Method for provisioning circuits on multiple parallel links with a single setup message

A method of initiating the setup of a circuit, comprising:

• calculating a circuit path through a network from a source switch to a destination switch;
• generating a setup message specifying links in the circuit path and indicating whether substitution of parallel links is permitted for the links in the circuit path, the setup message having a flag set to one of a first value indicating that substitution of parallel links is not permitted for any of the links in the circuit path and a second value indicating that substitution of parallel links is permitted for any of the links in the circuit path;
• transmitting the setup message along the circuit path using a network signaling protocol;
• allocating resources based on the setup message;
• and
• transmitting a de-allocation message to the source switch, the de-allocation message traversing the circuit path and de-allocating resources allocated based on the setup message, based on whether sufficient bandwidth for the circuit is available on the parallel link.

A method of provisioning a circuit, comprising:

• generating a setup message specifying a sequence of links in a path of the circuit and indicating whether substitution is permitted for specified links in the sequence of links;
• sequentially transmitting the setup message to each switch in the path of the circuit;
• and
• at each switch, in response to the setup message:
• determining whether sufficient bandwidth is available for the circuit on the specified links associated with the switch,
• if sufficient bandwidth is not available for the circuit on a respective specified link, determining whether substitution is allowed for the respective specified link based on the setup message, and
• if substitution is allowed for the respective specified link:
• substituting a parallel link for the circuit for the respective specified link in the path of the circuit;
• allocating bandwidth on the parallel link for the circuit;
• updating the setup message to replace the respective specified link with the parallel link in the sequence of links;
• allocating resources based on the setup message;
• and
• transmitting a de-allocation message to each switch, the de-allocation message traversing the path of the circuit and de-allocating resources allocated based on the setup message, based on whether sufficient bandwidth for the circuit is available on the parallel link.

A system comprising:

• means for receiving a setup message specifying a path within a network for transmitting information from a first switch to a second switch, the path comprising a plurality of links;
• means for determining whether sufficient bandwidth is available on a respective link of the plurality of links;
• means for substituting a substitute link for the respective link in the path, if sufficient bandwidth is not available on the respective link;
• means for allocating bandwidth on the substitute link;
• means for updating the setup message to replace the respective link with the substitute link in the path, wherein updating the setup message generates an updated setup message;
• means for allocating resources based on the setup message;
• and
• means for transmitting a crankback message to the first switch based on allocation of resources based on the setup message and based on whether sufficient bandwidth for a circuit is available on the substitute link.

A system comprising:

• means for determining a path within a network for transmitting information from a first switch to a second switch, the path comprising a plurality of links;
• means for generating a setup message comprising information that indicates, for each link among the plurality of links, whether substitution of a parallel link is permitted, and having a flag set to one of a first value indicating that substitution of parallel links is not permitted for any of the plurality of links in the path and a second value indicating that substitution of parallel links is permitted for any of the plurality of links in the path;
• means for allocating resources based on the setup message;
• means for transmitting a crankback message to the first switch based on allocation of resources based on the setup message and based on whether sufficient bandwidth for a circuit is available on the substitute parallel link;
• means for transmitting a crankback message to the first switch based on whether sufficient bandwidth for the circuit is available on the parallel link;
• and
• means for transmitting the setup message along the path.