ATM switch with multimedia traffic priority control
Peter A. Ganos, Michael N. Koukias, George K. Kokkinakis · European Transactions on Telecommunications · 1996
Abstract In this paper, a novel ATM switch with a dynamic multimedia traffic priority control scheme (HQMS: Hybrid combination of Queue Length Threshold and Minimum Laxity Threshold Scheme) is proposed. The ATM switch has the same basic topology as the Knockout switch, but employs a simplerN×Lconcentration scheme, which takes into account cells belonging to different priority levels. The structure of the switch supports two priority mechanisms. The first one is calledpriority discardingand acts as a local congestion control scheme within the switch fabric satisfying different cell loss requirements of different ATM traffic classes. The second one is calledpriority schedulingand uses two priority methods: aspace priority methodused for the control of the buffer space when an overflow condition occurs andor when the expiration of the maximum admissible delay of the delay sensitive cells takes place and theservice priority methodwhich assigns transmission priorities to the buffered cells. A hardware implementation of the two priority mechanisms of the HQMS is presented. The performance of the switch has been studied by simulation, considering three ATM classes (video, data, voice) with different source models. The results have shown that for a large range of traffic load, the proposed HQMS satisfies the loss and delay requirements of the three classes.