A FEASIBLE FRAMEWORK OF TRAFFIC CONTROL ON AN ATM WIDE-AREA NETWORK

In this paper, we propose a framework of traffic control to accommodat e multimedia connections on an ATM wide-area network. At the lower lay er, an efficient bandwidth allocation method and a constant time cell scheduling algorithm are provided in each network node. These mechanis ms have the capability of multiplexing traffics and satisfying diverse delay and loss performance requirements. At the higher layer, a three -phase connection establishment procedure is applied. It transforms th e end-to-end performance requirement of a connection request into loca l requirements for each intermediate node of a routing path. If the re quirements for each intermediate node can be satisfied, the connection is accepted; otherwise, another routing path will be examined. Withou t resort to any complicated rate control inside the network, in our sy stem, time distances between successive cells while they are passing t hrough the network are maintained by imposing an upper bound on the en d-to-end queueing delay of each cell. Simulation results show that the connection establishment overhead of our system is almost independent of the traffic load of the network. Its value is very small so that t he proposed framework is feasible in the future ATM networks. Besides, optimally transforming end-to-end performance requirement into those for each intermediate node to maximize the saturation load of the netw ork has been proved to be an NP-Hard problem. Two heuristic algorithms are proposed. Experiments are performed to evaluate these algorithms.