JP2003289326A - Data transmission apparatus, transmission method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To release, when switching a data communication line, an IP address by disconnecting the data communication line before switching and to perform smooth line switching without changing a display status. <P>SOLUTION: An information processing terminal 1 is made connectable to an Internet service provider via a plurality of data communication lines such as an ISDN line 4 and a PHS(R) radio communication line 6. When a data transmission rate DV decreases in accessing the communication destination server of the Internet by selecting one of the data communication lines and this transmission rate decrease is caused by an increase in the traffic volume of the data communication line, the communication destination server is accessed by using another data communication line. When a data transmission rate DV" thereon exceeds the data transmission rate DV, a new data communication line is used. After the amount of download becomes equivalent or superior to the present amount of download, the communication line is switched. Then, the IP address is released by disconnecting the former data communication line. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention enables data communication with a desired communication destination server by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. The present invention relates to a data transmission device, a transmission method and a program.

[0002]

2. Description of the Related Art As this type of data transmission device, for example, one described in Japanese Patent Laid-Open No. 2002-44179 is known. In this conventional example, when the transmission path state detecting means detects an abnormality on a predetermined transmission path, the transmission path is switched to another data transmission means different from the data transmission means for the transmission path in which the abnormality is detected. There is a description of a data transmission device that transmits data to a transmission line according to the priority order, and when the above abnormality is detected and the transmission line recovers, the data transmission line is changed again. ing.

[0003]

However, in the above-mentioned conventional example, when an abnormality is detected in the data transmission means in use, the data transmission means is switched to another data transmission means, so that the data transmission can be automatically switched. However, since the original transmission line is restored when the abnormal state of the transmission line is recovered, the abnormal line is maintained in the connected state, and this data transmission means uses a dynamic IP address. When the IP address is assigned, the IP address assignment state continues, and there is an unsolved problem that the limited IP address cannot be effectively used.

Further, when the abnormality of the transmission line occurs, the data transmission means is switched immediately, which is good in the case where the state of the other party does not change as in the video conference.
Web on desired communication destination server with Internet connection
There is also an unsolved problem that a continuous display cannot be obtained by simply switching the transmission line when accessing a page.

Therefore, the present invention has been made by paying attention to the unsolved problem of the above conventional example, and when the data communication line is switched, the data communication line before the switching is disconnected to release the IP address. Data transmission device, which can
It is intended to provide a transmission method and a program. Further, the present invention provides a data transmission device capable of performing smooth line switching without changing the display state of a Web page or the like when switching the data communication line,
Another object is to provide a transmission method and a program.

[0006]

In order to achieve the above object, a data transmission device according to a first aspect of the present invention is a data transmission device, wherein a data communication line selected from a plurality of data communication lines by a communication application dynamically assigns an IP address. A data transmission device configured to perform data communication with a desired communication destination server by receiving the data transmission speed detection means for detecting the data transmission speed of the selected data communication line, and the data transmission speed detection means. When the detected data transmission rate falls below a set value, a data transmission rate lowering point determining means for determining whether the data transmission rate is due to the traffic volume of the data communication line or the load of the communication destination server,
When the judgment result by the data transmission speed lowering point judging means is due to the traffic volume of the data communication line,
It is characterized in that it is provided with a line switching means for switching to another data communication line and disconnecting the current data communication line to release the IP address.

A data transmission device according to claim 2 is
In the invention according to claim 1, the data transmission rate lowering point determining means switches the communication destination server and detects a change in the data transmission rate to determine whether or not the data transmission rate is reduced due to the load of the communication destination server. It is characterized in that it is configured to judge. Further, claim 3
The data transmission apparatus according to claim 1 is the invention according to claim 1 or 2, wherein the line switching unit is configured to select a data communication line having a maximum data transmission speed among a plurality of data communication lines. It has a feature.

Furthermore, in the data transmission device according to claim 4, in the invention according to any one of claims 1 to 3, the line switching means uses the data communication line when switching the data communication line. The line switching is performed when the communication destination server is accessed and the download amount of the Web page becomes equal to or more than the download amount of the data communication line before switching.

Still further, in the data transmission method according to the fifth aspect, a desired communication destination server and data are received by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. A data transmission method for communication, comprising the step of detecting the data transmission rate of the selected data communication line, and the traffic volume of the data communication line when the detected data transmission rate drops below a set value. And the load on the communication destination server determines the cause of the decrease in transmission rate, and when the result of the determination in the step of determining the reduced transmission rate is due to the traffic volume of the data communication line, Time to switch to the data communication line and disconnect the current data communication line to release the IP address It is characterized by comprising switch between steps.

A data transmission method according to claim 6 is
In the invention according to claim 5, in the line switching step, when the data communication line is switched, the data communication line is used to access the destination server, and the download amount of the Web page is the data communication line before switching. The feature is that the line is switched when the download amount exceeds the limit.

Further, the program according to claim 7 is adapted to perform data communication with a desired communication destination server by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. And a step of detecting the data transmission speed of the selected data communication line, the traffic of the data communication line being detected when the detected data transmission speed falls below a set value. The cause of the decrease in transmission rate for determining whether the transmission rate is due to the load or the load of the communication destination server, and when the determination result in the determination step of the transmission rate decrease point is due to the traffic volume of the data communication line, Switch to the other data communication line and disconnect the current data communication line to the IP address It is characterized by executing released to the line switching step to the computer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes an information processing terminal including a computer such as a personal computer, and a keyboard 1a, a mouse 1b and a display 1c.
And is connected to the Internet service provider 2 via a plurality of data communication lines.

As data communication lines, there are a general public telephone line 3, an ISDN line 4, an ADSL line 5 and a PHS public wireless line 6. The general public telephone line 3 is a modem 3a
To the modem 2a of the Internet service provider 2 through the telephone exchange 3c of the general public telephone line 3b. The ISDN line 4 is connected to the router 2b of the Internet service provider 2 from the terminal adapter 4a via the ISDN exchange 4b.

The ADSL line 5 is branched from the ADSL modem 5a through the splitter 5c with the telephone 5b to the telephone exchange 5e at the telephone splitter 5d, and is connected to the Internet service provider 2 at the dedicated line 5g through the ADSL in-house device 5f. . The PHS public wireless line 6 wirelessly connects to the wireless base station 6b from the PHS modem card 6a attached to the information processing terminal 1, and from this wireless base station 6b to another Internet service provider 7 via a dedicated line.
Connect to.

The Internet service provider 2 has a mail server 2c, a WWW (World Wide Web) server 2d and a DNS server 2e, and is connected to the backbone network 8 of the Internet via a dedicated line 2f. Another Internet service provider 7 is also connected to 8.

When the Internet connection is selected, the information processing terminal 1 executes the communication control process shown in FIG. 2 as a timer interrupt process at predetermined time intervals. In this communication control process, first, in step S1, it is determined whether or not a desired WWW server SV connected to the Internet is being accessed, and when the access is not being made, the timer interrupt process is ended as it is, If the WWW server SV is being accessed, move to step S2,
By measuring the amount of received data within a predetermined time, the actual data transmission rate DV of the data communication line currently in use
Is detected, and then the process proceeds to step S3, in which the detected data transmission rate DV is equal to or lower than the data transmission rate threshold DV _TH set lower than the average data transmission rate of the data communication line currently in use at the normal time. Whether or not DV>
When it is DV _TH , it is judged that the data transmission rate of the data communication line currently in use is normal, and the timer interrupt processing is ended as it is.

The determination result of step S3 is DV ≦
If it is DV _TH, it is determined that the data transmission rate of the data communication line currently in use is decreasing, and the process proceeds to step S4. In this step S4, it is determined whether the cause of the decrease in the data transmission rate is due to the increase in the communication traffic amount between the information processing terminal 1 and the exchange or the increase in the load of the communication destination server currently accessed. judge. This determination is made by accessing the other predetermined destination server different from the desired WWW server SV by using the current data communication line, and thereby determining the data transmission rate D.
When V'is detected and the data transmission rate DV 'at this time exceeds the data transmission rate threshold DV _TH , the data communication line between the information processing terminal 1 and the exchange is normal, and the load on the destination server has increased. It is judged that the data transmission speed is lowered due to the above, and the timer interrupt processing is terminated as it is. When DV'≤DV _TH, it is judged that the communication line between the information processing terminal 1 and the exchange has become abnormal. Control goes to step S5.

In step S5, it is determined whether or not there is an unused data communication line other than the currently used data communication line. If there is no unused data communication line, the timer interrupt process is performed as it is. Exit
If there is an unused data communication line, the process proceeds to step S6. In this step S6, the data communication line with the highest data transmission speed is selected from the remaining data communication lines, a new connection is made using the selected data communication line, and the desired WWW server SV is accessed. The data transmission rate DV ″ is measured based on the amount of data received within the time, and then the process proceeds to step S7 to check whether the measured data transmission rate DV ″ is larger than the data transmission rate DV calculated in step S2. Judge, D
When V ″ ≦ DV, it is determined that the new data communication line has a slower data communication speed, and the step S5 is performed.
When DV ″> DV, it is determined that the new data communication line has a higher data communication speed, and the process proceeds to step S8.

In this step S8, the size of the downloaded data continues to be accessed to the desired WWW server SV by the new connection, and the size of the downloaded data when the desired Web page by the current connection is being downloaded. It is determined whether or not the above, and the download amount by the new connection is the desired We by the current connection.
If the size of the downloaded data on page b is less than the size of the data downloaded by the new connection, wait until the size of the data downloaded by the new connection is equal to or larger than the size of the data downloaded by the current connection, and the data size downloaded by the new connection is the data downloaded by the current connection. When the size is equal to or larger than the size, the process proceeds to step S9.

In this step S9, the data downloaded halfway through the current connection is discarded, and the display data is switched to the display data by accessing the WWW server SV on the new data communication line, and then the step S9.
In step 10, the old data communication line with a low data transmission speed is disconnected, the assigned IP address is released, and then the timer interrupt process is terminated.

Next, the operation of the above embodiment will be described.
Now, in the information processing terminal 1, for example, I
It is assumed that the SDN line 4 is selected and the desired WWW server SV connected to the Internet service 8 is accessed to access the desired Web page. In this state, the information processing terminal 1 is executing the communication control process of FIG. 2, the current data transmission rate DV is measured through the ISDN line 4, and the data transmission rate D
V is a preset ISDN data transmission rate threshold DV
If it exceeds _TH , it is judged as a normal transmission state and the timer interrupt processing is terminated, so that the current ISD
Continue accessing the web page via the N line 4.

However, the ISD measured in step S2
The data transmission rate DV of the N line 4 is the data transmission rate threshold D
When it becomes V _TH or less, it is determined that the data transmission state is abnormal, and it is determined whether the cause of the decrease in the data transmission rate DV is on the data communication line side or the increase in the load on the WWW server SV being accessed. To do. In this case, the determination is made by using the ISDN line 4 in a state where the display data on the current display is fixed and a predetermined W
Access to WW server and data transmission speed D
V ′ is calculated, and it is determined whether or not this is less than or equal to the data transmission rate threshold DV _TH . If DV ′> DV _TH , IS
The ISDN line 4 is judged to be in an overload state due to an increase in the number of accesses of the WWW server SV that is accessing instead of a decrease in the data transmission rate DV on the DN line 4, and the ISDN line 4 is terminated as it is. W through
The access state of the WW server SV is continued.

On the other hand, the data transmission rate DV 'when accessing a predetermined WWW server is the data transmission rate threshold DV.
When it is less than _TH , it is determined that the data transmission rate is decreased due to the increase in the traffic amount of the ISDN line 4, and the alternative data communication line is searched. That is, for example, the WW that is currently accessed by the ISDN line 4 by selecting the ADSL line 5 having the highest data communication speed and making a new connection.
The W server SV is accessed, the data transmission rate DV ″ on the ADSL line 5 is measured, and if the measured data transmission rate DV ″ exceeds the data transmission rate DV measured on the ISDN line 4, a new connection is made. When the size of the downloaded data exceeds the size of the downloaded data of the desired Web page by the current connection, after switching to the display state by the ADSL line 5, I
The SDN 4 is disconnected to release the IP address.

In addition, the WWW server SV on the ADSL line 5
Of data transmission rate DV ″ when ISDN is accessed is ISDN
If the data transmission rate DV measured on the line 4 is less than or equal to the data transmission rate DV, the process returns to step S5, and one of the remaining unconnected data communication lines is selected again to set the data transmission rate DV ″ on the selected data communication line. It is measured, and when this exceeds the data transmission rate DV measured by the ISDN line 4, when the size of the data downloaded by the new connection becomes equal to or larger than the size of the data downloaded by the desired Web page by the current connection. , The ISDN line 4 is disconnected and the IP address is released after switching to the display state of the information transferred by the newly connected data communication line. Further, when DV ″ ≦ DV, the remaining unselected data communication line is again selected. Repeatedly selecting one from the above, and measured the data transmission rate DV ″ on all the data communication lines. By the time line 4 is less than the data transmission rate DV measured is the end of the timer interrupt processing from step S5 to when data communication line unconnected runs out. As a result, WWW server SV of an ISDN line 4
The access status to is continued.

As described above, according to the above-described embodiment, the data transmission rate DV of the current data communication line is the data transmission rate DV in the state where one of the plurality of data communication lines is selected to access the Internet. When the threshold value becomes equal to or lower than DV _TH , it is determined whether the cause of the data transmission rate decrease is the increase in the traffic amount of the data communication line or the decrease in the processing capacity due to the increase in the number of accesses of the WWW server SV that has accessed. , The data transmission rate DV ″ is measured by another data communication line when the traffic amount of the data communication line is increased, and the measured data transmission rate DV ″ indicates the data transmission rate DV of the current data communication line. When it exceeds the limit, the data communication line is switched, but at this time, the desired Web page is downloaded on the newly connected data communication line. The line is switched when the size of the data becomes equal to or larger than the size of the downloaded data of the desired Web page on the currently connected data communication line, so that the user of the information processing terminal 1 does not notice the switching and is smooth. The line can be switched, and it is possible to reliably avoid giving the user of the information processing terminal 1 a feeling of strangeness.

In the above embodiment, whether the cause of the data communication line speed decrease is due to an overload condition due to an increase in the number of accesses to the WWW server SV being accessed or an increase in the traffic amount of the data communication line. The case has been described where the present data communication line is used to access another WWW server to measure the data transmission rate DV 'at that time, but the present invention is not limited to this. Command to check the reachability of the packet to the specified WWW server, not the one ping (Packet Internet G
Using the roper function, the WW of the communication destination following the ping
By specifying the IP address of the W server, ICMP E
The data transmission rate DV ′ may be measured based on the time from when the cho Request is sent to the communication destination WWW server until the response ICMP Echo Reply from the communication destination WWW server is received.

In the above embodiment, when switching from the currently connected data communication line to the newly connected data communication line, the size of the data downloaded by the new connection is the size of the data downloaded by the current connection. Although the case has been described where line switching is performed at the above stage, the present invention is not limited to this, and line switching may be performed at the time when downloading on a newly connected data communication line is completed. When setting up a new connection or downloading a desired Web page by a new connection, if the download of the desired Web page by the current connection is completed first, when the download by the current connection is completed,
The line may be switched to the new connection and the data downloaded by the new connection may be discarded. Further, in the above-described embodiment, as the data communication line connected to the information processing terminal 1, a general public telephone line, an IS
Although the case where the DN, ADSL, and PHS wireless communication lines are applied has been described, the present invention is not limited to this, and mobile phones, CATV, and optical fiber communication lines can also be applied, and information processing terminals of each data communication line can be used. It suffices if at least two of them are connected.

Furthermore, in the above-described embodiment, when selecting a data communication line other than the current data communication line, the case where the data communication line with the highest data communication speed is selected in order has been described, but the present invention is not limited to this. Instead, the connection fee can be selected in ascending order, a preset order can be selected, or an arbitrary selection can be made.

Furthermore, in the above embodiment, the case where the information processing terminal 1 is directly connected to the Internet service provider 2 or 7 through the data communication line has been described, but the present invention is not limited to this.
The present invention can also be applied to the case of connecting to the Internet service provider 2 or 7 using a plurality of data communication lines via a LAN.

[0030]

As described above, according to the invention according to claim 1, 5 or 7, the step of detecting the data transmission rate of the selected data communication line, and the detected data transmission rate is below the set value. When it decreases, it is judged whether it is due to the traffic amount of the data communication line or the load of the communication destination server, and when this judgment result is due to the traffic amount of the data communication line, another data communication line The IP address was released because the current data communication line was disconnected and the IP address was released.
It is possible to reliably prevent the address from being left as it is and to effectively use the limited IP address.

According to the second aspect of the invention, the data transmission rate lowering point judging means switches the communication destination server and detects the change in the data transmission rate, so that the data transmission rate is lowered due to the load on the communication destination server. Therefore, it is possible to accurately detect whether or not the transmission rate is decreased due to the increase in the traffic amount of the data communication line.

Further, according to the invention of claim 3, the line switching means is configured to select the data communication line having the maximum data transmission speed among the plurality of data communication lines. This has the effect of shortening the search time for searching for a high data communication line. Further, according to the invention of claim 4 or 6,
At the time of line switching, a new data communication line is used to access the destination server, and the line is downloaded when the desired Web page download amount exceeds the desired Web page download amount on the data communication line before switching. Since the switching is performed, the smooth switching can be performed without changing the display state, and it is possible to reliably prevent the user from feeling uncomfortable.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart illustrating an example of a communication control processing procedure executed by the information processing device.

[Explanation of symbols]

1 Information processing terminal 2,7 Internet Service Provider 3 general public telephone lines 4 ISDN line 5 ADSL line 6 PHS wireless communication line SV WWW server

Claims (7)

[Claims] 1. A data transmission device configured to perform data communication with a desired communication destination server by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. A data transmission rate detecting means for detecting a data transmission rate of the selected data communication line, and a traffic volume of the data communication line when the data transmission rate detected by the data transmission rate detecting means falls below a set value. Data transmission rate lowering point determining means for determining whether the data transmission rate lowering point is due to the load of the communication destination server, and when the determination result by the data transmission rate lowering point determining means is due to the traffic volume of the data communication line, Time to switch to another data communication line and disconnect the current data communication line to release the IP address Data transmission apparatus characterized by comprising switching and means. 2. The data transmission rate lowering point determining means determines whether or not the data transmission rate is reduced due to the load of the communication destination server by switching the communication destination server and detecting a change in the data transmission rate. The data transmission device according to claim 1, wherein the data transmission device is configured as follows. 3. The line switching means is configured to select a data communication line having a maximum data transmission speed among a plurality of data communication lines.
Alternatively, the data transmission device according to item 2. 4. The line switching means, when switching the data communication line, accesses the destination server using the data communication line, and downloads the Web page on the data communication line before the switching. 4. The data transmission device according to claim 1, wherein line switching is performed when the amount of data exceeds a certain amount. 5. A data transmission method for performing data communication with a desired destination server by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. A step of detecting the data transmission rate of the selected data communication line, and depending on the traffic volume of the data communication line or the load of the communication destination server when the detected data transmission rate falls below a set value. If the determination result in the transmission rate decrease cause determining step and the determination result in the transmission rate decrease location determining step are due to the traffic volume of the data communication line, the other data communication line is switched to and the current data communication is performed. A line switching step of disconnecting the line and releasing the IP address. Data transmission method. 6. In the line switching step, when a data communication line to be switched is selected, the data communication line is used to access the communication destination server, and the data communication amount before the switching is the amount of Web page download. 6. The data transmission method according to claim 5, wherein the line switching is performed when the download amount of the line or more is exceeded. 7. A data transmission apparatus adapted to perform data communication with a desired communication destination server by dynamically assigning an IP address to a data communication line selected from a plurality of data communication lines by a communication application. A program for detecting the data transmission rate of the selected data communication line, and if the detected data transmission rate falls below a set value, whether it is due to the traffic volume of the data communication line or the destination server When the determination result in the transmission rate lowering cause determining step for determining whether or not the load is caused by the load and the determination result in the transmission rate lowering point determining step is due to the traffic volume of the data communication line, while switching to another data communication line, Connect the current data communication line and the line switching step to release the IP address. A program characterized by causing performed Yuta.