RECONFIGURABLE DIFFSERV BASED QOS MODEL FOR REAL-TIME TRAFFIC.

The main architectures of the Internet adopts the best-effort model for traffic control. It is an unable to guarantee a timely delivery of data. To address this problem, a ?differentiated services? (DiffServ) is proposed by the IEFT (Internet engineering task force) as a simple and scalable solution for providing the quality of service (QoS) for Internet applications with various levels of services. In DiffServ, scheduling disciplines play an important role in achieving the required level of service in terms of various criteria (e.g., delay, jitter, throughput, and packet loss). In this paper, a Reconfigurable Scheduler Model (RSM) for real-time traffic through DiffServ router has been designed and implemented using OPNET Modular. The proposed scheduler applies the three most widely accepted queue schedulers in DiffServ routers; Priority Queuing (PQ), Class Based Weight Fair Queuing (CBWFQ) and Modified Deficit Round Robin (MDRR). The voice traffic can be scheduled using strict priority queue scheduler while the video and data traffic are scheduled by the CBWFQ and MDRR schedulers which can be interchanged according to the queue delay of the video traffic to provide better QoS. The performance evaluation shows an improvement in QoS parameters of voice and video traffics.