JP2003008611A - Data relay device and data relay method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the usability of the resources such as access routers, proxy servers and servers. SOLUTION: A data relay device comprises a cache 16 which temporarily stores TCP data transferred between different connections established on the LAN 10a and 10b in a TCP gateway, the cache control part 15 which accumulates required TCP data in the cache 16 after exchanging control information and TCP data be with the connection corresponding 14, the TCP connection terminating part 13a and 13b which independently terminate connections established on the LAN 10a and 10b of other connections' termination, and the connection corresponding part 14 which corresponds different connections and transfers the data stored in the cache 16 between different connections.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data relay device and a data relay method for transferring data between different connections in a computer network such as the Internet, LAN and WAN.

[0002]

2. Description of the Related Art There are various conventional data relay devices for transferring data between networks.
As one of them, for example, Nikkei Internet Technology March 1998 issue "Proxy server" (13
Some of them are disclosed in the publications on pages 0 to 137). FIG. 5 is a network configuration diagram of the data relay device disclosed in this publication. This conventional data relay device includes an Internet 501, a telephone network, an ISDN network,
An access network 502 including a CATV network and an ADSL network, a client terminal 503 such as a personal computer, a mobile information terminal, and a mobile phone that can access the Internet, and an access point 504 provided by an Internet service provider (ISP). ,
A server 505 that exists on the Internet and provides various data to the client terminal 503, a router 506 (or a firewall product) that exists in the access point 504, a proxy server 507, an access router 508, and an access point 504. Router 506 (or firewall product), a proxy server 507, and a LAN 510 (or switch) that connects between the access routers 508.

FIG. 6 is an explanatory diagram showing an operation sequence in each device by the conventional data relay device.
The client terminal 503 uses HTTP (Hyper T
Prior to a request such as ext Transfer Protocol (TCP), TCP (Transmission C)
TCP using the control protocol)
A connection is established (step 601 to step 604). These packets are transmitted to the proxy server 507 or the server 505 via the access router 508. In addition, here, 3-Handshake
Details of establishing a TCP connection are omitted. After the TCP connection is established, the client terminal 503 uses the TCP connection to execute HTTP.
The request is transmitted (step 605). The HTTP request is received by the proxy server 507 via the access router 508 (step 606). The proxy server 507 establishes a TCP connection with the server 505 and receives an HTTP request and a response as necessary. If the content of the HTTP request requested by the client terminal 503 exists in its own cache, the proxy server 507 reads the content and establishes the TC with the client terminal 503.
It is sent back to the P connection (steps 607 to 612). After processing all the requests from the client terminal 503 and sending all the contents to the client terminal 503, the proxy server 507 disconnects the TCP connection with the client terminal 503 (steps 613 to 616). In this example, the communication between the client terminal 503 and the proxy server 507 has been described as an example, but the client terminal 503
It is also possible to perform communication between the server and the server 505 in a similar sequence.

[0004]

However, in the conventional data relay apparatus, the server 505 or the proxy server 507 processes the request from the client terminal 503 and establishes the TCP connection until sending all the results. There is a need. Generally, the access line has a line speed of 28 Kbps to 1.5 Mbps, and in many cases, the effective throughput is lower than the line speed. A relatively high-speed LA for such a low-speed access line
When sending data from the proxy server 507 to the client terminal 503 via the N510, it is necessary to send a TCP packet from the proxy server 507 at a low throughput. Therefore, there is a problem that the resources of the proxy server 507 are bound for a long time, and as a result, the overall processing capability of the proxy server 507 decreases. The server 505 also has the same problem.

Further, in the access router 508, the data received from the relatively high speed LAN 510 is transferred to the LAN.
Since the data is transmitted to the access network 502 that is slower than the access network 502, data is accumulated inside the access router 508, and resources are tight. Therefore, there is a problem that processing performance is deteriorated due to resource shortage, TCP data is discarded, and other connections are adversely affected. Also, TCP
If the data is discarded, the TCP data needs to be retransmitted, which causes a problem that the transfer time becomes long.

The present invention has been made in view of the above,
An object of the present invention is to obtain a data relay device and a data relay method capable of improving the use efficiency of resources such as an access router, a proxy server, and a server. Another object of the present invention is to provide a data relay device and a data relay method that can perform data transmission at an appropriate throughput without adversely affecting other connections.

[0007]

In order to achieve the above object, a data relay device according to the present invention is a data relay device for transferring data between different connections established on a network. Storage means for temporarily storing the data to be stored, connection termination means for terminating the established connection independently of other connections, and correspondence between different connections, and storing them in the storage means. Connection correspondence means for transferring different data between different connections.

According to the present invention, the data transferred between the different connections is temporarily stored by the accumulating means, and the established connection is terminated independently of the other connections by the connection terminating means so that the connection can be handled. By differentiating different connections by means and transferring the data stored in the accumulating means by another connection, different connections can be handled independently while holding the data transferred on the network. Therefore, even if there is a large difference in the throughputs of different connections that are individually established in networks with different line speeds, the next data transfer by the other connection should be performed without waiting for the completion of the data transfer by one connection. You can As a result, congestion does not occur on the network, resource usage on the low-speed network side and high-speed network side is completely independent, resource usage time on the high-speed network side is short, and resource usage efficiency is improved. Can be made.

In the data relay apparatus according to the next invention, in the above invention, the connection termination means further determines the throughput of the connection.
It is characterized in that the connection handling means transfers the data stored in the storage means based on the determined throughput.

According to the present invention, the connection terminating means determines the connection throughput and the connection handling means transfers the data stored in the accumulating means based on the determined throughput. Appropriate data transfer is possible, and it is possible to prevent congestion in the network.

In the data relay device according to the next invention, in the above invention, the connection terminating means further determines the throughput of the connection based on the IP address of the terminal connected by the connection. The means transfers the data stored in the storage means based on the determined throughput.

According to the present invention, the connection terminating means determines the throughput of the connection based on the IP address of the terminal connected by the connection, and the connection handling means stores the connection throughput in the accumulating means based on the determined throughput. Because it transfers data
It becomes possible to transfer data more appropriately according to the throughput of the connection, and it is possible to prevent congestion in the network.

A data relay method according to the next invention is a data relay method for transferring data between different connections established on a network, wherein the data transferred between different connections is temporarily stored in a storage means. The accumulation step and the established connection
Make a connection termination step that terminates independently of other connections, and associate different connections,
A connection handling step of transferring the data stored in the storage means between different connections.

According to the present invention, the data transferred between the different connections in the storing step is temporarily stored in the storing means, and the connection established in the connection terminating step is terminated independently of other connections. , The data stored in the storage means is transferred to another connection after associating the different connections by the connection correspondence step, so that the different connections can be handled independently while holding the data transferred on the network. You can Therefore, even if there is a large difference in the throughput of different connections that are individually established in networks with different line speeds, the next data transfer by the other connection should be performed without waiting for the completion of the data transfer by one connection. You can As a result, congestion does not occur on the network, resource usage on the low-speed network side and high-speed network side is completely independent, resource usage time on the high-speed network side is short, and resource usage efficiency is improved. Can be made.

In the data relay method according to the next invention, in the above invention, the connection terminating step comprises:
Further, the connection throughput is determined, and the connection handling step transfers the data stored in the storage means based on the determined throughput.

According to the present invention, the connection throughput is determined by the connection termination step, and the data stored in the storage means is transferred based on the determined throughput by the connection handling step. Appropriate data transfer is possible, and it is possible to prevent congestion in the network.

In the data relay method according to the next invention, in the above invention, the connection terminating step comprises:
Furthermore, the throughput of the connection is determined based on the IP address of the terminal connected by the connection, and the connection corresponding step transfers the data stored in the storage means based on the determined throughput. It is characterized by being.

According to the present invention, the connection throughput is determined based on the IP address of the terminal connected by the connection in the connection termination step,
In the connection handling step, the data stored in the storage means is transferred based on the determined throughput, so that more appropriate data transfer depending on the throughput of the connection becomes possible and the congestion of the network can be prevented. .

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a data relay device and a data relay method according to the present invention will be described in detail below with reference to the accompanying drawings.

Embodiment 1. In the first embodiment, the data relay device of the present invention is applied to a TCP gateway which is an independent device. 1 is a block diagram showing a configuration of a TCP gateway which is Embodiment 1 of the present invention. As shown in FIG. 1, the TCP gateway 9 according to the first embodiment includes two line accommodating units 11a and 1a.
1b, two IP processing units 12a and 12b, and two T
The CP connection terminal units 13a and 13b, the connection corresponding unit 14, the cache 16, and the cache control unit 15 are mainly provided.

The line accommodation unit 11a accommodates the LAN 10a, and the line accommodation unit 11b accommodates the LAN 10b. Note that the LANs 10a and 10b may be other networks or lines directly connected by peer to peer. The IP processing unit 12a and the TCP connection termination unit 13a are connected to the line accommodation unit 11a.
Each processing described later is performed for the TCP connection established on the LAN 10a accommodated in the IP processing unit 12
b and the TCP connection termination unit 13b are TCP established on the LAN 10b accommodated in the line accommodation unit 11b.
Perform each process for the connection.

The IP processing units 12a and 12b are connected to each LAN 1
IP (Inter) for data in 0a and 10b
Net protocol), that is, data (packet) transmission / reception processing on the network. The TCP connection termination units 13a and 13b are
The processing of the TCP protocol and the termination of the connection in each of the LANs 10a and 10b are performed.
The TCP connection termination unit 13a terminates the connection of the LAN 10a independently of the LAN 10b, while the TCP connection termination unit 13b terminates the LAN 10b.
The termination of the connection is performed independently of the LAN 10a.

The connection handling unit 14 receives the control information and data from the TCP connection termination units 13a and 13b for each connection termination unit, and responds to the corresponding TCP.
It controls connections. Cache 1
Reference numeral 6 is for accumulating TCP data, and is specifically configured by a storage medium such as a RAM or a hard disk. The cache control unit 15 exchanges control information and data with the connection support unit 14, and stores necessary data in the cache 16. Also, the cache control unit 15
Reads data from the cache 16 as needed and sends it to the connection support unit 14. Here, the cache 16 and the cache control unit 15 constitute the storage means in the present invention. Further, the TCP connection terminating units 13a and 13b constitute the connection terminating means in the present invention, and the connection corresponding unit 14
Constitutes the connection handling means in the present invention.

FIG. 2 shows the T according to the first embodiment of the present invention.
3 is a block diagram showing an example of a configuration of a network using the CP gateway 9. FIG. As shown in FIG. 2, this network includes the Internet 201, a telephone network, and an IS.
An access network 202 including a DN network, a CATV network, an ADSL network, a personal computer (PC),
A personal digital assistant (PDA), a client terminal 203 such as a mobile phone capable of accessing the Internet, an access point 204 provided by an Internet service provider (ISP), etc., and various data existing on the Internet and provided to the client terminal 203. Server 205, which is included in the access point 204, and the TCP gateway 9 and router 206 (or firewall product) according to the first embodiment of the present invention in the access point 204.
, Proxy server 207, and access router 208
, A LAN 10a (or a switch) connecting the access router 208 and the TCP gateway 9, and a TC
P gateway 9, router 206, and proxy server 20
LAN 10b (or a switch) for connecting to the network 7 is included. Here, as described above, the LAN 10a
Is the line accommodation unit 11 of the TCP gateway in FIG.
a is connected to the LAN 10b and the TCP in FIG.
It is connected to the line accommodation unit 11b of the gateway.

In addition, in the network system according to the first embodiment, the client terminal side TCP connection 2 is provided between the client terminal 203 and the TCP gateway 9.
17 is established, and the server side TCP connection 218 is established between the TCP gateway 9 and the proxy server 207 (or the server 205 may be used).

Next, a data transfer process by the TCP gateway 9 of the first embodiment configured as described above will be described. FIG. 3 is an explanatory diagram showing a data transfer sequence when the TCP gateway 9 of the first embodiment is used.

The client terminal 203 uses HTTP (H
yper Text Transfer Protocol
ol) and other applications before requesting T
CP (Transmission Control P)
protocol) is used to establish a TCP connection. These packets are transmitted to the TCP gateway 9 via the access router 208 (steps 301 and 302). The TCP gateway 9 terminates the TCP connection here and returns a response (steps 303 and 304). At this point, the TCP connection 217 on the client terminal side is established. After that, TCP data (packet data) using the application request (for example, HTTP) from the client terminal 203 as data is received by the TCP gateway 9 through the client terminal side TCP connection 217 and the access router 208 ( Step 30
5, step 306).

The TCP gateway 9 stores the TCP data in the cache 16 via the cache control unit 15 and also addresses the destination included in the TCP data received in step 301 (for example, the proxy server 207).
A TCP connection is established in (step 307, step 308). At this point, the server side TCP connection 218 is established. After opening the TCP connection,
The CP gateway 9 reads the data stored in the cache 16 and sends the read data to the server-side TCP connection 218 in the format included in the TCP data section as application protocol data similar to the TCP data transmitted by the client terminal 203 ( Step 309). TCP gateway 9 that received the TCP data having the response as data in step 310
Stores the data content in the cache 16 and at the client terminal side T destined for the client terminal 203.
The data is transmitted as data on the CP connection 217 (step 311). In this way, the TCP gateway 9 is connected to the client terminal side TCP connection 217 between the client terminal 203 and the TCP gateway 9 and TC.
The server side TCP connection 218 between the P gateway 9 and the proxy server 207 is treated as an independent one,
The TCP data sent on the connection is temporarily stored in the cache 16, the response of receiving the data is returned to the source of the data, and then transmitted to the corresponding connection.

After that, for example, when the data transmission from the proxy server 207 ends and the server side TCP connection 218 between the TCP gateway 9 and the proxy server 207 becomes unnecessary, the server 205 generally sends this T connection.
Although the CP connection is disconnected, the TCP gateway 9 receives this and disconnects this connection (steps 316 and 317). TCP gateway 9
Even if the server-side TCP connection 218 between the proxy server 207 and the proxy server 207 is disconnected, if data destined for the client terminal 203 remains in the cache 16, the TCP gateway 9 reads the data and sends it to the client terminal 203 (step 318). , Step 31
9). When all the data destined for the client terminal 203 in the cache 16 has been transmitted and the receipt confirmation for the data has been received (step 320, step 32)
1), TCP gateway 9 is TCP on the client terminal side between TCP gateway 9 and client terminal 203
The connection 217 is disconnected.

Next, a detailed operation of data transfer inside the gateway 9 of the first embodiment will be described. Figure 4
FIG. 4 is an explanatory diagram showing a sequence of data transfer inside the TCP gateway 9 of the first embodiment.

When the TCP connection termination unit 13a receives the TCP SYN data from the client terminal 203 (step 401), if a new connection is accepted, the TCP SYN / A is applied to the corresponding connection.
CK data is returned (step 402). The client terminal 203 returns TCP ACK data to it (step 403). Thereby, the client terminal 20
3 and a TCP connection 217 on the client terminal side between the TCP connection terminating unit 13a and the TCP connection terminating unit 13a are established.

TCP connection 2 on the client terminal side
When 17 is established, the TCP connection termination unit 13a
Notifies the connection support unit 14 of the data to establish the connection (step 404). In response to this, the connection handling unit 14 creates control information that establishes the relationship between the corresponding connections, and issues a cache creation instruction to the cache control unit 15 (step 405). The cache control unit 15 receives it and prepares and opens a cache file in the cache 16 as preparation for cache creation. After the TCP connection 217 on the client terminal side is established, the client terminal 20
3 indicates the application data, which is HTTP data, as T
It is transmitted as CP data (step 406). TCP
The connection terminating unit 13a receives the TCP data and transmits the TCP data to the connection corresponding unit 14 (step 4).
07). The connection handling unit 14 instructs the cache control unit 15 to write the contents of the TCP data in the cache 16 (step 408), and the cache control unit 15 receives the TCP data in the cache file created. Write. Further, the TCP connection termination unit 13a returns a reception response (step 409) to the received TCP data to the client terminal 203.

The connection handling unit 14 then instructs the TCP connection termination unit 13b to generate a connection (step 410). TCP connection termination unit 13
b receives the instruction and sends TCP to the specified destination server.
The SYN data is transmitted (step 411). TCP
The connection termination unit 13b uses TCPSY from the server.
When N / ACK data is received (step 412), T
While returning the CP ACK data (step 41
3) The connection establishment unit 14 is notified of the establishment of the connection (step 414). Upon receiving the establishment of the server-side TCP connection 218, the connection handling unit 14 instructs the cache control unit 15 to read the data to be sent to that connection (step 415). In response to the instruction, the cache control unit 15 reads the contents of the cache file in the cache 16 and returns the contents to the connection correspondence unit 14 (step 416). The connection handling unit 14 instructs the TCP connection termination unit 13b to transmit the data read from the cache control unit 15 (step 417), and the TCP connection termination unit 13b.
Packetizes the data and sends it to the server side TCP connection 218 (step 418).

The TCP connection termination unit 13b receives the TCP data as the application data from the server side TCP connection 218 (step 41).
9), the received response of the received TCP data (TCP A
(CK data) is returned (step 421), and the data is notified to the connection interface 14 (step 420). The connection handling unit 14 writes the TCP data to the cache 16 by the cache control unit 15
(Step 422). When TCP data is continuously transmitted in a plurality of packets, the processing of the reception response, the notification to the connection corresponding unit 14 and the instruction to write the data to the cache 16 to the cache control unit 15 is repeated (step 427). -Step 430). The connection handling unit 14 instructs the cache control unit 15 to write, and then the TC on the client terminal side
The cache control unit 15 is instructed to read the data in order to transmit the data to the P connection 217 (step 423). Then, the connection support unit 14 receives the data read by the cache control unit 15 (step 424), and the TCP connection termination unit 13a.
(Step 425), the TCP connection terminating unit 13a transmits the data as TCP data to the client terminal side TCP connection 217 (step 426). The TCP connection termination unit 13a receives the TCP reception response (TCP ACK data) from the client terminal side TCP connection 217 (step 43).
1) The received TCP connection termination unit 13a requests new TCP data from the connection support unit 14 (step 432). In response to this, the connection handling unit 14 reads the data from the cache control unit 15 (steps 433 and 434) and instructs the TCP connection termination unit 13a to send the data (step 43).
5). The TCP connection termination unit 13a sends the data as TCP data to the client terminal side TCP connection 217 (step 436).

When data transmission from the server 205 is completed on the server side TCP connection 218, the server 205 transmits TCP FIN data (step 437). Upon receiving the data, the TCP connection terminating unit 13b sends back the TCP FIN / ACK data (step 438) and notifies the connection responding unit 14 of the disconnection of the connection (step 44).
0).

TCP connection 2 on the client terminal side
In 17, the processing of the same sequence (steps 441 to 449) as the above-described sequence is performed until the data stored in the cache 16 is completely sent. When the cache control unit 15 receives a data read request (step 449) and finishes sending all the cache data, it informs the connection responding unit 1 that there is no data.
4 is notified (step 450). Upon receiving the notification, the connection support unit 14 disconnects the client terminal side TCP connection 217 from the TCP connection termination unit 13.
a is instructed (step 451). T who received the instruction
When the CP connection termination unit 13a transmits TCP FIN data (step 452) and receives TCP FIN / ACK data (step 453), TCP
While sending ACK data (step 454),
The connection corresponding unit 14 is notified of the completion of the connection disconnection (step 455). Upon receiving the notification, the connection handling unit 14 instructs the cache control unit 15 to release the corresponding cache resource (step 456).

As described above, in the TCP gateway of the first embodiment, the two TCPs 217 on the client terminal side and the TCP connection 218 on the server side are treated independently by the TCP connection termination units 13a and 13b and the connection correspondence unit 14, and the connection is performed. Since the cache control unit 15 temporarily stores the intervening data in the cache 16 and returns the reception confirmation independently for each connection, the proxy server 207
(Or the server 205) has data as the client terminal 2
Data can be efficiently transferred without waiting for transmission of the next data until the reception response is received after reaching 03. Therefore, the resource use time on the LAN 10b side, which is a high-speed line, can be shortened, and the resource use efficiency can be improved.

Embodiment 2. The TCP gateway in the data relay apparatus according to the first embodiment operates without concern about the throughput of the TCP connection 217 on the client terminal side.
The P gateway notifies the negotiation result of the line speed between the access router 208 and the client terminal 203.

The configuration of the TCP gateway in the second embodiment and the network configuration using this TCP gateway are the same as the respective configurations of the first embodiment shown in FIGS. 1 and 2, and therefore description thereof will be omitted. The sequence of the data transfer process is also the same as the sequence of the data transfer process by the TCP gateway according to the first embodiment shown in FIGS. 3 and 4.

In the data relay device using the TCP gateway 9 of the second embodiment, step 401 shown in FIG.
Client terminal side TCP connection 217
TCP SYN data for establishing TCP
The line speed between the access router 208 and the client terminal 203 is stored in the option area of the header as the result of negotiation. As a result, the result of the negotiation of the line speed between the access router 208 and the client terminal 203 is transmitted to the TCP connection termination unit 1.
Notify 3a.

In the TCP connection termination unit 13a, the line speed as the result of the negotiation is read from the option area of the TCP data, and the client terminal side TCP connection 21 is read based on the read line speed.
7. Determine a throughput of 7. Then, the connection handling unit 14 sets the cache control unit 15 at an appropriate interval according to the throughput value so that congestion or the like does not occur.
The cache 16 is instructed to read the TCP data, and the read TCP data is transmitted to the client terminal 203 as TCP data.

As described above, in the TCP gateway according to the second embodiment, the connection terminating unit 13a determines the throughput of the client terminal side TCP connection 217, and the connection handling unit 14 performs TCP at appropriate intervals according to the throughput value. By transferring data, it is possible to prevent congestion in the network.

Embodiment 3. The TCP gateway of the second embodiment uses the option area of the TCP header to notify the line speed on the client terminal 203 side, but the TCP gateway of the third embodiment uses the access router instead of this option area. The access router 208 and the client terminal 203 are assigned an IP address assigned to the client terminal 203 by the client 208.
It detects the line speed between them.

The configuration of the TCP gateway in the third embodiment and the network configuration using this TCP gateway are the same as those of the first embodiment shown in FIGS. 1 and 2, and therefore their explanations are omitted. The sequence of the data transfer process is also the same as the sequence of the data transfer process by the TCP gateway according to the first embodiment shown in FIGS. 3 and 4.

In the data relay device according to the third embodiment, as shown in FIG.
At step 401 shown in FIG.
When the TCP gateway 9 receives the TCP SYN data for establishing the P connection 217, the TCP connection terminating unit 13a reads the source IP address of the IP header and obtains the IP address assigned to the client terminal 203 from the access router 208. get.

Then, the TCP connection termination unit 13a
Then, the line speed as a negotiation result between the access router 208 and the client terminal 203 is detected from the IP address assigned to the client terminal 203, and the throughput of the client terminal side TCP connection 217 is determined based on the detected line speed. .
Then, the connection handling unit 14 instructs the cache control unit 15 to read TCP data from the cache 16 at an appropriate interval so that congestion or the like does not occur depending on the value of the throughput, and the read TCP
The data is transmitted to the client terminal 203 as TCP data.

As described above, in the TCP gateway of the third embodiment, the connection termination unit 13a determines the throughput of the client terminal side TCP connection 217 from the IP address assigned to the client terminal 203, and the connection handling unit 14 determines this throughput. By transferring TCP data at appropriate intervals according to the value of, it is possible to prevent congestion in the network.

In the TCP gateways of the first to third embodiments, the part for terminating the TCP connection is logically divided into two parts, the client terminal side TCP connection terminating part 13a and the server side TCP connection terminating part 13b. However, in effect, one TCP connection termination unit is provided, and which connection is the value that identifies the connection (a provisional connection identifier, a combination of IP addresses / TCP port numbers for both sending and receiving, etc.) You may comprise so that it may judge.

Further, in the first to third embodiments, the data relay device of the present invention is realized by using an independent device called a TCP gateway. However, the access router 208 is used without using such an independent device. It can also be realized by adding functions similar to those of the TCP gateway of each embodiment to devices such as the proxy server 207 and the router 206.

[0050]

As described above, according to the present invention, since different connections can be treated independently, it is possible to prevent congestion on the network even when there is a large difference in throughput between different connections. There is an effect that it can be prevented. Further, according to the present invention, even when there is a large difference in throughput of different connections, the resource use time on the high-speed network side can be shortened, and the resource use efficiency can be improved. .

According to the next invention, it is possible to perform more appropriate data transfer according to the throughput of the connection and to prevent the occurrence of congestion in the network.

According to the next invention, it is possible to perform more appropriate data transfer according to the throughput of the connection based on the IP address of the terminal, and it is possible to prevent congestion in the network. .

According to the next invention, since different connections can be handled independently, it is possible to prevent congestion or the like from occurring on the network even when there is a large difference in throughput between different connections. Play. Further, according to the present invention, even when there is a large difference in throughput of different connections, the resource use time on the high-speed network side can be shortened, and the resource use efficiency can be improved. .

According to the next invention, it is possible to perform more appropriate data transfer according to the throughput of the connection and to prevent the occurrence of congestion in the network.

According to the next invention, it is possible to perform more appropriate data transfer according to the throughput of the connection based on the IP address of the terminal, and it is possible to prevent congestion in the network. .

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a TCP gateway according to first to third embodiments of the present invention.

2 is a network configuration diagram using the TCP gateway shown in FIG. 1. FIG.

FIG. 3 is an explanatory diagram showing a schematic sequence of data transfer by the TCP gateway shown in FIG. 1.

4 is an explanatory diagram showing a detailed sequence of data transfer by the TCP gateway shown in FIG. 1. FIG.

FIG. 5 is a network configuration diagram of a conventional data relay device.

FIG. 6 is an explanatory diagram showing a data transfer sequence of a conventional data relay device.

[Explanation of symbols]

3 client terminals, 8 access routers, 9 gateways, 10a, 10b LAN (network), 1
1a, 11b Line accommodation unit, 12a, 12b IP processing unit, 13a, 13b TCP connection termination unit, 14
TCP connection support unit, 15 cache control unit, 16 cache, 201 Internet, 20
2 access network, 203 client terminal, 204
Access point, 205 server, 206 router,
207 Proxy server, 208 Access router, 21
5 Cache control unit, 217 Client terminal side T
CP connection, 218 server side TCP connection, 501 Internet, 502 access network, 5
03 Client terminal, 504 access point,
505 server, 506 router, 507 proxy server, 508 access router, 509 LAN.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiichi Soda             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Ichihashi Tachiki             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. (72) Inventor Kazuyuki Kashima             2-3 2-3 Marunouchi, Chiyoda-ku, Tokyo             Inside Ryo Electric Co., Ltd. F-term (reference) 5K033 AA01 DA05 DB13 DB19                 5K034 AA02 BB06 HH21

Claims (6)

[Claims] 1. In a data relay device for transferring data between different connections established on a network, a storage means for temporarily storing data transferred between different connections and an established connection are provided. It is provided with a connection terminating unit that terminates independently of other connections, and a connection handling unit that associates different connections and transfers the data stored in the storage unit between the different connections. Data relay device. 2. The connection terminating means further determines the throughput of the connection, and the connection handling means transfers the data stored in the storage means based on the determined throughput. The data relay device according to claim 1, wherein: 3. The connection terminating means further determines the throughput of the connection based on the IP address of the terminal connected by the connection, and the connection handling means based on the determined throughput. The data relay device according to claim 1, wherein the data relay device transfers data stored in the means. 4. A data relay method for transferring data between different connections established on a network, the storing step of temporarily storing data transferred between different connections in a storing means. A connection termination step for terminating the established connection independently of other connections, and a connection handling step for associating different connections and transferring the data stored in the storage means between the different connections. A data relay method comprising: 5. The connection terminating step further determines the throughput of the connection, and the connection corresponding step transfers the data stored in the accumulating means based on the determined throughput. The data relay method according to claim 4, wherein 6. The connection terminating step further determines the throughput of the connection based on the IP address of a terminal connected by the connection, and the connection corresponding step comprises the accumulation based on the determined throughput. The data relay method according to claim 4, wherein the data stored in the means is transferred.