Packet-level traffic control for the Internet: a framework and its experimental validation

This paper presents a theoretical framework, which can be the basis for traffic control and resource management mechanisms, that provide QoS with quantitative guarantees in the Internet. The starting point is a fairly general traffic shaping algorithm for effective rate enforcement which is based on a packet spacing law. Multiplexing several independent shaped streams results in a tight upper bound to the queue-length distribution at the multiplexer. The algorithm effectively works with any kind of input traffic (non-stationary, non-Markovian, heterogeneous, long-range dependent (LRD), etc.). Based on the definition of shaped streams, we devise mechanisms for aggregating, splitting and policing such streams without affecting the queuing performance at subsequent network nodes. Also, a calculus for end-to-end QoS in this framework is presented. The theoretical statements are supported by simulation and experimental results on a network testbed. Since the enforced effective rate features the convenient additivity property ∑ifi=C, it can be handily used for many traffic control and accounting functions, like policing, admission control, bandwidth allocation and charging.