Patent ID: 8144617

Claim:
A packet transfer apparatus connected to a multicast packet distributing server and multicast packet receiving clients via a network, comprising: line container portions each of which contains lines connected to the network; a packet transfer portion which determines an output destination of a multicast packet received from each line and transfers the multicast packet to the output destination; and a control portion which controls the packet transfer apparatus; wherein the packet transfer portion receives multicast group joining messages via the lines and the line container portions, and sends the multicast group joining messages to the control portion, the control portion which counts and holds a number of the multicast group joining messages received from the packet transfer portion, the packet transfer portion stepwise increases or decreases transfer performance for transferring the multicast packet based on the number of the multicast group joining messages held by the control portion, and the control portion further holds information of bandwidth used in each multicast group of plural multicast groups; and the packet transfer portion increases or decreases transfer performance based on the number of the received multicast group joining messages held for each multicast group by the control portion and the bandwidth information.