Patent ID: 7742482

Claim:
A method comprising: establishing a point-to-multipoint (P2MP) tunnel across a network between an upstream router and two or more downstream routers using the Resource Reservation Protocol with Traffic Engineering (RSVP-TE), wherein each of the downstream routers are adjacent to the upstream router; receiving, with the upstream router, RSVP-TE advertisements that include upstream label assignment capability indications from one or more of the downstream routers of the tunnel, wherein the upstream assignment capability indications received from the downstream routers indicate whether the respective downstream router is capable of supporting upstream assigned labels; allocating an upstream assigned label to only the downstream routers of the tunnel from which the upstream label assignment capability indications were received, wherein allocating the upstream assigned label comprises sending a RSVP PATH message from the upstream router to each of the capable downstream routers of the tunnel, wherein each of the RSVP PATH messages includes a label object that specifies the upstream assigned label; receiving the RSVP PATH message having the label object with at least one of the downstream routers; outputting, from the at least one of the downstream routers to the upstream router, an RSVP RESV message without including any downstream assigned labels when the downstream router supports the type of label object included in the RSVP PATH message and is able to process the upstream assigned label; outputting, from the at least one of the downstream routers to the upstream router, an RSVP RESV message specifying an error when the downstream router does not support the type of label object included in the RSVP PATH message; and outputting, from the at least one of the downstream routers to the upstream router, an error message when the downstream router does supports the type of label object included in the RSVP PATH message but the downstream router is unable to process the upstream assigned label.