WO2007082424A1

WO2007082424A1 - A method for identifying multiple emulation traffic flow paths

Info

Publication number: WO2007082424A1
Application number: PCT/CN2006/002168
Authority: WO
Inventors: Huachen Zhang; Huaming Lu; Jian Qiao
Original assignee: Huawei Technologies Co., Ltd.
Priority date: 2006-01-23
Filing date: 2006-08-24
Publication date: 2007-07-26
Also published as: CN100433722C; CN1878136A

Abstract

A method for identifying multiple emulation traffic flow paths includes: in the mode of N to 1 that multiple emulation traffic flows are carried by one traffic flow path, the attachment circuit identifier identifying the sub-attachment circuit is set; one end of the pseudo wire sends the message which carries the attachment circuit identifier identifying the first sub-attachment circuit, and the other end of the pseudo wire searches the second sub-attachment circuit which has the same attachment circuit identifier according to the received attachment circuit identifier; if the second sub-attachment circuit and the pseudo wire work normally, the hardware forwarding table is sent down and the service message is forwarded. In the present invention, the identifier (AC-id) is used to identify the AC service, the different AC services are identified, the information of the emulation service is obtained veraciously, and the PW condition and the actual forwarding condition are consistent strictly. Therefore, the waste of the process resource and the network bandwidth resource of the nodes on the way is avoided when the traffic transmission could not be intercommunicated, meanwhile, the forwarding rate is increased.

Description

一种识别多条仿真业务流路径的方法技术领域 Method for identifying multiple simulation service flow paths

本发明涉及通信技术领域，尤其涉及一种基于端到端的伪线路仿真 The present invention relates to the field of communications technologies, and in particular, to an end-to-end pseudowire simulation.

( PWE3 , Pseudo-Wire Emulation Edge-to-Edge ) 的识别多条仿真业务流路径的方法。发明背景 (PWE3, Pseudo-Wire Emulation Edge-to-Edge) A method of identifying multiple simulated traffic flow paths. Background of the invention

目前，运营商在提供多种业务时，采用的基本都是并行或 "重叠" 的方式，即通过组建和维护多种网络，在呈现点针对每种不同的业务使用不同的接入设备。这样，除了使得网络规划更加复杂外，还增加了建设成本和运营成本。 At present, when operators provide multiple services, they basically adopt a parallel or "overlap" approach, that is, by setting up and maintaining multiple networks, and using different access devices for each different service at the presentation point. In this way, in addition to making network planning more complex, it also increases construction costs and operating costs.

为了提供统一的多业务网络平台， IETF开始了在包交换网络（ PSN ) 上传输任何业务（ X over PSN ) 的标准化工作，并将该工作命名为端到端的伪线路仿真，即 PWE3 ,该业务通过伪线（ PW )在客户边缘设备（ CE ) 与月艮务商设备（ PE, Provider Equipment )间建立附属电路（ AC, Attachment Circuit ), 以将 CE和 PE连接起来，实现可分为两种：一种是，一条仿真业务流路径只携带一条仿真业务流即 1 TO 1方式，此时一个 AC独占一个内部标签；另一种是，一条仿真业务流路径携带多条仿真业务流即 N T0 1方式，此时所有的 AC公用一个内部标签。一条仿真业务流路径携带多条仿真业务流的好处是可以更有效的使用 PW头。 In order to provide a unified multi-service network platform, the IETF began the standardization of transmitting any service (X over PSN) on the packet switched network (PSN), and named the work as end-to-end pseudo-line emulation, ie PWE3, the service. An auxiliary circuit (AC, Attachment Circuit) is established between the customer edge device (CE) and the Provider Equipment (PE) through the pseudowire (PW) to connect the CE and the PE. One is that one emulation service flow path carries only one emulation service flow, that is, 1 TO 1 mode. At this time, one AC monopolizes an internal label; the other is that one emulation service flow path carries multiple emulation service flows, that is, N T0 1 way, at this point all ACs share an internal tag. An emulated traffic flow path The benefit of carrying multiple emulated traffic flows is that PW headers can be used more efficiently.

PW的建立是两端服务商设备（PE, Provider Equipment )互相协商的结果，所以两端 PE要交互本地 PW转发状态。本地 F 的转发状态取决于需要进行仿真的 AC业务的状态、远端 PE的标签分发协议会话 ( LDP session ) 的状态以及承载伪线业务的外层隧道的状态。 The establishment of the PW is the result of mutual negotiation between the two Provider Equipments (PEs). Therefore, the PEs at both ends must exchange the local PW forwarding status. The forwarding state of the local F depends on the state of the AC service that needs to be simulated, and the label distribution protocol session of the remote PE. The status of the (LDP session) and the state of the outer tunnel carrying the pseudowire service.

在 N TO 1方式下， AC业务的状态取决于 PW对应的 N条子 AC状态的总和，现有协议网络模型中将 N TO 1方式下同时绑定同一条 PW的多条永久虛连接（PVC, Permanent Virtual Connect )合称为一条 AC, 本文遵从现有协议网络模型中的称法，但为了阐述方便，将 N T0 1方式下的 AC中的一条 PVC称为该 AC的一条子 AC, 对 AC业务的状态的确定为：如果在 W对应的多条子 AC中，当最后一条状态为正常工作状态（UP ) 的子 AC出现故障，转变成非正常工作状态（DOWN ) 时，也就是通常说的 DOWN掉了，则 AC的状态为 DOWN; 如果 PW对应的所有子 AC中第一条子 AC的状态为 UP, 则 AC的状态为 UP。 PE间相互通告 AC 状态的方式有两种： Martini 方式的通告和拓展的通告 In the N TO 1 mode, the state of the AC service depends on the sum of the N sub-AC states corresponding to the PW. In the existing protocol network model, multiple permanent virtual connections (PVCs) of the same PW are simultaneously bound in the N TO 1 mode. Permanent Virtual Connect is collectively referred to as an AC. This document complies with the terminology in the existing protocol network model. However, for the convenience of description, a PVC in the AC in the N T0 1 mode is called a sub-AC of the AC. The status of the service is determined as follows: If the sub-AC corresponding to the normal state (UP) fails in the multiple sub-ACs corresponding to W, and changes to the abnormal working state (DOWN), it is generally said. If the DOWN is off, the status of the AC is DOWN. If the status of the first sub-AC in all sub-ACs corresponding to the PW is UP, the status of the AC is UP. There are two ways for PEs to advertise AC status to each other: Notice of announcement and extension of Martini mode

( otification )方式的通告。 ( otification ) notification of the method.

1、 Martini方式的通告： 1. Announcement of Martini mode:

图 1为 Martini通告的示意图，如图 1所示，支设 PE1为本端 PE, PE2为远端 PE。在 PE1与 CE1之间的 AC1的状态、远端 PE的 LDP session 状态以及外层隧道即对应仿真业务流路径提供的隧道的状态同时为 UP, 本地 PW的转发状态为可转发， PE1向 PE2发送交互内层标签的标签映射（Mapping )报文，此时，如果 AC1的状态、远端 PE的 LDP session 状态以及外层隧道的状态三者中有一个 DOWN掉，则本地 PW的转发状态为不可转发，则 PE1向 PE2发送撤消（Withdraw )报文，并收回内层标签。如：在本地 PW的状态为 UP的情况下，只要 AC DOWN掉了，则本地 PW的转发状态为不可转发，发送 Withdraw报文，拆除协议。需要说明的是，图 1中所示的设备 P不对 PE1和 PE2间交互的 PWE3相关报文进行处理，仅是透传， PE1与 PE2间也可以直接相连。 Figure 1 is a schematic diagram of the Martini advertisement. As shown in Figure 1, PE1 is the local PE and PE2 is the remote PE. The state of the AC1 between PE1 and CE1, the LDP session state of the remote PE, and the state of the tunnel provided by the outer tunnel, that is, the corresponding simulated service flow path are both UP, the forwarding state of the local PW is forwardable, and PE1 sends the status to PE2. The mapping of the mapping of the inner label to the label of the inner label. In this case, if one of the status of the AC1, the LDP session status of the remote PE, and the status of the outer tunnel is DOWN, the forwarding status of the local PW is unavailable. After forwarding, PE1 sends an Withdraw message to PE2 and reclaims the inner label. For example, if the status of the local PW is Up, as long as the AC DOWN is lost, the forwarding status of the local PW is not forwarded, the Withdraw packet is sent, and the protocol is removed. It should be noted that the device P shown in FIG. 1 does not process the PWE3 related messages that are exchanged between PE1 and PE2, but only transparently transmits, and PE1 and PE2 can also be directly connected.

2、 Notification方式的通告：图 2为 Notification通告的示意图，假设 PE1为本端 PE, PE2为远端 PE,在 PE1与 CE1之间已建立 AC1 ,在 PE2与 CE2之间已建立 AC2。在 PE1与 PE2间通过发送 Mapping报文交互内层标签之后，只要配置不删除，协议就不拆除，只需通过发送 Notification报文交互双方的本地 PW状态。如: 在本地 PW的状态为 UP的情况下，只要 AC1 DOWN掉了，则本地 PW的转发状态为不可转发，但此时 PE1并不发送 Withdraw 报文拆除协议，而发送 Notification报文通告 PE2本地 PW的转发状态为不可转发，比如通过通告本地 PW的状态码来实现，保留内层标签，如图 2所示， Notification报文中包含本地 PW的状态码。 2. Notification of notification method: Figure 2 is a schematic diagram of the Notification notification. Assume that PE1 is the local PE and PE2 is the remote PE. AC1 is established between PE1 and CE1. AC2 is established between PE2 and CE2. After the internal label is exchanged between PE1 and PE2, the protocol is not deleted. The local PW status of the two parties is exchanged by sending a Notification packet. For example, if the status of the local PW is Up, the forwarding state of the local PW is not forwardable as long as the AC1 DOWN is lost. However, PE1 does not send the Withdraw packet teardown protocol, but sends a Notification packet to notify PE2. The forwarding state of the PW is not forwardable. For example, the local PW is saved by advertising the status code of the local PW. As shown in Figure 2, the notification packet contains the status code of the local PW.

在 Martini方式下，是否发送 Mapping报文取决于 AC的状态、对端 PE的 LDP session的状态以及外层隧道的状态是否同时为 UP, 只要三者的状态有一个为 DOWN, 则发送 Withdraw报文收回内层标签；在 Notification方式下，进行配置后，只要对端 PE的 LDP session的状态为 UP,则不管 AC的状态或者外层隧道的状态是否为 UP,都发送 Mapping 报文，而当 AC的状态或者外层隧道的状态为 DOWN后，更新本地的 PW状态码，并将本地的 PW状态码通过 Notification报文告知对端 PE。 In the Martini mode, whether the packet is sent depends on the status of the AC, the status of the LDP session of the peer PE, and the status of the outer tunnel. If the status of the three is DOWN, the device sends the Withdraw packet. The internal label is reclaimed. In the notification mode, if the status of the LDP session of the peer PE is Up, the mapping packet is sent regardless of whether the status of the AC or the outer tunnel is Up. After the state or the state of the outer tunnel is DOWN, the local PW status code is updated, and the local PW status code is notified to the peer PE through the Notification message.

Notification方式与 Martini方式的区别主要在于：只要配置不删除，就不拆除协议、回收内层标签，而只发送 Notification ^艮文通告本地 PW状态为不可转发状态，这样，当 AC的状态或者外层隧道的状态重新 UP 时，不需要重新再分配标签，只需再发送 Notification报文通告本地 PW 转发状态为可转发即可。可见，现有技术 Notification方式与 Martini方式相比，减少了 PE之间的消息报文的交互。 The difference between the notification mode and the Martini mode is as follows: As long as the configuration is not deleted, the protocol is not removed, the inner label is reclaimed, and only the notification is sent to notify the local PW status that the status is not forwardable. Thus, when the status or outer layer of the AC is When the status of the tunnel is re-up, you do not need to re-allocate the label. You only need to send a Notification packet to advertise the local PW forwarding status to forwardable. It can be seen that the prior art notification mode reduces the interaction of message messages between PEs compared with the Martini mode.

但 Notification方式与 Martini方式的一个共同的缺点在于：无法通告具体的 AC业务对的信息。图 3是现有技术 N TO 1方式下 PW网络示意图，如图 3 所示，其中子 AC1-子 AC3 ( subACl-subAC3 ) 和 subAC2-subAC⁴分别是两条业务流，组成两个子 AC业务对，并采用 N TO 1的方式复用伪线 1。 subACl和 subAC2分别接入 PE1不同的端口，两者状态组合形成 PE1处的 AC状态； subAC3和 subAC4分别接入 PE2不同的端口，两者状态组合形成 PE2处的 AC状态。 However, a common disadvantage of the Notification method and the Martini method is that it cannot advertise the information of a specific AC service pair. 3 is a schematic diagram of a PW network in the prior art N TO 1 mode, as shown in FIG. 3, where sub-AC1-sub AC3 (subACl-subAC3) and The subAC2-subAC ⁴ is two service flows, which form two sub-AC service pairs, and multiplex the pseudo-line 1 by using N TO 1. SubACl and subAC2 are respectively connected to different ports of PE1, and the two states are combined to form an AC state at PE1; subAC3 and subAC4 are respectively connected to different ports of PE2, and the states of the two are combined to form an AC state at PE2.

在 PE1处，当 PE1与远端 PE的 LDP session的状态以及外层隧道的状态均为 UP时，如果 subACl状态由 DOWN变为 UP，则 PE1处的 AC状态为 UP,本地 PW转发状态为可转发状态 ,此时或者发送 Mapping 报文，或者发送 Notification报文通告本地 PW状态为 UP。在 PE2处，当 PE2与对端 PE的 LDP session状态以及外层隧道的状态都为 UP时，如果 subAC4状态由 DOWN变为 UP, 则 PE2处的 AC状态为 UP, 此时 PE2的转发状态也为可转发状态。由于本地和远端的 PW转发状态都为可转发状态，所以 PW的状态为 UP, 下发辑转发表项。 If the status of the LDP session of the PE1 and the remote PE is UP, the AC status of the PE1 is Up and the local PW forwarding status is OK. The forwarding state is either the sending of the MAPP message or the notification of the local PW status. At PE2, when the LDP session status of the PE2 and the peer PE and the status of the outer tunnel are both UP, if the subAC4 status changes from DOWN to UP, the AC status at PE2 is UP, and the forwarding status of PE2 is also It is a forwardable state. The local and remote PW forwarding states are both forwardable. Therefore, the PW is in the Up state and the forwarding entry is sent.

但实际情况是， subACl和 subAC3才是一个业务对，所以 subACl 的业务信息通过 PW1到达 PE2后，如果 subAC3状态为 DOWN, subACl 的业务报文是会被 PE2丢弃的。由此可见，在这种状况下，无论是 Martini 方式还是 Notification方式都无法通告 AC的正确业务对信息，从而导致 subACl的业务信息通过 PW1到达 PE2后并不能最终转发到目的地，而是被丢弃，白白加大了沿途节点的处理负担，更为重要的是浪费了网络带宽资源。 The actual situation is that subACl and subAC3 are a service pair. Therefore, after subACl service information reaches PE2 through PW1, if subAC3 status is DOWN, subACl service packets are discarded by PE2. Therefore, in this situation, neither the Martini nor the Notification can advertise the correct service pair information of the AC. As a result, the service information of the subACl cannot be finally forwarded to the destination after being sent to the PE2 through the PW1, but is discarded. It has increased the processing burden of nodes along the way, and more importantly, wasted network bandwidth resources.

下面，以 ATM的 N TO 1报文封装帧格式为例，介绍现有技术对于 N TO 1方式下 PW业务的具体报文封装格式，其它业务的封装基本类似。表 1为现有技术 N TO 1 ATM PW报文帧封装格式示意图，表 2为现有技术 N TO 1 ATM PW报文帧中异步传输模式业务净荷（ATM Service Payload ) 具体封装格式示意图，如表 1、 2所示的封装格式，通过报文中所带的虚通道标识 /虛通路标识（VPI/VCI ) 区分具体的 AC, 协议中规定：要保证来自不同端口的 PVC的 VPI/VCI值各不相同，但是，在实际应用中是很难保证的。因此需要借助通过用户命令进行配置的输出The following describes the specific packet encapsulation format of the PW service in the N TO 1 mode. The encapsulation of other services is similar. Table 1 is a schematic diagram of a format of a packet encapsulation of an NTO 1 ATM PW packet in the prior art. Table 2 is a schematic diagram of a specific encapsulation format of an ATM service Payload in an N TO 1 ATM PW packet frame in the prior art, such as The encapsulation format shown in Tables 1 and 2 distinguishes the specific AC by the virtual channel identifier/virtual path identifier (VPI/VCI) carried in the packet. Regulation: To ensure that the VPI/VCI values of PVCs from different ports are different, but it is difficult to guarantee in practical applications. Therefore, you need to use the output configured by user commands.

VPI/输出 VCI ( outvpi/outvci )对来自各个端口的 PVC的 VPI/VCI值进行一个转换，做到全局唯一，以便当收到 N TO 1 ATM PW报文帧时，通过 outvpi/outvci来查找具体的 PVC, 对不同业务分别处理。对表 1和表 2中各字段的具体介绍可参见相关协议，这不再赘述。 The VPI/Output VCI (outvpi/outvci) performs a conversion on the VPI/VCI value of the PVCs from each port, so that it is globally unique, so that when the N TO 1 ATM PW message frame is received, the outvpi/outvci is used to find the specific PVC, processed separately for different businesses. For a detailed description of the fields in Table 1 and Table 2, refer to the related protocol, which is not described here.

包交换传输头（如果需要）（ PSN Transport Header ) Packet switched transport header (if required) (PSN Transport Header)

伪线头（ Pseudo Wire Header ) Pseudo Wire Header

标志位（Flag ) 预留（Res ) 长度 ( Length ) 序列号 Flag (Flag) Reserved (Res) Length (Length) Serial Number

( Sequence Number ) 异步传输模式业务净荷（ ATM Service Payload ) ( Sequence Number ) Asynchronous Transfer Mode Service Payload ( ATM Service Payload )

表 1 Table 1

控制字 (可选 ) ( Control Word ) Control word (optional) ( Control Word )

虛通道标识（VPI ) 虚通路标识（VCI ) 净荷类型标识（PTI ) 丢失优先级（C ) 异步传输模式净荷（ATM Payload ) 虚通道标识（VPI ) 虛通路标识（VCI ) 净荷类型标识（PTI ) 丢失优先级（C ) 异步传输模式净荷（ATM Payload ) Virtual Channel Identification (VPI) Virtual Path Identification (VCI) Payload Type Identifier (PTI) Loss Priority (C) Asynchronous Transfer Mode Payload (ATM Payload) Virtual Channel Identifier (VPI) Virtual Path Identifier (VCI) Payload Type Identifier (PTI) Loss Priority (C) Asynchronous Transfer Mode Payload (ATM Payload)

表 1和表 2所示的现有 N TO 1方式下 PW业务的具体报文封装格式的局限在于： The limitations of the specific packet encapsulation format of the PW service in the existing N TO 1 mode shown in Table 1 and Table 2 are as follows:

1 ) ^"应 PW出方向的 outvpi/outvci和入方向的 inputvpi/inputvci的值不一定相同，所以入方向和出方向都需要配置 PW和 PVC的绑定命令，如： a. PVC + PW + outvpi/outvci 1) ^"The value of the outvpi/outvci in the outbound direction of the PW and the inputvpi/inputvci in the inbound direction are not necessarily the same. Therefore, the binding commands of the PW and the PVC need to be configured in both the inbound and outbound directions, such as: a. PVC + PW + Outvpi/outvci

b. inputvpi/inputvci + PW + PVC b. inputvpi/inputvci + PW + PVC

这样，增加了用户配置的复杂性。 2 )'硬件实现较为复杂，查找效率较低。对于入方向，需要根据报文中的 inputvpi/inputvci , 获得对应的 PVC , vpi/vci的范围分别是 12位 /16位，但由于一般的设备支持的 PVC数目远小于 2的 28次方，所以在硬件上需要用 HASH来完成映射。 This increases the complexity of user configuration. 2) 'Hardware implementation is more complicated, and the search efficiency is lower. For the inbound direction, the corresponding PVC needs to be obtained according to the inputvpi/inputvci in the packet. The range of vpi/vci is 12 bits/16 bits respectively, but the number of PVCs supported by the general device is much smaller than the 28th power of 2, so HASH is required to complete the mapping on the hardware.

综上所述，现有技术由于无法通告 AC的正确业务对消息，在非业务对的 AC状态为 UP时，确定为 PW状态 UP, 但此时 PW又不能真正转发报文，导致了 PW状态和实际的转发状态不一致，此时，即使一端的 AC信息通过 PW伪线到达另一端的 PE，也不能被继续转发，而是被该 PE丟弃，从而浪费了沿途节点的处理资源和网络带宽资源的缺陷。发明内容 In summary, the PW state is determined by the PW state when the AC status of the non-service pair is Up, and the PW state is not forwarded. This is inconsistent with the actual forwarding state. In this case, even if the AC information of one end reaches the PE of the other end through the PW pseudowire, it cannot be forwarded, but is discarded by the PE, thus wasting the processing resources and network bandwidth of the nodes along the path. Defects in resources. Summary of the invention

有鉴于此，本发明的主要目的在于提供一种识别多条仿真业务流路径的方法，能够准确获知仿真业务对信息，使 PW状态和实际的转发状态一致，同时减轻沿途节点的处理负担，节约网络带宽资源。 In view of this, the main purpose of the present invention is to provide a method for identifying a plurality of simulated service flow paths, which can accurately learn the information of the simulated service, make the PW state and the actual forwarding state consistent, and reduce the processing load of the nodes along the path, saving Network bandwidth resources.

为达到上述目的，本发明的技术方案具体是这样实现的： In order to achieve the above object, the technical solution of the present invention is specifically implemented as follows:

一种识别多条仿真业务流路径的方法，在一条仿真业务流路径携带多条仿真业务流 N TO 1方式下，设置用于标识子附属电路业务对的附属电路标识；该方法还包括： A method for identifying a plurality of simulated service flow paths, wherein an emulation service flow path carries a plurality of emulation service flows N TO 1 mode, and an auxiliary circuit identifier for identifying a sub-attachment circuit service pair is set; the method further includes:

A. 伪线第一端发送携带有标识第一子附属电路所属子附属电路业务对的附属电路标识的通告报文，伪线第二端根据接收到的附属电路标识，查找具有相同附属电路标识的第二子附属电路； A. The first end of the pseudowire sends an advertisement message carrying the identifier of the auxiliary circuit identifying the service pair of the sub-attachment circuit to which the first sub-attachment circuit belongs, and the second end of the pseudo-line finds the same auxiliary circuit identifier according to the received accessory circuit identifier. Second sub-attachment circuit;

B. 若第二子附属电路和所述伪线均处于正常工作状态，下发硬件转发表项、转发业务报文。 B. If the second sub-auxiliary circuit and the pseudowire are in a normal working state, the hardware sends a publication item and forwards the service packet.

所述通告报文包括：告知所述第一子附属电路处于正常状态的正常通告报文，或告知所述第一子附属电路为非正常的非正常通告报文。所述通告报文为正常通告 ^艮文；所述步骤 Β具体包括： The advertisement message includes: a normal advertisement message that informs that the first sub-affiliated circuit is in a normal state, or informs that the first sub-affiliated circuit is an abnormal abnormal advertisement message. The advertisement message is a normal advertisement; the step Β specifically includes:

若所述第二子附属电路的状态为正常工作状态，进一步判断所述伪线状态是否正常， If the state of the second sub-auxiliary circuit is a normal working state, further determining whether the pseudowire state is normal,

若所述伪线为正常工作状态，则将位于所述伪线第二端的第二服务商设备中的所述子附属电路业务对中第一端子附属电路的状态置为正常工作状态，下发硬件转发表项、转发业务报文； If the pseudowire is in a normal working state, the state of the first terminal accessory circuit of the sub-auxiliary circuit service pair in the second service provider device at the second end of the pseudowire is set to a normal working state, and is sent The hardware forwards the entry and forwards the service packet.

若所述伪线为非正常工作状态，则将位于所述伪线第二端的第二服务商设备中的所述子附属电路业务对中第一端子附属电路的状态置为正常工作状态。 If the pseudowire is in an abnormal working state, the state of the first terminal accessory circuit of the sub-auxiliary circuit service pair in the second service provider device at the second end of the pseudowire is set to a normal working state.

该方法进一步包括： The method further includes:

若所述第二子附属电路的状态为非正常工作状态，则将位于所述伪线第二端的第二服务上设备中的所述第一子附属电路的状态置为正常工作状态。 If the state of the second sub-auxiliary circuit is an abnormal working state, the state of the first sub-auxiliary circuit in the second service-side device located at the second end of the pseudowire is set to a normal working state.

所述通告报文为非正常通告报文；所述步骤 Β具体包括：若所述第二子附属电路的状态为正常工作状态，进一步判断所述伪线状态是否正常， The notification message is an abnormal advertisement message. The step Β specifically includes: if the state of the second sub-auxiliary circuit is a normal working state, further determining whether the pseudowire state is normal,

若所述伪线为正常工作状态，则将位于所述伪线第二端的第二服务商设备中的所述子附属电路业务对中第一端子附属电路的状态置为非正常工作状态，并删除硬件转发表项； If the pseudowire is in a normal working state, setting a state of the first terminal accessory circuit of the sub-auxiliary circuit service pair in the second service provider device at the second end of the pseudowire to an abnormal working state, and Delete the hardware forwarding entry.

若所述伪线为非正常工作状态，则将位于所述伪线第二端的第二服务商中的所述子附属电路业务对中第一端子附属电路的状态置为非正常工作状态。 And if the pseudowire is in an abnormal working state, setting a state of the first terminal auxiliary circuit of the sub-auxiliary circuit service pair in the second service provider located at the second end of the pseudowire to a non-normal working state.

所述附属电路标识符携带在通告报文中设置的附属电路标识转发索引中。 The accessory circuit identifier is carried in an attached circuit identifier forwarding index set in the advertisement message.

所述判断伪线状态是否正常的方法为：若伪线两端的内层标签均已分配，则所述伪线状态为正常工作状态，否则，所述伪线状态为非正常工作状态。 The method for determining whether the pseudowire state is normal is: If the inner layer labels at both ends of the pseudowire are allocated, the pseudowire state is a normal working state; otherwise, the pseudowire state is an abnormal working state.

由上述技术方案可见，本发明的有益效果为：通过利用标识 AC业务对的 AC标识（ AC-id ), 识别不同的 AC业务对，准确获知了仿真业务对信息，使得 PW状态和实际的转发状态严格一致，避免了不能最终互通的业务传输而浪费沿途节点的处理资源和网络带宽资源；并且在 N TO 1方式下，本发明采用简单的 AC与 PW绑定的业务配置命令，配置量只有以前的一半；同时，由于采用 AC-id转发索引字段代替 VPI/VCI 字段来具体标识一条 PVC进行转发，筒化了硬件实现，通过查找 AC-id 对应的转发索引确定具体 PVC的信息，提高了转发速度。附图简要说明 As can be seen from the foregoing technical solutions, the beneficial effects of the present invention are: by using the AC identifier (AC-id) that identifies the AC service pair, identifying different AC service pairs, accurately obtaining the simulated service pair information, and making the PW state and the actual forwarding. The state is strictly consistent, and the processing resources and the network bandwidth resources of the nodes along the path are avoided in the service transmission that cannot be finally intercommunicated; and in the N TO 1 mode, the present invention adopts a simple AC and PW binding service configuration command, and the configuration amount is only At the same time, the AC-id forwarding index field is used instead of the VPI/VCI field to specifically identify a PVC for forwarding, and the hardware implementation is implemented. The information of the specific PVC is determined by looking up the forwarding index corresponding to the AC-id. Forwarding speed. BRIEF DESCRIPTION OF THE DRAWINGS

图 1为 Martini方式通告的网络示意图； Figure 1 is a schematic diagram of the network announced by the Martini mode;

图 2为 Notification方式通告的网络示意图； 2 is a schematic diagram of a network notified by a notification method;

图 3为现有技术 N TO 1方式下 PW网络示意图； 3 is a schematic diagram of a PW network in the prior art N TO 1 mode;

图 4为本发明 N T0 1方式下 PW网络示意图。实施本发明的方式 4 is a schematic diagram of a PW network in the N T0 1 mode of the present invention. Mode for carrying out the invention

本发明的核心思想是：在 N TO 1方式下，设置用于标识子附属电路业务对的附属电路标识；伪线一端发送携带有标识第一子附属电路的附属电路标识的通告报文，伪线另一端根据接收到的附属电路标识，查找具有相同附属电路标识的第二子附属电路；若第二子附属电路和所述伪线均处于正常工作状态，下发硬件转发表项、转发业务报文。 The core idea of the present invention is: In the N TO 1 mode, an auxiliary circuit identifier for identifying a sub-subsidiary circuit service pair is set; and a pseudowire end transmits an advertisement message carrying an auxiliary circuit identifier identifying the first sub-auxiliary circuit, and is pseudo- The other end of the line finds the second sub-attachment circuit having the same auxiliary circuit identifier according to the received accessory circuit identifier; if the second sub-affiliated circuit and the pseudowire are in a normal working state, the hardware forwarding entry and the forwarding service are delivered. Message.

为使本发明的目的、技术方案及优点更加清楚明白，以下参照附图并举较佳实施例，对本发明进一步详细说明。本发明基于 PWE3 的识别多条仿真业务流路径的方法包括以下过程：在配置 AC N TO 1方式 PW绑定命令时，设置用于标识 AC业务对的 AC-id转发索引配置项；在发送的 Notification报文中增加 AC-id转发索引字段，当对端收到 Notification报文后依据 AC-id转发索引寻找匹配 (对应）的子 AC, 只有当一条仿真业务流路径中 AC对的两端的状态都为 UP且 PW的状态也为 UP时，才下发硬件转发表项，转发业务报文，否则不转发业务^ ^艮文。具体方法如下： The present invention will be further described in detail below with reference to the drawings and preferred embodiments. The method for identifying a plurality of simulated service flow paths based on the PWE3 includes the following process: When configuring the AC N TO 1 mode PW binding command, setting an AC-id forwarding index configuration item for identifying an AC service pair; The AC-id forwarding index field is added to the notification packet. When the peer receives the notification packet, it searches for the matching (corresponding) sub-AC according to the AC-id forwarding index. Only the status of the two ends of the AC pair in the simulated service flow path. When the status is UP and the status of the PW is also Up, the hardware forwarding entry is sent and the service packet is forwarded. Otherwise, the service is not forwarded. The specific method is as follows:

1、在配置 AC的 N TO 1方式 PW绑定命令时 , 增加 AC-id转发索引的配置项，用于标识 AC业务对。 1. Configure the configuration item of the AC-id forwarding index to identify the AC service pair when you configure the NTO 1 PW binding command.

图 4是本发明 N TO 1方式下 PW网絡示意图，如图 4所示，例如，设置 subACl-subAC3业务对的 AC-id等于 1 , 设置 subAC2-subAC4业务对的 AC-id等于 2。 4 is a schematic diagram of a PW network in the N TO 1 mode of the present invention. As shown in FIG. 4, for example, the AC-id of the subACl-subAC3 service pair is set to 1 and the AC-id of the subAC2-subAC4 service pair is set to 2.

2、在发送的 Notification报文中增加 AC-id转发索引字段，通过 AC-id, 通告对端 PE本端与该 AC-id对应的子 AC的状态。 2. Add the AC-id forwarding index field to the sent notification packet, and advertise the status of the sub-AC corresponding to the AC-id on the peer PE.

结合图 4, 假设 PW一端如 PE1 的所有子 AC 中第一条子 AC是 subACl , 当 subACl的状态由 DOW 变为 UP时， PE1向对端如 PE2 发送 Notification报文，该 Notification报文中携带 subACl的 AC-id, 通告 subACl当前状态为 UP; As shown in Figure 4, it is assumed that the first sub-AC of all the sub-ACs of the PW, such as PE1, is sub-ACI. When the status of the sub-ACl is changed from the DOW to the UP, the PE1 sends a Notification packet to the peer, such as the PE2. The Notification packet carries the notification packet. The AC-id of the subACl, advertises that the current status of subACl is UP;

PE2接收到 Notification报文后，查找与该 Notification报文中携带的 AC-id匹配的子 AC业务，假设为 subAC3 , 如果位于 PE2的 subAC3 业务状态是 DOWN, 则 PE2将自身数据结构中对端即 PE1 的 subACl 的状态置为 UP; 如果位于 PE2的 subAC3业务状态也是 UP, 并且 PW 的状态为 UP, 则 PE2将自身数据结构中 PE1的 subACl的状态置为 UP 并下发硬件转发表项，开始转发业务报文，但是，若 PW 的状态为 DOWN, 则 PE2仅将自身数据结构中 PE1的 subACl的状态置为 UP。另外，假设 PW一端如 PE1 的所有子 AC 中最后一条子 AC是 subACl , 当 subACl的状态由 UP变为 DOW 时， PE1向对端如 PE2 发送 Notification报文，该 Notification报文中携带 subACl的 AC-id，通告 subACl当前状态为 DOWN; After receiving the Notification packet, PE2 searches for the sub-AC service that matches the AC-id carried in the Notification packet, which is assumed to be subAC3. If the subAC3 service status of PE2 is DOWN, PE2 will be the peer end of its own data structure. The status of the subACl of the PE1 is set to UP. If the subAC3 service status of the PE2 is also Up, and the status of the PW is Up, the PE2 sets the status of the subACl of the PE1 in the data structure to UP and sends the hardware forwarding entry. The service packet is forwarded. However, if the state of the PW is DOWN, PE2 only sets the state of subACl of PE1 in its own data structure to UP. In addition, it is assumed that the last sub-AC of all sub-ACs of the PW, such as PE1, is sub-ACI. When the status of sub-ACl changes from UP to DOW, PE1 sends a Notification packet to the peer, such as PE2. The Notification message carries the AC of subACl. -id, advertises the current status of subACl as DOWN;

PE2接收到 Notification报文后，查找与该 Notification报文中携带的 AC-id匹配的子 AC业务，假设为 subAC3，如果位于 PE2的 subAC3 业务状态是 UP, 且 PW的状态为 UP, 则 PE2将自身数据结构中对端即 PE1的 subACl的状态置为 DOWN, 并删除硬件转发表项，否则，仅将自身数据结构中 PE1的 subACl的状态置为 DOWN。这样， PE就能明确知道 PW状态、一条业务流路径中本端子 AC状态和对端子 AC状态了。 After receiving the Notification packet, PE2 searches for the sub-AC service that matches the AC-id carried in the Notification packet, which is assumed to be subAC3. If the subAC3 service status of PE2 is Up and the PW status is Up, PE2 will In the self-data structure, the peer, that is, the state of subACl of PE1 is set to DOWN, and the hardware forwarding entry is deleted. Otherwise, only the state of subACl of PE1 in its own data structure is set to DOWN. In this way, the PE can clearly know the PW status, the AC status of the terminal in a service flow path, and the AC status of the terminal.

本发明将 PW的状态和子 AC业务的状态进行严格的区分，并约定如果 PE两端 PW的标记都已经分配，即既给对端发了标记 Mapping消息，也收到了来自对端的标记 Mapping消息，则接收和发送两个方向的 PW的状态就是 UP, 否则 PW的状态就是 DOWN。这样做，使 PW的状态独立于 AC状态，状态的区分更明确，对协议的理解以及实现起来更力口清晰，同时也更加符合协议《dmft-ietf-pwe3-control-protocol-14.txt》中规定的 PWE3 Reference Model中对 PW的理解，也就是说， PW的状态应该和 AC状态独立。 The present invention strictly distinguishes the state of the PW from the state of the sub-AC service, and stipulates that if the PW tags of both ends of the PE are already allocated, that is, both the tagging message is sent to the peer end, and the tagging message from the peer end is also received. Then, the state of receiving and transmitting the PW in both directions is UP, otherwise the state of the PW is DOWN. In doing so, the state of the PW is independent of the AC state, the state is more clearly differentiated, the understanding of the protocol and the implementation are more clear, and it is more in line with the agreement "dmft-ietf-pwe3-control-protocol-14.txt" The PW is understood in the PWE3 Reference Model specified in the specification, that is, the state of the PW should be independent of the AC state.

3、调整 N TO 1方式的 FW报文帧封装格式 3. Adjust the FW message frame encapsulation format of the N TO 1 mode.

表 3是本发明 N TO 1 ATM PW报文帧中异步传输模式业务净荷的具体封装格式示意图，如表 3所示，以 ATM的 N TO 1方式的 PW报文帧封装格式的调整为例，说明本发明对于 N TO 1方式 PW封装报文格式的调整方案。将现有 N TO 1 ATM PW报文帧封装格式中的 VPI、 VCI 字段，改用 AC-id转发索引字段代替，并根据不同的 AC-id转发索引字段具体索引不同的 PVC。 Table 3 is a schematic diagram of a specific encapsulation format of the asynchronous transport mode service payload in the N TO 1 ATM PW packet frame of the present invention. As shown in Table 3, the adjustment of the PW packet frame encapsulation format of the ATM N TO 1 mode is taken as an example. The method for adjusting the format of the NTO 1 PW encapsulation packet is described. The VPI and VCI fields in the existing N TO 1 ATM PW packet frame encapsulation format are replaced by the AC-id forwarding index field, and the index words are forwarded according to different AC-ids. Segments specifically index different PVCs.

控制字（可选）（ Control Word ) Control word (optional) ( Control Word )

AC-id转发索引净荷类型标识（PTI ) 丟失优先级（ C ) AC-id forwarding index payload type identifier (PTI) loss priority (C)

异步传输模式净荷（ ATM Payload ) Asynchronous Transfer Mode Payload ( ATM Payload )

AC-id转发索引净荷类型标识（PTI ) 丢失优先级（ C ) AC-id forwarding index payload type identifier (PTI) loss priority (C)

表 3 table 3

对于其它伪线业务的 N TO 1封装格式的调整同理，如帧中继（FR ) 的仿真业务，也改用 AC-id转发索引来索引一条具体 FR业务流。 For the adjustment of the N TO 1 encapsulation format of other pseudowire services, such as the emulation service of Frame Relay (FR), the AC-id forwarding index is also used to index a specific FR service flow.

从以上可以看出，本发明通过引入子业务标识机制，使 PE设备可以区分出具体的 AC业务对，避免了由于非业务对的 AC UP导致的 PW 状态 UP, 而却不能真正转发 ·!艮文的状况。而且通过本发明机制，还可以避免通过 inputvpi/inputvci硬件查找对应的 PVC效率不高的问题。 As can be seen from the above, the present invention introduces a sub-service identification mechanism, so that the PE device can distinguish a specific AC service pair, and avoids the PW state UP caused by the AC UP of the non-service pair, but cannot be actually forwarded. The status of the text. Moreover, through the mechanism of the present invention, it is also possible to avoid the problem that the corresponding PVC is inefficiently searched by the inputvpi/inputvci hardware.

以上所述，仅为本发明的较佳实施例而已，并非用于限定本发明的保护范围，凡在本发明的精神和原则之内所做的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。 The above is only the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalents, improvements, etc., which are made within the spirit and principles of the present invention, should be included. It is within the scope of the invention.

Claims

权利要求书 Claim

1、一种识别多条仿真业务流路径的方法，在一条仿真业务流路径携带多条仿真业务流 N TO 1方式下，其特征在于，设置用于标识子附属电路业务对的附属电路标识；该方法还包括： A method for identifying a plurality of simulated service flow paths, wherein an emulation service flow path carries a plurality of emulation service flows N TO 1 mode, wherein the auxiliary circuit identifiers for identifying sub-affiliated circuit service pairs are set; The method also includes:

2、根据权利要求 1所述的方法，其特征在于，所述通告报文包括：告知所述第一子附属电路处于正常状态的正常通告报文，或告知所述第一子附属电路为非正常的非正常通告报文。 The method according to claim 1, wherein the advertisement message comprises: a normal advertisement message that informs that the first sub-affiliated circuit is in a normal state, or informs that the first sub-affiliated circuit is non- A normal abnormal notification message.

3、根据权利要求 1 所述的方法，其特征在于，所述通告报文为正常通告报文；所述步骤 B具体包括： The method according to claim 1, wherein the advertisement message is a normal advertisement message; the step B specifically includes:

4、据权利要求 3所述的方法，其特征在于，该方法进一步包括：若所述第二子附属电路的状态为非正常工作状态，则将位于所述伪线第二端的第二服务上设备中的所述第一子附属电路的状态置为正常工作状态。 4. The method of claim 3, wherein the method further comprises: if the state of the second sub-auxiliary circuit is an abnormal operating state, then the pseudo-location is located The state of the first sub-auxiliary circuit in the second service-on device at the second end of the line is set to a normal operating state.

5、根据权利要求 1 所述的方法，其特征在于，所述通告报文为非正常通告报文；所述步骤 B具体包括： The method according to claim 1, wherein the advertisement message is an abnormal advertisement message; the step B specifically includes:

6、根据权利要求 1 所述的方法，其特征在于，所述附属电路标识符携带在通告报文中设置的附属电路标识转发索引中。 The method according to claim 1, wherein the auxiliary circuit identifier is carried in an auxiliary circuit identifier forwarding index set in the advertisement message.

7、根据权利要求 3或 5所述的方法，其特征在于：所述判断伪线状态是否正常的方法为： The method according to claim 3 or 5, wherein: the method for determining whether the pseudowire state is normal is:

若伪线两端的内层标签均已分配，则所述伪线状态为正常工作状态，否则，所述伪线状态为非正常工作状态。 If the inner layer labels at both ends of the pseudowire are allocated, the pseudowire state is a normal working state; otherwise, the pseudowire state is an abnormal working state.