Patent ID: 7580368
Filing Date: 2009-08-25
Classification: H04L

Abstract:
1. A packet distribution control method in a multicast communication of one-to-many or many-to-many communication, said packet distribution control method comprising: checking, by an end node, as a sender end node that is capable of using both IP multicast and IP unicast and that joins the multicast communication, whether or not an end node as a receiver end node of a next packet distribution destination is capable of communicating in IP multicast; switching, by the sender end node, packet distribution to the receiver end node between IP multicast and IP unicast according to a result of the checking; and calculating a multicast distribution tree, in which a sender end node, among end nodes joining multicast communication obtains a multicast distribution tree with the sender end node as a root, wherein in the calculating, the sender end node registers end nodes targeted for the multicast distribution tree in a registration list, eliminates an internal end node with which the sender end node is capable of communicating in IP multicast from the registration list, specifies an end node that is a branch based on a distribution tree calculation algorithm from the registration list with the sender end node as a starting point, eliminates the branch end node and an internal end node of the branch end node from the registration list, adds the branch end node to the starting point, repeats the same processing on ahead portions from the branch end node, and thereby obtains the multicast distribution tree.