Network connection system and connection substitute correspondence client

• US 6,477,577 B1
• Filed: 09/16/1996
• Issued: 11/05/2002
• Est. Priority Date: 04/05/1996
• Status: Expired due to Fees

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: Asano, Kazuo
• Primary Examiner(s): Dinh, Dung C.
• Assistant Examiner(s): Kupstas, Tod
• Application Number:
  US08/714,532
• Time in Patent Office: 2,241 Days
• Field of Search: 395/200.33, 395/200.48, 395/200.49, 395/200.57, 395/200.16, 395/200.69, 395/200.75, 395/200.59, 709/203, 709/218, 709/219, 709/227, 709/239, 709/245, 709/229
• US Class Current: 709/227
• CPC Class Codes: H04L 61/2514 between local and global IP addresses
• 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]

Abstract

A connection substitute server substitutes a connection between a host machine having an informal address or a private address and a host machine out of an organization having a formal address and relays them. A correspondence relation between the host machine having no formal address and the connection substitute server has previously been registered as connection substitute server information in a name server. When receiving a communication request in which a host name of a connection request destination has been designated, a connection substitute correspondence client requests a retrieval of the connection substitute server information to the name server, requests a connection substitute with the host machine having the informal address or private address of the connection request destination to the connection substitute server recognized from the retrieval result, and enables a connection with the host machine which belongs to another organization and doesn'"'"'t have a formal address.

Claims

1. A network connection system, comprising:

a first organization with a host machine having a formal address;

a plurality of second organizations, each with a host machine having either an informal address or a local address;

a connection substitute server substituting a connection between the host machine belonging to the first organization and the host machine belonging to one of the plurality of second organizations and having no formal address and relaying information;

a name server in which, as registration information regarding the host machine belonging to the one of the plurality of second organizations and the connection substitute server of the second organization corresponding thereto, the name server comprising

a first record of an address including

first host retrieval information in which a domain name is coupled with a host name of the one of the second organizations,

first kind information showing that the registration information is an address, and

an address of the host of the one of the second organizations,

a second record of an address including

second host retrieval information in which a domain name is coupled with the host name of the one of the second organizations,

second kind information showing that the registration information is the connection substitute server, and

connection substitute server retrieval information in which a domain name is coupled with a host name of the connection substitute server of the one of the second organizations, and

a third record of an address including

third host retrieval information in which a domain name is coupled with the host name of the connection substitute server of the one of the second organizations,

third kind information showing that the registration information is the address, and

an address of the connection substitute server of the second organization have been registered, and

when a retrieval request using the host retrieval information of the one of the second organizations is received, in the retrieval at the first stage, connection substitute server retrieval information is obtained from said second record of the address, and in the retrieval at the second stage, the address of the second organization is obtained from said third record of the address by the connection substitute server retrieval information obtained by the retrieval at said first stage and responded to a request source.

2. A system according to claim 1, further comprising a connection substitute correspondence client requesting retrieval of said connection substitute server information, wherein said connection substitute correspondence client comprises:

a retrieving mechanism for requesting a retrieval to said name server by the communication request in which the host name of the connection request destination has been designated;

a control mechanism for instructing a connection with the connection request destination based on a retrieval result from said name server which was received by said retrieving mechanism; and

a connecting mechanism for connecting with said connection request destination based on a connecting instruction from said control mechanism.

3. A system according to claim 1, wherein when a registration of a formal address of said connection request destination is recognized by the retrieval of said name server, said control mechanism of said connection substitute correspondence client instructs said connecting mechanism to connect to a machine having the formal address of the connection request destination.

4. A system according to claim 1, wherein when a registration of the connection substitute server information of said connection request destination is recognized by the retrieval of said name server, said control mechanism of said connection substitute correspondence client instructs said connecting mechanism to connect to the connection substitute server recognized.

5. A system according to claim 1, wherein when neither a registration of the formal address of said connection request destination nor a registration of the connection substitute server information can be recognized by the retrieval of said name server, said control mechanism of said connection substitute correspondence client notifies of a connection error and finishes process.

6. A system according to claim 1, further comprising a connection substitute correspondence client requesting retrieval of said connection substitute server information, wherein said connection substitute correspondence client comprises:

an address retrieving mechanism for requesting a retrieval of address information of a connection request source to said name server when receiving the communication request in which the host name of the connection request destination has been designated;

a local address judging mechanism for judging whether the address information registered in said name server is a local address or not by the retrieval of said address retrieving mechanism;

a connection substitute server retrieving mechanism for requesting a retrieval of the connection substitute server information to said name server when said local address judging mechanism judges a registration of the local address;

a control mechanism for instructing a connection with the connection request destination based on a judgment result of said local address judging mechanism and a retrieval result of said connection substitute server retrieving mechanism; and

a connecting mechanism for connecting with said connection request destination based on a connecting instruction from said control mechanism.

7. A system according to claim 1, wherein when said local address judging mechanism discriminates a registration of a formal address of said connection request destination by the retrieval of said name server by said address information retrieving mechanism, said control mechanism of said connection substitute correspondence client instructs said connecting mechanism to connect with a host machine of the connection request destination having the formal address.

8. A system according to claim 1, wherein when the address information is not registered for the retrieval of said name server by said address retrieving mechanism, said control mechanism of said connection substitute correspondence client notifies of a connection error and finishes process.

9. A system according to claim 1, wherein when a registration of the connection substitute server information of said connection request destination is recognized by the retrieval of said name server by said connection substitute server retrieving mechanism, said control mechanism of said connection substitute correspondence client instructs said connecting mechanism to connect with the connection substitute server recognized.

10. A system according to claim 1, wherein when the connection substitute server information is not registered for the retrieval of said name server by said connection substitute server retrieving mechanism, said control mechanism of said connection substitute correspondence client notifies of a connection error and finishes process.