Voice and data integration at an ATM DSL access multiplexor

Abstract

We analyze cell loss and call blocking at an ATM-based DSL access multiplexor which integrates 2 types of calls onto a channel through a common buffer. Type-1 calls have stringent delay, but relaxed cell loss QoS requirement, and are representative of voice. Type-2 calls have stringent cell loss but relaxed delay QoS requirement, and are representative of Internet data. We study an access strategy that allocates separate buffers to the 2 cell types and assigns priority to the voice buffer in accessing the channel. We apply a fluid flow method to analyze both cell loss and call blocking of the two types of calls. These results are then used to size the admission region at the access node under loss and blocking constraints. Numerical results are presented which quantify the interaction between cell loss and call blocking and the utility of the priority scheme compared to the FIFO scheme in handling the two traffic types.