Method and apparatus for dynamic provisioning of reliable connections in the presence of multiple failures

A method of allocating protection paths in an optical network, the method comprising:

• responsive to a failure in the network, for each active lightpath affected by the failure, switching traffic from the affected active lightpath to a protection path thereof;
• subsequent to the switching, classifying as orphans all active lightpaths in the network that no longer have an available protection path as a result of the failure;
• and
• attempting to allocate a protection path to each of the orphans each time an active lightpath is released in the network.

A system for allocating protection paths after a failure in an optical network, the system comprising:

• means responsive to a failure in an active lightpath for switching traffic on the active lightpath to a protection path;
• means for identifying all active lightpaths in the network that no longer have an available protection path subsequent to the switching;
• and
• means for attempting to allocate a protection path to each of the identified active lightpaths each time an active lightpath is released in the network.