PERFORMANCE ANALYSIS OF AN ATM SWITCH SUPPORTING A CIRCUIT EMULATION TECHNIQUE

This paper deals with the performance evaluation of an ATM switch which implements the Circuit Emulation Mode (CEM). According to this approach, the switch is able to guarantee a constant switching delay to every cell belonging to isochronous calls, whereas a variable delay service is offered to non-isochronous cells. Moreover, a fully distributed control scheme for set-up of CEM calls, called the flooding technique, is described and analysed. An M/G/1/K queueing model, in which the service has been modelled taking into account the blocking characteristics of a delta network, has been utilized for the performance analysis of the flooding scheme. A mixed approach however, has been developed for the analysis of the overall switch performance. Obtained results show that the design constraints in terms of loss probability for the PM traffic can be satisfied by means a proper dimensioning of the network resources. Moreover, it is shown that the flooding technique can be used in a wide context, even if the CEM load is high or the call holding times are very short.