Researches in robust of intelligent optical networks

The robust of the optical networks is one of the most important issues the optical networks should take into account when they are put into practice. Two typical causes for the instability of the WR-ION are analyzed in the paper: One is associated with something abnormal in the network and resulting in some measures for the survivability of the networks, and the other results from the dynamic characteristics of the network, such as dynamic routing. And some algorithms were proposed by Tsinghua Univ. to enhance the robust of the ION, for example, a Low Priority Hello Reduction Algorithm to decrease the number of false alarms resulting from LSA storm, and an Active Choke of Inter-domain Routing algorithm to overcome inter-domain routing instability. And some assistant methods were also developed, for example a Soft Preempt Algorithm to modify congestion degree of the ION in case congestions occur, and a software solution to decrease the processing time of the RSVP-TE. Experiment and simulation results proved the algorithms effective.