Date Added: Jun 2011
Network survivability is a key area and many schemes have been studied for optical Dense Wavelength Division Multiplexing (DWDM) networks. These include pre-provisioned protection strategies for working/ backup path computation as well as post-fault restoration. With expanding deployments, multi-domain protection schemes have also been evolved for larger backbone networks. For example, SONET/SDH interconnection has been extended for "Localized" per-domain protection in, whereas others have also tabled more extensive "End-to-end" link/domain disjoint strategies. However, most optical survivability schemes are designed for single node/link failures. Given the proliferation of DWDM backbones, there is growing interest in developing schemes to handle multiple near-simultaneous, i.e., correlated, failures such as those resulting from large power outages, natural disasters, Weapons of Mass Destruction (WMD) attacks, etc.