Experimental Study to Analyze the Security Performance in Wireless LANs

摘要

In this paper, we present a comprehensive experimental study to analyze the security performance of a WLAN based on IEEE 802.11b/g standards in a congested and uncongested roaming and non-roaming scenarios at different packet lengths. Experimental results are obtained for a layered security model encompassing nine security layers in terms of throughput, response time, and encryption overheads, packet loss, frame loss and jitter. The performance impact of TCP and UDP traffic streams on secure wireless networks has also been studied. Through numerical results obtained from the testbed, we have presented quantitative and realistic findings for both security mechanisms as well as network performance. It establishes the fact that there is always a tradeoff between the security strength and the associated network performance that is performance decreases with increase in security strength. It is observed that under all the network scenarios non-roaming network performs better than roaming network. To analyze the benefits offered by a particular security protocol we have presented a relative security strength index model. Further we have presented the statistical analysis of our experimental data. We found that different security protocols have different robustness against mobility. By choosing the robust security protocol, network performance can be improved. The present performance analysis is significant and useful with reference to the assessment of the suitability of security protocols for given real time application.