Performance study of AAL2 protocol for low-bit-rate multimedia services

In order to support low-bit-rate delay-sensitive traffic consisting of short packets, typically the ATM adaptation layer type 2 (AAL2) has been proposed to provide both bandwidth efficiency and quality of services (QoS) delivery. To support multiple classes of low-bit-rate multimedia traffic, a packet scheduling discipline based on AAL2, referred as AAL2/SD, is proposed paper to efficiently carry multiple classes of traffic over ATM networks. Furthermore, to prevent serious performance degradation due to AAL2 multiplexing when there are cell losses, a buffer management scheme is also proposed to guarantee the QoS for each traffic type. We compare our proposed scheme to the AAL2 protocol using the static priority packet service discipline, called AAL2/SP, for different traffic types. Simulation results show that the AAL2/SD improves the throughput and average transfer delay compared to the AAL2/SP. Moreover, by using a simple buffer access control, packet loss can be effectively controlled.