Performance approximations for stream and elastic traffic in a multi-service priority system with blocking

Almost all traffic in todays networks can be classified as being either stream or elastic traffic. Stream traffic is generated by time-sensitive applications like VoIP, video etc and has strict bandwidth and delay requirements. Elastic traffic on the other hand is generated by applications such as file-transfers where the total download time is more important than inter- packet or end-to-end delay. The support of these two traffic types is possible either with a Differentiated (DiffServ) or an Integrated Services (IntServ) architecture. However, both DiffServ and IntServ rely on efficient scheduling mechanisms and control to meet the requirements of these traffic types. In order to meet the strict delay requirements of stream traffic, the choice of priority scheduling in inevitable. The danger with priority scheduling lies in its potential starvation of lower priority traffic classes for example the elastic traffic class. Therefore, it is essential to understand and capture t! he relation between stream and elastic traffic behaviour, priority scheduling and traffic control. In this paper we focus on developing simple yet effective approximations to capture this relationship. We assess the accuracy of the approximation against simulations and and other well-known simple and straightforward techniques for a wide range of parameters. Results show that our proposed technique is a considerable improvement to other standard approximation techniques and is at the same time not cumbersome.