Patent ID: 8670328

Claim:
A method for calculating an interlayer path, comprising: a label switch router (LSR) of a present layer selecting a path calculation element (PCE) of the present layer according to received discovery information of each PCE and sending thereto a path calculation request for the LSR, wherein the discovery information comprises: indication information and interlayer information, with the indication information indicating whether the PCE can be used as a default interlayer path calculation element of the present layer, and the interlayer information indicating a layer where the PCE is located and one or more adjacent layers thereof; when a path of the LSR is disconnected, selecting, based on the interlayer information, a path calculation element (PCE) of the next layer and sending thereto a path calculation request for the disconnected portion of the path until the path is connected; and replying a path calculation result to the PCE of the present layer.