Apparatus and a method for selecting an access router's protocol of a plurality of the protocols for transferring a packet in a communication system

An apparatus for selecting an access router's protocol in a communication system having an IP network which includes an ATM network as a core network, a plurality of access routers and an address resolution server, the access routers transferring an IP packet therebetween according to the selected protocol via the ATM network and the IP packet originated/terminated by IP users each having a user address assigned and accommodated in the respective access routers, the address resolution server receiving an address resolution request signal which includes an IP user address and responding to the address resolution request signal with an ATM address of the access router accommodating the IP user having the IP user address included in the signal, said apparatus comprising:

• storage means provided in the address resolution server, for storing therein a protocol type of the access router corresponding to the IP user address;
• protocol request means provided in a sending access router, for issuing the protocol request signal including the IP user address of a terminating user;
• protocol management means provided in the address resolution server and responsive to the protocol request signal, for referring to said storage means and responding to the protocol request signal with the protocol type of the receiving access router accommodating the IP user having the same IP user address as included in the protocol request signal;
• and
• protocol selection means provided in the sending access router, for selecting a protocol common to the sending and receiving access routers to transfer the IP packet based on the response by said protocol management means.

A method for selecting an access router's protocol in a communication system including a plurality of access routers for transferring a packet there between according to the selected protocol and a server for serving the access routers, the packet originated/terminated by users each having a user address assigned and accommodated in the respective access routers, said method comprising the steps of:

• (a) providing storage means in the server for storing therein a protocol type of the access router corresponding to the user address;
• (b) in a sending access router, issuing a protocol request signal to the server including the user address of a terminating user;
• (c) receiving the protocol request signal and referring to said storage means, responding to the protocol request signal with the protocol type of a receiving access router accommodating the user having the same user address as included in the protocol request signal;
• and
• (d) selecting a protocol common to the sending and receiving access routers to transfer the packet based on the response of step (c).

A method for selecting an access router's protocol in a communication system having an IP network which includes an ATM network as a core network, a plurality of access routers and an address resolution server, the access routers transferring an IP packet therebetween according to the selected protocol via the ATM network and the IP packet originated/terminated by IP users each having a user address assigned and accommodated in the respective access routers, the address resolution server receiving an address resolution request signal which includes an IP user address and responding to the address resolution request signal with an ATM address of the access router accommodating the IP user having the IP user address included in the signal, said method comprising the steps of:

• (a) in the address resolution server, providing storage means for storing therein a protocol type of the access router corresponding to t he IP user address;
• (b) in a sending access router, issuing the protocol request signal including the IP user address of a terminating user;
• (c) in the address resolution server, receiving the protocol request signal and referring to the storage means, responding to the protocol request signal with the protocol type of the receiving access router accommodating the IP user having the same IP user address as included in the protocol request signal;
• and
• (d) in the sending access router, selecting a protocol common to the sending and receiving access routers to transfer the IP packet based on the response in said step (c).

An apparatus for selecting an access router's protocol in a communication system having a first network which includes a second network, a plurality of access routers for transferring a packet therebetween according to the selected protocol via the second network and a server for serving the access routers, the packet originated/terminated by users each having a user address assigned and accommodated in the respective access routers, said apparatus comprising:

• storage means provided in the server, for storing therein a protocol type of the access router corresponding to the user address;
• protocol request means provided in a sending access router, for issuing a protocol request signal to the server including the user address of a terminating user;
• protocol response means provided in the server and responsive to the protocol request signal, for referring to said storage means and responding to the protocol request signal with the protocol type of a receiving access router accommodating the user having the same user address as included in the protocol request signal;
• and
• protocol selection means provided in the sending access router and based on the response by said protocol response means, for selecting a protocol common to the sending and receiving access routers to transfer the packet.

A method for selecting an access router's protocol in a communication system having a first network which includes a second network, a plurality of access routers for transferring a packet therebetween according to the selected protocol via the second network and a server for serving the access routers, the packet originated/terminated by users each having a user address assigned and accommodated in the respective access routers, said method comprising the steps of:

• (a) providing storage means in the server for storing therein a protocol type of the access router corresponding to the user address;
• (b) in a sending access router, issuing a protocol request signal to the server including the user address of a terminating user;
• (c) receiving the protocol request signal and referring to said storage means, responding to the protocol request signal with the protocol type of a receiving access router accommodating the user having the same user address as included in the protocol request signal;
• and
• (d) selecting a protocol common to the sending and receiving access routers to transfer the packet based on the response of step (c).