Multi-rail routing and spectrum assignment

A non-transitory machine-readable medium comprising executable instructions that, when executed by a processing system including a processor, facilitate performance of operations, the operations comprising:

• obtaining first data indicative of two or more first parallel links between a first pair of network nodes in a communications network, wherein the first data comprises a first indication of one or more first available frequency slots for a first one of the first parallel links, and wherein the first data comprises a second indication of one or more second available frequency slots for a second one of the first parallel links;
• obtaining second data indicative of at least one second link between a second pair of network nodes in the communications network, wherein the second data comprises a third indication of one or more third available frequency slots for the at least one second link;
• selecting, for the first pair of network nodes, either the first one of the first parallel links or the second one of the first parallel links, wherein the selecting results in a selected link, wherein the selecting is based upon the first data and the second data, and wherein the selecting is in accordance with an availability in the selected link of a particular available frequency slot;
• and
• outputting a route, wherein the route includes the selected link and the second link.

A method, comprising:

• obtaining, by a processing system including a processor, first data indicative of two or more first parallel links between a first pair of network nodes in a communications network, wherein the first data comprises a first indication of one or more first available frequency slots for a first one of the first parallel links, and wherein the first data comprises a second indication of one or more second available frequency slots for a second one of the first parallel links;
• obtaining, by the processing system, second data indicative of at least one second link between a second pair of network nodes in the communications network, wherein the second data comprises a third indication of one or more third available frequency slots for the at least one second link;
• selecting, by the processing system, for the first pair of network nodes, either the first one of the first parallel links or the second one of the first parallel links, wherein the selecting results in a selected link, wherein the selecting is based upon the first data and the second data, and wherein the selecting is in accordance with an availability in the selected link of a particular available frequency slot;
• and
• outputting, by the processing system, a route, wherein the route includes the selected link and the second link.