Abstract: Switch requests within a packet switch are allocated by processing switch request data for each input port to generate request data for each input port-output port pairing; and generating an allocation plan by sorting the request data relating to each of the input/output pairs in terms of their queue length, and for each such pair, considered in the sorted order, allocating as many of the requests in the queue as can be accommodated in the remaining time slots.

Abstract: In a packet switch, a switch request allocation plan is generated by reducing the number of queue requests VOQ relating to each of one or both sets of ports I1 .IN, O1 .ON, by a value such that the number of requests relating to each member of the set or sets of ports is no greater than the number of requests (frame value F) that can be handled by the switch (10). This reduction may be individually done for each queue. Alternatively all queues relating to a given port, or to any port, may have their length reduced by a single value determined by the size of the longest queue. A further stage may then apply other allocation rules to allocate requests remaining unallocated by the previous stage.

Abstract: In a packet switch, a switch request allocation plan is generated by reducing the number of queue requests VOQ relating to each of one or both sets of ports I1 . . . IN, O1 . . . ON, by a value such that the number of requests relating to each member of the set or sets of ports is no greater than the number of requests (frame value F) that can be handled by the switch (10). This reduction may be individually done for each queue. Alternatively all queues relating to a given port, or to any port, may have their length reduced by a single value determined by the size of the longest queue. A further stage may then apply other allocation rules to allocate requests remaining unallocated by the previous stage.