Label switched path OAM wrapper
View Patent ↗Methods and devices for logically segmenting an LSP so that OAM DTUs may be used to determine the performance and/or the status of LSP segments. To segment a previously determined LSP, a dedicated subpath (a logical LSP) within that predetermined LSP is defined between two LSRs that are capable of processing OAM DTUs. The source node (source LSR) establishes a logical LSP between itself and the destination node (destination LSR) using an LDP. In doing this, the logical LSP traverses a specific path and transits through specific nodes in that path. The source node then transmits an OAM DTU or any other specialized DTU to the destination node using a label specifically associated with the logical LSP that was established. The characteristic of the specific path traversed by the logical LSP can thus be determined by when, how, and if the specialized DTU is received by the destination node.
1. A method of routing an operation and maintenance (OAM) data transmission unit (DTU) in a multi-protocol label switched (MPLS) network, between a source node and a destination node, the MPLS network having a label switched path (LSP), the source node and the destination node being capable of processing OAM DTUs, the source node and the destination node having intermediate nodes disposed therebetween, the intermediate nodes including OAM nodes, the OAM nodes being capable of processing OAM DTUs, the method comprising:
a) defining segments of the LSP path in accordance with the source node, the destination node and the OAM nodes;
b) defining an OAM label for the DTU in accordance with the segments;
c) providing to the intermediate nodes instructions on at least one of how to forward the OAM DTU and how to process the OAM DTU; and
d) binding the OAM label to the OAM DTU in an OAM label field, the OAM DTU including an MPLS label in an MPLS label field, the OAM label field being distinct from the MPLS label field.
2. The method as claimed in claim 1 wherein the instructions include instructions on how to determine a performance of a segment.
3. A method as in claim 1 further comprising reserving resources in the OAM nodes in accordance with which the segments have been defined.
4. The method as claimed in claim 1 wherein providing to the intermediate nodes instructions is effected with a label distribution protocol.
5. The method as claimed in claim 1 wherein the OAM nodes include a label switched router.
6. The method as claimed in claim 5 wherein the instructions include routing instructions.