Dimensioning Playout Buffers from an ATM Network

Peter Key
Frank Kelly

Eleventh UK Teletraffic Symposium, Cambridge.
Performance Engineering in Telecommunications Networks (1994) 16A/1 - 16A/9.


The interaction of traffic streams within an ATM network raises several interesting questions concerning the size of buffers at various positions within the network. Even an initially deterministic input stream of cells will be perturbed by cross traffic, producing cell delay variation that varies across the network. In this paper we particularly focus on the dimensioning of playout buffers, and investigate how earlier work of van den Berg and Resing and of D'Ambrosio and Melen can be combined with classical bounds for the GI/G/1 queue to give insight into the output buffer required if a smooth playout of cells is to be achieved. We investigate the effect of both the number of stages across the network and the rate of the stream. A possibly surprising conclusion is that as the rate of the stream decreases the required output buffer size may actually increase. While the cell delay variation of small rate streams may cause no problems for buffers within the network, the cell delay variation introduced by the network may cause problems for the customer on output.

Available from IEEE, or here.