Network survivability in WDM

Network Survivability is a new field of research, and is viewed by many as distinct from the traditional areas of security and fault-tolerance. Information system survivability is defined as the capability of a system to fulfill its mission, in a timely manner, in the presence of attacks, failures, or accidents. Survivability is basically the ability of a system to continue its adequate performance in the presence of faults, failures and accidents. We find the network survivability by using ELF, availability model and MRM (markov reward model). It has been assumed that network topology and link capacity are known. Each link means to a fiber in the WDM network and number of wavelength in the link are represented by capacity of the link. First we find the ELF by using defined capacity and flow. After finding ELF we do the availability analysis of each link, than combine it with MRM model for evaluation of the survivability.