Abstract: A data processing system (20) schedules the allocation of a common bus (26), used by multiple service requesters (32). The system (20) creates a plurality of service request levels (44) and assigns each service requester (32) to one of the plurality of request levels (44). Services of the common bus (26) are provided to all service requesters (32) assigned to a first service request level (44) for each instance of providing service to one of the service requesters (32) assigned to a second service request level (44). The method then again provides services of the common bus (26) to all service requesters (32) assigned to the first service request level (44) for a single instance of providing service to one of the second level requesters (32).

Abstract: A communication network (10) includes packet switching nodes (18) in which packets from high speed data links (20, 22) are switched onto a multiplicity of low speed data links (26). Each node (18) includes a bulk RAM (30) which has a section (32) dedicated to implementing a multiplicity of logically independent FIFO buffers. A routing controller (46) controls DMA transfers of packets into and out from appropriate FIFO buffers. Packets are transferred into respective FIFO buffers consecutively and transferred out from respective FIFO buffers interleaved together.