Local Allocation of End - to - End Quality - of - Service in High - SpeedNetworks 1

Quality-of-service (QOS) requirements for applications in high-speed networks are typically speci-ed on an end-to-end basis. Mapping this end-to-end requirement to nodal requirements facilitates providing QOS guarantees and simpliies connection admission. In this paper, we evaluate strategies for local allocation of the end-to-end QOS. A QOS allocation policy is said to perform better than another when the maximum network load that it can support is greater. A major contribution of this work is the development of a nodal metric that predicts the relative performance of QOS allocation policies in a network setting. Computation of the nodal metric and direct evaluation of allocation policy performance for two simple network models yield valuable insight into the choice of allocation policies. It is found that with the packet loss probability as the QOS metric, there is little diierence in the performance of allocation policies in the regime of applications with low loss requirements. From a practical viewpoint, this suggests that a simple allocation policy may be adopted in this scenario with only a small decrease in carried load with respect to an optimal policy.