Patent ID: 8737394

Claim:
A route computation method, comprising: receiving, by a bottom-level path computation element (PCE) which manages a routing domain including a destination node, a path computation command, performing a route computation on the routing domain managed by the bottom-level PCE, obtaining a path segment set with a destination node serving as an endpoint, and sending the obtained path segment set to an upper-level PCE of the bottom-level PCE, wherein the path computation command carries information about routing domains that a path to be established between a source node and the destination node sequentially passes through; sending, by the upper-level PCE receiving the path segment set sent by a first lower-level PCE, the path computation command to a second lower-level PCE, which is next to the first lower-level PCE in the direction from the destination node to the source node, according to the routing domains that the path to be established between the source node and the destination node sequentially passes through, receiving path segment sets sent by all lower-level PCEs, and combining and sending all the received path segment sets to an upper-level PCE of the upper-level PCE, until a top-level PCE receives path segment sets sent by all lower-level PCEs of the top-level PCE, wherein the path computation command sent by the upper-lever PCE to the second lower-level PCE carries information of egress nodes of a path segment set to be computed by the second lower-level PCE, and said information of egress nodes of the path segment set to be computed by the second lower-level PCE is computed by the upper-level PCE according to information of the ingress node of each path segment of the path segment set sent by the first lower-level PCE; and combining, by the top-level PCE, all the received path segment sets to generate a set of paths between the destination node and the source node.