978-1-4673-5828-6/13/$31.00 ©2013 IEEE

SIP Over Next Generation Mobile Ad Hoc

Networks (MANETs)

Mazin Alshamrani

Center for Communication Systems Research (CCSR)

University of Surrey

Guildford, United Kingdom

m.alshamrani@surrey.ac.uk

Abstract— Most of the Future Internet users will be wirelessly

connected to IP clouds through different types of wireless

networks. Thus, the number of applications and devices will be

increased, and IPv6 insists to be applied. Voice over IP (VoIP) is

one of the most popular Internet applications which provide real

time voice communications between different parties and

network systems. The Quality of Service (QoS) for VoIP

influenced by the performance metrics which are signaling,

bandwidth, packet loss, delay, and jitter. The signaling is the

main parameter that manages and controls VoIP calls. One of

the most efficient signaling systems for VoIP is the Session

Initiation Protocol (SIP). MANETs consist of changeable

bandwidth with considerable delays which affects the VoIP QoS.

The first stage of my PhD research is to evaluate the

performance metrics of the SIP based VoIP applications over

IPv6 MANET using OPNET modeler with different voice Codecs

and Mobility Models. The evaluation results showed considerable

differences in the performance of the real-time applications

between different MANET routing protocols. In conclusion, SIP

acts poorly in IPv6, and both SIP signaling and IPv6 need to be

enhanced for real time applications over MANET.

Keywords— MANET; SIP; VoIP; QoS; IPv6; OPNET

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. 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 MANET such as the routing protocols, mobility model, voice codec, physical distance between calls parties, number of hops, node capacity, WLAN technology system, and calls durations. The main aims of this research is to enhance the SIP signaling for VoIP applications over Next Generation (IPv6) MANETs. An evaluation studied the SIP signaling for VoIP applications over different types of MANET protocols and using different voice codecs for both IPv4 and IPv6. The results of the evaluations used to determine the research gaps and possible contributions to enhance and develop the performance of SIP signaling to provide better QoS for VoIP over IPv6 MANET. The modeling and simulation works are implemented using OPNET modeler.

II. PHD RESEARCH PROGRESS

The progress so far is as following: Implement simulation works on OPNET for the SIP based VoIP for Approach of IPv4 MANETs. The results are used to justify the proposed solutions for the research area. The initial findings show that there are considerable delays for VoIP applications with different types of Voice codecs (DSR, IP-Telephony, LQS, and GSM) over different MANET’s routing protocols. IPv6 has more delays than IPv4 over all the proposed scenarios. AODV (Reactive Routing Protocol) and OLSR (Proactive Routing Protocol) had the best QoS over different voice codecs and mobility models (Static, Uniform, and Random) for both, SIP signaling and Voice data. The best effort for Voice codecs was with LQS then GSM then IP Telephony and the worst was with the PCM. The Number of hops affect the VoIP QoS. The TCP signaling features affect the SIP Signaling. So, the SIP timings depend on TCP timings. The SIP call setup times and the performance of RTP signaling are quite different from a routing protocol to another. The DSR has the worst performance for VoIP applications over MANET with all mobility models, while the AODV is the best. The SIP server position affects the SIP Signaling. SIP server mobility affects VoIP. Advance evaluation for the SIP based VoIP calls over IPv4 MANET using different voice codecs such as PCM, LQS, IP Telephony, and GSM. The evaluation targeted the main MANET protocols which are DSR, AODV, TORA, and OLSR to study the SIP signaling delays and the QoS of the VoIP calls with static, random, and uniform mobility models. The current work is on the IPv6 and how to support it for VoIP applications over MANET.

III. SIMULATIONS AND INTIAL RESULTS

The SIP based VoIP applications consist of two types of signaling: SIP signaling (TCP based) and voice data (UDP based) [2]. Both signaling systems have an impact on the VoIP QoS [3]. An evaluation study considered IEEE 802.11n as a wireless network standard for MANET models. The simulation works applied over four types of mobility models: Static, Uniform, Random, and Random All (with Mobile SIP Server). The parameters of the simulations identified depending on the features and the capabilities of MANET and VoIP applications compared with other evaluation studies as in [4] , [5] and [6]. Fig. 1 shows the simulation module design and the implementation of MANET models in OPNET.

Fig. 1. MANET Random Mobility Model at the simulation time: 20 Seconds.

The red arrows represent mobility directions for each node.

The initial results used to evaluate the SIP signaling for VoIP by considering different types of mobility models. Fig. 2 shows the average calls setup time for VoIP applications for AODV, DSR, and TORA MANET routing protocols over different mobility models using GSM voice codec. The Static and Uniform model have the best performance over all voice codecs, Random model has a very high delays (between 4 to 8 seconds), and the Random All has the worst SIP call setup time. The average setup time for VoIP calls is very unstable in Random mobility models of the effect of the TCP mechanism for SIP signaling and the hops number between MANET nodes.

Fig. 2. Average SIP Call Setup Time in Seconds (S). The Simulation time

600 Seconds (S).

IV. FUTURE WORKS

The future works will focus on VoIP over Next Generation (i.e.: IPv6) MANET. The results highlight the performance trade off and the differences between both IPv4 and IPv6 for SIP based VoIP applications. Furthermore, the SIP signaling enhancements and the SIP server performance will be considered for VoIP applications over IPv6 MANET. The millstones of future works: The initial works covered most of the main evaluation stages of this approach. However, the QoS development and the improvement are still not implemented yet. Then, employ Robust Header Compression (RoHC) over IPv6 MANET over different mobility models (Static, Uniform, and Random). Furthermore, the study will examine three different types of RoHC using SIP/TCP/IP headers compression, RTP/UDP/IP headers compression, and all headers compression of the real-time applications. Finally, the SIP/TCP timers and the retransmission algorithm are the main tasks in this research study to provide better performance for real time applications over IPv6 MANET.

ACKNOWLEDGMENT

The use of OPNET Modeler® version 17.1 in this research was facilitated through OPNET’s University Program.

LIST OF PUBLICATIONS

[1] M. Alshamrani, H. Cruickshank, Z. Sun, B. Elmasri, and V. H. Tafreshi, “Evaluation of SIP Signalling and QoS for VoIP Over OLSR MANET Routing Protocol,” Computer Modelling and Simulation (UKSim), 2013 UKSim 15th International Conference.

[2] M. Alshamrani, H. Cruickshank, Z. Sun, B. Elmasri, and V. H. Tafreshi, “SIP-based internetwork system between Future IP Networks and ZigBee based Wireless Personal Area Networks (WPAN),” Computer Science and Electronic Engineering Conference (CEEC), 2012 4th, pp. 206–211, 2012.

PAPERS UNDER REVIEW

[1] Evaluation of SIP Signalling and QoS for VoIP Ove MANETs Reactive Routing Protocols.

[2] Performance of SIP based VoIP Over Next Generaton OLSR MANET Routing Protocol.

MAIN REFERENCES

[1] K. Pandey and A. Swaroop, “A Comprehensive Performance Analysis of Proactive, Reactive and Hybrid MANETs Routing Protocols,” IJCSI International Journal of Computer Science Issues, Vol. 8, No. 3, 2011.

[2] A. B. Johnston, “SIP Understanding the Session Initiation Protocol,” third Edition, Artech House Publishers, 2009.

[3] S. Ganguly and S. Bhatnagar, “VoIP: Wireless, P2P and New Enterprise Voice Over IP,” Chichester, England: Wiley, 2008. Print.

[4] V. Sharma, J. Singh, and S. Gujral, “Performance evaluation of reactive routing protocols in MANET networks using GSM based voice traffic applications,” Optik-International Journal for Light and Electron Optics, 2012.

[5] K. Pandey and A. Swaroop, “A Comprehensive Performance Analysis of Proactive, Reactive and Hybrid MANETs Routing Protocols,” IJCSI International Journal of Computer Science Issues, Vol. 8, Issue 6, No. 3, 2011.

[6] M. K. J. Kumar and R. Rajesh, “Performance analysis of MANET routing protocols in different mobility models,” Proceedings of the International Journal of Computer Science and Network Security, IJCSNS, vol. 9, no. 2, pp. 22–29, 2009.