Service Instance Applied to MPLS Network

Domain-wide unique node identifiers and domain-wide unique service identifiers are distributed within a MPLS domain using routing system LSAs. Nodes on the MPLS network compute shortest path trees for each destination and install unicast forwarding state based on the calculated trees. Nodes also install multicast connectivity between nodes advertising common interest in a common service identifier. Rather than distributing labels to be used in connection with unicast and multicast connectivity, the nodes deterministically calculate the labels. Any number of label contexts may be calculated. The labels may either be domain wide unique per unicast path or per multicast, or may be locally unique and deterministically calculated to provide forwarding context for the associated path. Multicast and unicast paths may be congruent, although this is not a requirement.