Assessment of voice over IP as a solution for voice over ADSL

– This paper compares VoATM and VoIP in terms of their suitability for carrying voice traffic over DSL. ATM is currently the preferred protocol due to its built-in QoS mechanisms. Through simulations we show that IP QoS mechanisms can also be used to achieve comparable performance for voice traffic over DSL. Our performance metrics are the ETE delay of voice packets across the DSL access network and the bandwidth requirements of a voice call. We also propose an implicit signaling mechanism to provide admission control for individual voice calls over DSL. We implement a simulation model that uses our mechanism and perform simulations to verify its effectiveness. We conclude that by incorporating appropriate QoS mechanisms and implicit signaling, it is possible to achieve performance for VoIP comparable to that provided by ATM. In this case, the ubiquity of IP makes it a very attractive candidate for future deployments of VoDSL.