Dynamic adaptable bandwidth allocation with spare capacity in ATM networks

Abstract

Bursts from a number of variable bit rate sources allocated to a virtual path with a given capacity can inundate the channel. Buffers used to take care of such bursts can fill up rapidly. The buffer size limits its burst handling capability. With large bursts or a number of consecutive bursts, the buffers fill up and this leads to high cell losses. Channel reconfiguration with dynamic allocation of spare capacities is one of the methods used to alleviate such cell losses. In reconfigurable networks, spare capacity allocation can increase the channel rates for short durations, to cope with the excess loads from the bursts. The dynamic capacity allocations are adaptable to the loads and have fast response times. We propose heuristic rules for spare capacity assignments in ATM networks. By monitoring buffer occupancy, triggers which anticipate excess traffic can be used to assign spare capacities to reduce the cell loss probabilities in the network.