IP Telephony Development and Performance over IEEE 802.11g WLAN

With the adoption of the wireless LAN technology as one of the main ways to access the enterprise network, IP services have found another place where they can be implemented. In this paper we will show the test and performance used to develop the IP telephony network over the 802.11g wireless LAN of the Polytechnic University of Valencia. In order to make these measurements, we have used the open source PBX & Telephony platform: Asterisk and smartphones. We will show the results obtained about the delay, the jitter and the number of lost packets when the smartphones are in the same wireless cell and when they are roaming. Finally, we will calculate the amount of IP phones that can be working in a single access point and the bandwidth wasted in different cases. This work can be used to design VoIP and IP telephony wireless networks and to design wireless IP phones relocation algorithms.