Performance evaluation of QoS-routing methods for IP-based multiservice networks

This paper provides a performance analysis of lost/delayed traffic and control load for various quality of service (QoS)-routing methods, which control a network's response to traffic demands and other stimuli, such as traffic overloads, link failures, or node failures. Essentially all of the methods analyzed are already widely applied in operational networks worldwide, particularly in PSTN networks employing TDM-based technology. However, the methods are shown to be extensible to packet-based technologies, in particular, to Internet protocol (IP)based technologies. Results of performance analysis models are presented which illustrate the tradeoffs between various approaches. Based on the results of these studies as well as established practice and experience, methods for dynamic QoS routing and admission control are proposed for consideration in network evolution to IP-based technologies. In particular, we find that aggregated per-virtual-network bandwidth allocation compares favorably with per-flow allocation. We also find that event-dependent routing (EDR) methods for management of label switched paths perform just as well or better than the state-dependent routing methods with flooding, which means that EDR path selection has potential to significantly enhance network scalability. (C) 2002 Elsevier Science B.V. All rights reserved.