Multicasting in MPLS networks.

摘要

The explosive growth of the Internet has generated interests from researchers around the world. New applications of the Internet, such as video, audio and mission-critical applications, challenge researchers to develop more effective ways to deliver these applications to end users. Multicasting, QoS and MPLS emerge as new technologies and are being developed. The integration of MPLS, multicasting and/or QoS is still an open topic. RFC3353, released in August 2002, gives an overview of IP multicast in an MPLS environment. This thesis first presents RFC3353 in brief and then an extension to RFC for multicast aggregation and loop prevention in MPLS networks are discussed. FEC aggregation is proposed where IP header is not affected in the aggregation in MPLS networks. A mechanism to dynamically aggregate multicast traffic in MPLS network is presented in this thesis. Both source specific tree and shared tree are considered as network topologies. Multicast loops may exist in MPLS network during network transition. The multicast loop forming in PIM-SM, PIM-DM and DVMRP is discussed in MPLS networks. The Colored thread and the No thread mechanisms for multicast loop prevention are provided in this thesis. In addition to aggregation and loop prevention, DiffServ multicast traffic merging in MPLS networks is also considered in this thesis. Two multicast traffic merging modes, root-initiated and leaf-initiated, are discussed in such DiffServ-supported MPLS networks. Multicast routing protocols such as PIM-SM PIM-DM and DVMRP are considered here.