P-Cycle Based Protection Scheme In Mesh Networks

Nowadays, the existing transport networks can hardly bear the ever-growing data services, so ASON emerges as the times require. It adds intelligence and agility into the transport networks. And the ring-like network is also evolving to a more flexible mesh-like network.The ability to survive from failures is very important for mesh ASON because it can help the network avoid big loss of money and side-effect in the society. Therefore, research on mesh ASON survivability is of great practical value and is meaningful for theoretical research.This paper is based on the project "Survivability of Optical Networks" co-sponsored by BUPT and Bell Labs and lucent technologies. The paper firstly introduces the concept and mechanism of pre-configured cycles (p-Cycle), and proposes a p-cycle algorithm called Cycles surrounding Nodes, which is designed specially for node failures. Then the paper describes the idea which leads to the algorithm, the procedure of the algorithm, the evaluation system of the algorithm, the optimization of the cycles and the assignment of network resources onto the cycles.In order to equip ASON with p-cycles, this paper also brings forward two sets of failure processing procedures and signaling schemes using p-cycles. Each of them consists of schemes for single-link failure, multiple-link failure, single-node failure and multiple-node failure. The failure processing includes searching for p-cycles, protect switching when the failure appears and reversion. Of the two sets of schemes, one is simple and the other is complicated, and they each have their advantages. We can choose one of them according to the requirements. And these schemes can be used for reference.This paper also introduces the ASON simulation platform built using OPNET. The final part of the paper gives some of the simulation results for node failures using p-cycle. And the results are analyzed and the performances of the complicated scheme and the Cycles surrounding Nodes algorithm are acquired.