WO2009036637A1

WO2009036637A1 - Method for identifying monitoring sub-layer with use of exp field

Info

Publication number: WO2009036637A1
Application number: PCT/CN2007/003839
Authority: WO
Inventors: Zufa Yang
Original assignee: Zte Corporation
Priority date: 2007-09-17
Filing date: 2007-12-27
Publication date: 2009-03-26
Also published as: CN101127646A; CN100531075C

Abstract

A method for identifying the monitoring sub-layer with the use of EXP field includes: Step A, when enabling the monitoring sub-layer function of the label switched path in the multi-protocol label switching network, the label switching router at the incoming port of the monitoring sub-layer generating and forwarding the Operations, Administration and Maintenance OAM identification packet, the protocol data unit of the OAM identification packet including only one identification entry, and the EXP field of the identification entry being used for identifying the monitoring sub-layer; step B, the label switching router at the out-coming port of the monitoring sub-layer identifying and processing the OAM identification packet, if the EXP included in the received OAM protocol data unit belonging to the mapping value of the current monitoring sub-layer, then processing the payload of the OAM protocol data unit and terminating the forwarding of the OAM identification packet, otherwise, forwarding or discarding the received OAM identification packet. With the invention, the disadvantage of wasting the bandwidth resource of the MPLS path in the manner of identifications overlapping could be avoided, and the ability of the network in transmitting the client information could be increased.

Description

使用 EXP字段标识监视子层的方法技术领域 Method for identifying a monitoring sublayer using an EXP field

本发明涉及一种使用 EXP字段标识监视子层的方法，尤其涉及分组交换网络技术领域中，多协议标记交换 MPLS ( Multi-Protocol Label Switching ) 层网络中，使用 EXP字段标识子网连接监视子层和串联连接监视子层的方法。背景技术 The present invention relates to a method for identifying a monitoring sublayer by using an EXP field. In particular, in the field of packet switching network technology, in a Multi-Protocol Label Switching layer network, an EXP field is used to identify a subnet connection monitoring sublayer. And a method of connecting the monitoring sublayers in series. Background technique

多†办议标记交换 MPLS ( Multi-Protocol Label Switching )技术是一种结合了二层交换和三层路由的集成数据传输技术 , 能够支持网络层的多种协议，还可以兼容第二层的多种链路层技术。采用 MPLS技术的因特网协议 IP ( Internet Protocol )路由器以及异步转移模式 ATM ( Asynchronous Transfer Mode )、帧中继 FR( Frame Relay )交换机统称为标记交换路由器 LSR( Label Switch Router )。在由 LSR组成的 MPLS数据传输网络中，由于客户信息通过已知的连接进行转发，相对简化了网络层的复杂度， P条低了网络升级的成本。因此，在全球范围内， MPLS技术在核心网络得到了大规模应用。 Multi-Protocol Label Switching (MPLS) is an integrated data transmission technology that combines Layer 2 switching and Layer 3 routing. It can support multiple protocols at the network layer and is compatible with multiple layers at the second layer. Link layer technology. The MPLS-based Internet Protocol (IP) routers and the Asynchronous Transfer Mode (Asynchronous Transfer Mode) and the Frame Relay (FR) are collectively referred to as the Label Switch Router (LPR). In the MPLS data transmission network composed of LSRs, the customer information is forwarded through known connections, which simplifies the complexity of the network layer, and P reduces the cost of network upgrade. Therefore, on a global scale, MPLS technology has been applied on a large scale in the core network.

结合端到端伪线仿真 PWE3 ( Pseudo Wire Emulation Edge-to-Edge )技术和 MPLS隧道技术， MPLS交换网络可以支持链路层以及更低层次客户信息的传送，包括以太网 ETH ( Ethernet ) 、异步转移模式 ATM、帧中继 FR、结构化和非结构化的时分复用和复用器 TDM ( Time Division Multiplex and Multiplexer )等。这进一步地扩大了 MPLS技术的应用范围，使得 MPLS网络不仅能够应用在核心网络环境，也可以应用在汇聚和接入网络环境。 Combined with PWE3 (Pseudo Wire Emulation Edge-to-Edge) technology and MPLS tunneling technology, the MPLS switching network can support the transmission of link layer and lower-level customer information, including Ethernet ETH (Ethernet), asynchronous. Transfer mode ATM, Frame Relay FR, Structured and Unstructured Time Division Multiplex and Multiplexer TDM (Time Division Multiplex and Multiplexer). This further expands the application scope of MPLS technology, so that the MPLS network can be applied not only in the core network environment, but also in the aggregation and access network environment.

为便于提高 MPLS 网絡连接的生存能力和可维护性，国际电信联盟-电信标准邵 ITU-T ( International Telecommunication Union-Telecommunication Standardization Sector )组织已经为 MPLS 网络定义并制定了标 i己交换通道 LSP ( Label Switched Path )端到端的操作、维护与管理 OAM ( Operation, Administration and Maintenance )功能和机制，用于实现 MPLS层网络路径的故障管理和性能监视，并根据检测结果建立不同的告警状态。当 MPLS 网络支持基于路径的线性保护功能时， LSP端到端的 OAM功能建立的故障条件可作为路径保护倒换的依据。 In order to improve the survivability and maintainability of MPLS network connections, the International Telecommunication Union-Telecommunication Standardization Sector (ITU) has defined and developed LSPs for Labels. The Switched Path (Operation, Administration, and Maintenance) function and mechanism are used to implement fault management and performance monitoring on the MPLS layer network path, and establish different alarm states based on the detection result. When MPLS When the network supports the path-based linear protection function, the fault condition established by the OAM function of the LSP end-to-end can be used as the basis for path protection switching.

ITU-T还为 MPLS网络定义了串联连接监视 TCM ( Tandem Connection Monitoring ) 子层功能，但目前没有制定相应的实现机制。所述子层，是指嚢括在一个层网络中的一套附加传送处理功能和参考点。它是通过分解传送处理功能或参考点而形成的。所述串联连接，是指任意一组邻接的"链路连接"和 /或"子网络连接"。所述子网络，是指用于实现特殊特征信息的路由安排的一种拓朴构件。子网络存在于单个层网络之中，它由可用来传递特征信息的一组端口确定。子网络边界上的各端口之间的关联可由层网络的管理处理来构成和断开，从而改变它的连接性。当子网络连接建立后，通过这些端口与子网络连接的输入和输出的结合也就生成了参考点。一般而言，子网路可分块为由链路互连的更小的子网络；矩阵是子网络的一种特殊情况，它不能分块。所述子网络连接，是指一种跨越由子网絡的边界上的各"端口"的关联而形成的子网络来传递信息的"传送实体"。 ITU-T also defines the TCM (Tandem Connection Monitoring) sublayer function for the MPLS network, but there is no corresponding implementation mechanism. The sub-layer refers to a set of additional transport processing functions and reference points that are included in a layer network. It is formed by breaking down the transfer processing function or reference point. The tandem connection refers to any set of contiguous "link connections" and/or "sub-network connections". The subnetwork refers to a topology component for implementing routing arrangement of special feature information. A subnetwork exists in a single layer network, which is determined by a set of ports that can be used to convey feature information. The association between ports on the subnetwork boundary can be constructed and disconnected by the management process of the layer network, thereby changing its connectivity. When the subnet connections are established, the combination of the inputs and outputs connected to the subnets through these ports creates a reference point. In general, a subnet can be chunked into smaller subnetworks interconnected by links; a matrix is a special case of a subnetwork that cannot be chunked. The sub-network connection refers to a "transport entity" that transfers information across sub-networks formed by the association of "ports" on the boundaries of the sub-network.

子网络连接能够穿越子网絡透明地传递信息。它由子网络边界上的连接点划定界限，表示这些连接点之间的关联。当子网络连接建立后，通过这些端口与子网络连接的输入和输出的结合也就生成了参考点。一般而言，子网络连接由子网络连接和链路连接的级联构成。矩阵连接是子网络连接的特殊情况，它由单个 (不可分的)子网络连接构成。 Subnetwork connections can transparently convey information across subnetworks. It is delimited by the connection points on the subnetwork boundary, indicating the association between these connection points. When the subnet connection is established, the combination of the input and output of the subnet connection through these ports also generates a reference point. In general, a subnet connection consists of a cascade of subnetwork connections and link connections. A matrix connection is a special case of a subnetwork connection, which consists of a single (inseparable) subnetwork connection.

TCM子层用于部分 LSP或 MPLS子网连接的故障管理和性能监视。 The TCM sublayer is used for fault management and performance monitoring of partial LSP or MPLS subnet connections.

MPLS网络的一条 LSP可以配置多个 TCM子层，但不允许 TCM子层之间出现重叠。通常情况下， TCM子层应用在 MPLS层网絡同一管理域边界 LSR 之间或相邻管理域的邻接边界 LSR之间。 An LSP of an MPLS network can be configured with multiple TCM sublayers, but does not allow overlap between TCM sublayers. Generally, the TCM sublayer is applied between the LSRs of the same administrative domain boundary of the MPLS layer network or the adjacent boundary LSR of the adjacent management domain.

MPLS网络启用 TCM子层功能之后，可以基于子网连接建立告警条件。如果 MPLS网络支持基于 MPLS子网连接的保护功能，可以将 TCM子层产生的故障条件作为子网连接保护倒换的依据。不难看出，启用 TCM子层功能之后， MPLS网络的生存能力和可维护性得到进一步加强。 After the MPLS network enables the TCM sublayer function, an alarm condition can be established based on the subnet connection. If the MPLS network supports the protection function based on the MPLS subnet connection, the fault condition generated by the TCM sublayer can be used as the basis for the subnet connection protection switching. It is not difficult to see that after the TCM sublayer function is enabled, the survivability and maintainability of the MPLS network are further enhanced.

MPLS 网络并不限制分组头部的标记栈深度，因此，通常选择为 TCM 子层增加新的 MPLS垫层实现相应功能。对于这种实现方式，当 LSP存在嵌套的 TCM子层时，串联连接监视的端对端操作、维护与管理协议数据单元 TCM OAM PDU ( Protocol Data Unit )将包含多层标记条目。过深的标记栈将增加 MPLS层网络的路径开销，降^ (氐网络传送客户信息的能力。发明内容 The MPLS network does not limit the markup stack depth of the packet header. Therefore, it is usually chosen to add a new MPLS layer to the TCM sublayer to implement the corresponding function. For this implementation, when LSP exists When nested TCM sublayers, the end-to-end operation, maintenance, and management protocol data unit TCM OAM PDU ( Protocol Data Unit) for serial connection monitoring will contain multiple layer tag entries. A deep mark stack will increase the path overhead of the MPLS layer network and reduce the ability of the network to transmit customer information.

本发明要解决的技术问题是提供一种使用 EXP字段标识监视子层的方法。 The technical problem to be solved by the present invention is to provide a method of identifying a monitoring sublayer using an EXP field.

为了解决上述问题，本发明提供了一种使用 EXP字段标识监视子层的方法，包括如下步驟： In order to solve the above problem, the present invention provides a method for identifying a monitoring sublayer using an EXP field, including the following steps:

步驟 A: 启用多协议标记交换网络标记交换通道的监视子层功能时，所述监视子层入口标记交换路由器生成并向前发送操作维护与管理 OAM标记分组，所述 OAM标记分组的协议数据单元包含一个标记条目，所述标记条目的 EXP字段用于标识所述监视子层； Step A: When the monitoring sublayer function of the multi-protocol label switching network label switching channel is enabled, the monitoring sub-layer ingress label switching router generates and forwards an operation maintenance and management OAM marking packet, and the protocol data unit of the OAM marking packet Include a tag entry, the EXP field of the tag entry is used to identify the monitoring sublayer;

步驟 B: 所述监视子层出口标记交换路由器识别并处理所述 OAM标记分组，如果接收的 OAM协议数据单元包含的 EXP属于当前监视子层的映射值，处理该 OAM协议数据单元净荷，并终止该 OAM标记分组继续向前转发，否则，直接向前转发或丢弃接收的 OAM标记分组。 Step B: The monitoring sub-layer egress label switching router identifies and processes the OAM marking packet, and if the received EXP data unit includes an EXP that belongs to a mapping value of the current monitoring sublayer, processes the OAM protocol data unit payload, and The OAM tagged packet is terminated and forwarded forward, otherwise the received OAM tagged packet is forwarded or discarded directly.

进一步地，所述标记条目的标记值 lable为 14、 S值为 1、生存时间 TTL ( Time To Live, 生存时间）值为 1。 Further, the tag entry has a tag value of lable of 14, an S value of 1, and a time to live TTL (Time To Live) value of 1.

进一步地，属于同一条标记交换通道的多个监视子层，在每监视子层内部， OAM协议数据单元包含的 EXP保持唯一。 Further, the plurality of monitoring sublayers belonging to the same label switching channel, within each monitoring sublayer, the EXP included in the OAM protocol data unit remains unique.

进一步地，当所述监视子层之间存在嵌套关系时，存在嵌套关系的监视子层之间， 0AM协议数据单元包含的 EXP也保持唯一。 Further, when there is a nested relationship between the monitoring sublayers, between the monitoring sublayers of the nested relationship, the EXP included in the 0AM protocol data unit is also unique.

进一步地，步骤 A前还包括:标记交换通道穿过多协议标记交换网络的一个或多个管理域，选择在所述标记交换通道穿过的入口标记交换路由器和出口标记交换路由器之间、各管理域两个边界标记路由器之间和 /或相邻管理域部接标记路由器之间配置监视子层功能。进一步地，所述 0AM标记分组的外层标记条目中， LSP-S为 0, 指示所述 OAM标记分组承载的净荷不是客户信息。 Further, before step A, the method further includes: marking the switching channel through one or more management domains of the multi-protocol label switching network, selecting between the ingress label switching router and the egress label switching router that the label switching channel passes through, The monitoring sublayer function is configured between the management domain two border tag routers and/or the adjacent management domain stub tag routers. Further, in the outer label entry of the 0AM tag packet, LSP-S is 0, indicating The payload carried by the OAM tagged packet is not customer information.

进一步地，所述 OAM协议数据单元包含的 EXP取值范围为 0-7。 Further, the OAM protocol data unit includes an EXP value ranging from 0-7.

进一步地，标记交换通道同时启用端到端 OAM和监视子层功能时，所述 OAM协议数据单元包含的 EXP取值范围为 1-7。 Further, when the label switching channel simultaneously enables the end-to-end OAM and the monitoring sub-layer function, the OAM protocol data unit includes an EXP ranging from 1 to 7.

进一步地，所述标记交换通道是单向或双向的。 Further, the label switching channel is unidirectional or bidirectional.

进一步地，对于同一条标记交换通道，最大允许存在 8层监视子层。进一步地，所述监视子层是子网连接监视子层或串联连接监视子层。本发明提供的一种使用 EXP字段标识监视子层的方法，在保证这两种功能实现相对简单的同时，避免了采用标记堆叠方式浪费 MPLS路径带宽资源的弊端，增加了网络传送客户信息的能力。 Further, for the same label switching channel, a maximum of 8 layers of monitoring sublayers are allowed. Further, the monitoring sublayer is a subnet connection monitoring sublayer or a serial connection monitoring sublayer. The method for using the EXP field to identify the monitoring sublayer provides a relatively simple implementation of the two functions, and avoids the disadvantage of wasting the MPLS path bandwidth resource by using the label stacking method, thereby increasing the network's ability to transmit customer information. .

附图概迷 Drawing fan

图 1是本发明链路上 TCM OAM标记分组结构图； 1 is a structural diagram of a TCM OAM marking packet on a link of the present invention;

图 2是本发明无 TCM子层嵌套时的 MPLS网络结构； 2 is an MPLS network structure when the TCM sublayer is not nested according to the present invention;

图 3是本发明含 TCM子层嵌套时的 MPLS网络结构图。 FIG. 3 is a structural diagram of an MPLS network when the TCM sublayer is nested according to the present invention.

本发明的较佳实施方式本发明的核心思想是，选择采用 OAM PDU标记的 EXP字段标识监视子层，所述监视子层可以是是子网连接监视子层或串联连接监视子层。 BEST MODE FOR CARRYING OUT THE INVENTION The core idea of the present invention is to select an EXP field identified by an OAM PDU to identify a monitoring sublayer, which may be a subnet connection monitoring sublayer or a serial connection monitoring sublayer.

下面以串联连接监视子层为例，来详细描述本发明的方法。启用 MPLS 网络 LSP的 TCM功能时，属于同一条 LSP的所有 TCM子层，不管是否存在嵌套关系 , TCM子层监视的 TCM OAM PDU总是具有相同的标记栈深度，且仅包含一个标记条目，标记值为 14, EXP字段用于标识 TCM子层或子网连接监视子层， S值为 1 , TTL ( Time To Live, 生存时间）值为 1。 The method of the present invention will be described in detail below by taking a serial connection monitoring sublayer as an example. When the TCM function of the MPLS network LSP is enabled, all TCM sublayers belonging to the same LSP, regardless of whether there is a nested relationship, the TCM OAM PDUs monitored by the TCM sublayer always have the same mark stack depth and contain only one tag entry. The value of the tag is 14. The EXP field is used to identify the TCM sublayer or subnet connection monitoring sublayer. The S value is 1 and the TTL (Time To Live) value is 1.

属于同一条 LSP的多个 TCM子层，如果相互之间不存在嵌套关系，各 Multiple TCM sublayers belonging to the same LSP, if there is no nesting relationship with each other,

TCM子层 TCM OAM PDU标记的 EXP互不相关，仅要求在每 TCM子层内部保持唯一，不同对于存在嵌套关系的 TCM子层，除了在各 TCM子层内部保持 TCM OAM PDU标记的 EXP唯一之外，存在嵌套关系的各 TCM子层之间， TCM OAM PDU标记的 EXP也必须保持唯一。由于 MPLS标记的 EXP字段包含 3位二进制数，对于同一条 LSP，最大允许存在 8层 TCM子层。 The TCM sub-layer TCM OAM PDU marked EXP is irrelevant and only needs to be unique within each TCM sub-layer. For a TCM sublayer with a nested relationship, except for the EXP unique to the TCM OAM PDU tag within each TCM sublayer, the EXP marked by the TCM OAM PDU must remain unique among the TCM sublayers with nested relationships. . Since the EXP field of the MPLS label contains a 3-bit binary number, for the same LSP, a maximum of 8 layers of TCM sublayers are allowed.

本发明使用 EXP字段标识 TCM子层的方法，包括如下步骤： The method for identifying the TCM sublayer by using the EXP field includes the following steps:

步骤一： LSP穿过 MPLS层网络的一个或多个管理域，选择在所述 LSP 穿过的入口 LSR和出口 LSR之间、各管理域两个边界 LSR之间、相邻管理域邻接 LSR之间配置 TCM子层功能。 Step 1: The LSP passes through one or more management domains of the MPLS layer network, and is selected between the ingress LSR and the egress LSR through which the LSP passes, between the two LSRs of each management domain, and the adjacent management domain is adjacent to the LSR. Configure the TCM sublayer function.

步骤二： TCM子层入口 LSR生成并向前发送 TCM OAM标记分组。本发明链路上 TCM OAM标记分组如图 1所示， TCM OAM标记分组格式为：所述 LSP在 TCM子层入口 LSR上的标记条目， TCM OAM PDU。由 LSP-Label、 LSP-EXP, LSP-S、 LSP-TTL组成的外层标记条目是 MPLS 层网络选路标记。如果所述 LSP标记条目的 S值为 1 , 对于 TCM OAM标记分组，必须将其修改为 0, 指示 TCM OAM标记分组承载的净荷不是客户信息。其他字段的赋值处理等同于 LSP承载客户信息的标记分组。 Step 2: TCM sub-layer entry The LSR generates and forwards the TCM OAM tag packet. The TCM OAM marking packet on the link of the present invention is as shown in FIG. 1. The TCM OAM marking packet format is: a label entry of the LSP on the TCM sub-layer entry LSR, and a TCM OAM PDU. The outer label entry consisting of LSP-Label, LSP-EXP, LSP-S, and LSP-TTL is the MPLS layer network routing label. If the S value of the LSP tag entry is 1 , for the TCM OAM tag packet, it must be modified to 0, indicating that the payload carried by the TCM OAM tag packet is not client information. The assignment process of other fields is equivalent to the tag grouping of the LSP carrying customer information.

由 TCM-Label、 TCM-EXP, TCM-S、 TCM-TTL组成的内层标记是 TCM OAM PDU的标记条目。 TCM OAM PDU格式为： TCM-Label=14, 也就是标记值 =14, 指示 TCM OAM PDU包含 OAM信息； TCM-EXP=特定 TCM 子层映射值，属于相同 TCM子层的所有 TCM OAM PDU, TCM-EXP必须唯一。 TCM-S=1 , TCM-TTL=1 , TCM OAM PDU为净荷。 The inner tag consisting of TCM-Label, TCM-EXP, TCM-S, TCM-TTL is the tag entry for the TCM OAM PDU. The TCM OAM PDU format is: TCM-Label=14, that is, the tag value=14, indicating that the TCM OAM PDU contains OAM information; TCM-EXP=specific TCM sublayer mapping value, all TCM OAM PDUs belonging to the same TCM sublayer, TCM -EXP must be unique. TCM-S=1, TCM-TTL=1, TCM OAM PDU is the payload.

当所述 LSP包含多个 TCM子层时，如果 TCM子层之间不存在嵌套关系， TCM OAM PDU的 EXP只需要在每 TCM子层内部保持唯一，不同 TCM 子层 TCM OAM PDU的 EXP可以相同或不同。如图 2所示，单向 LSP-11 穿过两个管理域，共配置了三个 TCM子层。 TCM-A监视域 A的子网连接， TCM-AB监视相邻域 A和 B邻接 LSR之间的子网连接， TCM-B监视域 B 的子网连接。对于 TCM-A, TCM OAM标记分组在 LSR-11生成并发送，在 LSR-12终结并处理。对于 TCM-AB, TCM OAM标记分组在 LSR-12生成并发送，在 LSR-13终结并处理。对于 TCM-B, TCM OAM标记分组在 LSR-13 生成并发送，在 LSR-14终结并处理。由于三个 TCM子层之间不存在包含关系，任何 TCM子层的 TCM OAM标记分组都不会穿过其他 TCM子层，因此，不同 TCM子层的 TCM-EXP可以相同，也可以不同。 When the LSP includes multiple TCM sublayers, if there is no nested relationship between the TCM sublayers, the EXP of the TCM OAM PDU needs to be unique only within each TCM sublayer, and the EXP of the TCM OAM PDU of different TCM sublayers may be Same or different. As shown in Figure 2, the unidirectional LSP-11 traverses two administrative domains, and three TCM sublayers are configured. TCM-A monitors the subnet connection of domain A, TCM-AB monitors the subnet connection between adjacent domains A and B adjacent to the LSR, and TCM-B monitors the subnet connection of domain B. For TCM-A, the TCM OAM marker packet is generated and sent in LSR-11, terminated and processed at LSR-12. For TCM-AB, the TCM OAM marker packet is generated and sent in LSR-12, terminated and processed at LSR-13. For TCM-B, the TCM OAM marker packet is generated and sent at LSR-13, terminated and processed at LSR-14. Since there is no inclusion between the three TCM sublayers Relationship, any TCM OAM marker packet of the TCM sublayer will not pass through other TCM sublayers. Therefore, the TCM-EXP of different TCM sublayers may be the same or different.

当 TCM子层之间存在嵌套关系，除了要求 TCM OAM PDU的 EXP在每 TCM子层内部保持唯一之外，存在嵌套关系的 TCM子层 TCM OAM PDU 的 EXP也必须保持唯一，也就是存在嵌套关系的子层的 TCM OAM PDU的 EXP必须不相同。 When there is a nested relationship between the TCM sublayers, except for the EXP that requires the TCM OAM PDU to remain unique within each TCM sublayer, the EXP of the TCM sublayer TCM OAM PDU with nested relationships must also remain unique, that is, exist. The EXP of the TCM OAM PDU of the sublayer of the nested relationship must be different.

如图 3所示，单向 LSP-21穿过域（、 D、 E, 配置了三个 TCM子层。 TCM-C监视域 C的子网连接， TCM-D监视域 D的子网连接， TCM-E监视域 E的子网连接。 As shown in Figure 3, the unidirectional LSP-21 traverses the domain (, D, E, and three TCM sublayers are configured. The TCM-C monitors the subnet connection of the domain C, and the TCM-D monitors the subnet connection of the domain D, TCM-E monitors the subnet connection of domain E.

对于 TCM-C, TCM OAM标记分组在 LSR-21生成并发送，经过 LS -22, For TCM-C, the TCM OAM marker packet is generated and sent on LSR-21, passing LS-22.

LSR-23, LSR-24转发，到达 LSR-25之后终结并处理。对于 TCM-D, TCM OAM标记分组在 LSR-21生成并发送，到达 LSR-22之后终结并处理。对于 TCM-E, TCM OAM标记分组在 LSR-23生成并发送, 经过 LSR-24转发，到达 LSR-25 之后终结并处理。 TCM-C 完全包容 TCM-D和 TCM-E, 其 TCM-EXP必须不同于 TCM-D和 TCM-E的 TCM-EXP, 否则， LSR-22和 LS -25将不能正常区分当前终结和处理的 TCM OAM标记分组属于哪一个子层。 TCM-D和 TCM-E同为 TCM-C的嵌套子层，由于 TCM-D的 TCM OAM PDU不会穿过 TCM-E, TCM-E的 TCM OAM PDU也不会穿过 TCM-D, 因此， TCM-D和 TCM-E的 TCM EXP可以相同，也可以不同。 LSR-23, LSR-24 forwarded, terminated and processed after reaching LSR-25. For TCM-D, the TCM OAM marker packet is generated and sent at LSR-21, terminated and processed after reaching LSR-22. For TCM-E, the TCM OAM marker packet is generated and sent in LSR-23, forwarded by LSR-24, and terminated and processed after reaching LSR-25. TCM-C is fully compatible with TCM-D and TCM-E. Its TCM-EXP must be different from TCM-D and TCM-E TCM-EXP. Otherwise, LSR-22 and LS-25 will not be able to distinguish between current termination and processing. The TCM OAM marks which sublayer the packet belongs to. TCM-D and TCM-E are both nested sublayers of TCM-C. Since the TCM OAM PDU of TCM-D does not pass through TCM-E, the TCM OAM PDU of TCM-E will not pass through TCM-D. Therefore, the TCM EXP of TCM-D and TCM-E may be the same or different.

启用 TCM子层功能后，不影响所迷 LSP端到端 OAM标记分组、客户信息标记分组的正常转发和处理。如果 LSP同时启用端到端 OAM和 TCM 子层功能， TCM OAM PDU的 EXP取值范围为 1-7; 否则， TCM OAM PDU 的 EXP取值范围为 0-7。 After the TCM sub-layer function is enabled, the LSP end-to-end OAM tag grouping and the normal forwarding and processing of the customer information tag group are not affected. If the LSP is enabled with the end-to-end OAM and TCM sub-layer functions, the EXP value of the TCM OAM PDU ranges from 1 to 7. Otherwise, the EXP of the TCM OAM PDU ranges from 0 to 7.

步驟三： TCM子层出口 LSR识别并处理 TCM OAM标记分组。如果接收的 TCM OAM PDU包含的 EXP属于当前 TCM子层的映射值，处理该 TCM OAM PDU净荷，并终止 TCM OAM标记分组继续向前转发。否则，直接向前转发或丟弃接收的 TCM OAM标记分組。 Step 3: TCM Sublayer Exit The LSR identifies and processes the TCM OAM marker packet. If the received EXP of the TCM OAM PDU belongs to the mapping value of the current TCM sublayer, the TCM OAM PDU payload is processed, and the TCM OAM marked packet is terminated and forwarded forward. Otherwise, the received TCM OAM marker packet is forwarded or discarded directly.

如果 LSP是双向的，另一方向依然可以根据上述步骤实现 TCM子层功 If the LSP is bidirectional, the other direction can still implement the TCM sublayer function according to the above steps.

H 。本发明使用 TCM OAM PDU的 EXP字段标识 TCM子层。当 LSP包含嵌套的 TCM子层时，不需要为不同 TCM子层的 TCM OAM PDU净荷添加多层标记条目。由于属于同一条 LSP的所有 TCM OAM标记分组标记栈深度相同，在减少占用有效 MPLS网络带宽资源的同时，也相对简化了功能实现的复杂度。任何 TCM子层与 TCM OAM PDU的 EXP之间的映射方法，凡是使用 TCM OAM PDU的 EXP判断接收的 TCM OAM PDU是否属于当前 TCM子层的方法都不违背本发明的原则。 H. The present invention uses the EXP field of the TCM OAM PDU to identify the TCM sublayer. When the LSP contains nested TCM sublayers, there is no need to add multiple layer tag entries for TCM OAM PDU payloads of different TCM sublayers. Since all TCM OAM marking packet marking stacks belonging to the same LSP have the same depth, the complexity of function implementation is relatively simplified while reducing the bandwidth resources of the effective MPLS network. The mapping method between any TCM sublayer and the EXP of the TCM OAM PDU, whether using the EXP of the TCM OAM PDU to determine whether the received TCM OAM PDU belongs to the current TCM sublayer, does not violate the principles of the present invention.

应当理解的是，对本发明所在领域的普通技术人员来说，可以根据本发明的技术方案及其构思进行相应的等同改变或替换，而所有这些改变或替换，都应属于本发明所附权利要求的保护范围。 It should be understood that those skilled in the art to which the present invention pertains may make corresponding equivalent changes or substitutions in accordance with the technical solutions of the present invention, and all such changes or substitutions should be included in the appended claims. The scope of protection.

工业实用性 Industrial applicability

本发明提供的一种使用 EXP字段标识监视子层的方法，在保证这两种功能实现相对筒单的同时，避免了采用标记堆叠方式浪费 MPLS路径带宽资源的弊端，增加了网络传送客户信息的能力。 The invention provides a method for identifying a monitoring sublayer by using an EXP field, which ensures that the two functions realize a relatively simple operation, and avoids the disadvantage of wasting the MPLS path bandwidth resource by using the label stacking method, and increases the network transmission of the customer information. ability.

Claims

权利要求书 Claim

1、一种使用 EXP 字段标识监视子层的方法，其特征在于包括如下步骤： A method for identifying a monitoring sublayer using an EXP field, comprising the steps of:

步骤 A: 启用多协议标记交换网络标记交换通道的监视子层功能时，所述监视子层入口标记交换路由器生成并向前发送操作维护与管理 OAM标记分组，所述 OAM标记分组的协议数据单元包含一个标记条目，所述标记条目的 EXP字段用于标识所述监视子层； Step A: When the monitoring sublayer function of the multi-protocol label switching network label switching channel is enabled, the monitoring sub-layer ingress label switching router generates and forwards an operation maintenance and management OAM marking packet, and the protocol data unit of the OAM marking packet Include a tag entry, the EXP field of the tag entry is used to identify the monitoring sublayer;

步骤 B: 所述监视子层出口标记交换路由器识别并处理所述 OAM标记分组，如果接收的 OAM协议数据单元包含的 EXP属于当前监视子层的映射值，处理该 OAM协议数据单元净荷，并终止该 OAM标记分组继续向前转发，否则，直接向前转发或丟弃接收的 OAM标记分组。 Step B: The monitoring sub-layer egress label switching router identifies and processes the OAM marking packet, and if the received EXP data unit includes an EXP that belongs to a mapping value of the current monitoring sublayer, processes the OAM protocol data unit payload, and The OAM tagged packet is terminated and forwarded forward, otherwise the received OAM tagged packet is forwarded or discarded directly.

2、如权利要求 1所述的方法，其特征在于，所述标记条目的标记值 lable 为 14、 S值为 1、生存时间 TTL值为 1。 2. The method according to claim 1, wherein the tag entry has a tag value lable of 14, an S value of 1, and a lifetime TTL value of 1.

3、如权利要求 2所述的方法，其特征在于，属于同一条标记交换通道的多个监视子层，在每监视子层内部， OAM协议数据单元包含的 EXP保持唯一。 3. The method according to claim 2, wherein a plurality of monitoring sublayers belonging to the same label switching channel, within each monitoring sublayer, the EXP included in the OAM protocol data unit remains unique.

4、如权利要求 3所述的方法，其特征在于，当所述监视子层之间存在嵌套关系时，存在嵌套关系的监视子层之间， OAM协议数据单元包含的 EXP也保持唯一。 4. The method according to claim 3, wherein when there is a nested relationship between the monitoring sublayers, there is a nested relationship between the monitoring sublayers, and the EXP included in the OAM protocol data unit is also unique. .

5、如权利要求 1至 4任一所述的方法，其特征在于，步骤 A前还包括: 标记交换通道穿过多协议标记交换网络的一个或多个管理域，选择在所述标记交换通道穿过的入口标记交换路由器和出口标记交换路由器之间、各管理域两个边界标记路由器之间和 /或相邻管理域邻接标记路由器之间配置监视子层功能。 The method according to any one of claims 1 to 4, wherein before step A, the method further comprises: marking the switching channel through one or more management domains of the multi-protocol label switching network, and selecting the label switching channel The monitoring sublayer function is configured between the ingress label switching router and the egress label switching router, between the two border marking routers of each management domain, and/or between adjacent management domain adjacency marking routers.

6、如权利要求 5所述的方法，其特征在于，所述 OAM标记分组的外层标记条目中， LSP-S为 0, 指示所述 OAM标记分组承载的净荷不是客户信息。 The method according to claim 5, wherein in the outer tag entry of the OAM tag packet, the LSP-S is 0, indicating that the payload carried by the OAM tag packet is not client information.

7、如权利要求 6所述的方法，其特征在于，所述 OAM协议数据单元包含的 EXP取值范围为 0-7。 7. The method of claim 6, wherein the OAM protocol data unit The included EXP range is 0-7.

8、如权利要求 7所述的方法，其特征在于，标记交换通道同时启用端到端 OAM和监视子层功能时，所述 OAM协议数据单元包含的 EXP取值范围为 1-7。 The method according to claim 7, wherein when the label switching channel simultaneously enables the end-to-end OAM and the monitoring sub-layer function, the OAM protocol data unit includes an EXP value ranging from 1-7.

9、如权利要求 1至 4任一所述的方法，其特征在于，所述标记交换通道是单向或双向的。 9. A method according to any one of claims 1 to 4 wherein the label switching channel is unidirectional or bidirectional.

10、如权利要求 1所述的方法，其特征在于，对于同一条标记交换通道，最大允许存在 8层监视子层。 10. The method of claim 1 wherein for the same tag switched channel, a maximum of 8 layers of monitoring sublayers are allowed.

11、如权利要求 1所述的方法，其特征在于，所述监视子层是子网连接监视子层或串联连接监视子层。 11. The method of claim 1 wherein the monitoring sublayer is a subnet connection monitoring sublayer or a serial connection monitoring sublayer.