JP2836620B1 - Satellite communication system, route control method in the satellite communication system, and recording medium storing route control program - Google Patents

Abstract

The present invention provides a satellite communication system capable of resolving inconvenience caused by mismatch of control subjects, a route control method in the satellite communication system, and a recording medium storing the route control program. SOLUTION: When a client computer requests use of a logical communication path, a logical communication path from a server computer to the client computer is selected, and the selected logical communication path is connected to the server computer and the client computer. For this purpose, a route setting procedure is performed for the communication relay system, and when the use termination of the logical communication path is notified from the client computer, the path control of the logical communication path used by the client computer is released.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a satellite communication system for performing route control for distributing information from a computer to another computer when a communication relay system using a communication satellite is used. The present invention relates to a path control method and a computer-readable recording medium storing the path control program.

[0002]

2. Description of the Related Art In a communication relay system using a communication satellite, the same satellite is transmitted to a plurality of communication stations by using a multiplexing technique such as a frequency division multiplexing method, a time division multiplexing method or a cell multiplexing method. In many cases, they can be used simultaneously in relaying.

[0003] In such a use form, the same function as when a communication line exists for each communication relay is obtained. However, since the communication line does not physically exist, the communication path provided by the communication relay system for each communication relay is referred to as a logical communication path (Logical Ch).
channel) or a virtual communication path (Virtual Ch).
ann).

One of the features of a communication relay system using a communication satellite is that communication between an arbitrary computer having a function of transmitting information via a satellite and an arbitrary computer having a function of receiving information via a satellite. There are possible points. In order to realize such communication, which of the finite number of logical communication paths provided by the communication satellite by the multiplexing technique should be used with respect to the topology determined by the combination of the transmitting computer and the receiving computer. A path control method for controlling is required.

As a conventional route control method in satellite communication, there is a fixed route control method in which a logical communication path to be used is previously allocated to a transmitting computer or a receiving computer using a logical communication path.

As one method belonging to the fixed route control method, there is a known method described in Japanese Patent Application Laid-Open No. 9-64937. In this method, when a receiving computer requests a transmitting computer to transmit information, a transmitting request is made by designating a satellite line address, and the transmitting computer uses the address to transmit to the satellite line. This implements path control. Although there is no explicit description in this publication regarding the assignment of a logical communication path in a satellite line, the transmitting computer and the receiving computer are separated based on the satellite line address specified by the receiving computer. Since it is possible to use the same logical channel, it is clear that the address for the satellite link is used to identify this logical channel. Furthermore, in order to prevent contention regarding the use of the same logical communication path as that of the other receiving computers that may exist, the logical communication paths must be exclusive to each receiving computer in advance. It is obvious that it is necessary to assign to Therefore,
The known method described in this publication is a fixed route control method in which a logical communication path is fixedly assigned to a receiving computer.

However, since the number of logical communication paths that can be provided by the communication relay system by the multiplexing technique is finite, when such a fixed path control method is adopted, a combination of the transmitting computer and the receiving computer is used. Is limited by the number of logical communication paths.

Therefore, in order to cope with an increase in the number of transmission side or reception side computers that are going to receive the service of the communication system, it is necessary to use the same logical communication path in a time series for different connection forms. It is said.

[0009] As a route control method using the same logical communication path in a time series for different connection forms, an information transmitting computer (source user) manages the logical communication path in a communication relay system. A dynamic path control method is known in which a computer (network control center) is requested to assign a logical communication path, and a connection is made to a computer (transmission destination user) on the information receiving side via the network control center. JP-A-7-226705). FIG. 11 is a diagram illustrating a known method described in this publication.

[0010] Also, the information receiving computer requests the connection management computer, which manages the logical communication path in the communication relay system, to allocate the logical communication path, and the connection management computer is the information transmission source. A dynamic route control method for controlling a route from a service provider to a receiving computer by notifying a service provider and finally requesting the connection management computer from the service provider is known (Table of International Patent Publication) Hei 9-50518
No. 6). FIG. 12 is a diagram illustrating a known method described in this publication.

[0011]

Generally, in an information communication mode called a client-server model, when a client computer which is a receiving side of information requests distribution of information, a server computer which is a transmitting side of information is sent to the server computer. It is configured to transmit information.
In such a client-server model constructed using a communication relay system using a communication satellite, the same client computer is
When receiving multiple pieces of information in succession, without performing the logical channel assignment procedure every time information is distributed,
It is desirable to continue using the same logical communication path.

However, if a client-server model is constructed based on the above-described conventional dynamic path control method, the method based on Japanese Patent Application Laid-Open No. Hei 7-226705 makes it difficult to control the presence or absence of the second or subsequent distribution. Although the client computer on the receiving side controls the assignment of the logical communication path by the connection management computer, it is the server computer on the transmitting side. Therefore, this server computer controls the release of the assignment of the logical communication path. In the process of performing, there is a possibility that some trouble occurs.

For example, in the method of controlling assignment release, when the same distribution is requested from the same client computer to the server computer within a certain period of time, the same logical communication path is continuously used, and It is conceivable to adopt an algorithm that releases the assignment of the logical communication channel if there is no next request in time. However, according to such an algorithm, it is necessary to introduce a timer mechanism, and furthermore, the logical communication There is a problem that the utilization rate of the logical communication path is reduced because the reuse of the logical communication path is disabled for a certain period of time even after the use of the path is completed.

This problem can be solved by the method based on Japanese Patent Application Publication No. 9-505186 by allocating / releasing a logical communication path by the network control center based on a request from a client computer.

However, there is also a use form in which a client computer continuously receives information from a plurality of server computers, such as a use method called net surfing, which is one of use methods of the Internet. In such a usage form, in order for the client computer to continuously use the same logical communication path,
The method based on Japanese Patent Publication No. 9-505186 is not sufficient. The reason is that the actual assignment / release of the logical communication path by the network control center is controlled by the server computer based on the request of the client computer. This is because a logical communication channel cannot be used. Therefore, when information is received from a different server computer in a method of using such as Internet surfing, a method for switching a logical communication path to be used is required in the method based on Japanese Patent Publication No. 9-505186. There is a problem that the start of the next transfer is delayed by the implementation of the above, or the load increases due to the procedure itself. FIG. 13 is a diagram showing, in chronological order, a state of communication when a client computer continuously receives information from two server computers based on this known method.

Accordingly, it is an object of the present invention to provide a configuration in which a client computer for controlling the presence / absence of distribution controls a route control, and a server computer on the transmitting side does not participate in the route control. A satellite communication system capable of eliminating the inconvenience caused by separating the function of controlling distribution and the function of controlling assignment of logical channels as described above, a route control method in the satellite communication system, and the route control thereof An object of the present invention is to provide a recording medium storing a program.

[0017]

According to the present invention, at least one client computer for requesting distribution of information, at least one server computer for distributing information in response to the request, and a client computer and a server computer. A communication relay system using a communication satellite for providing a plurality of logical communication paths in communication, and a management computer for managing the plurality of logical communication paths, wherein the management computer performs logical communication from a client computer. A path setting procedure for the communication relay system to select a logical communication path to be used by the client computer when the use of the path is requested, and to connect the selected logical communication path to the server computer and the client computer; Client computer Satellite communication system configured to release the routing of logical communication path from a server computer to a client computer is provided when there is a use end notification logical communication path from the data.

According to the present invention, there are further provided a plurality of logical communication paths in communication between at least one client computer requesting information distribution and at least one server computer receiving the request and distributing information. A route control method in a satellite communication system including a communication relay system using a communication satellite and a management computer that manages a plurality of logical communication paths, wherein a client computer sends a request for information distribution to a server computer Requesting the management computer to use a logical communication path, the management computer selects a logical communication path used by the client computer to receive information distribution, and sets the selected logical communication path to the server computer and the client. Communication relay to connect to computer The stem for performs a route setting procedure,
When the information distribution from the server computer is completed, the client computer notifies the management computer of the end of the use of the logical communication path. Is provided, and a route control method in satellite communication for canceling the route setting for making the logical communication path available for another connection mode is provided.

According to the present invention, a plurality of logical communication paths are provided in communication between at least one client computer requesting information distribution and at least one server computer receiving the request and distributing information. A computer-readable recording medium storing a route control program in a satellite communication system including a communication relay system using a communication satellite, wherein the client computer is provided when a client computer requests use of a logical communication path. Selects a logical communication path to be used by the communication relay system, performs a path setting procedure for the communication relay system to connect the selected logical communication path to the server computer and the client computer, and terminates the use of the logical communication path by the client computer. If notified, Recording medium storing a routing control program for releasing the routing of logical communication path from server computer to the client computer is provided.

As described above, in the conventional dynamic route control method, the route control for the communication relay system is led by the transmission side computer in the usage form of the communication relay system, whereas the dynamic control according to the present invention is performed. In the route control method, a route control for the communication relay system is mainly performed by a client computer which is a receiving computer in a usage form of the communication relay system. For this reason, the inconvenience caused by the inconsistency of the control subjects can be eliminated.

Preferably, a two-way communication means is provided between the management computer and the client computer, and a request to use the logical communication path from the client computer and an end of the use of the logical communication path from the client computer. Is configured to be performed via the two-way communication means.

A request for use of the logical communication path from the client computer and a notification of the end of use of the logical communication path from the client computer are transmitted via the bidirectional communication means provided between the management computer and the client computer. It is preferably performed.

Further, preferably, when the path setting procedure is performed, the management computer transmits information necessary for using the selected logical communication path to the client computer via the bidirectional communication means. It is configured to notify.

After the route setting procedure is performed by the management computer in response to the above-mentioned request for using the logical communication path from the client computer, until the above-mentioned notification of the end of using the logical communication path is made. It is also preferable that the distribution of information from any server computer to the client computer is performed via a logical communication path. That is, since the logical communication path is allocated to the client computer, the distribution of information from the server computer to the client computer is performed via the logical communication path.

The communication relay system includes a proxy server, and the proxy server mediates the transfer of information between each client computer and each server computer, thereby transferring information from the server computer to the client computer. Is preferably configured to pass through a communication relay system.

After the route setting procedure is performed by the management computer in response to the above-mentioned request for using the logical communication path from the client computer, until the above-mentioned notification of the end of using the logical communication path is made. The client computer can be configured to continuously receive information from one or more server computers via the logical communication path without making a request for using the logical communication path again. It is also preferred that it is done.

[0027]

FIG. 1 is a block diagram schematically showing a configuration and a connection form of a satellite communication system according to an embodiment of the present invention.

In FIG. 1, reference numeral 10 denotes a group of client computers comprising a plurality of client computers requesting information distribution, 11 denotes a group of server computers comprising a plurality of server computers which receive the request and distributes information, and 12 denotes a group of client computers. and any client computer 10 _x belonging to 10 (subscript x identifies the particular client computer), any of the server computer 11 belonging to the server computer group 11
_y (subscript y identifies a particular server computer) are available in communication with a, in particular, in the communication directed from the server computer 11 _y to the client computer 10 _x, a plurality of logical communication channel by the multiplexing technique A communication relay system using a communication satellite 14 that provides a logical communication path group 13
Reference numeral 16 denotes a management computer having a function of managing the logical communication path group 13 in 2, and denotes a bidirectional communication means provided between the management computer 15 and the client computer group 10, respectively.

However, the client computer 10 _x
Is an information delivery from a client computer group 10, is intended to mean a computer information by specifying the destination address A _x is distributed. In this definition, when the destination address _Ax is a group address, when performing multicast identified by the group address, the client computer 10 _x is a plurality of computers having the same group address.

Although this embodiment is an example in which a plurality of client computers and a plurality of server computers are provided, substantially the same operation and effect can be obtained in a system including a single client computer and a single server computer. Obviously, can be obtained.

FIG. 2 is a block diagram schematically showing a hardware configuration of the management computer 15 of FIG.

As shown in FIG.
Is a main memory 15 storing a control program such as a CPU 150 and a path control management program 151a.
1, a file memory 152, a display device 153, an input device 154, an output device 155, and the like are connected to each other via a bus 156. Management computer 15
Performs the following control operation by the path control management program 151a.

FIG. 3 is a diagram showing a flow of a procedure at the start of communication of the satellite communication system of FIG. 1. The procedure at the start of communication will be described below.

As shown in the figure, the client computer 10 _x uses the bidirectional communication means 16 to establish the logical communication path group 13 in the communication relay system 12 prior to the information distribution request to the server computer 11 _y . The management computer 15 to be managed is requested to use (assign) a logical communication path.

[0035] Thus the management computer 15, by the route control manager 151a, a logical communication path 13 _z (subscript z is specified logical channel to use from the server computer 11 _y for information delivery to the client computer 10 _x Is identified), and the selected logical communication path _{13z is connected} to the server computer _11y.
A route setting procedure is performed on the communication relay system 12 to connect to the client computer 10 _x . Further, the bidirectional communication means 16 is used to notify the client computer 10 _x of information required by the client computer 10 _x to use the selected logical communication path 13 _z .

Thereafter, the client computer 10 _x
Makes a request to distribute information to the server computer 11 _y via the communication relay system 12. Accordingly, the server computer 11 _y is information distributed via the logical communication path 13 _z to the client computer 10 _x.

FIG. 4 is a diagram showing a flow of a procedure at the end of communication of the satellite communication system of FIG. 1. The procedure at the end of communication will be described below.

As shown in FIG.
When the information distribution from 1 _y is completed, the client computer 10 _x uses the two-way communication means 16 to the management computer 15 that manages the logical communication path 13 _z in the communication relay system 12, using the logical communication path 13 _z . Notify the end of use.

The management computer 15 notified of the end of the use of the logical communication path 13 _z operates as the route control management program 1.
By 51a, deallocates the logical communication path 13 _z which is utilized for the information delivered from the server computer 11 _y to the client computer 10 _x, the logical communication path 13 _z another connection mode and status available To cancel the route setting.

As is apparent from the above description, of the conventional dynamic route control methods, in the method based on Japanese Patent Application Laid-Open No. Hei 7-226705, the route control for the communication relay system by the management computer is performed in the usage form of the communication relay system. While the sending computer controlled it,
In the dynamic route control method according to the present invention, the route control for the communication relay system by the management computer is controlled by the client computer which is the receiving computer in the usage mode of the communication relay system. In a satellite communication system that uses a communication relay system that uses a communication satellite, the required hardware configuration is significantly different between the transmitting computer and the receiving computer. It cannot be obtained, and the present invention is not of a nature easily derived from the prior art.

Similarly, in a method based on Japanese Patent Application Laid-Open No. 9-505186, which is one of the conventional dynamic route control methods, the route control for the communication relay system is performed by the computer on the receiving side in the usage mode of the communication relay system. Has a similarity in that it is started by requesting, but the actual route control itself is similar to the method of Japanese Patent Laid-Open No. It is performed based on. Therefore, the present invention, which is characterized in that no transmitting computer is involved in the path control process, is not of a nature easily derived from the prior art.

[0042]

FIG. 5 is a block diagram schematically showing a configuration of a satellite communication system according to an embodiment of the present invention.

In this embodiment, an ATM is used on a digital signal.
(Asynchronous Transfer Mo
This is a satellite communication system for Internet connection using a communication relay system that provides a plurality of logical communication paths by cell multiplexing according to de). As an encapsulation technique for using an IP protocol used on the Internet on an ATM, a known technique known as RFC1483 is used.

In the figure, 50 is a group of client computers composed of a plurality of client computers requesting information distribution, 51 is a group of server computers composed of a plurality of server computers which distribute information in response to a request, and 52 is a group of client computers An arbitrary client computer 50 _x belonging to the server computer group 50 (subscript x identifies a specific client computer) and an arbitrary server computer 51 belonging to the server computer group 51
_y (the subscript y identifies a particular server computer). In particular, in the communication from the server computer 51 _y to the client computer 50 _x , a multiplexing technique is used to transmit data from a plurality of logical communication paths. A communication relay system using a communication satellite 54 that provides a logical communication path group 53, and 55 is a communication relay system 5
2, a management computer having a function of managing the logical communication path group 53, a bidirectional communication means 56 provided between the management computer 55 and the client computer group 50, and 57 an Internet.

Each client computer of the client computer group 50, for example, the client computer 50 _x , transmits bidirectional communication means 56 with a management computer 55 that manages the logical communication path group 53, and requests distribution to the server computer group 51. And a function 500 for accessing the Internet environment through a dial-up connection through a telephone line. Further, a digital signal receiving device 501 for enabling reception using the communication relay system 52 using the communication satellite 54 and a decoding device 502 for extracting ATM cells from the digital signal are provided. When extracting ATM cells from digital signals, VPI / VCI (Virtual
Path Identifier / Virtual
By specifying "Channel Identifier", it is possible to select only information related to predetermined communication from the logical communication paths multiplexed by the cell multiplexing function.

Each server computer of the server computer group 51 is connected to the Internet environment via the communication relay system 52,
It is assumed that a routing setting has been made to the satellite transmission router 520 in the communication relay system 52 for transmission to 0.

The communication relay system 52 using satellites
It is mainly composed of a satellite transmission router device 520 and a digital signal transmission device 521 destined for a communication satellite. Both devices 520 and 521 are connected by an OC-3 optical cable 522, and provide a plurality of logical communication paths by an ATM cell multiplexing function. 1/1 as VPI / VCI
FIG. 6 shows an example of an initial setting for the satellite transmission router 520 for providing 100 logical communication paths assigned １／1/100.

In FIG. 6, reference numeral 60 indicates the start of information defining a logical communication path, and reference numeral 61 indicates VPI / VCI =
A logical communication path having 1/1 exists, and "atm
-Vc 1 ".
Reference numeral 62 denotes the end of information defining a logical communication path.

The satellite transmission router 520 is connected to a management computer 55 for managing the logical communication path group 53 via a LAN line 523, and manages routing control information. That is, this satellite transmission router device 5
20 receives a communication relay request from the server computer 51, and receives the client computer 50 _{x as the} destination.
Looks up routing control information based on the address of the
Set 5 of logical communication paths provided by communication relay system 52
From three to identify the logical channel 53 _z to be actually used, VPI / VCI corresponding to the logical communication path 53 _z
And requests the digital signal transmission device 521 to transmit.

A digital signal relating to a specific communication transmitted from the digital signal transmitting device 521 can be received by the client computer 50 _x specifying this VPI / VCI.

The management computer 55 can perform two-way communication with the client computer 50 _x by an access function of the Internet environment. As described above, this management computer 55 is connected to the satellite transmission router device 520 via the LAN line 523,
The routing information of the satellite transmission router 520 can be controlled by a telnet protocol or the like.

[0052] Figure 7 is a diagram showing an example of a procedure of communication start in the embodiment of FIG. 5, the client computer 50 _x will be described procedure at the start of communication with the server computer group 51 or less.

The client computer 50 _x requests (via the two-way communication means 56) the use (assignment) of the logical communication path to the management computer 55 which manages the logical communication path group 53 through the Internet environment.

When the management computer 55 is requested by the client computer 50 _x to use the logical communication path, the logical communication path group 5 provided by the communication relay system 52
Logical communication path 5 to be used for the client computer 50 _x from the “free” state among the 3
3 _z Select, changes the state of the selected logical channel 53 _z to "in use".

[0055] Further, the management computer 55, to the satellite transmission router 520 as routing information for the address A _x of the client computer 50 _x, set so as to pass through a logical communication path 53 _z. Further, it notifies the client computer 50 _x of the VPI / VCI value relating to the logical communication path 53 _z using the Internet.

The client computer 50 _x notified of the VPI / VCI to be used performs the VPI / VCI notification from the management computer 55 in the decoding process when extracting ATM cells from the digital signal in its own station.
Use the value of VCI.

Thereafter, when a transmission is made from the server computer group 51 to the client computer 50 _x , the satellite transmission router 520 is set as a routing destination for the client computer group 50 in the server computer 51 _y . Since the logical communication path 53 _z is set as routing information for the satellite transmission router 520, a message arrives via the logical communication path 53 _z .

FIG. 8 is a diagram showing an example of a procedure for terminating communication in the embodiment of FIG. 5, and a procedure when the client computer 50 _x terminates communication with the server computer group 51 will be described below.

The client computer 50 _x sends a command to a management computer 55 that manages the logical communication path group 53.
The use termination of the logical communication path _53z is notified through the Internet environment.

As described above, the client computer 50
_When the use termination of the logical communication channel 53 _z is notified from _x ,
The management computer 55 uses the LAN line 523 to delete the routing information for the address A _x of the client computer 50 _x for the satellite transmission router 520 and change the state management of the logical communication path 53 _z to “ It is set to an "empty" state and can be used for relaying communications to other client computers.

Thereafter, when transmission is made from the server computer group 51 to the client computer 50 _x , the satellite transmission router 520 is set as the routing destination for the client computer group 50 in the server computer 51 _y . Since there is no routing information addressed to the client computer 50 _x for the satellite transmission router 520, no message arrives at the client computer 50 _x .

FIG. 9 is a block diagram schematically showing a configuration of a satellite communication system according to another embodiment of the present invention.

[0063] This embodiment, in the server computer 51 _y as in the embodiment of FIG. 5 is a case of adopting the method that does not manage the routing destination of the client computer group 50.

That is, in this embodiment, in addition to the configuration of the embodiment shown in FIG.
24 are installed. The proxy server 524 is connected from the server computer group 51 to the client computer group 5
0 is a computer that plays a role as an agent of the client computer group 50 in the information distribution addressed to “0”. When the client computer 50 _x utilizes a proxy server 524 when requesting the delivery of the server computer 51 _y, and requests the delivery to the server computer 51 _y as if the proxy server 524 as if its own requests information, Receive information. The proxy server 524 that has received the information has a role of transferring the received information to the client computer 50 _x that originally requested the information. In the proxy server 524, the satellite transmission router device 52 is used as a routing destination for the client computer group 50.
By setting 0, the server computer group 5
In 1, even if the routing destination for the client computer group 50 is not managed, only the information is transmitted to the proxy server 524 that is the request source of the information, and as a result, the satellite transmission router 520 is selected as the routing destination. Will be. The other configuration, operation and effect of this embodiment are exactly the same as those of the embodiment of FIG.

As described above, according to the present invention, a logical communication path provided by a communication relay system using a communication satellite is used in time series for a combination of different client computers and server computers. It is possible to do.

The assignment of the logical communication path is controlled based on the request from the client computer requesting the actual information distribution, so that this client computer can continuously exchange information with one or more server computers. When receiving the distribution, it is possible not to perform the route control every time, and to request the end of the route control when all the information distribution is completed.

The embodiments and examples described above all illustrate the present invention by way of example and not by way of limitation, and the present invention can be embodied in various other modified and modified forms. . Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0068]

As described in detail above, in the present invention,
When the client computer requests the use of the logical communication path, the logical communication path from the server computer to the client computer is selected, and the selected logical communication path is connected to the server computer and the client computer. The communication relay system is configured to perform a path setting procedure, and release the path control of the logical communication path used by the client computer when notified of the end of use of the logical communication path from the client computer. As described above, the route control for the communication relay system is performed by the client computer as the receiving computer in the usage form of the communication relay system, and is performed without the involvement of the server computer as the transmitting computer. Thus, it is possible to continuously use the same logical communication path in a plurality of information transfers without causing inconvenience due to the mismatch between the control entities.

FIG. 10 is a diagram showing, in chronological order, the state of communication when a client computer continuously receives information from two server computers according to the present invention. As is clear from comparison with the state of communication according to the known method shown in FIG. 13, according to the present invention, information transfer is performed continuously without switching the logical communication path. Problems such as a delay in the start of transfer of data and an increase in load due to the switching procedure.

[Brief description of the drawings]

FIG. 1 is a block diagram schematically showing a configuration and a connection form of a satellite communication system according to an embodiment of the present invention.

FIG. 2 is a block diagram schematically showing a hardware configuration of a management computer of FIG.

FIG. 3 is a diagram showing a flow of a procedure at the time of starting communication of the satellite communication system of FIG. 1;

FIG. 4 is a diagram showing a flow of a procedure at the end of communication of the satellite communication system of FIG. 1;

FIG. 5 is a block diagram schematically showing a configuration of a satellite communication system according to one embodiment of the present invention.

FIG. 6 is a diagram showing an example of an initial setting of the satellite transmission router device in the embodiment of FIG. 5;

FIG. 7 is a diagram showing an example of a procedure for starting communication in the embodiment of FIG. 5;

FIG. 8 is a diagram showing an example of a procedure for ending communication in the embodiment of FIG. 5;

FIG. 9 is a block diagram schematically showing a configuration of a satellite communication system according to another embodiment of the present invention.

FIG. 10 is a diagram showing an example of a flow of communication with a plurality of servers according to the present invention.

FIG. 11 is a diagram illustrating a dynamic path control method according to the related art.

FIG. 12 is a diagram showing another dynamic path control method according to the related art.

FIG. 13 is a diagram showing an example of a flow of communication with a plurality of servers in another dynamic path control method according to the related art.

[Explanation of symbols]

10,50 client computer group 10 _x, 50 _x any client computer 11, 51 server computer group, 11 _y, 51 _y any server computer 12, 52 a communication relay system 13, 53 logical communication channel group 13 _z, 53 _z Selected logical communication path 14, 54 Communication satellite 15, 55 Management computer 16, 56 Two-way communication means 57 Internet 150 CPU 151 Main memory 151a Route control management program 152 File memory 153 Display device 154 Input device 155 Output device 156 Bus 500 Access Function to Internet Environment 501 Digital Signal Receiving Device 502 ATM Cell Decoding Device 520 Satellite Transmission Router 521 Digital Signal Transmitting Device 522 OC-3 Optical Cable 523 L N line 524 proxy server

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H04L 12/56 H04B 7/15 H04L 12/28

Claims (12)

(57) [Claims] At least one client computer that requests distribution of information, at least one server computer that distributes information in response to a request, and a plurality of logical communication paths in communication between the client computer and the server computer A communication relay system using a communication satellite, and a management computer that manages the plurality of logical communication paths, wherein the management computer receives a request for use of a logical communication path from the client computer. If there is, select a logical communication path used by the client computer, and perform a path setting procedure to the communication relay system to connect the selected logical communication path to the server computer and the client computer,
A satellite configured to release route control of the logical communication path from the server computer to the client computer when a notification of use termination of the logical communication path is received from the client computer. Communications system. 2. A two-way communication means is provided between the management computer and the client computer, wherein the request for using a logical communication path from the client computer and the logical communication from the client computer are provided. The satellite communication system according to claim 1, wherein the notification of the end of use of the road is configured to be performed via the two-way communication means. 3. The management computer sends information necessary for using the selected logical communication path to the client computer via the bidirectional communication means when a path setting procedure is performed. The satellite communication system according to claim 2, wherein the satellite communication system is configured to be notified. 4. After the route setting procedure is performed by the management computer in response to the request from the client computer to use the logical communication path, the notification of the end of the use of the logical communication path is made. 2. The apparatus according to claim 1, wherein the server is configured to distribute information from any one of the server computers to the client computer via the logical communication path.
4. The satellite communication system according to any one of claims 1 to 3. 5. The communication relay system includes a proxy server, and the proxy server mediates transfer of information between each client computer and each server computer, thereby transmitting the information from the server computer to the client computer. The satellite communication system according to any one of claims 1 to 4, wherein transfer of information addressed to the satellite communication system is configured to pass through the communication relay system. 6. After the route setting procedure is performed by the management computer in response to the request for using the logical communication path from the client computer, the notification of the end of the use of the logical communication path is made. In the meantime, the client computer continuously receives information distribution from one or more server computers via the logical communication path without making a request for using the logical communication path again. The satellite communication system according to any one of claims 1 to 3, wherein the satellite communication system is configured to be able to perform the operation. 7. Communication using a communication satellite for providing a plurality of logical communication paths in communication between at least one client computer requesting information distribution and at least one server computer receiving the request and distributing information. A route control method in a satellite communication system, comprising: a relay system; and a management computer that manages the plurality of logical communication paths, wherein the client computer performs the management before the information distribution request to the server computer. Requesting a computer to use a logical communication path, the management computer selects a logical communication path used by the client computer to receive information distribution, and sets the selected logical communication path to the server computer and To connect to the client computer It performs a route setting procedure for the serial communication relay system, and information delivery from the server computer is completed,
The client computer notifies the management computer of the end of use of the logical communication path, and when the management computer is notified of the end of use of the logical communication path, releases the assignment of the logical communication path, A route control method in satellite communication, wherein the route setting for canceling the logical communication path so that another connection form can be used is released. 8. The request from the client computer to use a logical communication path and the notification from the client computer to end use of the logical communication path,
The method according to claim 7, wherein the method is performed via a two-way communication means provided between the management computer and the client computer. 9. When the management computer performs a path setting procedure, the management computer transmits information necessary for using the selected logical communication path to the client computer via the two-way communication means. 9. The method according to claim 8, wherein the notification is performed. 10. After receiving the request for using the logical communication path from the client computer and performing the path setting procedure by the management computer, the notification of the end of the use of the logical communication path is made. In the meantime, information distribution from any server computer to the client computer is performed via the logical communication path.
The method described in the section. 11. When the route setting procedure is performed by the management computer in response to the request for using the logical communication path from the client computer, the notification of the end of the use of the logical communication path is made. In the meantime, the client computer continuously receives information distribution from one or more server computers via the logical communication path without making a request for using the logical communication path again. 10. A method according to any one of claims 7 to 9, wherein the method can be performed. 12. Communication using a communication satellite for providing a plurality of logical communication paths in communication between at least one client computer requesting information distribution and at least one server computer receiving the request and distributing information. A computer-readable recording medium storing a route control program in a satellite communication system including a relay system, wherein the logical volume used by the client computer when the client computer requests use of a logical communication path. A communication path is selected, a path setting procedure is performed on the communication relay system to connect the selected logical communication path to the server computer and the client computer, and the client computer notifies the end of use of the logical communication path. If there was before Recording medium storing a routing control program for releasing the routing of the logical channel from the server computer to the client computer.