QoS provision and routing with stochastic guarantees

This work presents a methodology for providing QoS guarantees by considering the coupling between the scheduling mechanism and the routing schemes. Our main focus are rate-based schedulers and stochastic guarantees. We consider several traffic models and obtain for each an appropriate upper bound on the end-to-end delay tail distribution. With that at hand, we derive corresponding routing schemes that exploit the obtained bound. More specifically, we consider traffic with exponentially bounded burstiness (EBB) and stochastic QoS requirements. First, we extend previous results and provide an upper bound on the tail distribution of the end-to-end delay for packetized traffic and links with non-negligible propagation delays. Consequently, we formulate several routing schemes that identify feasible paths under various network optimization criteria. We demonstrate the efficiency of these routing schemes via simulation examples. Then, we consider traffic with (general) stochastic bounded burstiness (SBB). Here, we provide the corresponding upper bound on the end-to-end delay tail distribution for packetized traffic and links with propagation delays. Finally, focusing on the special case of a bounding function that is the sum of exponents, we design appropriate routing schemes.