Guaranteeing End-to-End Deadlines in ATM Networks

In this paper we address the issue of guaranteeing the end-to-end deadlines of hard real-time connections in an ATM network. In an ATM network, a set of hard real-time connections can be admitted only if the end-to-end delays of cells belonging to individual connections are not more than their deadlines. We systematically decompose an ATM network into constant delay and variable delay servers to facilitate the delay analysis. EEective traac description is the key part of such a process. We propose a comprehensive traac description function that provides adequate information about the worst case traac behavior of connections anywhere in the network. We also study some simple approximations of this function that perform reasonably well in practice. We analyze and compare the performance of ATM networks with FCFS and WRR link scheduling policies under diierent loading conditions.