Analysis of stable working for the buffered PPS

The parallel packet switch (PPS) attracts a lot of attention from the communications equipment vendors. However, a lack of the detailed analysis and understanding of the issues involved in congestion management has slowed down its recognition and deployment. We analyze the conditions of stable working for a PPS with buffered input demultiplexors. By comparing a PPS with a reference switch, we present a definition of stable working for the PPS architecture. The necessary and sufficient condition of stable working for a PPS is proposed and proved. Then we describe a family of dispatch algorithms for the PPS, and give the restriction of algorithms for guaranteeing stable working. Finally the minimum bound of PPS layers and core speedup are analyzed.