The Performance of Periodic Link-State Update in Wavelength-Routed Networks

Distributed lightpath establishment in wavelength- routed networks requires up-to-date link-state information to achieve blocking performance target. Invalid routing and wavelength assignment decisions caused by inaccurate link-state information may degrade network performance significantly as the lightpaths become more and more dynamic. In this paper, we evaluate the performance of periodic link-state update, where link-state information is exchanged between network nodes at regular intervals. By proposing an accurate analytical model as well as by carrying out extensive simulations, we show how different components of network blocking probability are affected by inaccurate information under different traffic loads, and provide insights into the high sensitivity of blocking performance to link- state update interval under light traffic loads. We demonstrate how the sensitivity could be affected by network connectivity as well.