Queueing protocol

摘要

A method of transmitting data on a communications network having two oppositely directed unidirectional buses (A,B) and a number of access units (4) coupled between buses, the method including the step of establishing a queue which is distributed in the access units and which controls when the access units can transmit data packets on the buses. When an access unit has a data packet (38) queued for transmission on bus A, it sends a REQ bit on bus B. The access units monitor the number of REQ bits passing and empty packets available so as to thereby establish the distributed queue. The access units are able to handle both data packets (38) which are suitable for information from computers and synchronous packets 36 which can be used for voice circuits.