Abstract :
Discusses a technique to force synchronous access onto CSMA/CD networks in order to minimise contention problems which make such a network generally unsuitable for carrying synchronous type traffic such as voice. Multiplexing the traffic from a number of voice sources and applying synchronous access, that is each node on the network attempting to transmit at regular intervals, can result in `pseudo-synchronous´ behaviour of the network, whereby a particular regular order of transmission is established and maintained, thus preventing nodes having to compete with each other in order to gain access to the network. This behaviour can, however, become unstable-under high traffic loads for example, where the established order of transmission becomes disturbed, resulting in a high level of collisions and hence unacceptable delays and losses. Two similar packet handling strategies are considered, one of which exhibits such properties and compares their effect upon the speech carrying capacity of the network under both voice and integrated loads