Constrained shortest path routing method
First Claim
1. A method for choosing a path in a network from a source to a destination, the network comprising a plurality of nodes, each node connected to a plurality of other nodes by links, each link having a weights reflecting at least first and second link parameters, paths connecting said source and said destination comprising a plurality of links, said paths being subject to a constraint on the cumulative value of said second parameter for links in a path, the method comprising the steps of:
- a. for paths from said destination to said source, performing a minimum-weight path identification based on said second parameter for paths in said network, thereby to generate labels identifying weights for said second parameter for each nodej to destination k, b. for paths from said source to said destination performing a minimum-weight path identification from said source using said first parameter as a link metric, and c. eliminating any nodes that would cause the constraint on said cumulative value for said second parameter to be violated.
6 Assignments
0 Petitions
Accused Products
Abstract
A real-time method for routing subject to an acceptable delay constraint between nodes in high-speed data networks, such as PNNI protocol networks, uses an illustrative two-phase algorithm employing Dijkstra'"'"'s algorithm at each phase. In an illustrative first phase, the Dijkstra SPF algorithm is used in seeking the shortest cumulative delay from the destination to the source, thereby generating cumulative delay labels from a node j to the destination node k. The delay results are then employed in the second phase, where the Dijkstra SPF algorithm is illustratively employed for determining administrative weight (AW) as the link metric subject to modification in accordance with results obtained in the first phase.
-
Citations
13 Claims
-
1. A method for choosing a path in a network from a source to a destination, the network comprising a plurality of nodes, each node connected to a plurality of other nodes by links, each link having a weights reflecting at least first and second link parameters, paths connecting said source and said destination comprising a plurality of links, said paths being subject to a constraint on the cumulative value of said second parameter for links in a path, the method comprising the steps of:
-
a. for paths from said destination to said source, performing a minimum-weight path identification based on said second parameter for paths in said network, thereby to generate labels identifying weights for said second parameter for each nodej to destination k, b. for paths from said source to said destination performing a minimum-weight path identification from said source using said first parameter as a link metric, and c. eliminating any nodes that would cause the constraint on said cumulative value for said second parameter to be violated. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
Specification