Patent ID: 7453884

Claim:
A method for routing a data packet through an explicit path in a data communication network, the data packet having an incoming global path identifier corresponding to the explicit path, the data communication network comprising a plurality of network nodes, each of the plurality of network nodes including a network device, the explicit path comprising a plurality of hops including a prior hop, a current hop, and a next hop, each of the plurality of hops being associated with one of the plurality of network nodes, the method comprising: receiving the data packet from the prior hop at the current hop in the network device; performing a look-up function into a forwarding table using an index based on the incoming global path identifier to determine a forwarding table entry related to the next hop to which the data packet should be forwarded; extracting an outgoing global path identifier for the data packet from the forwarding table entry, wherein the outgoing global path identifier for the data packet has been pre-calculated as a function of (1) the incoming global path identifier and (2) an identifier of the network device receiving the data packet at the current hop; replacing the incoming global path identifier with the outgoing global path identifier in the data packet; and forwarding the data packet to the next hop.