ISSN(Online): 2320-9801 ISSN (Print): 2320-9798 International Journal of Innovative Research in Computer and Communication Engineering (An ISO 3297: 2007 Certified Organization) Vol. 2, Issue 12, December 2014 10.15680/ijircce.2014.0212081 Copyright to IJIRCCE www.ijircce.com 7130 Evaluating the Impact of Routing and Queuing Techniques on the QoS of VoIP Over IP/MPLS Networks Azeddien M. Sllame, Mohamed Aljafari Faculty of Information Technology, University of Tripoli, Libya ABSTRACT: this paper describes performance evaluation of VoIP over IP/MPLS networks using OPNET tool. The simulation study is completed by running VoIP application in different network scenarioswith different interior routing protocols; namely: RIP, OSPF and EIGRP and with different queuing techniques to measure quality of service. However, the main network model is built of TCP/IP routers with MPLS routers in the core of the network case study (middle). This model enables different TCP/IP networks communicating to each other through the MPLS core routers. The following performance parameters: the delay (jitter) (sec), packet delay variation, packet end-to-end delay (sec), and number of packets sent/received are used to compare the efficiency of different networks. KEYWORDS: multimedia; VoIP; routing and QoS; queuing and QoS; IP networks; MPLS networks I. INTRODUCTION Multimedia streams require higher bandwidth than any other data types over the Internet. Besides that, the number of the Internet users are growing very vastly and their usage of the multimedia applications are increasing very rapidly too. In addition, users are asking more and more for advanced features of the multimedia applications. In turn, this is guided by mobile devices growth from the industry side; as well as by the rich features that are available on the social networks web sites [1]. Thestreaming of multimedia over the Internet requires special treatment in order to be completely delivered and played back in correct order and in continuous time with suitable degree of quality of service (QoS). However, such requirements can be listed as follows. First; packet sequencing, this is needed to report packet loss, make packet reordering, perform out-of-order decoding. Second; time-stamping and buffering, in order to provide continuous play out of the streams and to reduce delay jitter. Third, payload type identification and classification; this is to facilitate media interpretation and to do suitable conversions easily when needed. Fourth, error concealment; this is necessary to detect and repair errors by using redundancy or any other technique. Fifth; QoS; it is an essential requirement to keep multimedia streaming flow to the appropriate service level and to enhance QoS between senders and receivers. Last; rate control rule; this means making suitable adjustments during the stream flow to tolerate network congestion.Nowadays, multimillions of multimedia streams need to be transferred between different corners of the world’s continents through social networks and multimedia web sites with minimal delay overhead, with efficient routes, using appropriate level of adequate QoS. Hence, multicast routing has become the most crucial issue in international networking world’s infrastructure [2]. This paper presents a comparative study of the performance of routing algorithms on the main QoS parameters of VOIP traffic. The paper is organized as follows: Section 2 provides the literature review. Section 3 gives a brief insight about routing. Section 4 describes the main features of MPLS technology. Section 5describesa brief discussionof multimedia focusing primarily on the key QoS parameters of VoIP. Section 6 presents an analysis of the simulation results; and finally Section7 outlines the conclusion of this research. II. RELATED WORK There are several works have been carried out by other researchers in this field. However, this section gives an overview of some important research papers. In [12] authors demonstrated that OPNET can be used by network