Research And Improvement Of The Multicast Solutions In BGP/MPLS VPN

With the rapid development of Internet, more and more new services and applications have come forth. In order to improve the efficiency of data transmission, the IP multicast technology has been proposed and broadly accepted. At the same time, the technology of VPN has been widely adopted in Internet wide. And also, with the increment of application categories on VPN, more and more requirement of multicast technology in VPN has been raised.BGP/MPLS VPN is one kind of VPNs based on network. In BGP/MPLS VPN, MPLS is used to set up tunnels dynamically; different VPNs can share same address space by virtue of virtual routers and VPN-IPv4 address family; VPN routes are distributed by MP-BGP. So, it is suitable for big scale network, scalable well, and easy to deploy. Therefore, it has obtained multitudinous merchants' favors, and also plays the important role in the Next Generation Network.However, the application of multicast technology in BGP/MPLS VPN is up against many difficulties, one of which is scalability. With the increment of multicast group, multicast members and the number of VPNs, multicast states in BGP/MPLS VPN will be difficult to control, and the network is unable to deal with it.In one kind of the present solution people try to solve this problem by using 'Multicast Domain' model, while in another one they use multicast tree aggregation to do it. But both of the two solutions still have some faults.So in this paper the advantage and disadvantage of the present multicast resolutions has been analyzed, which is based on the mechanism of BGP/MPLS VPN and IP multicast was deeply researched. The works this paper has done list as follows:a) Researched two kind of present multicast solutions in BGP/MPLS VPN, analyzed their features in solving scalability problem.b) Put forward a multicast resolution based on proxy ,which limit the multicast in custom site wide by using proxy VPN multicast routers and P2MP multicast tunnel built by MPLS on the service providers' network. So it has efficiently improved the scalability of multicast in BGP/MPLS VPN.c) In order to test the new multicast solution, this paper designed and implemented a BGP/MPLS VPN which fit RFC2547 in the popular network simulator NS-2, and then designed and implemented the multicast solution on it.d) Proved the validity of the new multicast solution based on proxy and analyzed its scalability on our test environment based on NS-2.