JP2000156709A - Address converter and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert packet addresses at high speed and to further reduce the overall job amounts, in comparison with the case for generating an entire address conversion structure by using an application gateway, so as to convert addresses of only address information of a user data part when converting the addresses of packets. SOLUTION: This address converter is provided with a 1st address conversion means 4 that converts an address part of a packet into a global address, upon the receipt of a packet to which a local address is set or inversely converts a global address of the address part of a packet into a local address, upon the receipt of the packet with the global address set thereto and with a 2nd address conversion means 5 that converts address information into global address information upon the receipt of a packet, to which a local address is set when address information is set to a user data part of the packet or inversely converts the address information into local address information, when the address information is set to the user address part of the packet upon the receipt of the packet to which the global address information is set.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an address translation device and a recording medium for mutually translating local address information and global address information set in a packet.

[0002]

2. Description of the Related Art A terminal connected to a LAN connects a router between the LAN and the Internet, and another terminal connected to the Internet via the router (further, a terminal connected via a router). When communication is performed by mutually transmitting and receiving a packet in which an IP address is set between
The router connected between the AN and the Internet is a LAN
Local address of the above terminal (private address)
To a global address on the Internet and relay the packet.

Conventionally, a NAT mechanism automatically converts a local address (IP address) of a terminal into a global address on the Internet, transmits a packet, and reversely converts a global address of a reply packet from a partner terminal into a local address. And transmits the data to a terminal on the LAN, so that the terminal communicates with another terminal.

[0004] At this time, when address information is included in the user data portion of the packet (for example, ITU-T Recommendation H.323)
), The NAT mechanism described above cannot convert the address information in the user data part.
As shown in FIG. 5, an application gateway is provided so that the entire address including the address information in the user data section is collectively converted and relayed.

[0005]

As described above, when address information is included in the user data portion of a packet, it is necessary to provide an application gateway shown in FIG. 5 and perform address conversion for relaying. A problem has occurred.

[0006] The present invention solves these problems,
When converting the address of a packet, only the address information of the user data section is converted by the application gateway, thereby performing the address conversion of the packet at high speed and reducing the amount of work as compared with the case of creating the entire address conversion mechanism. It is intended to be.

[0007]

Means for solving the problem will be described with reference to FIG. In FIG. 1, a first address translation means 4 translates a local address and a global address of an address portion set in a packet into and out of each other.

The second address translation means 5 translates the local address and the global address of the address information of the user data portion set in the packet into and out of each other. Next, the operation will be described.

When the first address translation means 4 receives a packet in which a local address is set, it converts the address of the address portion of the packet into a global address, or when it receives a packet in which the global address is set, the address portion of the packet is Is converted back to a local address, and when the second address conversion means 5 receives a packet in which the local address is set, the address is converted to global address information when the address information is set in the user data portion of the packet. Alternatively, when a packet in which global address information is set is received, when address information is set in the user data portion of the packet, the address is inversely converted to local address information, and the converted packet is transmitted.

At this time, in the call control for connecting or disconnecting the communication source terminal and the communication destination terminal, the first address conversion means 4 and the second address conversion means 5 perform address conversion or address reverse conversion. In transmitting and receiving data during a call, the first address conversion means performs address conversion or reverse address conversion.

Therefore, when the address of the packet is translated, only the address information of the user data section is converted to the second address translation means 5 constituting the application gateway.
This makes it possible to perform address conversion / address reverse conversion, perform packet address conversion / address reverse conversion at high speed, and reduce the amount of work as compared with the case where the entire address conversion mechanism is created.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the embodiment and operation of the present invention will be described in detail sequentially with reference to FIGS.

FIG. 1 shows a system configuration diagram of the present invention.
In FIG. 1, a terminal 1 is a terminal (for example, a personal computer) connected to a LAN (1) 2;
(1) 2, connecting to a network (for example, the Internet) via a router / gateway 3 and communicating with a terminal (partner) 8 connected to the network via a router / gateway 7 and a LAN (2) 9 It is.

The LAN (1) 2 and the LAN (2) 9 connect the terminals 1 and 8 and perform data communication with each other by packets. In the LAN (1) 2 and the LAN (2) 9, the terminals are connected to each other based on local addresses and local address information to transmit and receive data in packets for communication.

The routers / gateways 3 and 7 are connected between the LAN and the network 6 and perform the address conversion of packets to be relayed. The first address conversion means 4 and the second address conversion means 5 are provided. It is composed of

The first address translation means 4 translates the address of the address portion of the packet into a global address when receiving the packet in which the local address is set,
Alternatively, when a packet having a global address set is received, the address in the address portion of the packet is inversely converted to a local address.

The second address conversion means 5 converts a packet having a local address set therein into global address information when address information is set in the user data portion of the packet at the time of reception, or sets the global address information. When address information is set in the user data portion of the packet at the time of reception, the packet is inversely converted to local address information.

The network 6 connects a large number of terminals directly or via the routers / gateways 3 and 7, sets address information in an address portion and a user data portion of a packet, and connects to each other to transmit and receive data. Network, for example, the Internet. In the network 6, the terminals are connected to each other based on the global address and the global address information to transmit and receive data in packets to perform communication. For this reason, between the LAN (1) 2 or LAN (2) 9 that connects and communicates with each other using the local address, and the network (Internet) 6 that connects and communicates with each other using the global address, The router / gateway 3, 7 translates / reverses a local address and local address information and a global address and global address information from each other, using a first address translation unit 4 and a second address translation unit 5 according to the present invention. This is realized using. The details will be sequentially described below.

FIG. 2 is a diagram for explaining the operation of the present invention. Here, the terminal (T1), the gateway (R1), and the partner terminal (T2) represent the terminal (T1) 1, the router / gateway 3, and the terminal (T2) 8, respectively, in FIG.

In FIG. 2, at step S1, the terminal (T1) transmits a setup packet. This is, for example, a packet (setup) before conversion in FIG.
As shown in (1), a setup packet in which the following information is set is transmitted to the gateway (R1).

Address part (first address conversion means 4)
), The source IP address: T1, the destination IP address: T2, the source port: any, the destination port: fixed, and the user data section (the address conversion is performed by the second address conversion means 5). (The same applies to the following.):-Source IP address: T1-Destination IP address: T2-Communication port: P1 Here, T1: Local IP address of T1 T2: Global IP address of T2 P1: Communication port number (arbitrary) is there. The MAC address is omitted.

At S2, since the call control port number is fixed by the gateway (R1), the local IP address is converted to the global IP address, and the call port number is stored (application conversion (second address conversion) + address). Translation (first address translation)). Thereby, the converted packet (setup) of FIG.
Are converted as follows.

Address part: Source IP address: T1 'Destination IP address: T2 Source port: Arbitrary Destination port: Fixed User data part: Source IP address: T1' Destination IP address: T2-Call port: P1 Here, T1 ': Global IP address of T1.

At S3, the terminal (T2) receives the packet after the address conversion at S2 as a setup packet. In step S4, a connect packet is transmitted. This is done by setting the following address and address information shown in the connection packet before conversion in FIG.

Address part: Source IP address: T2 Destination IP address: T1 'Source port: Fixed Destination port: Arbitrary User data part: Source IP address: T2 Destination IP address: T1 '・ Call port: Since the stored call port number of P2 S5 is fixed, it is converted from a global IP address to a local IP address and the call port number is stored (application conversion (second address conversion means) + address Translation (first address translation)). As a result, the address is converted as shown below in the converted packet (connect) of FIG.

Address part: Source IP address: T2 Destination IP address: T1 Source port: Fixed Destination port: Any User data part: Source IP address: T2 Destination IP address: T1 Communication port: P2 S6, the terminal (T1) receives the connect packet,
The call control is completed, and the terminal (T1) and the terminal (T2) are connected.

At S7, the terminal (T1) starts a call.
This is set and transmitted as described below before conversion of a packet from T1 to T2 in FIG. Address part: Source IP address: T1 Destination IP address: T2 Source port: P1 Destination port: P2 Since S8 has a fixed call control port number, it is converted from a local IP address to a global IP address. (Only address translation (first address translation)). As a result, the following address conversion is performed after the conversion of the packet from T2 to T1 in FIG.

Address part: Source IP address: T1 'Destination IP address: T2 Source port: P1 Destination port: P2 S9 is a packet converted and transmitted in S8 (call)
Is received by the terminal (T2) and a call is made. Then, the terminal (T
2) transmits a packet (call).

Since S10 is the call port number stored by the gateway (R1) that has received the packet (call) transmitted in S9, it is converted from a global IP address to a local IP address (address conversion (first address). Conversion) only). In this case, the following address shown before the conversion of the received packet from T2 to T1 in FIG. 3C described later is converted into the following address shown after the conversion.

Before conversion: Address part: Source IP address: T2 Destination IP address: T1 'Source port: P2 Destination port: P1 After conversion: Address part: Source IP address: T2 • Destination IP address: T1 • Source port: P2 • Destination port: P1 S11 ends the call.

In step S12, a disconnect packet is transmitted. In step S13, since the gateway (R1) has a fixed call control port number, the local IP address is converted to the global IP address, and the call port number is deleted from the storage area (application conversion (second address conversion) + address). Translation (first address translation)).

In S14, the packet terminal (T2) after the address conversion in S13 is received as a disconnect packet. In step S15, a disconnect response packet is transmitted.

In step S16, since the call control port number is fixed, the global IP address is converted to the local IP address (application conversion (second address conversion means) + address conversion (first address conversion)).

At S17, the terminal (T1) receives the disconnect response packet, and the call control disconnection is completed. As described above, the packet (setup) and the packet (connect) are transmitted and received between the terminal (T1) and the terminal (T2) and connected, the packet (call) is mutually transmitted and received, and the communication is performed. When performing a series of processing of transmitting and receiving a connection (connect) and a packet (disconnect response) between the terminal (T1) and the terminal (T2) and disconnecting the same,
The first address conversion means 4 performs conversion / reverse conversion between the local IP address and the global IP address in the address portion of the packet, and the second address conversion means 5
Thus, conversion / reverse conversion between the local IP address and the global IP address of the user data portion of the packet can be performed.

FIG. 3 shows an example of a packet according to the present invention. FIG.
3A shows an example of a packet (setup). Here, the packet before conversion (set pup) is S1 in FIG.
Is transmitted from the terminal (T1) to the gateway (R1), and the converted packet (setup) is a packet after the gateway (R1) performs address conversion, and is converted (set) as shown in the figure below. .

[0036] Here, T1: local IP address of T1 T1 ′: global IP address of T1 T2: global IP address of T2 P1: call port number (arbitrary) FIG. 3B shows an example of a packet (connect). Here, the packet (connect) before the conversion is the one that the terminal (T2) transmits to the gateway (R1) in S4 of FIG. 2, and the packet (connect) after the conversion is the gateway (R).
1) is the one after the address conversion, which is converted (set) as shown in the figure below.

[0037] FIG. 3C shows an example of a packet (call). here,
Before the conversion of the packet from T1 to T2, the terminal (T1) transmits the packet to the gateway (R1) in S7 of FIG. 2, and after the conversion, the address is converted by the gateway (R1). Is converted (set) as shown below.

[0038] Before the conversion of the packet from T2 to T1, S in FIG.
In step 9, the terminal (T2) transmits to the gateway (R1). After the conversion, the address is converted by the gateway (R1), and the address is converted (set) as shown in the figure below.

[0039] FIG. 4 shows an explanatory diagram of the present invention. This is described in ITU-T Recommendation H.264. An example applied to H.323 is shown. H. Since the data in H.323 corresponds to the packet (call) in FIG. 3C described above, the first address conversion means 4 converts the address portion in the packet (call) into the local IP address and the global I
The P-address and the P-address are mutually translated / reversed (there is no need to operate the second address translation means 5 because there is no address information in the user data portion of the packet (call)).

On the other hand, H. Since the call control of H.323 corresponds to the packet (setup) and the packet (connect) in FIGS. 3A and 3C described above, the address part in the packet (setup) and the packet (connect) is set to the first. The address conversion means 4 performs the address conversion / address reverse conversion between the local IP address and the global IP address, and the second address conversion means 5 converts the address information of the user data portion into the local IP address and the global IP address. Address conversion / address reverse conversion is performed mutually. At this time, since the second address translation means 5 is performed by the application program, it requires more time than the first address translation means 4, but all of them (the first
Address conversion means 4 and second address conversion means 4
The processing speed is significantly higher than when both are performed collectively by the application program.

[0041]

As described above, according to the present invention,
When translating the address of the packet, only the address information of the user data part is transferred to the second application gateway.
In the case where it is necessary to convert the address information in the address portion and the user data portion of the packet between the local IP address and the global IP address because the address conversion / reverse address conversion is adopted by the address conversion means 5 of FIG. In addition, address conversion / address reverse conversion can be performed easily and at high speed, and the amount of design work can be greatly reduced as compared with the case where the whole is performed by the application gateway.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of the present invention.

FIG. 2 is a diagram illustrating the operation of the present invention.

FIG. 3 is an example of a packet according to the present invention.

FIG. 4 is an explanatory diagram of the present invention.

FIG. 5 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 1, 8: terminal 2, 9: LAN 3, 7: router / gateway 4: first address converter 5: second address converter 6: network (Internet)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Katsumi Funatogawa 98 Uno-Ki-nu, Unoki-cho, Kawakita-gun, Ishikawa Pref. No. 2 Inside PF Yu Co., Ltd. (72) Inventor Susumu Okada 98 Uno Ki-nu, Unoki-cho, Kawakita-gun, Ishikawa Prefecture F-term inside FU Yu Co., Ltd. 5Reference 030 GA01 GA17 HB19 HC14 HD03 HD07 HD09 KA02 9A001 CC07 CC08 CC10 DD10 EZ02 JZ25 KK56

Claims (3)

[Claims] An address translation device for mutually translating local address information and global address information set in a packet, when receiving a packet in which a local address is set, translates an address of an address portion of the packet into a global address, Alternatively, first address conversion means for reversely converting the address of the address portion of the packet to a local address when receiving a packet in which the global address is set, and user data portion of the packet when receiving the packet in which the local address is set If the address information is set in the address, it is converted to global address information, or if a packet in which the global address information is set is received, if the address information is set in the user data part of the packet, the local address is set. Address conversion device is characterized in that a second address conversion means for inversely converting the broadcast. 2. The call control when a communication source terminal and a communication destination terminal are connected or disconnected is performed by the first address conversion means and the second address conversion means by performing address conversion and reverse address conversion. 2. The address translator according to claim 1, wherein the first address translator performs address translation and reverse address translation for data transmission and reception during a call. 3. When a packet with a local address set is received, the address of the address portion of the packet is converted to a global address, or when a packet with a global address set is received, the address of the address portion of the packet is changed to a local address. First address conversion means for performing reverse conversion, and when receiving a packet in which the local address is set, converting the address into global address information when address information is set in the user data portion of the packet, or setting global address information Computer-readable recording medium on which is recorded a program for functioning as second address conversion means for performing reverse conversion to local address information when address information is set in the user data portion of the received packet when the packet is received .