IP virtual private network constructing method and IP virtual private network

摘要

An edge node which receives an IP packet transmitted from a user adds thereto information including an external IP header and an IP virtual private network identifier for identifying each of a plurality of IP-VPNs present within a network to transfer the packet to a backbone node in the network. The edge node is assigned a plurality of different IP addresses in accordance with quality (required bandwidth) of an in-network packet.