A method comprises allocating a respective restoration path to protect
each of a plurality of primary paths in a network. Each primary path has
a plurality of nodes and at least two subpaths connecting the nodes of
the primary path. Each restoration path includes at least one link. Each
link protects at least one of the subpaths of the primary path. Each of
the subpaths of the primary path is protected. None of the links in the
restoration path is included in the corresponding primary path. At least
one of the links is shared among at least two restoration paths
corresponding to at least two of the primary paths.