The priority control mechanism is an effective method to support various classes of services. During the call setup, each service can be assigned a service class determined by a delay priority and a loss priority. A priority control in ATM network will shedule ATM cells' departing and discarding sequence based on their delay and loss priorities. Most priority control schemes proposed consider only one of these two priority types. Thus, this paper proposes a new priority control scheme to service delay-sensitive and loss-sensitive traffics simultaneously in ATM networks.
In the proposed loss-priority scheme, random access common buffer and fifo address buffer controller are used in order to achieve efficient buffer utilization. Also, CLP(cell loss priority)bit comparator is used in order to discard non-comforming cell according to buffer capacity.
In the proposed delay-priority scheme, CDWRR(Controllable dynamically weighed round robin) is used in order to support ABR service more efficiently than conventional mechanism. CDWRR has feed back mechanism compared with DWRR scheduling.
Through computer simulation, the existing methods (separated buffer + DW- RR scheduling) and proposed scheme are compared and analyzed. Simulation results show that the proposed scheme has superior performance to conventional schemes. in view of cell loss rate, mean delay time and throughput because of using the traffic control mechanism based on loss priority ans delay priority.
