Technical requirements of multi-service transport platform (MSTP) based on SDH -
Embedded with MPLS function
1 Scope
This standard specifies the overall technical requirements for realizing embedded MPLS functions on SDH-based MSTP equipment, including the requirements in functional model, functional requirements, control plane functions, data plane functions, interface characteristics, performance parameters and index, protection switching and network management of MSTP. Specific specifications on equipment for different levels of network applications will be specified separately.
This standard is applicable to SDH equipment which realize embedded MPLS functions, provide end-to-end QoS processing of Ethernet service, L2VPN service and Ethernet service and also provide multi-service transfer platforms (MSTP) with unified network management.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions of, any of these publications do not apply to this standard. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies.
GB/T 15941-1995 Requirements for synchronous digital hierarchy (SDH) optical fiber cable line systems
YD/T 1022-1999 Requirement of synchronous digital hierarchy (SDH) equipment function
YD/T 1061-2003 Specification of IP over SDH
YD/T 1162.1-2005 Multiple protocol label switching (MPLS) technical requirements
YD/T 1238-2002 Technical requirements for SDH multi-service transport platform
YD/T 1345-2005 Technical requirements for SDH-based MSTP - Embedded with RPR
YDN 099-1998 Synchronous optical transport network technology system (internal standard)
ITU-T G.7042 (2001) Link capacity adjustment scheme (LCAS) for virtual concatenated signals
ITU-T G.774.1 (2001) Synchronous digital hierarchy (SDH) – Bidirectional performance monitoring for the network element view
ITU-T G.841 (1998) Types and characteristics of SDH network protection architectures
ITU-T G.842 (1997) Interworking of SDH network protection architectures
ITU-T M.3100 (1995) Generic network information model
ITU-T Q.822 (1994) Stage 1, stage 2 and stage 3 description for the Q3 interface - Performance management
ITU-T X.733 (1992) Information technology - Open systems interconnection - Systems management: Alarm reporting function
ITU-T X.738 (1993) Information technology - Open systems interconnection - Systems management: Summarization function
ITU-T X.739 (1993) Information technology - Open systems interconnection - Systems management: Metric objects and attributes
ITU-T Y.1711 Operation & maintenance mechanism for MPLS networks
ITU-T Y.1720 Protection switching for MPLS networks
IEEE 802.17 Resilient packet ring (RPR)
IETF RFC 1661 The point-to-point protocol (PPP)
IETF RFC 1662 PPP in HDLC-like framing
IETF RFC 2205 Resource Reservation protocol (RSVP) - Version 1 functional specification
IETF RFC 2615 PPP over SONET/SDH
IETF RFC 2702 Requirements for traffic engineering over MPLS
IETF RFC 3031 Multiprotocol label switching architecture
IETF RFC 3032 MPLS label stack encoding
IETF RFC 3036 LDP specification
IETF RFC 3037 LDP applicability
IETF RFC 3209 RSVP-TE: Extensions to RSVP for LSP tunnels
IETF RFC 3210 Applicability statement for extensions to RSVP for LSP-tunnels
IETF RFC 3270 Multi-protocol label switching (MPLS) support of differentiated services
IETF RFC 3916 Requirements for pseudo-wire emulation edge-to-edge (PWE3)
IETF draft-ietf-mpls-rsvp-lsp-fastreroute Fast reroute extensions to RSVP-TE for LSP tunnels (Work in progress)
IETF-Draft-ietf-pwe3-control-protocol Pseudo-wire Setup and Maintenance - Using the Label Distribution Protocol (LDP) (Work in progress)
IETF Draft-ietf-pwe3-ethernet-encap-mpls Ethernet Encapsulation for pseudo-wire emulation edge-to-edge (Work in Progress)
IETF Draft-ietf-l2vpn-vpls-ldp L2VPN LDP Signaling (Work in progress)
3 Abbreviations
For the purposes of this standard, the following abbreviations apply.
AC Attachment Circuit
AF Assured Forwarding
APS Automatic Protection Switching
ATM Asynchronous Transfer Mode
BDI Backward Defect Indication
BE Best Effort
CE Costumer Equipment
CoS Class of Service
CV Packet Connectivity Verification Packet
Dserver Server Layer defect
DpeerME Peer Network Maintenance Entity Defect
DLOCV Loss of Connectivity Verification Defect
dTTSI_Mis Trail Termination Source Identifier Mismatch Defect
dTTSI_Mis Trail Termination Source Identifier Mismerge Defect
dExcess Receiving Excess Rate of CV
dUnknown Unknown Defect in the MPLS Network
ECC Embedded Control Channel
EF Expedited Forwarding
EPL Ethernet Private Line
EVPL Ethernet Virtual Private Line
EPLAN Ethernet Private LAN
EVPLAN Ethernet Virtual Private LAN
ER Explicit Routing
ETH Ethernet
FDI Forward Defect Indication
FEC Forwarding Equivalence Class
FF Fixed Filter
FCS Frame Check Sequence
FS Forced Switch
GFP Generic Framing Procedure
HEC Header Error Check
HDLC High Level Data Link Control
IP Internet Protocol
LAPS Link Access Procedure-SDH
LCAS Link Capacity Adjustment Scheme
LDP Label Distribution Protocol
Foreword III
1 Scope
2 Normative references
3 Abbreviations
4 Model of MSTP embedded with MPLS function
4.1 Diagram of MSTP embedded with MPLS function
4.2 Reference model of MSTP embedded with MPLS function
4.3 Network architecture of MSTP embedded with MPLS
5 Requirements of MSTP embedded with MPLS function
5.1 Service process
5.2 Ethernet interface function
5.3 Flow classification
5.4 Layer 2 switching function requirements (optional)
5.5 MPLS processing layer function requirements
6 Control plane (CP) requirements
6.1 Signaling function requirements
6.2 MPLS OAM (optional)
6.3 QoS
6.4 MPLS traffic engineering (optional)
6.5 MPLS protection function
6.6 L2VPN
7 Data plane function requirements
7.1 Flow classification
7.2 Ethernet adaptation at edge node PE of MSTP network
7.3 Ethernet data processing at intermediary equipment P node of MSTP network
7.4 MPLS label architecture - PW label and tunnel label
7.5 MPLS label switching function
7.6 Functional requirements of adaptation of MPLS frames to SDH VC
8 Application of MSTP Embedded with MPLS - L2VPN
8.1 Ethernet service types supported by L2VPN provided by MSTP embedded with MPLS
8.2 L2VPN reference model and functional components
9 Performance indexes
9.1 Performance indexes of SDH layer
9.2 Performance indexes of MPLS layer
10 Requirements for interface
11 Protection switching
11.1 Protection mode
11.2 SDH protection switching
11.3 MPLS layer protection
11.4 Coordination of MPLS protection and SDH protection
12 NMS
12.1 Overview of NMS
12.2 Fault management function
12.3 Performance management function
12.4 Configuration management functions
12.5 Interface capability
12.6 Security management function
12.7 Basic billing management information
Annex A (Informative) Combination of MPLS and RPR
Annex B (Informative) Interconnection requirements
1 范围
本标准规定了基于SDH的MSTP设备上实现内嵌MPLS功能的总体技术要求，包括MSTP的功能模型、功能要求、控制面功能、数据面功能、接口特性、性能参数和指标、保护倒换、网络管理方面的要求。对于不同层次网络应用的具体设备规范另行制定。
本标准适用于SDH设备上实现内嵌MPLS功能，提供以太网业务端到端的QoS处理、L2VPN以太网业务，同时提供统一网管的多业务传送节点(MSTP)。
2 规范性引用文件
下列文件中的条款通过本标准的引用而成为本标准的条款。凡是注日期的引用文件，其随后所有的修改单(不包括勘误的内容)或修订版均不适用于本标准，然而，鼓励根据本标准达成协议的各方研究是否可使用这些文件的最新版本。凡是不注日期的引用文件，其最新版本适用于本标准。
GB/T 15941-1995 同步数字体系(SDH)光缆线路系统进网要求
YD/T 1022-1999 同步数字体系(SDH)设备功能要求
YD/T 1061-2003 基于LAPS的IP over SDH
YD/T 1162.1-2005 多协议标记交换(MPLS)技术要求
YD/T 1238-2002 基于SDH的多业务传送节点技术要求
YD/T 1345-2005 基于SDH的多业务传送节点(MSTP)技术要求——内嵌内嵌弹性分组环(RPR)功能部分
YDN 099-1998 光同步传送网技术体制(暂行规定)
ITU-T G7042 (2001) 链路容量调整规程
ITU-T G774.1 (2001) 同步数字体系(SDH)—从网元考虑的双向性能监测
ITU-T G841 (1998) SDH网保护结构的类型与特性
ITU-T G842 (1997) SDH网保护结构的互通
ITU-T M.3100 (1995) 通用网络信息模型
ITU-T Q.822 (1994) Q3接口的一级、二级和三级描述-性能管理
ITU-T X.733 (1992) 信息技术-开放系统互连-系统管理：告警报告功能
ITU-T X.738 (1993) 信息技术-开放系统互连-系统管理：摘要功能
ITU-T X.739 (1993) 信息技术-开放系统互连-系统管理：测量客体和属性
ITU-T Y.1711 MPLS OAM机制
ITU-T Y.1720 MPLS保护倒换
IEEE 802.17 弹性分组环(RPR)
IETF RFC 1661 点到点协议(PPP)
IETF RFC 1662 类似HDLC帧中的端对端协议
IETF RFC 2205 RSVP功能要求
IETF RFC 2615 在SONET/SDH上的PPP
IETF RFC 2702 MPLS流量工程要求
IETF RFC 3031 MPLS体系结构
IETF RFC 3032 MPLS标签栈编码
IETF RFC 3036 LDP规程(LDP Specification)
IETF RFC 3037 LDP应用性
IETF RFC 3209 RSVP-TE：应用于隧道LSP的RSVP协议的扩展
IETF RFC 3210 应用于LSP隧道的RSVP扩展的应用说明
IETF RFC 3270 支持DiffServ服务的MPLS
IETF RFC 3916 PWE3总体要求
IETF draft-ietf-mpls-rsvp-lsp-fastreroute 应用于LSP隧道的RSVP-TE的快速重路由扩展(Work in Progress)
IETF-Draft-ietf-pwe3-control-protocol 伪线建立和使用LDP维护(Work in Progress)
IETF Draft-ietf-pwe3-ethernet-encap-mpls PWE3以太网封装(Work in Progress)
IETF Draft-ietf-l2vpn-vpls-ldp L2 VPN LDP信令(Work in Progress)
3 缩略语
下列缩略语适用于本标准。
AC Attachment Circuit 直连电路
AF Assured Forwarding 保障转发
APS Automatic Protection Switching 自动保护倒换
ATM Asynchronous Transfer Mode 异步转移模式
BDI Backward Defect Indication 后向缺陷指示
BE Best Effort 尽力而为
CE Costumer Equipment 用户设备
CoS Class of Service 业务等级
CV Packet Connectivity Verification Packet 连通性检验包
Dserver Server Layer defect 服务层缺陷
DpeerME Peer Network Maintenance Entity Defect 对等网络维护实体缺陷
DLOCV Loss of Connectivity Verification Defect 连续性确认丢失缺陷
dTTSI_Mis Trail Termination Source Identifier Mismatch Defect 路径终结源标识不匹配缺陷
dTTSI_Mis Trail Termination Source Identifier Mismerge Defect 路径终结源标识错误聚合缺陷
dExcess Receiving Excess Rate of CV 接收的CV包频率超额缺陷
dUnknown Unknown Defect in the MPLS Network MPLS网络中的未知缺陷
ECC Embedded Control Channel 嵌入式控制通路
EF Expedited Forwarding 快速转发
EPL Ethernet Private Line 以太网专线
EVPL Ethernet Virtual Private Line 以太网虚拟专线
EPLAN Ethernet Private LAN 以太网专网
EVPLAN Ethernet Virtual Private LAN 以太网虚拟专网
ER Explicit Routing 显式路由
ETH Ethernet 以太网
FDI Forward Defect Indication 前向缺陷指示
FEC Forwarding Equivalence Class 转发等价类
FF Fixed Filter 固定过滤
FCS Frame Check Sequence 帧校验序列
FS Forced Switch 强制倒换
GFP Generic Framing Procedure 通用成帧规程
HEC Header Error Check 帧头错误校验
HDLC High Level Data Link Control 高级数据链路控制
IP Internet Protocol 互连网协议
LAPS Link Access Procedure-SDH 链路接入协议-SDH
LCAS Link Capacity Adjustment Scheme 链路容量调整规程
LDP Label Distribution Protocol 标记分发协议
LOCV Loss of Connectivity Verification 连通性检验丢失
LSP Label Switched Path 标记交换路径
LSR Label Switching Router 标记交换路由器
MAC Media Access Control 介质访问控制
MPLS Multiprotocol Label Switching 多协议标记交换
MS Manual Switch 人工倒换
MSP Multiplex Section Protection 复用段保护
MSTP Multi-Service Transport Platform 多业务传送节点
NNI Network to Network/Network Node Interface 网络(节点)到网络(节点)之间的接口
OAM Operations，Administration and Maintenance 操作、管理、维护
P Provider 运营商核心设备
PE Provider Equipment 运营商边缘设备
PW Pseudo-Wire 伪线
PWE3 Pseudo-Wire Emulation Edge-to-Edge 边缘到边缘的伪线仿真
PPP Point-to-Point Protocol 点对点协议
PMD Physical Medium Dependent 物理媒质相关
QoS Quality of Service 服务质量
RPR Resilient Packet Ring 弹性分组环
RRO RECORD_ROUTE Object 记录路由对象
RSVP Resource Reservation Protocol 资源预留协议
SDH Synchronous Digital Hierarchy 同步数字体系
SE Shared Explicit 共享显式
SF Signal Fail 信号失效
SNCP Sub-Network Connection Protection 子网连接保护
TE Traffic Engineering 流量工程
TTL Time to Live 存活时间
TTSI Trail Termination Source Identifier 路径终结源标识
UNI User-Network Interface 用户网络接口
VB Virtual Bridge 虚拟网桥
VLAN Virtual Local Area Network 虚拟局域网
4 内嵌MPLS的MSTP功能模型
4.1 内嵌MPLS的MSTP功能框图
本标准定义是基于SDH平台的，内嵌MPLS功能且提供统一网管的多业务传送节点(MSTP)。其关键特征为：以太网业务适配到MPLS层，然后映射到SDH通道中传送。(也可以是以太网业务适配到MPLS层，然后映射到RPR层，再映射到SDH通道中传送)
内嵌MPLS的MSTP的功能模型如图1所示。
PDH接口
ATM接口
以太网接口
STM-N接口
ATM层处理
二层交换
二层交换
二层交换
RPR MAC层处理
MPLS 层处理
再生段开销处理
RPR MAC 层处理
复生段开销处理
VC映射
交叉连接
复用段开销处理
再生段开销处理
STM-N接口
STM-N接口
注：MSTP内嵌MPLS层处理时，RPR MAC层处理可选。MPLS和RPR结合应用参见附录A。
图1 内嵌MPLS的MSTP功能框图
对于内嵌MPLS的基于SDH的MSTP，具体的功能要求如下：
1)应满足YD/T 1022-1999和YDN 099-1998中规定的SDH节点基本功能要求；
2)应满足YDT 1238-2002中规定的基于SDH的多业务传送节点基本功能要求；
3)应支持在MPLS上承载以太网业务，具体的功能要求应遵循本标准第5章的规定，以太网业务适配到MPLS层应遵循本标准第7章的规定；
4)PLS承载以太网时，应保证以太网业务的透明性；
5)少支持静态LSP指配方式；
6)具备MPLS信令动态建立LSP(可选)；
7)具备MPLS操作管理维护功能(可选)；
8)具备MPLS LSP保护功能(可选)；
9)提供L2VPN业务；
10)具备在MPLS层按服务等级调度业务的能力；
11)具备将MPLS帧映射到SDH层传送并指配SDH虚容器作为传送通道的功能，应支持采用VC级联通道作为承载业务的传送通道。
4.2 内嵌MPLS的MSTP功能参考模型
4.2.1 内嵌MPLS的MSTP参考模型图
