Patent ID: 7050448
Filing Date: 2006-05-23
Classification: H04L

Abstract:
1. A masking unit for use in a data packet switching system of the type having a memoryless cross-bar switch providing cyclic connections between ingress routers and egress routers, the ingress routers providing incoming packet buffering on a virtual output queue and being arranged to generate switch connection requests when a virtual output queue contains a data packet, characterised in that the masking unit is arranged to receive all of the switch connection requests and to randomly mask connection requests and wherein the masking unit includes a comparator for each virtual output queue, the masking unit is arranged to receive with each request an associated weight value, and to feed the weight values to the corresponding comparators together with a stream of randomly generated values, the comparators being arranged to produce respective random bit streams whose proportion of 1's to 0's is determined by the corresponding weight values, and the masking unit being arranged to use each random bit stream for masking out the requests from the corresponding virtual output queue.