Analysis of a Markov-Modulated Fluid Model for Multimedia Traffic with Loss and Delay Priorities

Abstract

This paper presents a complete fluid-flow analysis of a traffic control mechanism in an ATM multiplexer, known as Nested Threshold Cell Discarding with Multiple Buffers. NTCD/MB is a buffer management scheme that implements loss and delay priority queueing strategies in order to satisfy a wide range of quality-of-service requirements. We consider a heterogeneous mix of traffic which consists of real-time traffic with a stringent cell delay requirement, and nonreal-time traffic with a stringent cell loss requirement. Moreover, a proportion of real-time cells has an additional stringent loss requirement. Cell arrivals are mode led using a fluid-flow modeling approach. The system we analyze consists of two buffers interacting via a common server. The steady-state probability distribution for the buffers' content as well as other performance statistics are obtained. Our approach is based on computing the conditional probability distributions of the buffers and using this information to find the desired unconditional stationary distributions. This approach can be used, in general, to analyze multiple dependent systems of buffers. Numerical examples based on the analysis are used along with simulations to study the performance of NTCD/MB. It is shown that NTCD/MB can be used effectively to provide performance guarantees on different cell loss and delay requirements of the traffic.