Abstract: A method of modifying the routing of lightpaths without interrupting service, scheduling long maintenance windows or the need to delete and recreate lightpath definitions is disclosed. The solution utilizes a combination of non-disruptive bridge and roll techniques and uses temporary end to end protection or segment protection to change the routing of the working or protection part of the lightpath without having to take the lightpath out of service. The solution relies on lambda level switching hardware support and software at the two endpoint nodes to coordinate in the event of an operator-initiated protection switch, the switching of connections from the working path to the protected path. Protection switching can be configured to be end to end, single segment only or multi hop protection depending on the application.

Abstract: This invention proposes a method for enabling segment protection, whereby one or more hops in the lightpath are protected by either a dedicated or shared wavelength. This provides a more cost effective solution for the service provider such that they only need to configure protection, and therefore deploy equipment, to those sensitive portions of the network rather than dedicating wavelengths and equipment for protection end-to-end for a lightpath. Further, allowing protecting wavelengths to be shared for protection, gives further flexibility and therefore, savings, to the service provider. To utilize lightpath segment protection and sharing the protection between multiple lightpaths requires the new mesh networking capabilities of the network elements and new network management tools to configure, and monitor these protected lightpaths.