Using new results for tight bounds on link-level performance for (s,r,p)-regulated traffic, we are able to develop the tools necessary for the efficient and accurate design and engineering of networks with envelope-regulated traffic. Our results are very promising in that they open new avenues for network design and engineering by providing an end-to-end framework that is less conservative, and hence more efficient, than the conventional network calculus framework based on worst-case bounds.
First we define several effective bandwidths that can be used to design and engineer networks with (s,r,p)-regulated traffic when the end-to-end performance is the average delay. In particular we study the impact of the peak rate p on the performance of the link-level model. The main result of this part is that it is indeed possible to define effective bandwidths that meet all the requirements for accuracy and simplicity for use in network design and engineering.
We then examine the optimal partitioning of the end-to-end QoS budget into link-level constraints, an important issue in networks with heterogeneous links. The three major results of this part are that 1) the peak rate parameter p has a important impact on the results and hence cannot be neglected, 2) we can obtain very substantial gains in efficiency (and hence in revenues) if we partition the end-to-end QoS budget optimally between the heterogeneous links of a network and 3) we can define fast and accurate approximations for the allocation that could be used in network design.
This work has been done in collaboration with Prof. A. Girard (INRS-Telecom) and Hyunjoon Cho.