Inter-domain TE-LSP with IGP extensions
AssigneeCisco Technology, Inc.
InventorsJean-Philippe Vasseur, Stefano B. Previdi
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Abstract
A technique propagates reachability information for a tail-end node of a traffic engineering (TE) label switched path (LSP) to a head-end node of the TE-LSP in a computer network. The TE-LSP preferably spans multiple domains of the network such that the tail-end node resides in a domain that is different (remote) from the domain of the head-end node. The inter-domain information propagation technique employs an Interior Gateway Protocol (IGP) to transmit the remote reachability information from a target node residing in the same domain as the tail-end node to the head-end node. The head-end node uses the remote information to calculate routes, i.e., address prefixes and associated attributes, reachable from the tail-end node for insertion into its routing table.
Claims19
A method for propagating reachability information for a tail-end node of a traffic engineering (TE) label switched path (LSP) to a head-end node of the TE-LSP in a computer network, the TE-LSP spanning multiple domains of the network such that the tail-end node resides in a domain that is remote from the domain of the head-end node, the method comprising:
- transmitting, via an Interior Gateway Protocol (IGP) advertisement, the reachability information from the target node residing in the domain of the tail-end node to the head-end node;
- receiving, at the head-end node, the transmitted reachability information;
- calculating, at the head-end node, routes reachable from the tail-end node using the received information;
- and
- inserting the calculated routes into a routing table of the head-end node.
A system for propagating reachability information for a tail-end node of a traffic engineering (TB) label switched path (LSP) to a head-end node of the TE-LSP in a computer network, the TE-LSP spanning multiple domains of the network such that the tail-end node resides in a domain that is remote from the domain of the head-end node, the system comprising:
- an Interior Gateway Protocol (IGP) advertisement configured to carry the reachability information from a target node residing in a domain of the tail-end node to the head-end node;
- a memory of the head-end node configured to store received reachability information;
- a processor of the head-end node implementing a routing information base (RIB) to calculate routes reachable from the tail-end node using the received reachability information;
- and
- the memory of the head-end node further configured to maintain a routing table of the head-end node that stores the calculated routes.
An apparatus for propagating reachability information for a tail-end node of a traffic engineering (TE) label switched path (LSP) to a head-end node of the TE-LSP in a computer network, the TE-LSP spanning multiple domains of the network such that the tail-end node resides in a domain that is remote from the domain of the head-end node, the apparatus comprising:
- means for transmitting, via an Interior Gateway Protocol (IGP) advertisement, the reachability information from the target node residing in the domain of the tail-end node to the head-end node;
- means for receiving, at the head-end node, the transmitted reachability information;
- means for calculating, at the head-end node, routes reachable from the tail-end node using the received information;
- and
- means for inserting the calculated routes into a routing table of the head-end node.
A computer readable medium containing executable program instructions for propagating reachability information for a tail-end node of a traffic engineering (TE) label switched path (LSP) to a head-end node of the TE-LSP in a computer network, the TE-LSP spanning multiple domains of the network such that the tail-end node resides in a domain that is remote from the domain of the head-end node, the executable program instructions comprising program instructions for:
- transmitting, via an Interior Gateway Protocol (IGP) advertisement, the reachability information from the target node residing in the domain of the tail-end node to the head-end node;
- receiving, at the head-end node, the transmitted reachability information;
- calculating, at the head-end node, routes reachable from the tail-end node using the received information;
- and
- inserting the calculated routes into a routing table of the head-end node.
Dependencies are inferred from the claim text.