Efficiency of routing and resilience mechanisms in packet-switched communication networks

In this work we compare the efficiency of various routing and resilience mechanisms. Their path layout determines the utilisation of links in the network under normal operation and in failure scenarios. For the comparison, the performance measure is the maximum utilisation rho(S) of all links for a set of protected failures S. A routing mechanism is considered more efficient than another if it leads to a lower maximum link utilisation rho(S). We consider standard and optimised versions of IP routing and rerouting, optimised routing using explicit paths and end-to-end protection switching., as well as standard and optimised versions of Multiprotocol label switching (MPLS) fast reroute. The results show that routing optimisation reduces the maximum link utilisation significantly both with and without failure protection. The optimisation potential for resilient routing is limited by the applied mechanism and depends heavily on the network structure and the set of protected failure scenarios S. Copyright (C) 2009 John Wiley & Sons, Ltd.