Improving QoS through Traffic Smoothing

                        Edward W. Knightly
                         EECS Department
                University of California, Berkeley

			      and 

			  Paola Rossaro
		       Wind River Systems
		 	   Alemeda, CA


The burstiness of variable bit rate traffic makes it difficult to
simultaneously make efficient use of network resources and provide
end-to-end performance guarantees.  In this paper, we present a
smoothing scheme that allows network clients to optimize their quality-
or price-of-service to respectively reduce their end-to-end delay bound
or decrease their resource requirements from the network.  Whether or
not smoothing results in a net benefit to the network client depends on
the the network load, the number of hops traversed, the burstiness of
the stream, and the desired end-to-end delay bound.  Hence, our scheme
tells network clients if they should smooth, and if so, how much they
should smooth to achieve the maximum benefit.  We first derive the
analytical foundations for the scheme, and then perform empirical
investigations using traces of MPEG compressed video