Routing tag encoding in self-routing multicast networks

In this paper, we propose an efficient routing tag encoding scheme for a class of self-routing multistage multicast networks. In this scheme, each multicast connection request is expressed as a tag sequence, which can be used to efficiently set up connection paths along the multicast tree in a self-routing manner. The new encoding scheme requires only a small constant number of buffers at each input on switches in the network, and the time delay at each stage caused by the routing tag handling is also a constant. Two efficient offline algorithms for generating a properly ordered multicast routing tag sequence are also presented in this paper. The encoding scheme can be applied to a general class of multicast networks constructed by the recursive decomposition approach.