Path control device and path control method

摘要

The invention is aimed at determining a cross over router on the occasion of a migration of a mobile terminal connected to a network during communication in the network in which the transfer part and the control part are separated from each other. The path control device receives path control information from each router and stores the information as a path control table, thereby shares the path control information with the transfer part (S1). Thereupon a pre-migration path between the mobile terminal and the correspondent terminal is recognized (S2). Thereafter, on the occasion of a migration of a mobile terminal, the path control device predicts a post-migration path between the mobile terminal and the correspondent terminal after migration (S4), and makes a comparison between the pre-migration path "#C-R3-R2-R1-#M" extending from the correspondent terminal #C up to the mobile terminal #M and the post-migration path "#C-R3-R2-R6-#M" obtained by the prediction in S4 so as to derive "#C-R3-R2" as a common part. A router R2 being the closest to the mobile terminal #M in the common part is determined as the cross over router (S5).