Double Link Failure Protection using a Single P-cycle

Internet is powered by the world wide optical network and hence, survivability of optical network is extremely important. Sometimes, the protection for the two failed links interfere with each other and as a consequence only one failure can be protected. In a large optical network, failure probability of two links with overlapping protection can be high, as these links will be very likely geographically closer. Also, two link failure protection makes the network more resilient by taking care of double failures having overlapping protection. An innovative method for network survivability against two link failure is introduced in this paper. Further, to take care of this scenario, double cycle method (DB) which uses two cycles to protect a link has been described in this paper. Integer linear program (ILP) is formulated for the proposed as well as DB method. It was observed that the proposed method is simpler and performs better than the DB method.