Apparatus for diversely routing optical wavelengths across a
point-to-point subnetwork. An optical network includes a first optical
ring having at least first, second, and third nodes adjacently
positioned; a second optical ring having at least fourth, fifth, and
sixth nodes adjacently positioned, pairs of optical fibers link the
adjacent nodes; a point-to-point subnetwork having at least first,
second, third, and fourth optical fibers optically coupling the first and
second optical rings. The first node is configured to route working bands
across the first optical fiber to the fifth node and to route a copy of
the working bands to the second node. The second node is configured to
route either the copy of the working bands or a select subset of the copy
of the working bands across the third optical fiber to the fourth node.