Patent ID: 8767741

Claim:
A method of establishing a point-to-multipoint (P2MP) tunnel across a network between an upstream router and two or more downstream routers using a label distribution protocol, the method comprising: outputting, to the upstream router, 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 from the downstream routers indicate whether the respective downstream router is capable of supporting upstream assigned labels, and wherein the advertisements from the downstream routers that are capable of supporting upstream assigned labels comprise label distribution protocol Hello messages including a Capability object with a set flag; receiving a message having a label object with the at least one of the downstream routers, wherein the message requests a P2MP tunnel and the label object specifies an upstream assigned label allocated to the downstream routers of the P2MP tunnel that output the advertisements carrying the upstream label assignment capability indications; outputting, from the at least one of the downstream routers to the upstream router, a message to establish the P2MP tunnel without including any downstream assigned labels when the downstream router supports the type of label object included in the message and is able to process the upstream assigned label; outputting, from the at least one of the downstream routers to the upstream router, a message specifying an error when the downstream router does not support the type of label object included in the message from the upstream router requesting the P2MP tunnel.