Constraint-based shortest path first method for dynamically switched optical transport networks
First Claim
1. A traffic network element (“
- TNE”
) in a network, the TNE comprising;
a traffic engineering network database (“
TEND”
) that stores network topology information for the network and bandwidth availability information for links in the network;
a routing engine that receives a request for a label switched path (“
LSP”
) through the network with specified constraints, processes network topology information from the TEND to create a network graph comprising links meeting the specified constraints, and computes a primary path through the network, wherein the primary path comprises links selected from the network graph; and
wherein if two or more links have the same cost, the one of the links having the greatest number of data-bearing channels is selected to comprise a portion of the primary path.
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Accused Products
Abstract
Method and apparatus for implementing a constraint-based shortest path first (“CSPF”) technique for dynamically switched optical transport networks are described. One embodiment comprises a traffic network element (“TNE”) in a network comprising a traffic engineering network database (“TEND”) that stores network topology information for the network and bandwidth availability information for links in the network; and a routing engine that receives a request for a label switched path (“LSP”) with specified constraints, processes network topology information from the TEND to create a network graph comprising links meeting the specified constraints, and computes a primary path through the network, wherein the primary path comprises links selected from the network graph.
67 Citations
22 Claims
-
1. A traffic network element (“
- TNE”
) in a network, the TNE comprising;a traffic engineering network database (“
TEND”
) that stores network topology information for the network and bandwidth availability information for links in the network;a routing engine that receives a request for a label switched path (“
LSP”
) through the network with specified constraints, processes network topology information from the TEND to create a network graph comprising links meeting the specified constraints, and computes a primary path through the network, wherein the primary path comprises links selected from the network graph; andwherein if two or more links have the same cost, the one of the links having the greatest number of data-bearing channels is selected to comprise a portion of the primary path. - View Dependent Claims (2, 3, 4, 5)
- TNE”
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6. A method of computing an explicit route through a network comprising:
-
receiving a path setup request message for a new traffic flow in the network, wherein the path setup request message includes specified constraints on the path; generating a network graph from network information stored in a traffic engineering network database (“
TEND”
), wherein links not meeting the specified constraints for the path are not included in the graph; andcalculating a primary explicit route through the network from the generated network graph, wherein a link with a maximum number of data-bearing channels is selected for inclusion in the primary explicit route in a case in which two or more links have a same cost. - View Dependent Claims (7, 8, 9, 10, 12, 13)
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11. A method of computing an explicit route through a network comprising:
-
receiving a path setup request message for a new traffic flow in the network, wherein the path setup request message includes specified constraints on the path; generating a network graph from network information stored in a traffic engineering network database (“
TEND”
), wherein links not meeting the specified constraints for the path are not included in the graph; andcalculating a primary explicit route through the network from the generated network graph; calculating a backup explicit route from a regenerated network graph; wherein the calculating a primary explicit route and the calculating a backup explicit route are performed using a least cost analysis; and wherein a link with a maximum number of data-bearing channels is selected from the regenerated network graph for inclusion in the backup explicit route in a case in which two or more links have a same cost.
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14. A traffic network element (“
- TNE”
) in a network, the TNE comprising;means for storing network topology information for the network and bandwidth availability information for links in the network; and means for processing information from the TEND to create a network graph comprising links meeting specified constraints in a request for a label switched path (“
LSP”
) and calculating a primary explicit route through the network, wherein the primary explicit route comprises links selected from the network graph and wherein if two or more links have the same cost, the one of the links having the greatest number of data-bearing channels is selected to comprise a portion of the primary explicit route. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22)
- TNE”
Specification