Patent ID: 8923295

Claim:
A method in a first network node for signaling a point-to-multipoint traffic path from one ingress node to a plurality of egress nodes in a network, which traffic path includes a plurality of source-to-leaf sub paths, wherein each source-to-leaf sub path is set up between the ingress node and an egress node, the method comprising: encoding the point-to-multipoint traffic path using an encoding scheme to produce a number of path descriptors; and including the number of path descriptors in at least one path message, sending the at least one path message to at least one second network node to enable routing of traffic according to the point-to-multipoint traffic path, wherein the encoding scheme includes producing a common explicit route object as one of the number of path descriptors, wherein the common explicit route object specifies a list consisting of nodes, a downlink from the first network node, that every source-to-leaf sub path traversing the second network node and belonging to the point-to-multipoint traffic path traverse; wherein the encoding scheme further comprises producing at least one sub path descriptor, the sub path descriptor specifying a list of nodes, a downlink from the first network node and excluding any node listed in the common explicit mute object, that one of the source-to-leaf sub paths traverses to reach the egress node of that source-to-leaf sub path; and wherein the common explicit route object includes a specification of an egress node as a destination address of a source-to-leaf sub path only if the list of the common explicit route object identifies at least the final part of a source-to-leaf sub path.