Differentiated Service Queuing Strategies for Internet Telephony

Abstract

This paper evaluates two different strategies for configuring Edge-Router queues in Telephony over IP scenario. In such scenario the introduction of DiffServ aimed at differentiate traffic streams in order to achieve different levels of Quality of Service. The relationship between DiffServ-class IP streams and edge-router queues seems to be a critical point for the end-to-end performance of the IP transport network. So, we make a simulation-based study in order to discover the advantages and disadvantages of different edge-router configurations in a multi-provider and multi-service IP backbone transport network. We have considered two different queue configuration strategies, called “queue-to-service” and “queue-to-provider”. They are characterized by a different way of assigning DiffServ codepoint to edge-router queues. The “queue-to-service” considers aggregate packet streams on the basis of the service class, while “queue-to-provider” make the same on the basis of TOIP Service Provider. The simulation results show the convenience of using “queue-to-service” in order to get better performance both in Quality of Service and network efficiency.