Communicating method between IPv4 terminal and IPv6 terminal and IPv4-IPv6 converting apparatus

• US 7,072,339 B2
• Filed: 10/23/2001
• Issued: 07/04/2006
• Est. Priority Date: 11/01/1996
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Tsuchiya, Kazuaki, Ikeda, Naoya, Hamamoto, Shinichi, Watanabe, Ken, Yasue, Toshikazu, Atarashi, Yoshifumi, Sumikawa, Munechika, Miyamoto, Takahisa, Higuchi, Hidemitsu
• Primary Examiner(s): Nguyen, Steven
• Assistant Examiner(s): Nguyen, Phuongchau Ba
• Application Number:
  US09/983,146
• Publication Number:
  US 20020021705A1
• Time in Patent Office: 1,715 Days
• Field of Search: 370/338, 370/400, 370/401, 370/402, 370/389, 370/465, 370/466, 370/475, 709/227, 709/229, 709/245, 709/249
• US Class Current: 370/392
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/251 between different IP versions
• CPC Class Codes: H04L 61/2542 involving dual-stack hosts
• CPC Class Codes: H04L 61/255 Maintenance or indexing of mapping tables
• CPC Class Codes: H04L 61/2567 for reachability, e.g. inquiring the address of a correspondent behind a NAT server
• CPC Class Codes: H04L 61/4511 using domain name system [DNS]
• CPC Class Codes: H04L 61/5014 using dynamic host configuration protocol [DHCP] or bootstrap protocol [BOOTP]
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/167 Adaptation for transition between two IP versions, e.g. between IPv4 and IPv6 translation of Internet protocol [IP] addresses H04L61/2503
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

In an apparatus, there are provided an IP transmitting and receiving unit for transmitting and receiving an IPv4 packet and an IPv6 packet; an IP header converting unit for performing a mutual conversion of the IPv4 packet and the IPv6 packet by an IP header conversion; a DNS substituting unit for receiving a domain information capturing request sent from an IPv4 terminal or an IPv6 terminal and substituting its process; an IPv4 address capturing unit for capturing an IPv4 address from a DHCP server; and an IP address conversion information holding unit for holding an IPv6 address of the IPv6 terminal and the IPv4 address captured by the IPv4 address capturing unit in correspondence to each other. Thus, a communication with the IPv4 terminal can be executed without preliminarily fixedly allocating the IPv4 address to the IPv6 terminal.

Claims

1. A method for performing communications between a first terminal using IPv4 as a communication protocol and a second terminal using IPv6 as a communication protocol comprising the steps of:

receiving from said first terminal a first message requesting an IPv4 address as an IP address of said second terminal;

sending a second message inquiring of an IP address of said second terminal to a manager apparatus which manages IPv4 address information or IPv6 address information;

when receiving a third message containing a first IPv6 address possessed by said second terminal, said third message being sent from said manager apparatus in response to said second message, performing recognition that said first 12v6 address thus received differs in a protocol version from the IPv4 address requested by said first terminal;

converting said first IPv6 address into an arbitrary first IPv4 address;

sending a fourth message containing said first IPv4 address as an IP address of said second terminal to said first terminal, said first IPv4 address having a same protocol version as that of the IP address requested by said first terminal;

receiving from said first terminal an IPv4 packet having an IPv4 header containing said first IPV4 address as a destination address and a second IPv4 address possessed by said first terminal as a source address;

converting said first IPv4 address into said first IPv6 address;

converting said second IPv4 address into an arbitrary second IPv6 address;

converting said IPv4 header into an IPv6 header containing said first IPv6 address as a destination address and said second IPv6 address as a source address;

creating from said IPv4 packet an IPv6 packet having the IPv6 header thus converted; and

sending said IPv6 packet to said second terminal.

2. The method according to claim 1, further comprising the steps of:

storing said first IPv4 address and said first IPv6 address in correspondence to each other; and

in said step of converting said first IPv4 address, converting said first IPv4 address into said first IPv6 address stored correspondingly thereto.

3. The method according to claim 2, wherein said first IPv4 address is an IPv4 address temporarily allocated to said second terminal.

4. The method according to claim 1, wherein said second IPv4 address converting step further comprises the substeps of:

sending a fifth message requesting an IPv6 address to an apparatus which allocates IPv6 addresses;

receiving a sixth message containing said arbitrary second IPv6 address, said sixth message being sent from said apparatus in response to said fifth message; and

converting said second IPv4 address into said second IPv6 address.

5. The method according to claim 4, wherein said second IPv4 address and said arbitrary second IPv6 address are stored in correspondence to each other.

6. The method according to claim 1, further comprising the steps of:

previously storing said second IPv4 address and said arbitrary second IPv6 address in correspondence to each other; and

in said second IPv4 address converting step, converting said second IPv4 address into said second IPv6 address stored correspondingly thereto.

7. The method according to claim 1,wherein:

in said second message sending step, said second message is sent to a first manager apparatus which manages IPv4 address information, and

if it is decided that said third message is not received from said first manager apparatus, said second message is sent to a second manager apparatus which manages IPv6 address information.

8. A method for performing communications between a first terminal using IPv4 as a communication protocol and a second terminal using IPv6 as a communication protocol, comprising the steps of:

receiving a first message requesting an IPv4 address as an IP address corresponding to a domain name of said second terminal, said first message being sent from said first terminal;

sending a second message inquiring of an IP address corresponding to the domain of said second terminal to a DNS apparatus which manages IPv4 domain information or IPv6 domain information;

when receiving a third message containing a first IPv6 address possessed by said second terminal, said third message being sent from said DNS apparatus in response to said second message, converting said first IPv6 address thus received into an arbitrary first IPv4 address in order to notify said first terminal of an IP address having a same protocol version as that of the IP address requested from said first terminal;

sending a fourth message containing said first IPv4 address as an IPv4 address of said second terminal to said first terminal;

receiving from said first terminal an IPv4 packet having an IPv4 header containing said first IPv4 address as a destination address and a second IPv4 address possessed by said first terminal as a source address;

converting said first IPv4 address into said first IPv6 address;

converting said second IPv4 address into an arbitrary second IPv6 address;

converting said IPv4 header into an IPv6 header containing said first IPv6 address as a destination address and said second IPv6 address as a source address;

creating from said IPv4 packet an IPv6 packet having the IPv6 header thus converted; and

sending said IPv6 packet to said second terminal.

9. The method according to claim 8, wherein in said second message sending step, said second message is sent to a DNS apparatus which manages IPv6 domain information in a case where an IP address of said second terminal could not be obtained even if said second message had been sent to a DNS apparatus which manages IPv4 domain information.

10. A method for performing communications between a first terminal connected to an IPv4 network and a second terminal connected to an IPv6 network, comprising the steps of:

receiving a first message requesting an IPv4 address as an IP address corresponding to a domain name of said second terminal, said first message being sent from said first terminal;

sending a second message inquiring of an IP address corresponding to the domain of said second terminal to a DNS apparatus which manages domain information of an IPv4 network or domain information of an IPv6 network;

when receiving a third message containing a first IPv6 address possessed by said second terminal, said third message being sent from said DNS apparatus in response to said second message, converting said first IPv6 address thus received into an arbitrary first IPv4 address in order to notify said first terminal of an IP address having a same protocol version as that of the IP address requested from said first terminal;

sending a fourth message containing said first IPv4 address as an IPv4 address of said second terminal to said first terminal;

receiving from said first terminal an IPv4 packet having an IPv4 header containing said first IPv4 address as a destination address and a second IPv4 address as a source address;

converting said first IPv4 address into a second IPv6 address;

converting said second IPv4 address into an arbitrary IPv6 address;

converting said IPv4 header into an IPv6 header containing said first IPv6 address as a destination address and said second IPv6 address as a source address;

creating from said IPv4 packet an IPv6 packet having the IPv6 header thus converted; and

sending said IPv6 packet to said second terminal.

11. The method according to claim 10, wherein said second message sending step, said second message is sent to a DNS apparatus which manages IPv6 address information in a case where an IP address of said second terminal could not be obtained even if said second message had been sent to a DNS apparatus which manages IPv4 address information.

12. A method for performing communications between a first terminal using IPv4 as a communication protocol and a second terminal using IPv6 as a communication protocol, comprising the steps of:

receiving from said first terminal a first message requesting an IPv4 address as an IP address of said second terminal;

sending a second message inquiring of an IP address of said second terminal to a manager apparatus which manages IPv4 address information or IPv6 address information;

when receiving a third message containing a first IPv6 address possessed by said second terminal, said third message being sent from said manager apparatus in response to said second message, performing recognition that said first IPv6 address thus received differs in a protocol version from an IPv4 address requested by said first terminal;

converting said first IPv6 address into an arbitrary first IPv4 address;

sending a fourth message containing said first IPv4 address as an IP address of said second terminal to said first terminal, said first IPv4 address having a same protocol version as that of the IP address requested by said first terminal;

receiving from said first terminal an IPv4 packet having an IPv4 header containing said first IPv4 address as a destination address;

converting said first IPv4 address into said first IPv6 address;

converting said first IPv4 header into an IPv6 header containing said first IPv6 address as a destination address;

creating from said IPv4 packet an IPv6 packet having the IPv6 header thus converted; and

sending said IPv6 packet to said second terminal.

13. The method according to claim 12, further comprising the steps of:

storing said first IPv4 address and said first IPv6 address in correspondence to each other; and

in said first IPv4 address converting step, converting said first IPv4 address into said first IPv6 address stored correspondingly thereto.

14. The method according to claim 13, wherein said first IPv4 address is an IPv4 address temporarily allocated to said second terminal.

15. The method according to claim 12, wherein in said step of converting said IPv4 header into said IPv6 header, a second IPv4 address possessed by said first terminal contained as a source address in said IPv4 header of said IPv4 packet is converted into an arbitrary second IPv6 address.

16. The method according to claim 12, wherein said step of converting said IPv4 header into said IPv6 header comprises the substeps of:

sending a fifth message requesting an IPv6 address to an apparatus which allocates IPv6 addresses;

receiving a sixth message containing an arbitrary second IPv6 address, said sixth message being sent from said apparatus in response to said fifth message; and

converting a second IPv4 address possessed by said first terminal contained as a source address in said IPv4 header of said IPv4 packet into said second IPv6 address.

17. The method according to claim 16, wherein said second IPv4 address and said second IPv6 address are stored in correspondence to each other.

18. The method according to claim 12, further comprising the steps of:

previously storing a second IPv4 address possessed by said first terminal and an arbitrary second IPv6 address in correspondence to each other; and

in said step of converting said IPv4 header into said IPv6 header, converting said second IPv4 address contained as a source address in said IPv4 header of said IPv4 packet into said second IPv6 address stored correspondingly thereto.

19. The method according to claim 12, wherein:

in said second message sending step, said second message is sent to a first manager apparatus which manages IPv4 address information, and

if it is decided that said third message is not received from said first manager apparatus, said second message is sent to a second manager apparatus which manages IPv6 address information.

20. A method for performing communications between a first terminal connected to an IPv4 network and a second terminal connected to an IPv6 network, comprising the steps of:

receiving from said first terminal a first message requesting an IPv4 address as an IP address corresponding to a domain name of said second terminal;

sending a second message inquiring of an IP address corresponding to the domain of said second terminal to a DNS apparatus which manages domain information of an IPv4 network or domain information of an IPv6 network;

when receiving a third message containing a first IPv6 address possessed by said second terminal, said third message being sent from said DNS apparatus in response to said second message, performing recognition that said first IPv6 address thus received differs in a protocol version from an IPv4 address requested by said first terminal;

converting said first IPv6 address into an arbitrary first IPv4 address;

sending a fourth message containing said first IPv4 address as an IP address of said second terminal to said first terminal, said first IPv4 address having a same protocol version as that of the IP address requested by said first terminal;

receiving from said first terminal an IPv4 packet having an IPv4 header containing said first IPv4 address as a destination address;

converting said first IPv4 address into said first IPv6 address;

converting said IPv4 header into an IPv6 header containing an IPv6 address of said second terminal as a destination address;

creating from said IPv4 packet an IPv6 packet having the IPv6 header thus converted; and

sending said IPv6 packet to said second terminal.

21. The method according to claim 20, wherein said second message sending step, said second message is sent to a DNS apparatus which manages IPv6 domain information in a case where an IP address of said second terminal could not be obtained even if said second message had been sent to a DNS apparatus which manages Ipv4 domain information.