Patent ID: 7283537

Claim:
A network system wherein IP packets according to a service requested by a terminal are sent to one of a plurality of service providers, said network system comprising: a plurality of IP networks that each utilize a different network layer protocol, the plurality of IP networks including at least a first IP network, a second IP network, and a third IP network; and a packet exchange, provided between the plurality of IP networks, said packet exchange receiving an IP packet in a first network layer protocol format to be sent from the first IP network, determining a destination network among the second IP network and the third IP network based upon a destination address specified by the IP packet in the first network layer protocol format, and converting the IP packet in the first network layer protocol format, wherein the IP packet in the first network layer protocol format is converted to a second network layer protocol format if said second IP network is the destination address that is determined and the IP packet of the first network layer protocol format is converted to a third network layer protocol format if said third IP network is the destination address that is determined.