JP2006352753A - Protocol converter and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protocol converter capable of achieving name resolution (acquisition of an IP address) using the SIP (Session Initiation Protocol) for an application compatible with the DNS (Domain Name System) but incompatible with the SIP. <P>SOLUTION: A computer program disclosed herein includes: a step (S2) of acquiring a name resolution request of a FDQN with respect to the DNS Session Initiation Protocolfrom the application compatible with the DNS but incompatible with the SIP; a step (S4) of generating a SIP-URI on the basis of the FDQN being an object of the name resolution request; a step (S5) of making an establishment request of a SIP session by using the generated SIP-URI; and a step (S7) of receiving an IP address in response to the SIP session establishment request and informing the application about the IP address. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a protocol conversion device and a computer program.

  Conventionally, in IP (Internet Protocol) telephone (also called Internet telephone) using VoIP (Voice over Internet Protocol) and file exchange, SIP (Session Initiation Protocol) is one of the signaling protocols.・ Protocol) is adopted. SIP is an application layer signaling protocol that provides a dynamic mapping function between SIP-URI (address on SIP) and IP address, enabling establishment of peer-to-peer communication between dynamic hosts (For example, refer nonpatent literature 1).

As another technology for establishing peer-to-peer communication, a mapping function between an FDQN (Fully Qualified Domain Name) and an IP address provided by DNS (Domain Name System) is used between hosts. Is known to realize the establishment of peer-to-peer communication (see, for example, Non-Patent Documents 2 and 3). With this technology, peer-to-peer communication between hosts can be established if the application supports name resolution by DNS. However, in order to establish peer-to-peer communication between dynamic hosts, a dynamic DNS function capable of mapping a dynamic IP address and an FDQN is necessary.
IETF RFC 3261 "SIP: Session Initiation Protocol", [online], June 2002, World Wide Web Consortium, [searched May 13, 2005], Internet <URL: http://www.ietf.org/ rfc / rfc3261.txt> IETF RFC 1034 "DOMAIN NAMES-CONCEPTS AND FACILITIES", [online], June 2002, World Wide Web Consortium, [searched May 13, 2005], Internet <URL: http://www.ietf.org /rfc/rfc1034.txt> IETF RFC 1035 "DOMAIN NAMES-IMPLEMENTATION AND SPECIFICATION", [online], June 2002, World Wide Web Consortium, [Search May 13, 2005], Internet <URL: http://www.ietf.org /rfc/rfc1035.txt>

  In order to perform the above-described peer-to-peer communication using SIP, applications such as IP telephone and file exchange need to support SIP. However, since SIP is a latecomer of similar protocols such as ITU-T “H.323”, there are few that support existing applications. For this reason, there are not many applications that can be applied to peer-to-peer communication, and there is a problem that a new SIP-compliant application must be developed.

  On the other hand, when dynamic DNS is used, there are the following problems. In dynamic IP address registration using dynamic DNS, since host authentication is difficult, it is difficult to prevent fraud related to IP address registration. Also, the use of a public DNS name space on the Internet is not suitable for private use purposes such as businesses. For this reason, it is desirable to perform name resolution (acquisition of IP address) using SIP that supports host authentication at the time of address registration.

  The present invention has been made in consideration of such circumstances, and its purpose is to use name resolution (IP address) using SIP for an application that supports DNS but does not support SIP. It is an object of the present invention to provide a protocol conversion apparatus that can realize the acquisition of

  Another object of the present invention is to provide a computer program for realizing the protocol conversion apparatus of the present invention using a computer.

  In order to solve the above-described problem, the protocol conversion apparatus according to the present invention acquires a name resolution request for acquiring a name resolution request of FDQN for DNS from an application that supports DNS but does not support SIP. Means, SIP-URI creation means for creating a SIP-URI based on the FDQN that is the object of the name resolution request, and SIP session establishment for making a SIP session establishment request using the created SIP-URI It is characterized by comprising request means and notification means for receiving an IP address of a reply to the SIP session establishment request and notifying the application.

  The protocol conversion apparatus according to the present invention further comprises FDQN name resolution requesting means for performing a name resolution request of the FDQN to the DNS when acquisition of an IP address by the SIP session establishment request fails. Features.

  The computer program according to the present invention also has a function of acquiring a name resolution request for FDQN for a DNS from an application that supports DNS but does not support SIP, and an FDQN that is a target of the name resolution request. A function for creating a SIP-URI, a function for making a SIP session establishment request using the created SIP-URI, and an IP address in response to the SIP session establishment request. The function of notifying is realized in a computer.

In the computer program according to the present invention, when acquisition of an IP address by the SIP session establishment request fails, the computer program further realizes a function of performing a request for name resolution of the FDQN to the DNS. .
As a result, the above-described protocol converter can be realized using a computer.

  According to the present invention, based on the FDQN name resolution request to the DNS, the FDQN is converted into a SIP-URI and a SIP session establishment request is made. Therefore, the IP address mapped to the SIP-URI is assigned to the SIP session establishment request. It can be obtained as a reply. As a result, it is possible to realize name resolution (acquisition of an IP address) using SIP for an application that supports DNS but does not support SIP.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing an overall configuration of a communication system to which a protocol conversion apparatus according to an embodiment of the present invention is applied. In the communication system shown in FIG. 1, a personal computer (PC) 1, an SIP server 2, and a PC 3 are connected to a communication network that supports the Internet protocol (IP), and perform IP packet communication via the communication network. The personal computers (PCs) 1 and 3 are connected to the SIP server 2 respectively.

  The SIP server 2 has a mapping function between an address (SIP-URI) on a session initiation protocol (SIP) and an IP address.

  “Mail.p2pvpn.xxx.com” is assigned to the PC 3 as an absolute domain name (FDQN) in the domain name system (DNS). In the FDQN “mail.p2pvpn.xxx.com”, “mail” is a host name and “p2pvpn.xxx.com” is a domain name. That is, the PC 3 is a host named “mail” in the domain “p2pvpn.xxx.com”. Note that it is not essential to register the FDQN “mail.p2pvpn.xxx.com” of the PC 3 on an actual DNS server.

  Also, “mail@p2pvpn.xxx.com” is assigned to the PC 3 as the SIP-URI. In the SIP-URI “mail@p2pvpn.xxx.com”, “mail” is a host name and “p2pvpn.xxx.com” is a domain name. That is, the PC 3 is a host named “mail” in the domain “p2pvpn.xxx.com”.

  Further, “address A” is assigned to the PC 3 as an IP address. This IP address “address A” is mapped to FDQN “mail.p2pvpn.xxx.com” in DNS (not shown). On the other hand, in the SIP server 2, the IP address “address A” is mapped as SIP-URI “mail@p2pvpn.xxx.com”.

  FIG. 2 is a block diagram showing a software configuration of the PC 1 that realizes the protocol conversion apparatus according to the embodiment of the present invention. As shown in FIG. 2, the PC 1 has an operating system (OS) 11 and an application program 12 and a protocol conversion program 13 that operate on the OS.

  The application program 12 has a peer-to-peer communication function using an IP address. The application program 12 supports name resolution by DNS, and makes an inquiry (name resolution request) for obtaining an IP address from the FDQN. Note that the application program 12 does not support SIP.

FIG. 3 shows a part of the internal configuration of the OS 11. As illustrated in FIG. 3, the OS 11 includes a TCP / IP unit 21 that supports TCP (Transmission Control Protocol) and IP. The application program 12 performs communication based on TCP / IP via the TCP / IP unit 21.
In the present embodiment, the OS 11 is provided with a protocol conversion interface unit 22 that interfaces with the protocol conversion program 13.

  Next, with reference to FIG. 4, the operation | movement which concerns on the protocol conversion of this embodiment in the communication system of FIG. 1 is demonstrated. FIG. 4 is a sequence chart of protocol conversion processing according to an embodiment of the present invention. In this example, a procedure for starting peer-to-peer communication using an IP address from PC1 to PC3 is shown.

  First, in the PC 1, the application program 12 makes an inquiry to the DNS for obtaining the IP address of the PC 3 from the FDQN “mail.p2pvpn.xxx.com” of the PC 3 (name resolution request “mail.p2pvpn.xxx.com”). (Step S1). The FDQN “mail.p2pvpn.xxx.com” that is the target of the name resolution request is, for example, manually input by the user of the PC 1 by key operation.

  The name resolution request “mail.p2pvpn.xxx.com” is input to the TCP / IP unit 21. Here, the TCP / IP unit 21 outputs the name resolution request “mail.p2pvpn.xxx.com” to the protocol conversion interface unit 22 (step S2). In the TCP / IP unit 21, a protocol conversion interface unit 22 is set in advance as an output destination of the name resolution request. As a result, a step (S2) of acquiring a request for FDQN name resolution for the DNS from an application that supports DNS but does not support SIP is realized.

  Upon receiving the name resolution request “mail.p2pvpn.xxx.com”, the protocol conversion interface unit 22 activates the protocol conversion program 13 and instructs the name resolution request “mail.p2pvpn.xxx.com” (step S3). ).

  Next, the protocol conversion program 13 creates a SIP-URI based on the FDQN “mail.p2pvpn.xxx.com” of the name resolution request “mail.p2pvpn.xxx.com” (step S4). Specifically, the host name “mail” and the domain name “p2pvpn.xxx.com” are extracted from the FDQN “mail.p2pvpn.xxx.com”. The extracted host name “mail” and domain name “p2pvpn.xxx.com” are applied to the SIP-URI format [SIP: // “host name” @ “domain name”]. As a result, the SIP-URI “SIP: //mail@p2pvpn.xxx.com” is completed.

  Next, the protocol conversion program 13 performs a call (SIP session establishment request) with the SIP-URI “SIP: //mail@p2pvpn.xxx.com” to the SIP server 2 (step S5).

  Next, in response to the call, the SIP server 2 returns an IP address “address A” mapped to the SIP-URI “SIP: //mail@p2pvpn.xxx.com” (SIP session establishment request response) ( Step S6).

  Next, the protocol conversion program 13 notifies the returned IP address “address A” to the protocol conversion interface unit 22 (step S7). Here, the protocol conversion program 13 applies the IP address “address A” to the DNS IP address notification format and outputs it to the protocol conversion interface unit 22.

  Next, the protocol conversion interface unit 22 outputs the IP address “address A” in the DNS IP address notification format to the TCP / IP unit 21 (step S8). The TCP / IP unit 21 outputs the IP address “address A” in the DNS IP address notification format to the application program 12 (step S9). As a result, the application program 12 receives the IP address “address A” as a response from the DNS.

  Next, the application program 12 starts peer-to-peer communication with the PC 3 using the IP address “address A” via the TCP / IP unit 21 (step S10).

  According to the above-described embodiment, based on the FDQN name resolution request to the DNS, the FDQN is converted into a SIP-URI and a SIP session establishment request is made to the SIP server. As a result, since the IP address mapped to the SIP-URI can be acquired from the SIP server, name resolution (using SIP) for an application that supports DNS but does not support SIP ( IP address acquisition) can be realized.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention.
For example, in the above-described embodiment, in order to cope with the case where the SIP-URI “SIP: //mail@p2pvpn.xxx.com” to be called is not registered in the SIP server 2, the protocol conversion program 13 is DNS An inquiry function may be provided. Specifically, if the response from the SIP server 2 is an IP address acquisition failure in step S6 of FIG. 4, the protocol conversion program 13 sends a name resolution request “mail.p2pvpn.xxx.com” to the DNS. I do. As a result, even if name resolution (IP address acquisition) using SIP fails, IP address acquisition can be performed using DNS.

1 is a block diagram showing an overall configuration of a communication system to which a protocol conversion apparatus according to an embodiment of the present invention is applied. It is a block diagram which shows the software structure of PC1 which implement | achieves the protocol converter which concerns on one Embodiment of this invention. It is a block diagram which shows a part of internal structure of OS11 shown in FIG. It is a sequence chart of the protocol conversion process which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,3 ... Personal computer (PC), 2 ... SIP server, 11 ... Operating system (OS), 12 ... Application program, 13 ... Protocol conversion program, 21 ... TCP / IP part, 22 ... Protocol conversion interface part

Claims (4)

Name resolution request acquisition means for acquiring an FDQN name resolution request for DNS from an application that supports DNS but does not support SIP;
SIP-URI creation means for creating a SIP-URI based on the FDQN that is the target of the name resolution request;
SIP session establishment request means for making a SIP session establishment request using the created SIP-URI;
A notification means for receiving an IP address in response to the SIP session establishment request and notifying the application;
A protocol converter characterized by comprising:   2. The protocol according to claim 1, further comprising: FDQN name resolution requesting means for performing a name resolution request of the FDQN to the DNS when acquisition of an IP address by the SIP session establishment request fails. Conversion device. A function for acquiring a name resolution request of FDQN for DNS from an application that supports DNS but does not support SIP;
A function of creating a SIP-URI based on the FDQN that is the target of the name resolution request;
A function of requesting establishment of a SIP session using the created SIP-URI;
A function of receiving an IP address in response to the SIP session establishment request and notifying the application;
A computer program for causing a computer to realize the above. 4. The computer program product according to claim 3, further comprising a function of causing the computer to perform a request for name resolution of the FDQN to the DNS when acquisition of an IP address by the SIP session establishment request fails.

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