Evaluation of SIP Signalling and QoS for VoIP over OLSR MANET Routing Protocol

This paper evaluates the SIP based VoIP applications over the Optimized Link State Routing protocol (OLSR) as a proactive routing protocol for Mobile Ad Hoc Networks (MANET) using Static, Uniform, and Random mobility models. The evaluation considered PCM, LQS, IPTelephony, and GSM voice codecs to study the SIP signaling performance and the voice Quality of Service (QoS) for VoIP calls over OLSR MANET. The simulation efforts performed in OPNET Modeler 17.1. The results show that VoIP over OLSR MANET has good performance over Static and Uniform mobility models while it has variable performance with Random models. SIP signaling has large delays compared with the voice signaling which reduce the VoIP performance and increases the call's duration. In addition, GSM and LQS based VoIP calls have an acceptable level of QoS while PCM and IP-Telephony based VoIP calls have a low level of QoS over different types of mobility models. Furthermore, the location and the mobility of SIP server affect the number of hops and the SIP signaling performance between the different parties of the VoIP call.

I. Introduction

MANET is one of the most common wireless networks with dynamic distributions of mobile devices that move in different types of mobility systems [1]. MANET has different types of routing protocols, and each routing protocol has its own characteristics over different types of applications and mobility models. This evaluation study considered OLSR as a proactive routing protocol for MANET. On the other hand, voice over IP (VoIP) is one of the most common applications over different types of network systems. Different factors affect the VoIP QoS over OLSR MANET such as the mobility model, voice codec, physical distance between calls parties, hops number, node capacity, WLAN technology system, and calls durations. The main aim of the evaluation study is to examine the QoS and SIP signaling for VoIP applications over OLSR MANET with moderate node capacity, different types of mobility models, and different voice codecs.