Patent ID: 8165107

Claim:
A method for obtaining path information, comprising: receiving, by a source Path Computation Element (PCE), a path computation request from a Path Computation Client (PCC); sending a Path Computation Element Protocol (PCEP) message to a next-hop PCE in a PCE sequence, so as to enable the PCEP message to arrive at a destination PCE and enable a PCEP connection to be set up between the source PCE and the destination PCE; determining a confluent PCE in the PCEP connection according to the PCE sequence; sending the path computation request to the next-hop PCE in the PCE sequence according to the PCEP connection so as to enable the path computation request to arrive at the destination PCE; computing, by the source PCE, a shortest path from a source node to an egress border node in a domain covered by the source PCE after receiving the path computation request, and sending a computation result to the next-hop PCE; and computing, by the next-hop PCE, a shortest path from the source node to an egress border node in a domain covered by the next-hop PCE by using the received computation result, and sending a computation result to another next-hop PCE subsequent to the next-hop PCE until the confluent PCE; computing, by the destination PCE, a shortest path from a destination node to an ingress border node in a domain covered by the destination PCE after receiving the path computation request, and sending the computation result to a previous-hop PCE; computing, by the previous-hop PCE, a shortest path from the destination node to an ingress border node in a domain covered by the previous-hop PCE by using the received computation result, and sending a computation result to another previous-hop PCE prior to this previous-hop PCE until the confluent PCE; and computing, by the confluent PCE, a shortest path from the source node to the destination node according to received computation results from a previous-hop PCE and a next-hop PCE, and sending computed shortest path information to the source PCE.