ANALYSIS OF VOIP TRAFFIC IN WIRED AND WIRELESS LANS
Keywords:
VoIP, QoS, Jitter, Delay, Packet Loss RatioAbstract
This paper is an experimental study to analyze the performance of Voice Over IP (VoIP) traffic over wired and wireless Local Area Networks (LANs) by observing VoIP Quality Of Service (QoS) parameters, these parameters comprise jitter, delay and packet loss ratio. Two widely deployed LANs technologies (IEEE 802.3Ethernet in wired and IEEE 802.11G in wireless) are chosen as the test environment to conduct this study, the test methodology adopted in this study is based on simulation of real voice traffic in both network environments, thus the study was conducted in the laboratory using real equipment. In order to evaluate VoIP traffic performance, Quality of Service (QoS) parameters on the Real-Time Transport Protocol (RTP) packet transmission under different background traffic loads are measured, File Transport Protocol (FTP) traffic is used as the back ground traffic. A set of graphs representing the jitter and delay graphs versus the RTP packets number are produced. The test results show that at high network loads, VoIP traffic in both network environments suffers high delay and jitter values. Also it shows that performance of VoIP traffic in wireless is much worse than the performance in Ethernet under the same load conditions. In both Ethernet and wireless, it was noticeable that there is a strong linear correlation between RTP packets delay and packet loss ratio.
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References
[1] Bandwidth Monitor. (2009) [Online]. Available at: (Accessed: 10 July 2009).
[2] Cai, L., Xiao, Y., Shen, X. S. & Mark, J. W. (2006) 'VoIP over WLAN: Voice capacity, admission control,QoS, and MAC', International Journal of Communication Systems, 19 (4), pp. 491 - 508 InterScience [Online]. Available at: (Accessed: 22 August 2009 ).
[3] The enterprise is ready for wireless VoIP.Is wireless VoIP ready for the enterprise? (No date) [Online]. Available at: (Accessed: 14 July 2009).
[4] FileZilla the free solution. (2009) [Online]. Available at: (Accessed: 23 August 2009)
[5] Guo, F. & Chiueh, T. (No date) Comparison of QoS Guarantee Techniques for VoIP over IEEE802.11 Wireless LAN. [Online]. Available at: (Accessed: 21 August 2009).
[6] NEC Unified Solutions (No date) What VOIP Requires From a Data Network. [Online]. Availableat: (Accessed: 17 August 2009).
[7] Ortiz, C., Frigon, J.F., Sans, B. & Girard, A. (2008) 'Effective Bandwidth Evaluation for VoIP Applications in IEEE 802.11 Networks', Wireless Communications and Mobile Computing Conference, 2008. IWCMC '08. International, pp. 926-931 IEEE [Online]. Available at: (Accessed: 15 August 2009)
[8] Rango, F. D., Tropea, M., Fazio, P. & Marano, S. (2006) 'Overview on VoIP: Subjective and Objective Measurement Methods', International Journal of Computer Science and Network Security, 6 [Online]. Available at: (Accessed: 25July 2009).
[9] Roychoudhuri, L., Al-Shaer, E. & Brewster, G. B. (2006) 'On the impact of loss and delay variation on Internet packet audio transmission', Computer Communications, 29 (10), pp. 1578-1589 Science Direct [Online]. Available at: (Accessed: 1 August 2009).
[10] Zubairi, J. A. & Zuber, M. (2000) Suny Fredonia campus network simulation and performance analysis using OPNET. [Online]. Available at: (Accessed: 1 August 2009).
