The Affects of Different Queuing Algorithms within the Router on QoS VoIP application Using OPNET

Voice over Internet Protocol (VoIP) is a service from the internet services that allows users tocommunicate with each other. Quality of Service (QoS) is very sensitive to delay so that VOIP needs it.The objective of this research is study the effect of different queuing algorithms within the router on VoIPQoS.In this work, simulation tool “OPNET Modeler version 14.0” is used to implement the proposednetwork (VoIP Network). The proposed network is a private network for a company that has twolocations located at two different countries around the world in order to simulate the communicationswithin the same location as a local and the communications between two locations as a long distanceand analyze VoIP QoS through measuring the major factors that affect the QoS for VoIP according tointernational telecommunication union (ITU) standards such as: delay, jitter and packet loss.In this research , a comparison was carried out between different queue algorithms like First inFirst out (FIFO), Priority queue (PQ) and Weight Fair Queuing (WFQ) and it was found that PQ andWFQ algorithms are the most appropriate to improve VoIP QoS .