This paper studies the problems of dedicating routes to connections
in optical networks.  In optical networks, the vast
bandwidth available in an optical fiber is utilized by partitioning
it into several channels, each at a different optical wavelength.
A connection between two nodes is assigned a specific wavelength,
with the constraint that no two connections sharing a link in the
network can be assigned the same wavelength.  This paper classifies
several models related to optical networks and presents optimal or
near-optimal algorithms for permutation routing
in many of these models.