PATH SELECTION METHOD AND NETWORK SYSTEM, PATH COMPUTATION ELEMENT

摘要

A method for path selection includes: the middle domain determines a path cost of inter-domain link from the middle domain to the destination node domain based on the received path cost of inter-domain link sent by the source node domain, and then sends it to the destination node domain; the middle domain receives the optimum service path from the destination node domain to the destination node returned from the destination node domain, wherein the optimum service path is determined based on the path cost of inter-domain link sent by the middle domain, and determines the optimum service path from the middle domain to the destination node based on the said optimum service path received and sends it to the source node domain, so as to make the source node domain determine the optimum service path from the source node to the destination node based on the said optimum service path sent by the middle domain. Accordingly, the embodiment of the present invention provides a network system and path computation element. The solution of the embodiment of the present invention can improve the efficiency of optimum service path selection.