Method for obtaining cross-domain separation paths and path calculation unit

The invention discloses a method for obtaining cross-domain separation paths. The method comprises: when cross-domain separation path calculation requests are received, obtaining K pairs of candidate separation domain sequences according to cross-domain network abstract topology; traversing the K pairs of the candidate separation domain sequences, generating, for via domains of the candidate separation domain sequences in a network, corresponding intra-domain path calculation requests, and sending the intra-domain path calculation requests of the domains; when at least one pair of intra-domain paths aiming at the intra-domain path calculation requests are received, configuring each intra-domain path in the at least one pair of the intra-domain paths to a corresponding position in the K pairs of the candidate separation domain sequences, and forming K pairs of candidate cross-domain separation paths; and determining one pair of the cross-domain separation paths in the K pairs of the candidate cross-domain separation paths, and sending the cross-domain separation paths as calculation results of the cross-domain separation path calculation requests. K is a positive integer. And the invention further discloses a method for obtaining the cross-domain separation paths and a related path calculation unit.