Trunking performance analysis of AAL2 for VBR voice transport

This paper analyzes the trunking performance of ATM Adaptation Layer Type 2 (AAL2) for variable bit rate (VBR) voice transport. In order to transmit voice traffic over ATM networks, unstructured and structured circuit emulation services using AAL1 were proposed as possible standard-based methods. However, although AAL1 is offered as a standard-based solution by some ATM equipment manufacturers, it is not considered an optimum solution, in terms of bandwidth utilization efficiency, for voice transport due to the lack of support of multiple individual voice users per ATM connection, compression, and silence suppression. In order to satisfy the critical need in the market for voice-over-ATM, AAL2 is defined in the ITU-T Recommendation I.363.2 which is designed with the capabilities to support multiple voice users per ATM connection and transport compressed/silence-suppressed VBR voice traffic. In this paper, we conduct detailed quantitative analysis of the trunking performance of AAL2