Selective survivability with disjoint nodes and disjoint lightpaths for layer 1 VPN

This paper deals with the problem of survivable routing and wavelength assignment in layer 1 virtual private networks (VPNs). The main idea is link-disjointly routing the selected lightpaths specified by the customer. The customer identifies some sites or some connections, and their related lightpaths are routed link-disjointly through the providerpsilas network. Selective survivability gives the customer, flexibility of selecting important elements (nodes or connections) in its network. Our results shows that the amount of resources used in selective survivability scheme is only slightly more than the resources used by shortest path routing.