An approach to solving a multicasting scalability issue in MPLS networks using state encoding

We propose an approach that handles the scalability issue in multicast communication in terms of increasing the number of IP flows over MPLS networks. The proposed scheme depends on state encoding of the interfaces of each router that a multicast tree passes through. Each router assigns a code for each multicast tree that passes through it and these state codes are collected and sent back to the ingress router. At the ingress router, the concatenation of all state codes can be considered as a code for the multicast tree that carries the data streams of the corresponding session. The ingress router uses the tree codes. to classify multicast sessions into forwarding equivalence classes (FEC). If two multicast sessions have the same code, they are classified to the same FEC and given the same label. This procedure results in a reduction in label usage and provides the capability to aggregate different multicast data streams. Compared with previous work, which maintains the IP addresses of each core and labeled egress router (LER) of the tree, our proposed scheme needs less memory space to maintain the code of the multicast tree.