Patent ID: 6985959
Filing Date: 2006-01-10
Classification: H04J,H04L

Abstract:
1. A method of establishing explicit constrained edge-to-edge paths in a one of an Internet Protocol (IP), MPLS and Optical network that uses a modified open shortest path first (OSPF) routing protocol for constraint route distribution and path computation, comprising steps of: provisioning at least one OSPF router in the network that supports constraint path setup with traffic engineering route exchange router (TE-X) functionality to provide edge routers in the network with access to explicit constraint routes; sending traffic engineering link state advertisement (TE-LSA) messages directly via unicast from the OSPF routers to only a nearest one of the at least one TE-X, without flooding the TE-LSAs to other routers in the network, to permit each of the at least one TE-X to maintain a traffic engineering link-state database (TE-LSDB) to compute constraint-based traffic engineering routes; and querying the nearest one of the at least one TE-X to obtain an explicit edge-to-edge path satisfying specified traffic engineering (TE) constraints.