Patent ID: 7593340

Claim:
A method for multi-domain route computation, comprising: determining a top layer Path Computation Element; computing, by the top layer Path Computation Element, a route between computation domains of immediate lower layer Path Computation Elements of the top layer Path Computation Element, the top layer Path Computation Element sending route computation tasks to its immediate lower layer Path Computation Elements according to the route computation result; computing, by a Path Computation Element which receives the route computation task, route between computation domains of its immediate lower layer Path Computation Elements if it is not a bottom layer Path Computation Element, and sending route computation tasks to its immediate lower layer Path Computation Elements according to the route computation result; computing, by the bottom layer Path Computation Element, the route of its computation domain, and sending the route computation result to its immediate upper layer Path Computation Element; sending, by a Path Computation Element which receives the route computation result, the route computation result received and a computation result computed by itself before to its immediate upper layer Path Computation Element, if the Path Computation Element receiving the route computation result is not the top layer Path Computation Element; summarizing, by the top layer Path Computation Element, the route computation results and computing a route from a source node to a destination node.