Most previous research on MPLS/GMPLS recovery management has focused on efficient routing or signaling methods from single failures. However, multiple simultaneous failures may occur in large-scale complex virtual paths of MPLS/GMPLS networks. In this paper, we present a dynamic MPLS/GMPLS path management strategy in which the path recovery mechanism can rapidly find an optimal backup path which satisfies the resilience constraints under multiple link failure occurrences. We derived the conditions to test the existence of resilience-guaranteed backup path, and developed a decomposition theorem and backup path construction algorithm for the fast restoration of resilience-guaranteed backup paths, for the primary path with an arbitrary configuration. Finally, simulation results are presented to evaluate the performance of the proposed approach.

Recent advances in broadband communication and computing technology have accelerated the proliferation of Internet protocol-based multimedia conferencing services in large-scale enterprises. Most of the research on session initial protocol (SIP)-based multimedia conferencing, however, has been limited in scalability due to the centralized management of conference control by a single server. In order to overcome this limitation, we have designed policy-based distributed management architecture for a large-scale enterprise conferencing service by extending the Internet Engineering Task Force's (IETF's) approach. The salient feature of the proposed management architecture is that in addition to the distribution of media processing, both participant membership control and authorization functions are dynamically distributed in accordance with the management policy in order to improve scalability. In order to implement these distributed management functions, we have extended both SIP and conference policy control protocols of the IETF. We also show the procedures for the distributed conference management using the extended SIP signaling methods. Finally, we have evaluated by simulation the performances of the proposed architecture in comparison with the centralized architecture of the IETF. The simulation results show that the proposed architecture greatly improves scalability.