JP2003258920A - Method for connecting different networks, system for data communication between different networks, and converter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for a connection between different networks which enables packet communication between different networks 1 and 2 by making a specified ATM-SVC connected converter (CV) 4 receive an incoming packet from an IP network and performing protocol conversion when an ATM- SVC network 1 and IP network 2 are connected. <P>SOLUTION: When a plurality of converters (CV) 4 are installed in a part 3 for connection between the ATM network 1 and IP network 2, IP routing of a destination IP address to an end address is not always done through an ATM-SVC connected converter #4. Under these circumstances, a specified converter #4 having SVC connections with converters #1 to #3 is provided with a function of transferring data and the converters #1 to #4 are each equipped with a function of notifying other converters of an SVC connection and its destination address when its device completes the SVC connection or a registering function of holding information on the notification when the notification is received. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a converter and a protocol conversion method for communicating packets between an ATM-SVC network and an IP network.

[0002]

2. Description of the Related Art Conventionally, a converter having a function of connecting an ATM-SVC network and an IP network and realizing packet communication has not been known.

[0003]

[Problems to be Solved by the Invention] ATM-SVC network and I
When the converter is provided with the function of connecting to the P network and realizing packet communication, this converter needs a protocol conversion function for connecting different networks. Such a protocol conversion function is an ATM-SVC-based and IP-based protocol conversion function in a lower layer of the protocol stack. If there is only one converter having such a conversion function, this enables packet communication between different networks. However, assuming a connection configuration, multiple converters are actually used in consideration of reliability. Will be installed. However, when a plurality of converters are installed, there may occur a case where data cannot be connected to a specific converter that is in the ATM-SVC connection at the time of connection request.

The present invention has been made in view of such a technical problem, and when a connection between an ATM-SVC network and an IP network is made, a packet incoming from the IP network is transferred to a specific converter which is ATM-SVC connected. ATM-SV that allows incoming calls and protocol conversion to enable packet communication between different networks
It is characterized by providing a connection technology between the C network and the IP network.

[0005]

According to another aspect of the present invention, there is provided a method of connecting different networks, wherein each of a plurality of converters installed at a connecting portion between an ATM-SVC network and an IP network establishes an SVC connection by itself. And storing the correspondence between the SVC number and the destination IP address, and transmitting the correspondence information between the own identification number and the destination IP address with which the SVC connection is established to another converter; and the plurality of converters. Each step of receiving transfer data from another converter and storing correspondence information between the converter identification number and the destination IP address with which the SVC connection is established, and a packet received by each of the plurality of converters at its own device. The destination IP address of the data is checked, the destination IP address of which the SVC connection is established by another converter by referring to the corresponding information
If the address is an address, transferring the incoming packet data to the other converter, and when each of the plurality of converters receives the incoming packet data transferred from the other converter, sets the destination IP address below the data link layer. And converting the protocol into an end node address and sending it to the corresponding end node address.

An inter-different data communication system according to a second aspect of the present invention comprises a plurality of converters installed at a connecting portion between an ATM-SVC network and an IP network, and each of the plurality of converters connects itself by SVC. Is established, the correspondence between the SVC number and the destination IP address is stored, and the correspondence information between the own identification number and the destination IP address with which the SVC connection is established is transmitted to another converter, and another converter. Function to store the correspondence data with the identification number of the converter and the destination IP address with which the SVC connection has been established, and to check the destination IP address for the packet data received at the device itself, By referring to the correspondence information, if the destination IP address is an SVC connection established by another converter, the incoming packet data is sent to the other converter. And a function of sending the incoming packet data from another converter, performing protocol conversion using the destination IP address as the end node address in the data link layer or lower, and sending the data to the corresponding end node address. It is characterized by that.

The converter of the third aspect of the present invention is an S converter by itself.
Correspondence information between the means for storing the correspondence between the SVC number and the destination IP address when the VC connection is established, and the identification number of the own machine and the destination IP address where the SVC connection is established when the SVC connection is established by itself. To the other converter, and the destination I established by the identification number of the converter and the SVC connection by receiving the transfer data from the other converter.
A means for storing the correspondence information with the P address and the destination IP address of the packet received at the own device are checked, and the destination IP address with which the SVC connection is established by another converter is referred by referring to the correspondence information. And a means for transferring an incoming packet to the other converter in some cases.

According to a fourth aspect of the present invention, there is provided a method for connecting between different networks, comprising:
A step in which a converter installed at a connection part between the M-SVC network and the IP network receives an IP address inquiry from another network and returns an own IP address; A step of holding the correspondence between the IP address and the source IP address in the other network and the own IP address; and the destination IP address of the packet data from the other network received by the converter from the other network to the own IP address. In which the destination IP address in the own network is replaced, and the own IP address is replaced in the source IP address in the other network of the packet originating from the other network and sent out to the own network. Packet data originated from the home network in which the destination IP address in the home network is the source IP address and the home IP address is the destination IP address In contrast, the destination IP address is replaced with the source IP address in the other network, and the source IP address of the packet data originated in the own network is replaced with the own IP address and is sent to the other network. It is a feature.

A different inter-network data communication system according to a fifth aspect of the present invention comprises a converter installed at the connection between the ATM-SVC network and the IP network, and the converter is an I-network from another network.
A function of receiving a P address inquiry and returning an own IP address, and a destination IP in the own network for the address inquiry
Address and the function of holding the correspondence between the source IP address in the other network and the own IP address, and for the packet data originating from the other network received from the other network to the own IP address, the destination IP address is stored in the own network The destination IP address is replaced, and the source I of the packet data originating from the other network in the other network
A function of transferring the own IP address to the P address and sending it out into the own network, and a destination IP address in the own network from within the own network as a source IP address, and the own IP address as the destination IP
With respect to the packet data originating from the own network as an address, the destination IP address is replaced with the source IP address in the other network, and the source IP address of the packet data originated from the own network is replaced with the own IP address. It is characterized by having a function of sending out to the net.

According to the sixth aspect of the invention, a converter receives an IP address inquiry from another network and returns the own IP address, a destination IP address in the own network and a source IP address in the other network of the address inquiry. Of the transfer address holding means for holding the correspondence between the IP address and the own IP address, and the transfer IP address holding means for the destination IP address of the packet data originated from another network which is received from another network to the own IP address. The own network destination I that is held
The P address is replaced, and the own IP address is replaced with the source IP address in the other network of the packet data originating from the other network and sent out in the own network, and the destination IP address in the own network is transmitted from within the own network. With respect to the packet data originating from the own network having the original IP address and the own IP address as the destination IP address, the source IP address in the other network held by the replacement address holding means is relocated to the destination IP address. And the source IP of the packet data originating from the own network
It is provided with an IP address replacing means for replacing the own IP address with the address and sending it to another network.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 1 shows a functional configuration of a data communication system between different networks according to a first embodiment of the present invention. The feature of the first embodiment is that it is applied when the method of using the destination IP address as the end node is adopted, and it is not always necessary to use the ATM-
Each converter # 1 does not necessarily go through the converter (here, converter # 4) connected by SVC.
To # 3 have a function of transferring data to a specific converter # 4 connected by SVC. In order to enable this data transfer function, each converter # 1 to # 4 has a function of notifying other converters of the SVC connection and its destination address when the SVC connection is established in the own device. When it receives this notification, it has a registration function to retain that information.

First, as shown in FIG. 2, ATM networks 1 and I
When connecting to the P network 2, it is necessary to perform protocol conversion. Therefore, a converter (CV) 4 that performs protocol conversion is installed in the connection unit 3 between networks.

The connection form between the different networks 1 and 2 is (1) AT
When a user of the M network 1 roams out, the mobile network 5 connects to the ATM network 1 to connect the IP network to the ATM network, and (2) the roaming-in user of another network from the other network mobile device 6 ATM that connects to its own IP network 2.
There is a network → IP network connection. Therefore, the converter CV4 is required to have a protocol conversion function capable of coping with both the connection forms.

In FIG. 2, ISP (Inter
net Service Provider) 11
I am an Internet connection service provider. GGSN (G
gateway GPRS Support Node)
A node 12 performs access control (connection notification, incoming call notification, etc.) with the ISP in each of the IP network and the ATM network. SGSN (Serving GPRS Supp)
The ort Node 13 is a subscriber node (or a visited node), and manages subscriber information of a mobile subscriber in the visited area. The subscriber information is HLR (Home Location Resi) when the mobile device is powered on.
Ster). And SGSN
Determines whether or not a connection can be made based on subscriber information when a mobile device makes or receives a call, and controls connection to a connection destination. BG (Bo
The rder Gateway) 14 is a gateway that controls the connection between the different networks 1 and 2. The BG 14 is interposed between the GRX network 2A and the IP network 2B of another company even within the same IP network 2.

In order to connect the different networks 1 and 2 smoothly and with high reliability, a connection system having redundancy as shown in FIG. 3 must be used. That is, the BG1 at the demarcation point 3 between the ATM network 1 and the IP network 2
4 to the converter (CV) 4 of the ATM-SVC network 1, and the converter (CV) 4 connects to the GGSN 12 and SGSN 13 in the ATM network 1. Then, in consideration of the detour function at the time of failure, it is desirable to install a plurality of converters CV4. Here, DNS (Domai)
n Name System 15 is a domain name system used on the Internet and designated by a user: APN (Access Point).
Name) to the IP address of the connection destination GGSN.

FIG. 4 shows the converter (C
V) 4 is shown. At the connection section 3 between the ATM network 1 and the IP network 2, a border gateway (BG) 14
If a converter (CV) 4 is installed on the ATM network 1 side of the network and the user of the own network 1 roams in from the IP network 2 by the own mobile device 5, the CV 4 sets the destination IP address of the GGSN 12 as the end node. Alternatively, the address of the SGSN 13 is set and the protocol is converted.

FIG. 5 shows a functional configuration of the converter (CV) 4, which is an ATM-SVC / IP network protocol conversion unit 2
1, ARF function / GMMS address converter 22, GTP
-Con protocol conversion unit 23, converter (CV)
The data transfer unit 24 and the data holding unit 25 are provided.

The ATM-SVC / IP inter-network protocol converter 21 is L1 / L between the ATM-SVC network 1 and the IP network 2.
2 Protocol conversion is performed. The protocol stack is shown in FIG. The packet stack protocol stack of the ATM network 1 is APL, GTP-U, UDP-IP, ATM.
The protocol stacks of packet data of the IP network 2 are APL, CTP-U, UDP-IP, L1 / L1. In CV4, protocol conversion is performed between the L1 / L2 layer of the lowest layer and the ATM layer, but since the destination address of the end node is held, UDP-I is used.
For P and GTP-U, just steal (peek).

ARF function (Access link R
The elay function function / GMMS address conversion unit 22 converts the ARF protocol and the standard DNS protocol. FIG. 7 shows its function. When the mobile device 5 of the own network roams to the other network 2, A of the other network 2
When the address cannot be resolved by PN, ATM network of own network 1
To the other network 2 of the inquiry source
12 IP addresses as C.I. P. C. Reply with req.
The IP address returned at this time is the GG of the end node.
This is the IP address of SM12.

GTP-Con protocol converter 23
GTP-Con SCCP protocol and GTP-
Converts from the Con UDP-IP protocol. This conversion function is based on ARF protocol and GTP on SCCP.
It has a function of converting a -C signal into a UDP-IP signal and vice versa, and performs mutual conversion between the IF protocol stack 31 and the DNS protocol stack 32 shown in FIG.

Data transfer unit 24 between converters (CVs)
The data holding unit 2 creates correspondence information between the CV identification number and the destination address when the own CV establishes the SVC connection.
In addition to holding it in 5, the corresponding information of the own CV number-destination address is notified to other CVs. The CV-to-CV data transfer unit 24 also confirms the destination address of the received packet, refers to the correspondence management table data of the data holding unit 25, and identifies the CV number for SVC connection from the destination address, and the corresponding CV. Forward incoming packets to.

The data holding unit 25 holds the data as the correspondence data 26 between the CV identification number and the destination address when the own CV establishes the SVC connection, and at the same time, stores the SVC-CV number from the other CV notified from the other CV. The correspondence data is held as correspondence management table data 27. These data are shown in Figure 1.
It is shown in.

FIG. 1 shows the CV-destination address correspondence management function of the converter (CV) data transfer unit 24. (I) Each converter (here, CV # 4)
Creates the correspondence information 26 between the CV identification number and the destination address at the time when its own CV # 4 establishes the SVC connection and holds it in the data holding unit 25. (Ii) At the same time, the CV # 4 notifies the other CV # 1 to CV # 3 of the correspondence information of its own CV number-destination address. (Iii) Each C that received the notification
The V # 1 to CV # 3 store the received CV number-destination correspondence data in the data holding unit 25 of the own device as shown in the correspondence management table 27 shown in the figure. (Iv) Then, for example, when a packet arrives at the CV # 3 from the other network 2 to the own network 1, the CV-to-CV data transfer unit 24 confirms the destination address and refers to the data in the address correspondence management table 27. SVC
The CV # 4 to which the connection is established is specified, and the incoming packet is transferred. (V) CV # 4 to which the packet is transferred is
The received packet is referred to the destination address correspondence information 26 held in the data holding unit 25, and is transmitted to the corresponding SVC.

FIG. 9 also shows the transfer process (corresponding to the processes (iv) and (v) in FIG. 1) by the inter-CV data transfer unit 24. The traffic 15 from the other network 2 to the SGSN 13 of the own network 1 is the IP of the SGSN 13 of the own network 1.
Since the IP routing is performed only by being aware of the address, it is not always connected to CV # 4 where the SVC connection is established. Therefore, when the CV # 3 to which the SVC connection has not been established receives this packet data, the CV # 4 to which the SVC connection has established the received data is referred to by referring to the management table 27 of the data holding unit 25 of the own device. Transfer to.

As described above, according to the inter-network data communication system of the first embodiment and the inter-network connection method used by the inter-network data communication system, the traffic 15 from the other network 2 to the SGSN 13 of the own network 1 is not always required. C where SVC connection is established
CV that is not connected to V but SVC connection is not established
When such packet data is received, the packet data is transferred to the CV where the SVC connection is established, so that packet communication can be performed seamlessly between different networks, and the system reliability is improved by having multiple CVs. In addition, even if there are a plurality of CVs, packets from other networks can be reliably delivered to a specific CV that has established an ATM-SVC connection.

Next, the converter according to the second embodiment of the present invention and the inter-network connection method used by the converter will be explained. FIG. 10 shows a functional configuration of a data communication system between different networks according to the second embodiment of the present invention. The feature of the second embodiment is that the destination IP address is not the end node address but the converter address, and the converter (C
In V), the method of replacing the destination IP address and the sender address is adopted.

In the data communication system between different networks of the second embodiment, an ATM network (own network) 1 and an IP network (other network) 2
In the case where a plurality of CVs are installed in the connection part with the network to ensure the reliability of the system, the IP network ( When receiving an incoming call from the other network 2 to the ATM network (own network) 1, the end address to be notified to the connection request of the SGSN 13 of the other network 2 is set to a specific converter address, and then the specific CV that received the incoming call. After inquiring the packet data from the other network 2 for the true destination IP address of the ARF, G in the own network 1 which is the true end address
Connect to GSN12 or SGSN.

In order to enable this data communication function, as in the first embodiment, as shown in FIG. 2, the connection section 3 between the ATM network (own network) 1 and the IP network (other network) 2 is connected. A converter (CV) 4 having the above-mentioned function is installed. Figure 1
Reference numeral 1 indicates the function of the converter (CV) of the second embodiment. A border gateway (BG) 1 is provided at a connection portion 3 between an ATM network (own network) 1 and an IP network (other network) 2.
CV4 is installed on the ATM network 1 side of No. 4, and if the user of the own network 1 roams in from the IP network (other network) 2 at the own network mobile device 5, the CV4 sets the destination IP address of the incoming packet of the CV4. It is converted into an address and notified to the SGSN 13 of the partner network 2, and a packet addressed to its own address is received from the SGSN 13. Then, the protocol conversion of the received packet data is performed, and the packet data is transmitted to the GGSN 12 of the regular IP address in the own network 1.

FIG. 12 shows a functional configuration of the converter (CV) 4, which has the same ARF function / GM as that of the first embodiment.
An ATM-SVC / IP inter-network protocol conversion unit 2 that includes an MS address conversion unit 22 and a GTP-Con protocol conversion unit 23 and has a function different from that of the first embodiment.
6 and GTP-U and UDP-IP as new functions
The terminal processing unit 27 and the IP address rearrangement unit 28 are provided.

ARF function / GMMS address conversion unit 22
As in the first embodiment, as shown in FIG. 7, when the mobile device 5 of the own network roams to the other network 2, A of the other network 2
When the address cannot be resolved by PN, ATM network of own network 1
To the other network 2 of the inquiry source
12 IP addresses as C.I. P. C. Reply with req.
However, the IP address returned at this time is an IP address of CV4, unlike the first embodiment.

GTP-Con protocol converter 23
Is the same as in the first embodiment, as shown in FIG.
TP-Con SCCP protocol and GTP-Co
Converts to nUDP-IP protocol.

ATM-SVC in the second embodiment
The / IP network protocol conversion unit 26 performs protocol conversion between the ATM-SVC network 1 and the IP network 2 as shown in FIG. The packet data protocol stacks of the ATM network 1 are APL, GTP-U, UDP-IP and ATM, and the packet data protocol stacks of the IP network 2 are APL, CTP-U, UDP-IP and L1 / L1. In CV4, the lowest layer among them is the L1 / L2 layer-
Protocol conversion is performed between ATM layers. In addition, the GTP-U, UDP-IP termination processing unit 27, which is new in the second embodiment, terminates UDP-IP and GTP-U.
The IP address transfer unit 28 determines the destination I of the packet data.
The P address and sender IP address are replaced. These processes will be described later in detail.

A different network connection method by the different network data communication system according to the present embodiment will be described with reference to FIG. (Xi) The own network mobile device D sends the GGSN 12 of the own network ATM network 1 in the IP network (other network) 2 to the destination IP address (A
PN = docomo. jp), and the call origination request is issued. (Xii) In response to this call request, the SGS of the other network 2
N13 (assuming IP address #C) is the DN in the network.
Request address translation from S16, but (xiii) D
The NS 16 cannot find the corresponding address in the network 2 and returns an unknown response to the SGSN 13. (Xiv) is
When this unknown response is received, an inquiry is sent to the ATM network 1. At this time, the destination IP address is AP
N = docomo. It remains jp.

(Xv) ATM network 1 converter (CV) 4
(IP address is #B) is SGSN1 of other network 2
It responds to the inquiry from 3 with its own IP address #B.

(Xvi) The SGSN 13 of the other network 2 uses this #B
When the address response is received, the connection request with the destination address of #B and the source address of #A is sent to the ATM network 1
Call. In response to this connection request, the (xvii) converter (CV) 4 sends the original destination IP address AP to the ARF 17
N = docomo. issue an address translation request for jp, and (xviii) ARF17 is the corresponding end node GG
The address #A of SN12 is returned.

(Xix) When the CV 4 receives the address response #A from the ARF 17, it stores the correspondence between its own address #B and the end node address #A, and requests the GGSN 12 of the end node IP address #A for connection. Then, the GGSN 12 connects and notifies the CV 4 when (xx) connection is completed. Upon receiving the connection completion notification, the (xxi) CV 4 notifies the requesting SGSN 13 of the other network 2 of the connection completion, and the (xxii) SGSN 13 notifies the originating mobile device D of the connection completion. As a result, the packet source sender mobile station D and APN = docomo. A connection is established with the GGSN 12 of the own network 1 that manages jp.

(Xxiii) Thereafter, the packet data transmitted from the mobile device D is delivered to the converter (CV) 4 as the packet data PK1 having the destination address #B and the source address #C in the SGSN 13, and C
The IP addresses are rearranged so that the V4 becomes the destination IP address #A and the source address #B, and the packet data PK2 in the own network is converted to the GGSN1 of the IP address #A.
Send to 2. On the contrary, the IP address of the packet data PK3 (destination IP address #B, sender address #A) from the GGSN 12 is replaced by the CV4, and the packet data PK4 (destination IP address #C, sender address #A) is transferred. #B) and send to the SGSN 13 of the other network 2.

As a result, in the inter-network data communication system of the second embodiment and the inter-network connection method used by the inter-network data communication system, the own network mobile device 5 roams into the own network 1 from the other network 2. When there are multiple converters, S
A specific converter that establishes a VC connection can be fixedly terminated, and seamless roaming between different networks is enabled. In addition, by localizing a converter having a protocol conversion function at the connection between different networks, it is possible to construct an economical network.

[0039]

As described above, according to the present invention, if a plurality of converters (CVs) are installed in the connection section in the case of connection between different networks, the IP network, which is another network, can be connected to the own network. ATM-S
The traffic to the GGSN or SGSN of the VC network is not necessarily connected to the CV with which the SVC connection is established, but if the CV without the SVC connection receives such packet data, the SVC connection is established. Since it is transferred to the CV, packet communication can be performed seamlessly between different networks, and the reliability of the system can be improved by providing a plurality of CVs. Moreover, even if there are a plurality of CVs, other networks can be used. Packets from ATM-SVC
It is possible to reliably make an incoming call to a specific CV that has established a connection.

Further, according to the present invention, when the own mobile station roams from the other IP network to the ATM-SVC network of the own network, even if there are a plurality of converters (CVs), the SVC A specific converter that has established a connection can be fixedly received, which enables seamless roaming between different networks. Further, by localizing the CV having the protocol conversion function at the connection between different networks, it is possible to construct an economical system.

[Brief description of drawings]

FIG. 1 is a block diagram showing an operation of a data communication system between different networks according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing the configuration of an inter-network data communication system according to the first and second embodiments of the present invention.

FIG. 3 is a block diagram showing a configuration on the ATM-SVC network side in the inter-different network data communication system according to the first and second embodiments of the present invention.

FIG. 4 is an explanatory diagram of a data conversion operation by the data communication system between different networks according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a functional configuration of a converter in the inter-network data communication system according to the first embodiment of this invention.

FIG. 6 is an explanatory diagram of a protocol conversion process performed by the converter used in the first embodiment of the present invention.

FIG. 7 is an explanatory diagram of APN → GMMS address resolution processing by the converter according to the first embodiment of the present invention.

FIG. 8 is a GTP-Con SCCP / GTP-Con provided by the converter according to the first embodiment of the present invention.
Explanatory drawing of UDP-IP conversion processing.

FIG. 9 is an explanatory diagram of inter-converter data transfer processing by the converter according to the first embodiment of the present invention.

FIG. 10 is a block diagram showing an operation of a data communication system between different networks according to a second embodiment of the present invention.

FIG. 11 is an explanatory diagram of a data conversion operation by the data communication system between different networks according to the second embodiment of the present invention.

FIG. 12 is a block diagram showing a functional configuration of a converter in a data communication system between different networks according to a second embodiment of the present invention.

FIG. 13 is an explanatory diagram of protocol conversion processing performed by a converter used in the second embodiment of the present invention.

[Explanation of symbols]

1 ATM-SVC network (own network) 2 IP network (other network) 2A GRX network 2B IP network of other companies 3 Network connection 4 converter (CV) 5 Own network mobile device 6 Other network mobile 11 Internet Service Provider (ISP) 12 GGSN 13 SGSN 14 BG (Border Gateway) 16 DNS 17 ARF 18 GMMS 21 ATM-SVC / IP network protocol conversion unit 22 ARF function / GMMS address converter 23 GTP-Con Protocol Converter 24 Data converter between converters 25 Data storage 26 ATM-SVC / IP inter-network protocol converter 27 GTP-U, UDP-IP termination processing unit 28 IP address transfer unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Mutsumi Miki             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo (72) Inventor Kazuo Sugiyama             2-11-1, Nagatacho, Chiyoda-ku, Tokyo Stock             Ceremony company NTT Docomo F-term (reference) 5K030 GA12 HA08 HA10 HD05 KA05                       KX23 LB15 LD11 MD07

Claims (6)

[Claims] 1. Each of a plurality of converters installed at a connection between an ATM-SVC network and an IP network stores a correspondence between an SVC number and a destination IP address when an SVC connection is established by itself, And, a step of transmitting the correspondence information of the identification number of the own device and the destination IP address with which the SVC connection is established to the other converter, and each of the plurality of converters receives the transfer data from the other converter and identifies the converter. Number and SVC
Storing the correspondence information with the destination IP address with which the connection is established; each of the plurality of converters checks the destination IP address for the packet data received by itself, and refers to the correspondence information to determine the other Transferring the incoming packet data to the other converter when the destination IP address has established an SVC connection in the converter, and when each of the plurality of converters receives the incoming packet data from another converter And a step of performing protocol conversion using the destination IP address as the end node address in the data link layer and below and sending the protocol to the corresponding end node address. 2. A plurality of converters installed at the connection between the ATM-SVC network and the IP network, each of the plurality of converters having an SVC number and a destination IP address when the SVC connection is established by itself. The function of storing the correspondence between the converter and the corresponding IP address of the own machine and the destination IP address with which the SVC connection is established, and the function of receiving the transfer data from the other converter and identifying the converter. A function that stores the correspondence information between the number and the destination IP address with which the SVC connection is established, and the destination IP address is checked for the packet data that arrived at the device itself, and the SVC connection is made by another converter by referring to the correspondence information. When the destination IP address has been established, the function to transfer the incoming packet data to the other converter, and the incoming call from the other converter. Data communication between different networks, which has a function of performing protocol conversion using the destination IP address as an end node address below the data link layer and sending the packet data to the corresponding end node address when the packet data is transferred. system. 3. The SV when the SVC connection is established by itself.
Means for storing the correspondence between the C number and the destination IP address, and means for transmitting the correspondence information between the identification number of the own machine and the destination IP address for which the SVC connection is established to another converter when the SVC connection is established by the own machine And a means for receiving the transfer data from another converter and storing the correspondence information of the identification number of the converter and the destination IP address with which the SVC connection is established, and the destination IP address for the packet arriving at the own device. A converter comprising means for checking and referring to the correspondence information, and transferring the incoming packet to the other converter if the destination IP address has established an SVC connection with the other converter. 4. A step in which a converter installed at a connection part between an ATM-SVC network and an IP network receives an IP address inquiry from another network and returns an own IP address, and the converter inquires the address. Destination IP address in own network and source IP address in other network and own IP
Holding a correspondence with an address, the converter transposes the destination IP address in the own network to the destination IP address of the packet data originating from the other network which is received from the other network to the own IP address, and A step of transposing the own IP address to a source IP address in the other network of the packet data originating from the other network and sending out the source IP address in the own network, wherein the converter transmits the destination IP address in the own network from within the own network For the packet data originating from the own network, which has the IP address and the own IP address as the destination IP address,
The source IP address in the other network is replaced with the destination IP address, and the source I of the packet data originating in the own network is transferred.
A method for connecting between different networks, comprising the step of replacing the own IP address with the P address and sending it to another network. 5. A converter installed at a connection between an ATM-SVC network and an IP network, wherein the converter receives an IP address inquiry from another network and returns an own IP address, and the address. A function of retaining the correspondence between the destination IP address of the inquiry and the source IP address in the other network and the own IP address, and the destination for the packet data originating from the other network that is received from the other network to the own IP address A function of transferring the destination IP address in the own network to the IP address, and a function of transferring the own IP address to the source IP address in the other network of the packet data originating from the other network and sending the same to the own network; The destination IP address for the packet data originated from the own network whose destination IP address in the own network is the source IP address and whose own IP address is the destination IP address Different network, which has a function of transferring the source IP address in the other network to the network and transferring the source IP address of the packet data originating in the own network to the other network Inter-data communication system. 6. Means for receiving an IP address inquiry from another network and returning the own IP address, and correspondence between the destination IP address in the own network and the source IP address in the other network of the address inquiry and the own IP address. And a reassignment address retaining means that retains the reassignment address retaining means that retains the The internal destination IP address is replaced, and the own IP address is transferred to the other network source IP address of the other network originated packet data and sent to the own network, and the own network destination IP address from within the own network Is the source IP address and the own IP address is the destination IP address
The destination IP address is replaced with the source IP address in the different network held by the replacement address holding means, and the source IP address of the packet data originated in the own network is replaced with the own IP address. A converter comprising an IP address transfer means for sending to.