High-performance copy networks for multicast fast packet switching systems
Chao-Li Tarng · 1991
This dissertation is concerned with the design, modeling, performance analysis, and simulation of copy networks in supporting multicast fast packet switching systems for broadband integrated services digital networks (B-ISDN). The dissertation is in two parts. First, a high performance copy network is proposed. The new network employs a bit-parallel Banyan multistage interconnection network (MIN) and requires no intermediate buffering. The simple structure and distributed processing capabilities of the copy network make it highly suitable for packet replication in multicast fast packet switching systems. Although contention for links can occur within the MIN, a novel two-phase copy process is developed to achieve high throughput with low delay. An analytical performance model with a special structure of Markov chains, called a branching process, is formulated. Numerical results using this model for a constant number of copies as well as for a geometrically distributed number of copies show that the proposed copy network achieves very low packet blocking probability. Simulation results are provided to confirm the analytical model and the memory requirements for the copy network are determined. In the second part of this dissertation, the issues of fairness and performance analysis of non-blocking copy networks are addressed. The copy process of such networks is normally achieved by first assigning incoming packets a set of monotone address intervals which corresponds to the output ports of a MIN. Then the packets are routed through the MIN for replication. However, the implementation of such address assignment can result in an unfair access to the copy network. We provide a solution for achieving fairness by cascading a shift-sequence permutation (SSP) MIN at the front end to rotate the input ports. A new analytic method based on generating functions is developed to evaluate the exact blocking probabilities of copy networks. The method is then extended to investigate the performance of the copy network under two priority classes of traffic.