| 摘要 |
<p>A fast packet switching system comprises an interconnection network associated with a distributed control structure composed of a plurality of processing units (UC1-1 ... UC3-16) managing the routing at the virtual call level. At least some of said processing units associated each with a group of network inputs/outputs store bandwidth occupancy data relevant to the interstage links which can be reached from the inputs of said group and are included between said inputs and a central network stage where there is a maximum number of alternative paths or, respectively, bandwidth occupancy data relevant to interstage links which lead to the outputs of said group and are included between said stage and the output, said data being updated whenever a new call is routed. When a virtual call is to be routed, the processing units associated with the input or respectively the output involved in the connection, evaluate each, on the basis of the up-to-date conditions of bandwidth occupancy and of the bandwidth requirements of the new call, a cost function of the connection along the portion of each of the possible routing paths included between the input and the stage where there is the maximum number of alternative paths, or respectively for the portion of each routing path included between such stage and the output; the results of the evaluations carried out by said units are combined together in one of the units which determined a global cost function for the individual connection paths and forwards the call on the path presenting the minimum cost function.</p> |
