一种多协议标签交换网络的保护切换方法 技术领域 Protection switching method for multi-protocol label switching network
本发明涉及多协议标签交换（MPLS )技术， 更准确地说， 涉及一 种 MPLS网络的保护切换方法。 发明背景 The present invention relates to Multi-Protocol Label Switching (MPLS) technology and, more particularly, to a protection switching method for an MPLS network. Background of the invention
作为下一代网络的关键技术， MPLS技术在 DP网络中扮演着越来越 重要的角色。 MPLS技术最初是为提高路由器转发速度而提出的， 但是 由于其固有的优点， 它在流量工程、 虚拟个人网络（VPN )、 服务质量 ( QoS )等方面也得到了广泛的应用， 日益成为大规模 IP网络的重要标 准。 As a key technology for next-generation networks, MPLS technology plays an increasingly important role in DP networks. MPLS technology was originally proposed to improve router forwarding speed, but due to its inherent advantages, it has also been widely used in traffic engineering, virtual personal network (VPN), quality of service (QoS), etc. An important standard for IP networks.
随着 MPLS技术越来越成为 IP网络多业务承载的关键技术， MPLS 网络的故障检测和保护切换已经成为重要课题。 保护切换技术对于提高 MPLS网络的可用性和稳定性具有关键意义。 保护切换意味着对受保护 的标签交换路径 ( LSP )路由的预计算和资源的预分配，可以保证在 LSP 连接失效或者中断后快速重新获得网络资源。 As MPLS technology becomes more and more the key technology for multi-service bearer of IP networks, fault detection and protection switching of MPLS networks has become an important issue. Protection switching technology is critical to improving the availability and stability of MPLS networks. Protection switching means pre-computation of the protected label switched path (LSP) routes and pre-allocation of resources to ensure fast re-acquisition of network resources after the LSP connection fails or is interrupted.
图 1所示为现有技术中 MPLS网络保护切换示意图。 如图 1所示， 在正常情况下，工作流量（ working traffic )从入口标签交换路由器（ Ingress LSR )发送到出口 LSR ( Egress LSR )。 同时， 在入口 LSR周期性地插 入检测报文， 在出口 LSR接收该检测报文。 在入口 LSR插入的检测报 文可以为连通性验证（CV )拫文或者快速故障检测（FFD )报文。 当出 口 LSR在一定时间.内:不能接收到检测报文时，出口 LSR则判定工作 LSP 出现故障， 并通过反向路径向入口 LSR发送后向缺陷指示（BDI )消息 以通知入口 LSR该工作 LSP已经出现故障。入口 LSR收到 BDI消息后， 将工作流量切换到保护 LSP上。 也就是说， 在正常情况下， 工作流量交 换到工作 LSP, 当出口 LSR在一定时间内不能接收到检测报文时， 出口 LSR通过反向路径向入口 LSR发送 BDI消息， 然后入口 LSR将工作流 ' 量切换到保护 LSP。FIG. 1 is a schematic diagram of switching protection of an MPLS network in the prior art. As shown in Figure 1, under normal circumstances, the working traffic is sent from the ingress LSR to the egress LSR. At the same time, the detection packet is periodically inserted in the ingress LSR, and the detection packet is received at the egress LSR. The detection packet inserted in the ingress LSR may be a connectivity verification (CV) message or a fast failure detection (FFD) message. When the egress LSR is within a certain time. When the detection packet cannot be received, the egress LSR determines that the working LSP is faulty, and sends a backward defect indication (BDI) message to the ingress LSR through the reverse path to notify the ingress LSR of the working LSP. A failure has occurred. After the ingress LSR receives the BDI message, Switch the work flow to the protection LSP. That is, under normal circumstances, the working traffic is switched to the working LSP. When the egress LSR cannot receive the detection packet within a certain period of time, the egress LSR sends a BDI message to the ingress LSR through the reverse path, and then the ingress LSR will process the workflow. The quantity switches to the protection LSP.
在入口 LSR插入的 FFD报文和 CV报文的格式相同， 但是发送周 期不同。 通常 CV报文为 1秒（s ) 间隔， 而 FFD报文的报文间隔最低 可以达到 10毫秒（ms ), 并且一般默认值为 50ms。 The format of the FFD packet and the CV packet inserted in the ingress LSR are the same, but the transmission period is different. Generally, the CV packet is at the interval of 1 second (s), and the interval of the FFD packet is at least 10 milliseconds (ms), and the default value is 50 ms.
可以看出， 现有技术中首先根据检测报文的接收状况来判断工作 LSP的工作状况，然后再根据工作 LSP的工作状况来决定是否执行切换， 因此 LSP保护切换的快慢主要取决于检测报文发送的快慢。如果检测报 文发送得越快，那么检测出 LSP故障并进行 LSP切换的速度就越快。但 是， 实际中检测报文的发送速度却是有限制的， 检测报文并不能发送得 太快。 因为如果检测报文发送速度过快， 那么当 LSP的数量达到一定程 度时， 会极大地增加 CPU的处理负担。 所以在现有技术中， 在相同的 CPU处理能力下， 被保护的 LSP数量和 LSP保护切换速度之间存在矛 盾， 过快的检测报文发送速度会对支持保护的 LSP数目造成限制。 It can be seen that, in the prior art, the working status of the working LSP is first determined according to the receiving status of the detecting packet, and then the switching is performed according to the working status of the working LSP. Therefore, the speed of the LSP protection switching mainly depends on the detection packet. The speed of sending. The faster the detection message is sent, the faster the LSP failure is detected and the LSP is switched. However, the actual transmission speed of the detection packet is limited, and the detection packet cannot be sent too fast. Because if the detection packet is sent too fast, when the number of LSPs reaches a certain level, the processing load of the CPU is greatly increased. Therefore, in the prior art, there is a contradiction between the number of protected LSPs and the LSP protection switching speed under the same CPU processing capability. The excessively fast detection packet sending speed limits the number of LSPs that support protection.
而且， 由于在现有技术中为了保证快速切换通常需要有较快的检测 报文发送速度， 但是检测报文发送速度过快却会占用大量的网络带宽等 网络资源， 从而会影响正常业务的使用。 例如： 假设检测报文为 FFD报 文， 并且 FED报文的发送周期为 10ms, 也就是一秒钟发送 100个 FFD 报文， FFD报文的大小为 44字节， 那么当 LSP的数'目为 10K条时， 检 测报文占用的带宽大约为 （44bytex8 ) x ( lOOOms/lOms ) x 10000 = ' 352Mbps。..由此可见，，此时检测报文佘占 i 大量的网络带宽， 从而影响 正常业务的使用。 发明内容Moreover, in the prior art, in order to ensure fast switching, a fast detection packet sending speed is usually required, but detecting a packet sending speed too fast may occupy a large amount of network resources such as network bandwidth, thereby affecting the use of normal services. . For example, if the detection packet is an FFD packet, and the transmission period of the FED packet is 10 ms, that is, 100 FFD packets are sent in one second, and the size of the FFD packet is 44 bytes. When it is 10K, the bandwidth occupied by the detection packet is approximately (44bytex8) x (100OOms/lOms) x 10000 = '352Mbps. As can be seen, at this time, the detection packet occupies a large amount of network bandwidth, thereby affecting the use of normal services. Summary of the invention
有鉴于此，本发明的主要目的是提出一种 MPLS网络保护切换方法， 以在保证 LSP保护切换速度的同时支持保护更多数量的 LSP。 In view of this, the main object of the present invention is to propose an MPLS network protection switching method to support protection of a larger number of LSPs while ensuring LSP protection switching speed.
为达到上述目的， 本发明的技术方案是这样实现的： In order to achieve the above object, the technical solution of the present invention is achieved as follows:
—种多协议标签交换 MPLS网络保护切换方法， 包括： - Multi-protocol label switching MPLS network protection switching method, including:
A、在入口标签交换路由器 LSR和出口 LSR之间建立工作标签交换 路径 LSP和保护 LSP,并为所述工作 LSP的待保护部分建立快速重路由 FRR LSP, 入口 LSR通过工作 LSP向出口 LSR发送工作流量并插入检 测报文； A. Establish a working label switching path LSP and a protection LSP between the ingress label switching router LSR and the egress LSR, and establish a fast rerouting FRR LSP for the to-be-protected part of the working LSP, and the ingress LSR sends the working LSR to the egress LSR through the working LSP. Traffic and insert detection packets;
B、 如果 FRR LSP所连接的入口节点检测到工作 LSP出现故障， 入 口节点将工作流量由工作 LSP切换到 FRR LSP; B. If the ingress node connected to the FRR LSP detects that the working LSP is faulty, the ingress node switches the working traffic from the working LSP to the FRR LSP.
C、 如果所述出口 LSR不能接收到检测报文， 出口 LSR通过反向路 径向入口 LSR发送后向缺陷指示消息， 入口 LSR将工作流量切换到保 护 LSP。 C. If the egress LSR cannot receive the detection packet, the egress LSR sends a backward defect indication message through the reverse path radial ingress LSR, and the ingress LSR switches the working flow to the protection LSP.
在入口 LSR将工作流量切换到保护 LSP之后， 还包括： 如果出口 LSR重新接收到检测报文，停止向入口 LSR发送后向缺陷指示消息，入 口 LSR将工作流量切换到工作 LSP。 After the ingress LSR switches the working traffic to the protection LSP, the method further includes: if the egress LSR receives the detection packet again, stops sending the backward defect indication message to the ingress LSR, and the ingress LSR switches the working traffic to the working LSP.
所述入口 LSR切换工作流量为： 如果入口 LSR在预定的时间长度 之内接收不到出口 LSR发来的后向缺陷指示消息，则将工作流量切换到 工作 LSP。 The ingress LSR handover working traffic is: If the ingress LSR does not receive the backward defect indication message sent by the egress LSR within a predetermined length of time, the working flow is switched to the working LSP.
所述待保护部分为工作 LSP中任意一个工作节点； The to-be-protected part is any working node in the working LSP;
步骤 A所述建立 FRR LSP为： 在工作 LSP中该任意一个工作节点 的入口和出口之间建立 FRk LSP'。 · '、' ' ' ' ' ' ' ' ' 所述待保护部分为在工作 LSP 中任意两个工作节点之间的工作链 路； 步驟 A所述建立 FRR LSP为： 在工作 LSP中该任意两个工作节点 之间的工作链路的两端建立 FRR LSP。The FRR LSP is established in step A as follows: FRk LSP' is established between the entry and the exit of the working node in the working LSP. · ', '''''''' The part to be protected is the working link between any two working nodes in the working LSP; The FRR LSP is set up in step A: The FRR LSP is established at both ends of the working link between the two working nodes in the working LSP.
步骤 A所述建立 FRRLSP为： 建立不少于一条的 FRR LSP。 The FRRLSP is established as follows: Create no less than one FRR LSP.
步骤 B为： 当检测到所述工作节点的端口状态不正常时， 将工作流 量切换到 FRR LSP。 Step B is: when it is detected that the port status of the working node is abnormal, the working traffic is switched to the FRR LSP.
当检测到所述工作链路的链路连接状态不正常时， 将工作流量切换 到 FRRLSP。 When it is detected that the link connection status of the working link is abnormal, the working traffic is switched to the FRRLSP.
所述的 Said
所述 CV报文的发送周期为 1.秒；所述 FFD报文的发送周期大于 10 毫秒。 The sending period of the CV packet is 1. Second; the sending period of the FFD packet is greater than 10 milliseconds.
从以上的技术方案中可以看出， 本发明提出的 MPLS网络保护切换 方法中， 在入口 LSR和出口 LSR之间的待保护部分建立 FRR LSP; 然 后当 FRR LSP的入口节点检测到工作 LSP出现故障时， FRR LSP的入 口节点将工作流量切换到 FRR LSP; 然后当出口 LSR检测到该故障时， 入口 LSR再将工作流量由 FRR LSP切换到保护 LSP。 所以， 本发明通 过将 FRR LSP和保护 LSP相结合而实现了对工作 LSP的保护切换。 由 机制可以比通过检测报文更快地检测到 LSP故障， 因此在检测报文发现 故障之前， 工作流量已经通过 FRR LSP获得了保护。所以本发明首先获 得了比现有技术更快的 LSP保护切换速度。 同时， 由于提供了比检测报 文更快速的保护切换， 因此可以不需要高速发送检测报文， 所以可以在 不增加 CPU负担的情况下支持保护更多数目的 LSP。例如，可以将 FFD 报文设置成' ,50ms的发送周期， 对于优先级不高但仍需要使用□ LSP保护 的业务甚至可以使用发送频率为 1个 /秒的 CV报文，所以在相同的 CPU 处理能力下， 应用本发明可以支持更多的 LSP。 同时， 现有技术中检测报文频繁收发所带来网络带宽等资源的消耗As can be seen from the above technical solution, in the MPLS network protection switching method proposed by the present invention, the FRR LSP is established in the to-be-protected part between the ingress LSR and the egress LSR; and then the ingress node of the FRR LSP detects that the working LSP is faulty. The ingress node of the FRR LSP switches the working traffic to the FRR LSP. Then, when the egress LSR detects the fault, the ingress LSR switches the working traffic from the FRR LSP to the protection LSP. Therefore, the present invention implements protection switching to the working LSP by combining the FRR LSP and the protection LSP. The mechanism can detect the LSP failure faster than the detection packet. Therefore, before the detection packet finds the fault, the working traffic has been protected by the FRR LSP. Therefore, the present invention first obtains a faster LSP protection switching speed than the prior art. At the same time, since a protection switching is performed faster than the detection packet, it is not necessary to transmit the detection packet at a high speed, so that it is possible to support protection of a larger number of LSPs without increasing the CPU load. For example, the FFD message can be set to ', 50ms transmission period. For services with low priority but still need to use □ LSP protection, even CV packets with a transmission frequency of 1/sec can be used, so the same CPU With the processing capability, the application of the present invention can support more LSPs. At the same time, in the prior art, the consumption of resources such as network bandwidth caused by frequent detection and reception of packets is detected.
.也能显著降低。 以 50ms的发送周期发送 FF.D报文为例， .同样支持 10K 条 LSP, 此时所需要的网络带宽为： (44Bytex8) x ( 1000ms/50ms ) xlOK < 70Mbps, 为未使用 FRR LSP时的约 1/5; 而当使用 CV报文时， 需要 的网絡带宽为： （44Bytex8) χ10Κ = 3.52Μ, 此时网络带宽消耗甚至已经 可以基本忽略不计。 因此， 应用本发明后， 还极大地节省了网络带宽， 并且因此使得网絡的性能得到了显著优化。 附图简要说明Can also be significantly reduced. For example, the FF.D packet is sent in the 50ms transmission period. The same network bandwidth is required: (44Bytex8) x (1000ms/50ms) xlOK < 70Mbps, when the FRR LSP is not used. About 1/5; When using CV messages, the required network bandwidth is: (44Bytex8) χ10Κ = 3.52Μ, at this point the network bandwidth consumption can even be negligible. Therefore, after the application of the present invention, the network bandwidth is also greatly saved, and thus the performance of the network is significantly optimized. BRIEF DESCRIPTION OF THE DRAWINGS
图 1为现有技术中 MPLS网络保护切换示意图。 FIG. 1 is a schematic diagram of MPLS network protection switching in the prior art.
图 2为本发明 MPLS网络保护切换方法流程图。 2 is a flowchart of a method for switching an MPLS network protection according to the present invention.
图 3为本发明一实施例的 MPLS网络保护切换示意图。 FIG. 3 is a schematic diagram of MPLS network protection switching according to an embodiment of the present invention.
图 4为本发明另一实施例的 MPLS网络保护切换示意图。 实施本发明的方式 FIG. 4 is a schematic diagram of MPLS network protection switching according to another embodiment of the present invention. Mode for carrying out the invention
为了使本发明的目的、 技术方案和优点更清楚， 下面结合附图和具 体实施方式对本发明作进一步描述。 The present invention will be further described in conjunction with the accompanying drawings and specific embodiments.
本发明的核心思想是： 在入口 LSR和出口 LSR之间建立工作 LSP 和保护 LSP, 并为工作 LSP的待保护部分建立 FRR LSP; 当 FRR LSP 的入口节点检测到工作 LSP出现故障吋， FRR LSP的入口节点将工作流 量切换到 FRR LSP; 当出口 LSR不能接收到检测报文时， 出口 LSR通 过反向路径向入口 LSR发送 BDI,入口 LSR将工作流量切换到保护 LSP。 The core idea of the present invention is: establishing a working LSP and a protection LSP between the ingress LSR and the egress LSR, and establishing an FRR LSP for the to-be-protected part of the working LSP; when the ingress node of the FRR LSP detects that the working LSP is faulty, the FRR LSP The ingress node switches the working traffic to the FRR LSP. When the egress LSR cannot receive the detection packet, the egress LSR sends the BDI to the ingress LSR through the reverse path, and the ingress LSR switches the working traffic to the protection LSP.
图 2为本发明 MPLS网络保护切换方法流程图。 如图 2所示， 包 '以下步骤： ' ' ■ ' ' 2 is a flowchart of a method for switching an MPLS network protection according to the present invention. As shown in Figure 2, the package 'The following steps: ' ' ■ ' '
步驟 201: 在入口 LSR和出口 LSR之间建立工作 LSP和保护 LSP, 并为工作 LSP的待保护部分建立 FRR LSP, 入口 LSR通过工作 LSP向 出口 LSR发送工作流量并插入检测报文。. , - 在这里， 在入口 LSR和出口 LSR之间建立工作 LSP、 保护 LSP和 FRR LSP。工作 LSP用于在正常情况下将工作流量从入口 LSR发送到出 口 LSR。 保护 LSP用于当出口 LSR检测到工作 LSP出故障时通知入口 LSR将工作流量切换到保护 LSP, 其中入口 LSR通过工作 LSP向出口 LSR发送工作流量， 并通过工作 LSP周期性地向出口 LSR发送检测艮 文。 当出口 LSR在一定时间内不能接收到检测报文时， 则认定工作 LSP 出现故障， 此时出口 LSR通过反向路径向入口 LSR发送 BDI消息， 然 后入口 LSR再将工作流量从工作 LSP发送到保护 LSP。Step 201: Establish a working LSP and a protection LSP between the ingress LSR and the egress LSR. An FRR LSP is set up for the to-be-protected part of the working LSP. The ingress LSR sends the working traffic to the egress LSR through the working LSP and inserts the detection packet. . , - Here, a working LSP, a protection LSP, and an FRR LSP are established between the ingress LSR and the egress LSR. The working LSP is used to normally send work traffic from the ingress LSR to the egress LSR. The protection LSP is used to notify the ingress LSR to switch the working traffic to the protection LSP when the egress LSR detects that the working LSP is faulty. The ingress LSR sends the working traffic to the egress LSR through the working LSP, and sends the detection to the egress LSR periodically through the working LSP. Yan Wen. When the egress LSR cannot receive the detection packet within a certain period of time, it determines that the working LSP is faulty. At this time, the egress LSR sends a BDI message to the ingress LSR through the reverse path, and then the ingress LSR sends the working traffic from the working LSP to the protection. LSP.
在入口 LSR和出口 LSR之间的待保护部分进一步建立 F R LSP的 目的是为了对工作 LSP中的某个工作节点或者某段工作链路进行保护。 既可以在入口 LSR和出口 LSR之间的某个工作节点的入口和出口之间 建立 FRR LSP, 也可以在入口 LSR和出口 LSR之间的某个工作链路的 两端建立 FRR LSP。 在这里， FRR LSP的数目可以只有一条， 也可以有 多条，并且 FRR LSP上不需要插入检测报文，只需要手动配置 FRRLSP 与工作 LSP的保护绑定。由于 FRRLSP的故障检测是通过硬件来实现， 所以 FRI^检测机制可以比工作 LSP 中的检测报文更快地检测到工作 LSP故障， 当 FRR LSP所保护的工作节点或者工作链路出现故障时，将 能够更快地发现故障， 并且执行切换。 The F R LSP is further established to protect the working node or the working link in the working LSP. An FRR LSP can be established between the ingress and egress of a working node between the ingress LSR and the egress LSR, or an FRR LSP can be established on both ends of a working link between the ingress LSR and the egress LSR. Here, the number of FRR LSPs can be one or more, and the FRR LSP does not need to be configured with the detection packet. You only need to manually configure the protection binding between the FRRLSP and the working LSP. Since the fault detection of the FRRLSP is implemented by hardware, the FRI^ detection mechanism can detect the working LSP failure faster than the detection packet in the working LSP. When the working node or the working link protected by the FRR LSP fails, It will be able to find the fault faster and perform the switch.
步骤 202:如果 FRRLSP所连接的入口节点检测到工作 LSP出现故 障， 入口节点将工作流量由工作 LSP切换到 FRR LSP。 Step 202: If the ingress node connected to the FRRLSP detects that the working LSP is faulty, the ingress node switches the working traffic from the working LSP to the FRR LSP.
在 FRR LSP的保护切换由 MPLS设备的硬件完成，时间一般在 20ms 到 50ms以内， 可以达到电信网络的 50ms可靠性要求。 当 KRR LSP所 保护的工作节点出现故障时， FRR LSP所连接的入口节点检测到该工作 节点的端口状态不正常， 将工作流量切换到 FRR LSP; 当 FRR LSP所 保护的工作链路出现故障时， FRR LSP所连接的入口节点检测到该工作 链路的链路连接状态不正常时， 将工作流量切换到 FRRLSP。 也就是， 无论是工作链路或者工作节点发生故障， FRR LSP的入口节点会首先检 测到故障， 并立即将工作流量切换到 FRR LSP。 优选地， 当 FRR LSP 用于保护工作 LSP中的工作节点时， FRR LSP的入口节点检测该工作 节点的端口状态， 并当检测到端口状态不正常时， 该入口节点将工作流 量切换到 FRR LSP。 当 FRR LSP用于保护工作 LSP中的工作链路时， FRRLSP的入口节点检测所保护的工作链路的链路连接状态， 并当检测 到链路连接状态不正常时， 该入口节点将工作流量切换到 FR LSP。 其 中， FRR LSP的入口节点是指 FRR LSP入口处的工作节点。 优选地， FRR LSP的入口节点就是入口 LSR。The protection switching of the FRR LSP is completed by the hardware of the MPLS device, and the time is generally within 20ms to 50ms, which can meet the 50ms reliability requirement of the telecommunication network. When the working node protected by the KRR LSP fails, the ingress node connected to the FRR LSP detects the work. The port status of the node is abnormal, and the working traffic is switched to the FRR LSP. When the working link protected by the FRR LSP fails, the ingress node connected to the FRR LSP detects that the link connection status of the working link is abnormal. Switch the work flow to FRRLSP. That is, whether the working link or the working node fails, the ingress node of the FRR LSP first detects the fault and immediately switches the working traffic to the FRR LSP. Preferably, when the FRR LSP is used to protect the working node in the working LSP, the ingress node of the FRR LSP detects the port status of the working node, and when detecting that the port status is abnormal, the ingress node switches the working traffic to the FRR LSP. . When the FRR LSP is used to protect the working link in the working LSP, the ingress node of the FRRLSP detects the link connection status of the protected working link, and when detecting that the link connection status is abnormal, the ingress node will work traffic. Switch to FR LSP. The ingress node of the FRR LSP refers to the working node at the entrance of the FRR LSP. Preferably, the ingress node of the FRR LSP is the ingress LSR.
步骤 203: 如果出口 LSR不能接收到检测报文， 出口 LSR通过反向 路径向入口 LSR发送 BDI消息，入口 LSR将工作流量切换到保护 LSP。 Step 203: If the egress LSR cannot receive the detection packet, the egress LSR sends a BDI message to the ingress LSR through the reverse path, and the ingress LSR switches the working traffic to the protection LSP.
当工作流量切换到 FRR LSP后的一定时间后， 出口 LSR在一定时 间内不能接收到入口 LSR通过工作 LSP发送的检测报文， 出口 LSR通 过反向路径向入口 LSR发送 BDI消息， 入口 LSR然后再将工作流量从 FRRLSP切换到保护 LSP。在这里， 由于 FRR LSP的预留带宽通常并不 多， 因此一般还会再将工作流量切换到保护 LSP中， 从而更好地保证工 作流量的传送。 After a certain period of time after the working traffic is switched to the FRR LSP, the egress LSR cannot receive the detection packet sent by the ingress LSR through the working LSP for a certain period of time. The egress LSR sends a BDI message to the ingress LSR through the reverse path, and then enters the LSR. Switch the working traffic from the FRRLSP to the protection LSP. Here, since the reserved bandwidth of the FRR LSP is usually not much, the working traffic is generally switched to the protection LSP to better ensure the transmission of the working traffic.
然后， 在故障消除之后， 例如入口 LSR在一段时间之内没有接收到 出口 LSR的 BDI消息， 入口 LSR将工作流量从保护 LSP切换回工作 LSP, - .· . - ：. . · · . . '■■' 从以上的过程可以看出， 由于: FRR LSP已经提供了 50ms以内的保 护切换， 并且比通过检测报文而执行保护切换更加快速， 因此没有必要 在工作 LSP中插入发送速度很快的检测报文，检测报文发送周期可以不 需要以. 10ms或者 20ms等间隔高速发送 .例如， 假设检测报文为 FDD 报文， 则可以将 FFD报文定成大于或者等于 50ms的发送周期。 对于优 先级不高但仍需要使用 LSP保护的业务， 甚至可以^用 CV报文（ 1个 / 秒）。 所以， 在相同的 CPU处理能力下， 应用本发明可以支持保护更多 数目的 LSP。 而且， 由于检测报文的发送频率不用很高，'因此还极大地 节省了网络带宽， 并因此使得网络的性能得到显著优化。Then, after the fault is removed, for example, the ingress LSR does not receive the BDI message of the egress LSR within a period of time, and the ingress LSR switches the working traffic from the protection LSP back to the working LSP, - . . . - : . . . ■■' As can be seen from the above process, since: FRR LSP has provided protection switching within 50ms, and it is faster to perform protection switching than by detecting packets, so it is not necessary A detection packet with a fast transmission speed is inserted in the working LSP, and the detection packet transmission period does not need to be transmitted at a high speed of .10ms or 20ms. For example, if the detection packet is an FDD packet, the FFD packet can be determined. A transmission period greater than or equal to 50 ms. For services with low priority but still need to use LSP protection, you can even use CV packets (1 / sec). Therefore, with the same CPU processing power, the application of the present invention can support the protection of a larger number of LSPs. Moreover, since the transmission frequency of the detection message is not so high, 'therefore, the network bandwidth is also greatly saved, and thus the performance of the network is significantly optimized.
同时， 在出口 LSR检测到工作 LSP出现故障之前， 工作流量已经 快速切换到了 FRRLSP， 所以可以更大程度地保护业务流量的连续性。 一般而言， FRR可以多保护 10 - 30ms左右的工作流量， 这对于某些实 时性和可靠性要求严格的业务是非常关键的。 . 图 3为本发明一实施例的 MPLS网络保护切换示意图。如图 3所示， 在入口 LSR ( A )和出口 LSR ( D )之间有两条 LSP， 分别为工作 LSP 和保护 LSP, 这两条 LSP组成一对端到端 LSP保护组。 在正常情况下， 工作 LSP将工作流量从入口 LSR发送到出口 LSR。 同时， 在入口 LSR 周期性地插入检测报文，出口 LSR通过检测报文的接收状况来判断工作 LSP的工作状况，然后再根据工作 LSP的工作状况来决定是否切换到保 护 LSP。 同时， 在 A点与 C点之间， 还有一条经过 H、 I点的 FRRLSP, 以保护节点 B。 如图 3所示， 该条 FRR LSP的入口节点就是入口 LSR。 在 FRR LSP上不需要插入检测报文，只需要由管理员手动配置 FRRLSP 与工作 LSP的保护绑定。 At the same time, before the egress LSR detects that the working LSP is faulty, the working traffic has been quickly switched to the FRRLSP, so the continuity of the service traffic can be protected to a greater extent. In general, FRR can protect more than 10 - 30ms of work traffic, which is critical for certain real-time and reliability-critical services. FIG. 3 is a schematic diagram of MPLS network protection switching according to an embodiment of the present invention. As shown in Figure 3, there are two LSPs between the ingress LSR (A) and the egress LSR (D), which are the working LSP and the protection LSP. The two LSPs form a pair of end-to-end LSP protection groups. Under normal circumstances, the working LSP sends the working traffic from the ingress LSR to the egress LSR. At the same time, the ingress LSR periodically inserts the detection packet, and the egress LSR determines the working status of the working LSP by detecting the receiving status of the packet, and then determines whether to switch to the protection LSP according to the working status of the working LSP. At the same time, between point A and point C, there is another FRRLSP passing through points H and I to protect node B. As shown in Figure 3, the ingress node of the FRR LSP is the ingress LSR. You do not need to insert a detection packet on the FRR LSP. You only need to manually configure the protection binding between the FRRLSP and the working LSP.
在正常的网络条件下， 工作流量经 A B - C - D的工作 LSP从 A. 点到达 D ,点。 当 B:节点或 Α、.··Β节:点间的工作链路出现故障时， 入口. LSR在出口 LSR能够检测出故障之前就已经检测出故障，并且入口 LSR 立刻将工作流量从 A - Β - C快速切换到 A - H - 1 - C。 FRR LSP的保护 '切换由设备的硬件完成， 时间一般在 20ms以内， 可以达到电信网络的 50ms可靠性要求。 将工作流量切换到. A - H - 1 - C后， 当出口 LS 在 一定时间内不能接收到检测报文时， 则认定工作 LSP出现故障， 此时出 口 LSR通过反向路径向入口 LSR发送 BDI消息，然后入口 LSR再将工 作流量从 FRR LSP切换到保护 LSP, 即切换后工作流量经 A - E - F - G - D到达出口 LSR。Under normal network conditions, the working flow reaches the D point from the A. point through the working LSP of the AB-C-D. When B: node or Α, .. Β: When the working link between the points fails, the entry LSR detects the fault before the exit LSR can detect the fault, and the ingress LSR immediately puts the working traffic from A - Β - C quickly switches to A - H - 1 - C. FRR LSP protection 'Switching is done by the hardware of the device, and the time is generally within 20ms, which can meet the 50ms reliability requirement of the telecommunication network. After the working flow is switched to .A - H - 1 - C, when the egress LS fails to receive the detection packet within a certain period of time, the working LSP is determined to be faulty. At this time, the egress LSR sends the BDI to the ingress LSR through the reverse path. The message then the ingress LSR then switches the working traffic from the FRR LSP to the protection LSP. That is, the working traffic after the handover reaches the egress LSR via A - E - F - G - D.
在这里， 可以在工作 LSP中的任意单个节点或者任意工作链路两端 建立 FRR LS 例如， 还可以在节点 B和节点 C之间建立 FRR LSP, 以保护节点 B和节点 C之间的工作链路。在实际组网中， RLSP的数 目可以不止一条， 同样 A点与 B点之间也可以有大量的 LSP保护组。 由于 FRR LSP的存在， 当 FRR LSP所保护的工作节点或者工作链路发 生故障时， 工作流量能够快速切换到 FRR LSP上，在检测报文发现工作 LSP故障并从入口 LSR切换到保护 LSP之前， 工作流量已经通过 FRR LSP得到保护， 所以可以更大程度得保护业务流量的连续性。 而且由于 提供了比检测报文更快速的保护切换， 因此可以不需要高速发送检测报 文， 从而可以增加保护 LSP的数量。 Here, the FRR LS can be established at any single node or any working link in the working LSP. For example, an FRR LSP can be established between the Node B and the Node C to protect the working chain between the Node B and the Node C. road. In actual networking, the number of RLSPs can be more than one. Similarly, there can be a large number of LSP protection groups between point A and point B. When the working node or the working link protected by the FRR LSP fails, the working traffic can be quickly switched to the FRR LSP. Before the detection packet finds that the working LSP is faulty and is switched from the ingress LSR to the protection LSP, Work traffic has been protected by FRR LSPs, so the continuity of service traffic can be protected to a greater extent. Moreover, since a protection switching is performed faster than the detection packet, it is not necessary to transmit the detection packet at a high speed, thereby increasing the number of protection LSPs.
同时，入口 LSR发出的检测报文给网络带宽等资源的消耗也能显著 降低， 以 50ms频率发送 FFD报文为例—， 同样支持 10K条 LSP, 此时所 需要的网络带宽为： （44Bytex8) X ( 1000ms/50ms ) xlOK < 70Mbps, 为 未使用 FRR LSP时的约 1/5; 当使用 CV报文时为： （44Bytex8) χ10Κ = 3.52Μ, 基本已经可以忽略不计， 所以极大地节省了网络带宽， 从而网 络的性能也得到显著优化。 - . '·::;.在某些无法设置保护 'LSP.或保护 LSP出现问题的情况下.,也可以通 过 FRR LSP达到一定程度的保护效果。 如图 4所示， 除了工作 LSP以 夕卜， Α点与 D -点之间无法提供另外一条端到端的保护 LSP，在此情况下， 出口 LSR在检测到工作 LSP出现故障时无法提供保护 LSP。 此时， 也 可以在网.络中设置 FRR LSP, 例如图 4中的位于 A .点与 C点之间、 保 护节点 B的经过 H、 I点的 FRR LSP, 仍然可以在 B节点或 A、 B节点 间链路出现故障时提供快速保护， 在故障恢复后， 再将工作流量切回到 工作 LSP上。At the same time, the detection packet sent by the ingress LSR can significantly reduce the consumption of resources such as network bandwidth. For example, the FFD packet is sent at a frequency of 50 ms—and 10 K LSPs are also supported. The required network bandwidth is: 44Bytex8. X ( 1000ms/50ms ) xlOK < 70Mbps, which is about 1/5 when FRR LSP is not used. When using CV message: (44Bytex8) χ10Κ = 3.52Μ, basically negligible, so the network is greatly saved. The bandwidth, and thus the performance of the network, is also significantly optimized. - . '·::;. In some cases where the protection 'LSP' or protection LSP cannot be set. A certain degree of protection can also be achieved by the FRR LSP. As shown in FIG. 4, in addition to the working LSP, another end-to-end protection LSP cannot be provided between the defect and the D-point. In this case, The egress LSR cannot provide protection LSPs when it detects that the working LSP is faulty. In this case, you can also set the FRR LSP in the network. For example, the FRR LSP between point A and point C in Figure 4 and the protection node B passing through H and I points can still be in node B or A. When the link between the B nodes fails, fast protection is provided. After the fault is recovered, the working traffic is switched back to the working LSP.
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， 所作的任何修改、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, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.