System and method for protecting optical light-trails

Logic for providing protection for a network, the logic embodied in a medium and operable to:

• establish a light-trail through a sequence of nodes of an optical network, the sequence of nodes coupled by a first fiber and by a second fiber;
• communicate traffic through a plurality of connections of the light-trail, a connection operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes;
• detect that the light-trail has a failure;
• establish a protection light-trail corresponding to the light-trail;
• and
• communicate the traffic of the plurality of connections through the protection light-trail.

An optical network operable to carry optical traffic in a plurality of multiplexed wavelengths, the optical network comprising:

• a plurality of nodes comprising a sequence of nodes through which a light-trail is established, the sequence of nodes coupled by a first fiber and by a second fiber, the plurality of nodes operable to:
• communicate traffic through a plurality of connections of the light-trail, a connection operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes;
• at least one node of the plurality of nodes operable to:
• detect that the light-trail has a failure;
• and
• establish a protection light-trail corresponding to the light-trail;
• and
• the plurality of nodes further operable to:
• communicate the traffic of the plurality of connections through the protection light-trail.

A system for providing protection for a network, comprising:

• means for establishing a light-trail through a sequence of nodes of an optical network, the sequence of nodes coupled by a first fiber and by a second fiber;
• means for communicating traffic through a plurality of connections of the light-trail, a connection operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes;
• means for detecting that the light-trail has a failure;
• means for establishing a protection light-trail corresponding to the light-trail;
• and
• means for communicating the traffic of the plurality of connections through the protection light-trail.

A method for providing protection for a network, comprising:

• communicating traffic through a light-trail established through a sequence of nodes of an optical network, the sequence of nodes coupled by a first fiber and by a second fiber, the traffic flowing through the first fiber from upstream to downstream, the sequence of nodes comprising a first number of nodes, the light-trail operable to support a second number of connections, a connection operable to communicate traffic from a source node of the sequence of nodes to one or more destination nodes of the sequence of nodes, the second number equivalent to a combination of the first number taken two at a time;
• detecting that the light-trail has a failure;
• establishing a failed span comprising the failure, the first fiber comprising an upstream remnant segment and a downstream remnant segment, the upstream remnant upstream from the failure, the downstream remnant downstream from the failure;
• creating a wrap-around segment from a portion of the second fiber, the wrap-around segment comprising a loop-back path of the failed span;
• forming a protection light-trail from the upstream remnant segment, the wrap-around segment, and the downstream remnant segment, forming the protection light-trail further comprising:
• configuring one or more protection switches of one or more nodes upstream of the failed span, the configured switches operable to:
• split the traffic to yield a plurality of copies of the traffic;
• provide a first copy to the upstream remnant segment;
• and
• provide a second copy to the wrap-around segment;
• configuring one or more switches of one or more nodes downstream from the failed span, the configured switches operable to:
• receive traffic from the downstream remnant segment;
• receive traffic from the wrap-around segment;
• and
• combine the received traffic;
• and
• communicating the traffic of the connections through the protection light-trail by:
• routing a first connection having a first source node in the upstream remnant segment and having a first destination node in the downstream remnant segment through the wrap-around segment;
• routing a second connection having a second source node in the upstream remnant segment and a second destination node in the upstream remnant segment through the upstream remnant segment;
• and
• routing a third connection having a third source node in a downstream remnant segment and a third destination node in the downstream remnant segment through the downstream remnant segment.