A buffer management and channel allocation strategy for QoS support in an ATM switch

We consider an ATM switch that handles two types of traffic: voice and best-effort data. Voice is delay-sensitive while data is loss-sensitive. Contention at output ports is resolved by output queuing. The output buffer is organized into two virtual queues, one for voice and the other for data. To meet the delay QoS of voice, the channel is allocated to the respective queue with a probability that depends on the congestion level in that queue. We present a model and analysis of the output queues and calculate the waiting time and loss performance under two specific channel allocation strategies. The results indicate that the proposed channel allocation strategy is quite effective in maintaining a balance between the QoS objectives of the two traffic types.