Single-service quality differentiation

Abstract

This paper proposes a scheme for quality of service differentiation for single-service networks that is based on the use of two separate forms of traffic control at the transport layer: Streams are controlled by means of probe-based admission control and elastic flows are controlled by TCP. The controls allow separation of traffic into two distinct service classes. The stream class is designed to provide a consistent quality for interactive audiovisual communication, as favored by human perception. It is responsive to load variations as an aggregate through blocking of sessions, while TCP is responsive on the flow level. Streams can be isolated against disturbances from probes and TCP flows by means of error-control coding. We show that the two traffic controls can coexist without starvation, and the proposed scheme might thus provide a first step towards differentiated services end-to-end.