or T1s), it MUST be N bytes in length. Each byte represents a number to be subtracted from the CID to get the timeslot number for each physical interface. For example, if the CID mapping bases parameter consists of the bytes 20 and 60, this signifies that timeslot 1 of trunk 1 corresponds to CID 21, and timeslot 1 of trunk 2 is called 61.
CID映射基数是一个可选参数；它的存在和长度由长度场决定。如果AAL2 CID值到物理接口和时隙的映射是静态配置的，或者如果采用AAL2开关[Q.2630.1]，则不得出现此参数。如果存在，且通道属于N个物理接口（即N个E1s或T1s），则其长度必须为N字节。每个字节表示要从CID中减去的数字，以获得每个物理接口的时隙号。例如，如果CID mapping bases参数由字节20和60组成，则表示中继线1的时隙1对应于CID 21，中继线2的时隙1称为61。
This interface parameter is specified in [RFC4446], and its usage is explained in [RFC4623]. It MUST be omitted in the FEC of all TDM PWs excluding trunk-specific NxDS0 services with CAS using the CESoPSN encapsulation. In the case of these services, it MUST be present in the PW FEC if the payload size specified value P differs from Nx(number of frames per trunk multiframe).
此接口参数在[RFC4446]中指定，其用法在[RFC4623]中解释。在所有TDM PW的FEC中必须省略它，不包括使用CESoPSN封装的CAS的中继特定NxDS0服务。在这些服务的情况下，如果有效负载大小指定值P不同于Nx（每个中继多帧的帧数），则它必须存在于PW FEC中。
This is a new interface parameter. Its Interface Parameter ID (0x0B) has been assigned by IANA, and its format is shown in Figure 1 below:
这是一个新的接口参数。其接口参数ID（0x0B）已由IANA分配，其格式如下图1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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter ID | Length |R|D|F|X|SP |CAS| RSVD-1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0| PT | RSVD-2 | FREQ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter ID | Length |R|D|F|X|SP |CAS| RSVD-1 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0| PT | RSVD-2 | FREQ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1. Format of the TDM Options Interface Parameter Sub-TLV
图1。TDM选项接口参数子TLV的格式
The fields shown in this diagram are used as follows:
此图中显示的字段使用如下：
Parameter ID Identifies the TDM PW Options interface parameter, 0x0B.
参数ID标识TDM PW Options接口参数0x0B。
Length 4, 8, or 12 (see below).
长度4、8或12（见下文）。
R The RTP Header Usage bit: if set, indicates that the PW endpoint distributing this FEC expects to receive RTP header in the encapsulation. RTP header will be used only if both endpoints expect to receive it. If this bit is cleared, Length MUST be set to 4; otherwise, it MUST be either 8 or 12 (see below). If the peer PW endpoint cannot meet this requirement, the Label Mapping message containing the FEC in question MUST be rejected with the appropriate status code (see Section 4 below).
R RTP头使用位：如果设置，则表示分发此FEC的PW端点希望在封装中接收RTP头。只有当两个端点都希望接收RTP头时，才会使用RTP头。如果该位被清除，则长度必须设置为4；否则，它必须是8或12（见下文）。如果对等PW端点无法满足此要求，则必须使用适当的状态代码拒绝包含相关FEC的标签映射消息（请参阅下面的第4节）。
D The Differential timestamping Mode bit: if set, indicates that the PW endpoint distributing this FEC expects the peer to use Differential timestamping mode in the packets sent to it. If the peer PW endpoint cannot meet this requirement, the Label Mapping message containing the FEC in question MUST be rejected with the appropriate status code (see Section 4 below).
D差分时间戳模式位：如果设置，则表示分发此FEC的PW端点期望对等方在发送给它的数据包中使用差分时间戳模式。如果对等PW端点无法满足此要求，则必须使用适当的状态代码拒绝包含相关FEC的标签映射消息（请参阅下面的第4节）。
F, X Reserved for future extensions. MUST be cleared when distributed and MUST be ignored upon reception.
F、 X为将来的扩展保留。分发时必须清除，接收时必须忽略。
SP Encodes support for the CESoPSN signaling packets (see [RFC5086]):
SP编码对CESoPSN信令包的支持（参见[RFC5086]）：
o '00' for PWs that do not use signaling packets
o 对于不使用信令数据包的PW，“00”
o '01' for CESoPSN PWs carrying TDM data packets and expecting Customer Edge (CE) application signaling packets in a separate PW
o “01”用于承载TDM数据包且预期客户边缘（CE）应用程序信令包位于单独PW中的CESoPSN PW
o '10' for a PW carrying CE application signaling packets with the data packets in a separate PW
o “10”用于承载CE应用信令包的PW，数据包位于单独的PW中
o '11' for CESoPSN PWs carrying TDM data and CE application signaling on the same PW
o “11”用于在同一PW上承载TDM数据和CE应用信令的CESoPSN PW
CAS MUST be cleared for all types of TDM PWs excluding trunk-specific NxDS0 services with CAS. For these services, it encodes the trunk framing like the following:
必须为所有类型的TDM PW清除CAS，不包括带有CAS的中继特定NxDS0服务。对于这些服务，它对主干帧进行如下编码：
o '01' - an E1 trunk
o “01”-E1中继
o '10' - a T1/ESF trunk
o '10'-a T1/ESF中继线
o '11' - a T1 SF trunk
o '11'-a T1 SF中继线
RSVD-1 and RSVD-2 Reserved bits, which MUST be set to 0 by the PW endpoint distributing this FEC and MUST be ignored by the receiver.
RSVD-1和RSVD-2保留位，分配此FEC的PW端点必须将其设置为0，并且接收器必须忽略。
PT Indicates the value of Payload Type in the RTP header expected by the PW endpoint distributing this FEC. A value of 0 means that the PT value check will not be used for detecting malformed packets.
PT表示分发此FEC的PW端点所期望的RTP报头中的有效负载类型的值。值为0表示PT值检查将不用于检测格式错误的数据包。
FREQ Frequency of timestamping clock in units of 8 kHz.
时间戳时钟的频率，单位为8 kHz。
SSRC Indicates the value of the Synchronization source ID (SSRC ID) in the RTP header expected by the PW endpoint distributing this FEC. A value of 0 means that the SSRC ID value check will not be used for detecting misconnections. Alternatively, Length can be set to 8 in this case.
SSRC表示分发此FEC的PW端点所期望的RTP报头中的同步源ID（SSRC ID）的值。值为0表示SSRC ID值检查将不用于检测错误连接。或者，在这种情况下，长度可以设置为8。
Notes:
笔记：
1. This interface parameter MAY be omitted in the following cases:
1. 在下列情况下，可省略此接口参数：
a) SAToP PWs that do not use RTP header [RFC4553].
a) 不使用RTP标头的SAToP PWs[RFC4553]。
b) Basic CESoPSN NxDS0 services without CE application signaling [RFC5086].
b) 无CE应用信令的基本CESoPSN NxDS0服务[RFC5086]。
c) TDMoIP AAL1 mode 0 or 2 PWs that do not use RTP .
c) 不使用RTP的TDMoIP AAL1模式0或2 PW。
d) TDMoIP AAL2 PWs that do not relay CAS signaling and do not use RTP.
d) 不中继CAS信令且不使用RTP的TDMoIP AAL2 PW。
2. This interface parameter MUST be present in the following cases:
2. 在以下情况下，此接口参数必须存在：
a) All TDM PWs that use RTP headers.
a) 使用RTP头的所有TDM PW。
b) CESoPSN PWs that carry basic NxDS0 services and use CESoPSN signaling packets to carry CE application signaling. This case is discussed in detail in Section 4 below.
b) 承载基本NxDS0服务并使用CESoPSN信令包承载CE应用信令的CESoPSN PW。本案例将在下文第4节中详细讨论。
c) CESoPSN PWs that carry trunk-specific NxDS0 services with CAS.
c) CESoPSN PWs，通过CAS承载特定于中继的NxDS0服务。
d) TDMoIP AAL1 mode 1 PWs.
d) TDMoIP AAL1模式1 PWs。
e) TDMoIP AAL2 PWs that relay CAS signaling.
e) 中继CAS信令的TDMoIP AAL2 PWs。
3. If RTP header and possibly the Differential timestamping mode are used, the value of the Length field MUST be set to 8 or 12 in order to accommodate the Timestamping Clock Frequency and SSRC fields.
3. 如果使用RTP报头和可能的差分时间戳模式，则必须将长度字段的值设置为8或12，以适应时间戳时钟频率和SSRC字段。
4. Usage or non-usage of the RTP header MUST match for the two directions making up the TDM PW. However, it is possible to use the Differential timestamping mode in just one direction.
4. RTP头的使用或不使用必须与构成TDM PW的两个方向相匹配。然而，可以仅在一个方向上使用差分时间戳模式。
[RFC5086] states that basic NxDS0 services can be extended to carry CE application signaling (e.g., CAS) in special signaling packets carried in a separate PW.
[RFC5086]指出，可以扩展基本NxDS0服务，以在单独PW中承载的特殊信令包中承载CE应用信令（例如CAS）。
The following rules define the setup of matching pairs of CESoPSN PWs using the PW ID FEC and the extensions defined above:
以下规则使用PW ID FEC和上面定义的扩展来定义CESoPSN PW匹配对的设置：
1. The two PWs MUST:
1. 两个PW必须：
a) Have the same PW type.
a) 具有相同的PW类型。
b) Use the same setup method (i.e., either both use the PWId FEC, or both use the Generalized PW FEC).
b) 使用相同的设置方法（即，两者都使用PWId FEC，或都使用通用PW FEC）。
c) Have the same values of all the Interface Parameters listed in Section 3.1 above with the exception of the code point in the SP field of the TDM Options parameter:
c) 除TDM Options参数的SP字段中的代码点外，具有上述第3.1节中列出的所有接口参数的相同值：
i) For the PW carrying TDM data packets, the SP bits MUST be set to '01'.
i) 对于携带TDM数据包的PW，SP位必须设置为“01”。
ii) For the PW carrying the signaling packets, the SP bits MUST set to '10'.
ii）对于承载信令分组的PW，SP位必须设置为“10”。
2. If the PWId FEC has been used:
2. 如果已使用PWId FEC：
a) The value of PW ID for the CESoPSN PW carrying TDM data packets MUST be even.
a) 承载TDM数据包的CESoPSN PW的PW ID值必须为偶数。
b) The value of PW ID for the CESoPSN PW carrying CE application signaling MUST be the next (odd) value after the (even) PW ID of the CESoPSN PW carrying TDM data packets.
b) 承载CE应用信令的CESoPSN PW的PW ID值必须是承载TDM数据分组的CESoPSN PW的（偶数）PW ID之后的下一个（奇数）值。
When using the Generalized PW FEC for the setup of the two PWs, no specific rules for matching the two FECs are defined. Implementation-specific mechanisms MAY be employed to verify the proper matching of the TDM data PW with its associated CE signaling PW.
当使用通用PW FEC设置两个PW时，未定义匹配两个FEC的特定规则。可采用特定于实现的机制来验证TDM数据PW与其相关联的CE信令PW的适当匹配。
If one of the two associated PWs has been established and the other failed to be established, or for any reason fails after having been established, the established PW MUST be torn down.
如果两个相关PW中的一个已建立，而另一个未建立，或由于任何原因在建立后失败，则必须拆除已建立的PW。
In addition to the status codes defined in Sections 5.1 and 7.2 of [RFC4447], the following status codes defined in [RFC4446] MUST be used to indicate the reason of failure to establish a TDM PW:
除了[RFC4447]第5.1节和第7.2节中定义的状态代码外，[RFC4446]中定义的以下状态代码必须用于指示未能建立TDM PW的原因：
1. Incompatible bit-rate:
1. 不兼容比特率：
a) In the case of a mismatch of T1 encapsulation modes (basic vs. octet-aligned).
a) 在T1封装模式不匹配的情况下（基本与八位组对齐）。
b) In the case of a mismatch in the number of timeslots for NxDS0 basic services or trunk-specific NxDS0 services with CAS.
b) 如果NxDS0基本服务或特定于中继线的NxDS0服务与CAS的时隙数量不匹配。
2. CEP/TDM misconfiguration:
2. CEP/TDM配置错误：
a) In the case of a mismatch in the desired usage of RTP header.
a) 如果RTP报头的预期用途不匹配。
b) In the case of a mismatch of the desired Timestamping Clock Frequency.
b) 在期望时间戳时钟频率不匹配的情况下。
c) In the case of a mismatch of expected signaling packets behavior for basic CESoPSN NxDS0 services extended to carry CE application signaling in separate signaling packets.
c) 在基本CESoPSN NxDS0服务的预期信令分组行为不匹配的情况下，扩展以在单独的信令分组中承载CE应用信令。
d) In the case of trunk-specific NxDS0 services with CAS if the framing types of the trunks are different.
d) 对于具有CAS的特定于中继的NxDS0服务，如果中继的帧类型不同。
e) In the case of TDMoIP AAL1 PWs with different AAL1 modes specified by the endpoints.
e) 对于TDMoIP AAL1 PW，端点指定了不同的AAL1模式。
3. The generic misconfiguration error MAY be used to indicate any setup failure not covered above.
3. 一般配置错误可用于指示上述未涵盖的任何设置故障。
In cases 2a, 2b, 2c, and 2e above, the user MAY reconfigure the endpoints and attempt to set up the PW once again.
在上述情况2a、2b、2c和2e中，用户可重新配置端点并再次尝试设置PW。
In the case of 2d, the failure is fatal.
在2d的情况下，故障是致命的。
Note that setting of the Control bit (see Section 2 above) to zero MUST result in an LDP status of "Illegal C-Bit".
注意，将控制位（见上文第2节）设置为零必须导致LDP状态为“非法C位”。
The TDM PW control word carries status indications for both attachment circuits (L and M fields) and the PSN (R field) indication (see [RFC4553], [RFC5086], and [RFC5087]). Similar functionality is available via use of the PW Status TLV (see Section 5.4.2 of [RFC4447]). If the latter mechanism is employed, the signaling PE sends its peer a PW Status TLV for this PW, setting the appropriate bits (see Section 3.5 of [RFC4446]):
TDM PW控制字携带连接电路（L和M字段）和PSN（R字段）指示的状态指示（参见[RFC4553]、[RFC5086]和[RFC5087]）。通过使用PW状态TLV可获得类似功能（见[RFC4447]第5.4.2节）。如果采用后一种机制，信令PE向其对等方发送该PW的PW状态TLV，设置适当的位（参见[RFC4446]第3.5节）：
o Pseudowire Not Forwarding o Local Attachment Circuit (ingress) Receive Fault o Local Attachment Circuit (egress) Transmit Fault o Local PSN-facing PW (ingress) Receive Fault o Local PSN-facing PW (egress) Transmit Fault
o 伪线不转发o本地连接电路（入口）接收故障o本地连接电路（出口）传输故障o面向PW的本地PSN（入口）接收故障o面向PW的本地PSN（出口）传输故障
As long as the TDM PW interworking function is operational, usage of the Status TLV is NOT RECOMMENDED in order to avoid contention between status indications reported by the data and control plane. However, if the TDM PW interworking function (IWF) itself fails while the PWE3 control plane remains operational, a Status TLV with all of the above bits set SHOULD be sent.
只要TDM PW互通功能运行，不建议使用状态TLV，以避免数据和控制平面报告的状态指示之间的争用。但是，如果TDM PW互通功能（IWF）本身在PWE3控制平面保持工作状态时发生故障，则应发送设置了上述所有位的状态TLV。
Most of the IANA assignments required by this document are already listed in [RFC4446]. Additional assignments have been made for four Interface Parameter Sub-TLV types (see Section 3.1):
本文件要求的大多数IANA分配已在[RFC4446]中列出。对四种接口参数子TLV类型进行了额外分配（见第3.1节）：
o TDM Options (0x0B) o Number of TDMoIP AAL1 cells per packet (0x0E) o TDMoIP AAL1 mode (0x10) o TDMoIP AAL2 Options (0x11)
o TDM选项（0x0B）o每个数据包的TDMoIP AAL1单元数（0x0E）o TDMoIP AAL1模式（0x10）o TDMoIP AAL2选项（0x11）
This document does not have any additional impact on the security of PWs above that of basic LDP-based setup of PWs specified in [RFC4447].
除[RFC4447]中规定的基于LDP的PWs基本设置外，本文件对PWs的安全性没有任何其他影响。
Sharon Galtzur has reviewed one of the previous versions of this document. Y. (J.) Stein would like to thank Barak Schlosser for helpful discussions.
Sharon Galtzur审查了本文件的一个以前版本。Y.（J.）Stein要感谢巴拉克·施洛瑟的有益讨论。
[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。
[RFC5036] Andersson, L., Ed., Minei, I., Ed., and B. Thomas, Ed., "LDP Specification", RFC 5036, October 2007.
[RFC5036]Andersson，L.，Ed.，Minei，I.，Ed.，和B.Thomas，Ed.，“LDP规范”，RFC 5036，2007年10月。
[RFC4447] Martini, L., Ed., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006.
[RFC4447]Martini，L.，Ed.，Rosen，E.，El Aawar，N.，Smith，T.，和G.Heron，“使用标签分发协议（LDP）的伪线设置和维护”，RFC 4447，2006年4月。
[RFC4446] Martini, L., "IANA Allocations for Pseudowire Edge to Edge Emulation (PWE3)", BCP 116, RFC 4446, April 2006.
[RFC4446]Martini，L.，“伪线边到边仿真（PWE3）的IANA分配”，BCP 116，RFC 4446，2006年4月。
[RFC4623] Malis, A. and M. Townsley, "Pseudowire Emulation Edge-to-Edge (PWE3) Fragmentation and Reassembly", RFC 4623, August 2006.
[RFC4623]Malis，A.和M.Townsley，“伪线仿真边到边（PWE3）碎片化和重组”，RFC 46232006年8月。
[RFC4553] Vainshtein, A., Ed., and YJ. Stein, Ed., "Structure-Agnostic Time Division Multiplexing (TDM) over Packet (SAToP)", RFC 4553, June 2006.
[RFC4553]Vainstein，A.，Ed.，和YJ。Stein，Ed.“数据包上的结构不可知时分复用（TDM）（SAToP）”，RFC4553，2006年6月。
[RFC5086] Vainshtein, A., Ed., Sasson, I., Metz, E., Frost, T., and P. Pate, "Structure-Aware Time Division Multiplexed (TDM) Circuit Emulation Service over Packet Switched Network (CESoPSN)", RFC 5086, December 2007.
[RFC5086]Vainstein，A.，Ed.，Sasson，I.，Metz，E.，Frost，T.，和P.Pate，“分组交换网络上的结构感知时分多路复用（TDM）电路仿真服务（CESoPSN）”，RFC 5086，2007年12月。
[RFC5087] Y(J). Stein, Shashoua, R., Insler, R., and M. Anavi, "Time Division Multiplexing over IP (TDMoIP)", RFC 5087, December 2007.
[RFC5087]Y（J）。Stein，Shashoua，R.，Insler，R.，和M.Anavi，“IP时分多路复用（TDMoIP）”，RFC 5087，2007年12月。
[Q.2630.1] ITU-T Recommendation Q.2630.1, December 1999, AAL type 2 signaling protocol - Capability set 1
[Q.2630.1]ITU-T建议Q.2630.11999年12月，AAL 2型信令协议-能力集1
[RFC4805] Nicklass, O., Ed., "Definitions of Managed Objects for the DS1, J1, E1, DS2, and E2 Interface Types", RFC 4805, March 2007.
[RFC4805]Nicklass，O.，Ed.“DS1、J1、E1、DS2和E2接口类型的托管对象定义”，RFC 4805，2007年3月。
[RFC4842] Malis, A., Pate, P., Cohen, R., Ed., and D. Zelig, "Synchronous Optical Network/Synchronous Digital Hierarchy (SONET/SDH) Circuit Emulation over Packet (CEP)", RFC 4842, April 2007.
[RFC4842]Malis，A.，Pate，P.，Cohen，R.，Ed.，和D.Zelig，“同步光网络/同步数字体系（SONET/SDH）分组电路仿真（CEP）”，RFC 4842，2007年4月。
Authors' Addresses
作者地址
Alexander ("Sasha") Vainshtein ECI Telecom 30 ha-Sivim St., PO Box 500 Petah-Tiqva, 49517 Israel
Alexander（“Sasha”）Vainstein ECI Telecom 30 ha Sivm St.，邮政信箱500 Petah Tiqva，以色列49517
EMail: Alexander.Vainshtein@ecitele.com
EMail: Alexander.Vainshtein@ecitele.com
Yaakov (Jonathan) Stein RAD Data Communications 24 Raoul Wallenberg St., Bldg C Tel Aviv 69719 ISRAEL
以色列特拉维夫C栋拉乌尔沃伦堡大街24号雅科夫（乔纳森）斯坦无线电数据通信公司，邮编69719
Phone: +972 3 645-5389
EMail: yaakov_s@rad.com
Phone: +972 3 645-5389
EMail: yaakov_s@rad.com
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