A Novel Queuing Method for DiffServ Traffic over Resilient Packet Ring Networks

Resilient Packet Ring (RPR) is a new kind of metropolitan area network which technically provides complete flexibility in defining service classes that can be sold to the end user.  On the other side, the IETF Diffserv group has created specific definitions for class based services over IP networks. Hereby, we are going to propose a more effective queuing for RPR which considers the mapping between DiffServ and RPR QOS provisioning mechanisms. This novel method is used to support the requested quality for IP over RPR delivery. Only the standard PHBs have been considered for such a mapping consisting EF (expedited forwarding), AF (assured forwarding), and default PHB. The EF class is preferred to be transmitted via class A, while AF class is more distinctive. AF includes four different flows each including up to three drop precedence. To improve the quality for AF flows, we have proposed a multi-level queuing method considering different levels of drop precedence. The default PHB is also preferred to be mapped as class C traffic. Our proposed method has been investigated using some simulations over NS۲. The simulation results have shown superior performance in terms of loss and delay parameters.