Dynamic Renegotiation of UPC Parameters for Arbitrary Traffic Sources in ATM Networks

摘要

In networks based on the Asynchronous Transfer Mode (ATM),traffic sources are subjected to a Usage Parameter Control (UPC) function which employs a deterministic algorithm to control or shape the emitted cell stream.The UPC parameters constitute a traffic descriptor which is part of a traffic contract that is negotiated with the network provider at connection set-up time.The network makes connection admission control (CAC) decisions based on the negotiated UPC-based traffic descriptor.However,the source traffic characteristics may change dramatically on a slow time-scale,making the initially negotiated UPC descriptor inappropriate for the entire traffic stream.Allowing the source to dynamically renegotiate UPC parameters over time is a viable means of accommodating sources with slow time-scale variations.This paper develops a methodology for estimating and dynamically renegotiating UPC parameters for an arbitrary source in an ATM network environment.The methodology makes no specific modeling assumptions on the user cell stream,is robust for a wide class of traffic streams,and permits trade-offs to be made in the choice of the UPC parameters according to the constraints imposed by the source.