QUEUING IMPACT ON VOIP QUALITY OF SERVICE (QOS) IN TELECOM NETWORKS

摘要

Today's Internet only provides Best Effort Service. Traffic is processed as quickly as possible, but there is no guarantee of timelines or actual delivery. With the rapid transformation of the Internet into a commercial infrastructure, demands for service quality have rapidly developed. People of the modern world are very much dependent on various network services like VOIP, Videoconferencing and File Transfer. Voice over Internet Protocol is a service from the Internet services that allows users to communicate with each other. Quality of Service is very sensitive to delay so that Voice over Internet Protocol needs it. The objective of this research is to study the effect of different queuing algorithms within the router on Voice over Internet Protocol Quality of Service. In this work, simulation tool OPNET Modeler is used to implement the proposed network (Voice over Internet Protocol Network). The proposed network consists of two logical subnets one for clients and one for servers located at two different countries around the world, the core network connecting the two subnets is composed of 10 routers connected in half mesh topology in order to simulate the communications between two locations as a long distance and analyze Voice over Internet Protocol Quality of Service through measuring the major factors that affect the Quality of Service for Voice over Internet Protocol according to international telecommunication union standards such as: delay, jitter, end to end delay and packet loss. Different types of Traffic Management systems are used in those services. Queuing is one of the very vital mechanisms in traffic management system. Each router in the network must implement some queuing discipline that governs how packets are buffered while waiting to be transmitted. This paper gives a comparative analysis of six queuing systems FIFO, Priority queueing, Weight Fair Queuing, MWRR, DWRR and MDRR.