PATH SWITCHING - A QUASI-STATIC ROUTING SCHEME FOR LARGE-SCALE ATM PACKET SWITCHES

A quasi-static routing scheme called path switching for large-scale AT M packet switch systems is proposed in this paper, Recently, the Clos network has been used as the modal for many large-scale ATM switch arc hitectures, In which the most difficult issue is path and bandwidth as signment for each connection request, The static routing scheme, such as multirate circuit switching, does not fully exploit the statistical multiplexing gain, In contrast, the dynamic routing scheme, such as s traight matching, requires slot-by-slot computation of route assignmen t. Path switching is a compromise of these two routing schemes, It use s a predetermined periodical connection pattern in the central stage, look-ahead selection in the input stage, and output queueing in the la st stage, The scheduling of path switching consists of rapacity assign ment and route assignment. The capacity assignment is constrained by t he quality of service of connection requests, The route assignment is based on the time-space interleaving of the coloring of bipartite mult igraphs. We show that path switching can handle multirate and multimed ia traffic effectively in the Clos network.