Multiplexing regulated traffic streams: design and performance

The main network solutions for supporting QoS rely on traffic policing (conditioning, shaping). In particular, for IP networks the IETF has developed Intserv (individual flows regulated) and Diffserv (only aggregates regulated). The regulator proposed could be based on the (dual) leaky-bucket mechanism. This explains the interest in network element performance (loss, delay) for leaky-bucket regulated traffic. This paper describes a novel approach to the above problem. Explicitly using the correlation structure of the sources´ traffic, we derive approximations for both small and large buffers. Importantly, for small (large) buffers the short-term (long-term) correlations are dominant. The large buffer result decomposes the traffic stream in a stream of constant rate and a periodic impulse stream, allowing direct application of the Brownian bridge approximation. Combining the small and large buffer results by a concave majorization, we propose a simple, fast and accurate technique to statistically multiplex homogeneous regulated sources. To address heterogeneous inputs, we present similarly efficient techniques to evaluate the performance of multiple classes of traffic, each with distinct characteristics and QoS requirements. These techniques, applicable under more general conditions, are based on optimal resource (bandwidth and buffer) partitioning. They can also be directly applied to set GPS (generalized processor sharing) weights and buffer thresholds in a shared resource system