Restoration path calculation considering shared-risk link groups in mesh networks

A network manager for a mesh network having a plurality of nodes interconnected by a plurality of links, the network manager adapted to determine a restoration path corresponding to a primary path for a new service in the mesh network, wherein:

• for each of a plurality of candidate restoration paths associated with the primary path:
• the network manager is adapted to determine whether the primary path requires any additional restoration bandwidth to be reserved on any link of the candidate restoration path based on whether, for each link of the candidate restoration path, the primary path is SRLG-disjoint from each other primary path that is currently protected by that link, wherein:
• a shared risk link group (SRLG) is a set of two or more links, for which a failure of any one link in the SRLG is associated with a relatively high risk of failure of the other links in the SRLG;
• and
• two paths are SRLG-disjoint if no two links in the two paths are members of any one SRLG;
• and
• the network manager is adapted to generate a path cost for the candidate restoration path, wherein the path cost is a function of whether any such additional restoration bandwidth is required;
• and
• the network manager is further adapted to select the restoration path for the new service based on the path cost for each candidate restoration path.