Method for realizing multicast in PBB_VPLS network

Abstract

The invention provides a method for realizing multicast in a PBB_VPLS network, comprising the following steps of: releasing a binding relationship between a VPLS instance and a multicast tree to other found PEs by a root node PE and building the root node PE and sub-nodes and other relevant PEs as a multicast tree for receiving leaf nodes; and forwarding a multicast message according to the multicast tree after the root node receives the multicast message. by the method, the multicast message is distributed according to a typical tree-shaped structure and the copy step of the multicast message can be currently finished by an entrance PE and undertaken by a branch node P in the multicast tree, thereby saving plenty of wideband waste caused by multicast copy and improving the utilization rate of a multicast wideband.

Description

technical field [0001] The present invention relates to multicast technology, especially a kind of layered virtual private network service (H-VPLS, Hierarchical Virtual Private LAN Service) network that introduces carrier backbone bridge (PBB, Provider BackboneBridges) technology, namely PBB_VPLS network, realizes multicast method. Background technique [0002] The Internet Engineering Task Force (IETF, The Internet Engineering Task Force) RFC4762 defines a Hierarchical Virtual Private LAN Service (H-VPLS, Hierarchical Virtual Private LAN Service) architecture to enhance the scalability of a pseudowire (PW). [0003] H-VPLS reduces the full mesh connection of provider edge (PE, Provider Edge) devices in the network by connecting user edge (CE, Customer Edge) devices to the access network, and then connecting to the high-level core network through the access network quantity. IETF RFC4762 defines two H-VPLS network access architectures, one is access using Multi-Protocol La...

AI Technical Summary

Problems solved by technology

No matter which access method is used, there are two scalability issues: First, the learning and forwarding of Medium Access Control (MAC) addresses are based on the user MAC address (CMAC). Therefore, when the virtual When the private LAN service (VPLS, Virtual Private LAN Service) instance increases, the user MAC address will increase accordingly, which leads to scalability problems

In this way, two copies of the same message need to be transmitted between PE1 and P, resulting in a waste of bandwidth.

[0009] From the point of view of the multicast implementation method in the existing PBB_VPLS network, when the PBB_VPLS core network forwards the multicast traffic, it needs to rely on the ingress PE (such as figure 1 Middle PE1) copies the multicast message according to the number of receiving CEs, and then sends it to each receiving CE through multiple pseudowires. If each pseudowire passes through the same shared path (such as figure 1 If the path from PE1 to P) transmits data, multiple copies of the same multicast packet may appear on the shared path, thus wasting the multicast bandwidth. Especially for video services, when there are many receiving CEs, the bandwidth The consumption will even make PE unbearable

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