Patent ID: 8599683

Claim:
A system for changing a delivery path of multicast traffic, the system comprising: a plurality of routers via which the multicast traffic is transferred from a sender to a plurality of receivers through a delivery tree that is determined at least based on a multicast routing protocol and includes a set of delivery paths each communicably coupling the sender and one of the plurality of receivers, the plurality of routers each configured to: include a multicast routing table storing transfer control information for transferring the multicast traffic through the delivery tree; generate delivery path information that stores information on a first delivery path used for transferring the multicast traffic in a normal operational state, and information on a second delivery path used as an alternative to the first delivery path when the first delivery path is not working; perform, upon detecting a link failure on the first delivery path, delivery-path change processing, based on the delivery path information, that changes an active pair of interfaces for actually transferring the multicast traffic, from a first pair of interfaces along the first delivery path to a second pair of interfaces along the second delivery path without waiting for the multicast routing table being updated using the multicast protocol; transmit a delivery-path change message to first one or more routers positioned along the second delivery path so that the first one or more routers perform the delivery-path change processing based on the delivery-path change message; and perform, upon receiving a delivery-path change message, the delivery-path change processing based on the received delivery-path change message.