Method for realizing muti-casting in BGP/MPLS VPN

Abstract

The invention discloses method for implementing multicast in virtual private network of boundary gateway protocol / multiple label switch BGP / MPLS VPN. The method includes steps: (1) finding out periphery routers PE supplied by all service providers in same multicast virtual private network MVPN; (2) building full interlinked virtual circuit PW among found PE, the PW connects to multicast virtual route forwarding table MVRF one-to-one correspondence to MVPN on two ends PE; (3) when multicast packet inside MVPN passes through network of multiple label switch / internet protocol MPLS / IP of service providers, entry PE forwards PW bound to MVRF to exit PE; based on PW of receiving the multicast packet, the exit PE of having received multicast packet determines MVRF the multicast packet belongs to; then the exit PE forwards the multicast packet through MVRF.

Description

technical field [0001] The invention relates to the field of border gateway protocol / multi-protocol label switching virtual private network (BGP / MPLSVPN), in particular to a method for realizing multicast in BGP / MPLS VPN. Background technique [0002] RFC2547 defines the method of establishing a virtual private network (VPN) in a multi-protocol label switching / Internet Protocol (MPLS / IP) network, that is, BGP / MPLS VPN, but RFC2547 only defines the implementation method of unicast IP VPN, and does not define How to implement multicast in BGP / MPLS VPN, that is, MVPN (Multicast VPN). Hereinafter, the VPN supporting multicast is referred to as MVPN for short. [0003] In order to realize multicast in BGP / MPLS VPN, a multicast domain (MD) method has appeared. The basic realization principle of this method is: deploy protocol independent multicast (PIM ) protocol, and assign a unique multicast IP address within the P network range to each multicast virtual private network (MVPN)...

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Problems solved by technology

[0006] Second, the GRE encapsulation and decapsulation process needs to be processed by a network processor (NP), which not only increases the cost of PE equipment but also causes a bottleneck in the multicast forwarding performance within the MVPN

[0007] Third, although Multi-Protocol Label Switching (MPLS) is deployed in the P network, when the multicast packets in the MVPN traverse the P network, they cannot be forwarded on the MPLS Label Switching Path (LSP), but through the multicast IP Address addressing is used for forwarding, so various features bound on the LSP, such as traffic engineering (TE), reliable quality of service (QoS) or fast convergence, cannot be inherited by multicast packets forwarded in the MVPN

In this way, although the on-demand distribution of multicast data packets in the MVPN is realized, the P network needs to maintain a large number of DATA MDTs, and the number of DATA MDTs is not easy to control

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