JP2003032310A - Relay server - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay server that realizes communication between network devices in a plurality of local systems via the Internet and attains participation of the other network device to the communication. SOLUTION: A terminal going to make communication logs in the relay server 4 to reserve an access, in advance. Then a terminal 11 transmits access request information to terminals 21, 51 to the relay server 4 to allow in-group communication among the terminals 11, 21, 51. An access information storage section 43 stores the group access information in this case. The other network device requests the relay server 4 to search access information and can receive the result of search. A terminal uses the received access information to make a subscription request to a group and consolidates the groups and reproduces communication by using the past access information.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay server that communicates with a plurality of network devices and relays communication between the network devices.

[0002]

2. Description of the Related Art FIG. 8 is an explanatory diagram showing an example of a general system using the Internet. In the figure, 1 and 2 are local systems, 3 is the Internet, 11 and 12,
21, 22 are terminals, 13, 23 are gateways, 14,
24 is a LAN. Local system 1 is terminal 1
1, a terminal 12, a gateway 13 and the like are connected by a LAN 14 and configured. The gateway 13 is L
It is connected to the Internet 3 together with AN14,
The Internet can be used from various network devices such as the terminals 11 and 12 on the LAN 14. The same applies to the local system 2, which includes the terminal 21 and the terminal 2.
2, a gateway 23 and the like are connected by a LAN 24. The gateway 23 is connected to the Internet 3 together with the LAN 24.
The Internet can be used from various network devices such as the above terminals 21 and 22. Of course, in the local systems 1 and 2, various other devices may be connected by the LANs 14 and 24.

In such a system, normally one or a plurality of global IP addresses are assigned to the local systems 1 and 2, but the global IP address is assigned to each network device in the local systems 1 and 2. It's not done. A private IP address is assigned to each network device in each of the local systems 1 and 2, and the gateways 13 and 23 convert the private IP address into a global IP address by using a function such as NAT or IP masquerade. is doing. Such an IP
Using the gateways 13 and 23 having the address conversion function, for example, in the local system 1, the terminals 11 and 12 use the Internet 3 via the gateway 13. Also in the local system 2, the terminals 21 and 22 use the Internet 3 via the gateway 23.

Further, the gateways 13 and 23 or other network devices have a function such as a firewall and a proxy server, and a configuration in which each terminal uses the Internet 3 through these devices is also used. Improves system safety.

Here, for example, if an attempt is made to access the terminal 11 in the local system 1 from the Internet 3, the global IP address of the gateway 13 can be known, but the private I
You cannot know the P address. Therefore, the terminal 11 cannot be accessed from outside the local system 1 by the normal connection method. There are also cases where sites that accept access are restricted by the firewall function of the gateway 13. Of course, the same applies to the terminal 12, and the same applies to the terminals 21 and 22 in the local system 2.

Further, the terminal 11 in the local system 1
And terminal 12, terminal 21 and terminal 2 in the local system 2
2 usually has only a client function, and does not have a server function that receives information from other network devices. Therefore, the terminals 11, 12, 21, 2
Information cannot be transmitted from other network devices to these terminals unless the other network device is accessed from 2.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and realizes communication between network devices in a plurality of local systems via the Internet, and An object of the present invention is to provide a relay server that enables other network devices to participate in communication.

[0008]

According to the present invention, in a relay server, a communication means capable of communicating with a plurality of network devices, and a control means for relaying communication between a plurality of network devices via the communication means, The control means has a storage means for storing connection information on the network device relayed, and the control means stores the connection information in the storage means in response to an inquiry about the connection status received via the communication means. It is characterized by answering.
Thereby, for example, the communication status of the other party who is going to communicate can be grasped in advance. Further, for example, when the information indicating the group of a plurality of network devices relaying communication is stored as the connection information,
It is possible to know in advance the status of groups that can participate in communication. The inquiry can be made by specifying the network device or by making a search request to obtain the search result of the connection information.

Further, by receiving the instruction information for the inquiry about the connection status in advance, it is possible to determine whether to reply the connection information when the inquiry about the connection status is actually received. By this, for example, it is instructed not to reply the connection information for the communication that you do not want to disclose, and for the communication that is open, it is instructed to reply the connection information. It becomes possible to give an instruction such as answering.

When relaying communication between a plurality of network devices, another network device participates in a group composed of the plurality of network devices, merges groups, or divides a group. It is also possible to do such as. When participating or merging, an upper limit may be set to limit the number.

Further, the connection information can be held even after the relay of the communication is completed, and the relay of the communication can be reproduced according to the request based on the held connection information. in this case,
It is also possible to specify connection information and request reproduction.

Furthermore, it is possible to provide a priority to communication with the network device and guarantee the bandwidth as needed. As a result, it becomes possible to support communication by applications that require real-time processing.

[0013]

1 is a block diagram showing an example of a communication system including an embodiment of a relay server of the present invention. In the figure, the same parts as those in FIG. 4 is a relay server, 41 is a communication unit,
42 is a control unit, 43 is a connection information storage unit, 5 is a local system, 51 is a terminal, 52 is a gateway, and 53 is LA.
N. Although only one terminal is shown in each local system, a plurality of terminals may exist.

The local system 5 is a system similar to the local systems 1 and 2, and is constructed by connecting a terminal 51, a gateway 52 and the like via a LAN 53. The gateway 52 is connected to the Internet 3 together with the LAN 53, and the Internet can be used from various network devices such as the terminal 51 on the LAN 53.

The relay server 4 is connected to the Internet 3 and has a global IP address. It is possible to communicate with various network devices via the Internet 3 using this global IP address. The relay server 4 includes, for example, the communication unit 41, the control unit 42,
It can be configured to include the connection information storage unit 43. The communication unit 41 can communicate with a plurality of network devices via the Internet 3.

The control unit 42 receives a login request sent from a network device via the communication unit 41,
The communication path is secured by maintaining the connection with the network device. Also, in this way, receive the login request,
When a communication channel is secured, the communication channel is maintained until it is logged out. Also, a plurality of connections may be provided between one network device. Then, when receiving the connection request information from the network device that is communicatively connected, the network device that has requested the connection and the network device that is requested to be connected and is communicatively connected to the relay server 4 according to the connection request information. Alternatively, it relays data transfer with a group composed of a plurality of network devices. This realizes communication between network devices. For example, it is possible to realize one-to-many communication or one-to-many communication between one network device and one or a plurality of other network devices. Of course, one-to-one communication is also possible.

When relaying the data transfer with each network device, the control unit 42 stores the connection information between the network devices relayed at that time in the connection information storage unit 43.
Stored in. For example, in the case of one-to-one communication, information specifying both network devices may be stored as connection information. Alternatively, information about a group composed of a plurality of network devices can be stored as connection information. Such connection information can be disclosed to some or all of the other network devices according to the settings made by the communicating network device. The setting can be made, for example, in advance, or at the time of logging in to the relay server 4 of the network device, or by instructing after the login.

The control unit 42 also receives a reference request or a search request from another network device that is connected to the connection information, searches the connection information stored in the connection information storage unit 43, and returns the search result. If the connection information is set to be public, the connection information is returned to the request source. The requesting network device transmits a connection request to the relay server 4 by designating a desired network device or group based on the connection information received from the relay server 4, thereby communicating with the designated network device or group. Can communicate. Furthermore, the communication can be terminated, the groups can be divided or merged, and the like, according to a request from the network device that is performing the communication.

Further, according to the request from the network device, the control unit 42 retrieves the connection information at the time of the communication performed in the past from the connection information storage unit 43, and based on the connection information, between the network devices logged in. It is possible to relay communication in. This makes it possible to easily start communication in a group of a plurality of network devices that frequently communicate with each other.

FIG. 2 is an explanatory diagram of an example of a procedure for performing communication between a plurality of network devices in an example of a communication system including the embodiment of the relay server of the present invention.
Note that, in each of the following explanatory diagrams, a gateway and the like are omitted, and only the TCP / IP connection between each terminal (network device) and the relay server 4 is shown.
In addition, the line segment showing each connection is shown by a broken line when it is not used for communication with other network devices by the protocol of the application layer, and by a solid line when it is used for communication with other network devices. ing. The same applies to each of the following explanatory diagrams.

In FIG. 2A, the terminal 11 is communicatively connected to the relay server 4 through the connection 1. Similarly, the terminals 21 and 51 are also communicatively connected to the relay server 4 by the connections 2 and 3. At this point, it is assumed that each connection is not used for communication with other network devices.

To secure the connection with the relay server 4 as described above, a login request may be made to the relay server 4 via the Internet 3. A connection with the relay server 4 is established at the time of login, and then the established connection can be used to communicate with the relay server 4. Here, terminal 1
1, a terminal 21, and a terminal 51 are network devices in the local system 1, the local system 2, and the local system 5, respectively. The relay server 4 can connect to the gateways 13, 23, and 52, but cannot directly connect to the terminals 11, 21, and 51. Further, as described above, the terminals 11, 21, and 51 cannot directly communicate with each other. However, by using the global IP address of the relay server 4, it is possible to connect to the relay server 4 from the terminals 11, 21, and 51 via the gateways 13, 23, and 52. Therefore, by making a login request to the relay server 4 from the terminal 11, the terminal 21, and the terminal 51, bidirectional communication between the relay server 4 and the terminal 11, the terminal 21, and the terminal 51 that made the login request can be performed. Each will be possible.

At the time of login, the network device sends information necessary for login, such as a user ID and a password, to the relay server 4. Relay server 4
Authentication is performed based on the received user ID and password. By this authentication, connection with an unspecified third party can be avoided and safety can be ensured. If the authentication fails because the connection information is not registered or the password is incorrect, the relay server 4 determines that the terminal 1
Negative response to 1 or connect as is 1
Disconnect. If the authentication is successful, a positive response is given to the logged-in network device, and thereafter, the connection is controlled to be maintained until the connection is disconnected. The connection can be maintained by periodically sending a connection holding command to the relay server 4 and obtaining a confirmation response from the relay server 4.

Further, various kinds of setting information can be sent to the relay server 4 at the time of login. For example, when the logged-in network device is communicating with another network device, the connection information is disclosed or notified to some or all of the other network devices, or is set not to be disclosed and notified. be able to. Of course, such settings can be dynamically changed even after login.

In response to the login request as described above, for example, the terminal 11, the terminal 21, and the terminal 51 are communicably connected to the relay server 4 and the communication path is secured. Terminal 21
And connection request information for the terminal 51 to the relay server 4.
Upon receiving the connection request information from the terminal 11, the relay server 4 recognizes that the connection destinations indicated in the connection request information are the terminals 21 and 51, and secures them with the terminal 21. The connection request information from the terminal 11 is transferred through the connection 2 and the connection 3 secured with the terminal 51. If the response returned from the terminal 21 is an affirmative response, the connection 2 secured with the terminal 21 is stored as being used for communication with the terminal 11, and the response returned from the terminal 51 is an affirmative response. If so, the connection 3 secured with the terminal 51 is stored as being used for communication with the terminal 11. Then, the responses returned from the respective terminals 21 and 51 are returned to the terminal 11.

When the terminals 21 and 51 make an affirmative response to the connection request from the terminal 11, FIG.
As shown in, it becomes possible to communicate from the terminal 11 to the terminal 21 and the terminal 51. That is, the relay server 4 receives the information sent from the terminal 11 through the connection 1, and transfers the received information to the terminal 21 through the connection 2 and the terminal 51 through the connection 3. As a result, the information sent from the terminal 11 through one connection reaches the plurality of terminals (terminal 21 and terminal 51). Of course, when an affirmative response is returned only from some network devices, only the network device that has made the affirmative response is subject to communication relay.

Since each connection is bidirectional,
Conversely, it is also possible to receive the data sent from the terminal 21 and send the received data to the terminal 11, or to receive the data sent from the terminal 51 and send the received data to the terminal 11. . In this way, the terminal 21 and the terminal 5 are connected using one connection between the terminal 11 and the relay server 4.
It is possible to realize one-to-many communication with a plurality of network devices such as one. Of course, the data sent from the terminal 21 can be sent to the terminals 11 and 51, or the data sent from the terminal 51 can be received and the received data can be sent to the terminals 11 and 21.

When communication is performed between a plurality of network devices in this way, information for specifying a group such as a group name and a keyword is registered as connection information for a group formed by the network devices that are performing communication. can do. This registration can be performed in response to a request from a network device that is a member of the group. Alternatively, the information specifying the group may be associated with the member network device in advance. It is possible to set such information that specifies a group as to whether or not the information is disclosed to other network devices and is disclosed only to some network devices.

Such connection information can be retrieved from other network equipment. For example, if a group name or keyword is registered as connection information,
It is possible to request the relay server 4 to perform a keyword search from another network device. In the relay server 4, when the search request is received, the control unit 42 searches the connection information stored in the connection information storage unit 43. Then, of the connection information of the search result, only the connection information open to the requester of the search is returned to the requesting network device. Of course, in addition to the keyword search, the connection information may be requested to be disclosed by specifying the ID of the network device. It is also possible to request all the connection information of the network device in communication or the group, which is open to the requesting network device.

By searching for such connection information, the user using the requesting network device determines whether or not the other party with whom he / she wants to communicate is in communication, and which group he / she wants to join. Etc. can be known. With this as a clue, it is possible to join a group in communication as described below.

FIG. 3 is an explanatory diagram of an example of a procedure for joining a group in an example of a communication system including the embodiment of the relay server of the present invention. In the figure, 61 is a terminal. In the example shown in FIG. 3, the terminal 11, the terminal 21, the terminal 51
In the case where the terminal 61 newly joins in a state where communication is performed among the three parties, The terminal 6
Reference numeral 1 is also a network device similar to the terminals 11, 21, 21, and the like. It is assumed that the terminal 61 logs in to the relay server 4 in advance and secures the connection with the relay server 4.

In FIG. 3A, terminal 11 and terminal 2
1. The terminal 51 performs data transfer with the relay server 4, and the relay server 4 relays the data to realize communication between the terminal 11, the terminal 21, and the terminal 51. At this time, the terminal 11, the terminal 21, and the terminal 51 form a group, and information specifying the group is stored in the connection information storage unit 43 in the relay server 4 as connection information. The connection information of the group formed by the terminals 11, 21, and 51 is set to be openable to at least the terminal 61.

In this state, the terminal 61 requests the relay server 4 to search for the connection information as described above, so that various connection information including the connection information of the group formed by the terminal 11, the terminal 21, and the terminal 51. Is obtained.
When the terminal 61 joins the group composed of the terminal 11, the terminal 21, and the terminal 51, the connection information of the group composed of the terminal 11, the terminal 21, and the terminal 51 is used from the obtained connection information. , And makes a connection request to the relay server 4. If the connection request is approved, then FIG.
As shown in (B), the terminal 61 joins the group and can perform communication between the terminals in the group including the terminal 11, the terminal 21, the terminal 51, and the terminal 61.

The connection request may be approved by presetting, for example, whether or not another network device can join the group, only transmission is possible, and only reception is possible. Alternatively, each network device in the group or a representative network device may be inquired about approval or disapproval of subscription, and the result may be followed.

It is also possible to set an upper limit on the number of network devices that can join the group and limit the number of network devices that can join. In this case, for the group to which the network device has already subscribed up to the upper limit, the relay server 4 rejects further subscription.

FIG. 4 is an explanatory diagram of an example of a procedure for merging groups in an example of a communication system including the embodiment of the relay server of the present invention. In the figure, 71 and 81 are terminals. In the example shown in FIG. 3, one network device (terminal 61) joins the group. In addition, groups can also be merged. Figure 4
In the example shown in (A), the terminal 11, the terminal 21, and the terminal 51 communicate with each other through the relay of the relay server 4,
It constitutes a group a. In addition, the terminal 61, the terminal 71,
The terminals 81 also communicate with each other through the relay of the relay server 4 and form a group b. In this way, the relay server 4 can relay communication for each of the plurality of groups. In the state shown in FIG. 4A, the group a and the group b are communicating with each other separately, and cannot communicate with each other.

In this state, it is assumed that the connection information of the group a is open to at least one of the terminals of the group b, and the merge request is issued from the group b to the group a. In this case, the terminal that is a member of the group b, for example, the terminal 61 requests the relay server 4 to search the connection information as described above, and obtains various connection information including the connection information of the group a. Then, by using the obtained connection information of the group a, the relay server 4 is requested to merge into the group a. The relay server 4 informs the group a of the merge request, and if approved, the group b merges with the group a as shown in FIG.
It becomes possible to perform communication between each terminal in the group configured by the terminal 21, the terminal 51, the terminal 61, the terminal 71, and the terminal 81.

When requesting a merger, it is necessary to obtain approval from each network device in the group,
Alternatively, when there is a network device that represents a group, it is possible to limit the request source so that the merge request is issued from the network device.
In addition, regarding the group that received the merger request, the approval of the merger should be obtained from each network device in the group, or if there is a network device representing the group, the merger shall be performed on that network device. Can be approved. When the number of group members is limited, it is possible to reject the merger or selectively join the group.

With the merger of groups, the connection information stored in the relay server 4 for each group will be unified, but which of the keywords registered by each group will remain? , Or both keywords can be merged.

FIG. 5 is an explanatory diagram of a procedure example when terminating communication with a group in an example of a communication system including the embodiment of the relay server of the present invention. When communication is being performed between the network devices in the group as described above, it is possible to terminate the communication of some network devices with other network devices in the group.

The example shown in FIG. 5 (A) shows a state in which communication is being performed among the four parties, terminal 11, terminal 21, terminal 51, and terminal 61. In this state, for example, the terminal 6
When the terminal 1 terminates the communication with the group, the terminal 61 sends a disconnection request to the relay server 4 to disconnect the communication.
Upon receiving the disconnection request from the terminal 61, the relay server 4 deletes the terminal 61 from the members of the group, and the terminal 1
1, the relay between the terminal 21, the terminal 51 and the terminal 61 is stopped. As a result, as shown in FIG.
The information sent from the terminal 1, the terminal 21, and the terminal 51 is not sent to the terminal 61. Of course, the relay of communication among the terminals 11, 21, and 51 is continued. The TCP / IP connection between the terminal 61 and the relay server 4 may be maintained as it is, or the TCP / IP connection itself may be disconnected.

The fact that the terminal 61 has left the group member means that the terminal 1 which is another member of the group.
You may make it notify to 1, the terminal 21, and the terminal 51.
Alternatively, various modifications are possible, such as notifying only the network device representing the group.

FIG. 6 is an explanatory diagram of an example of a procedure for dividing a group in an example of a communication system including the embodiment of the relay server of the present invention. In the example shown in FIG. 5, the network device ends the communication. However, for some network devices in the group, communication may be continued in another group while maintaining the communication between the network devices. It is possible.

The example shown in FIG. 6A shows a state in which six network devices, that is, the terminal 11, the terminal 21, the terminal 51, the terminal 61, the terminal 71 and the terminal 81 are communicating. In this state, for example, the terminal 61 and the terminal 7
The case where the terminal 81 and the terminal 81 terminate the communication with the terminal 11, the terminal 21, and the terminal 51 while maintaining the communication between these network devices will be described.

In such a case, any one of the terminal 61, the terminal 71, and the terminal 81, for example, the terminal 61, sends a request for dividing the group together with the terminal 71 and the terminal 81 to the relay server 4.
Send to. In the relay server 4, the terminals 61, 71 and 81 are deleted from the communication relay targets of the original group,
Information from the terminals 11, 21, and 51 is transferred to the terminal 61,
Do not relay to the terminals 71 and 81. further,
The connection information that groups the terminal 61, the terminal 71, and the terminal 81 is generated, and the relay of communication between the three parties of the terminal 61, the terminal 71, and the terminal 81 is continued. At this time, the terminal 6
1, the information from the terminal 71 and the terminal 81 is the terminal 11 and the terminal 2.
1, do not relay to the terminal 51. As a result, FIG.
As shown in (B), the group including the terminal 11, the terminal 21, and the terminal 51 and the group including the terminal 61, the terminal 71, and the terminal 81 communicate with each other independently.

The group division request may be made from one network device as described above, or may be made from the network devices that are members of each group. Also, after the group is split,
Information about the missing member may be notified to the remaining member's network device or the representative network device.

Various settings for a group that newly starts communication in response to a division request may be copied from the group before division, or default settings may be applied. For example, if a keyword that identifies a group is stored as connection information, the keyword of the original group may be copied immediately after division, the keyword may be registered at the time of division, or the keyword may be added until registration is received. It is possible to leave it out.

In this way, by relaying the communication by the relay server 4, one-to-one, one-to-many, and many-to-many communication is possible, and other network devices join or disconnect during communication.
Alternatively, groups can be freely merged or divided.

When the relay server 4 communicates between a plurality of network devices as described above, the connection information (the network device that was in communication, keywords, and other setting information) at that time is transmitted after the communication is completed. Can also be left. For example, this may be left according to the request from the network device that was communicating, or may be left automatically.

As described above, when the connection information at the time of communication remains after the communication is completed, it is possible to reproduce the communication by using this connection information. FIG. 7 is an explanatory diagram of a procedure example when reproducing communication in an example of a communication system including the embodiment of the relay server of the present invention. In the example shown in FIG. 7, the connection information when communication is performed in the group including the terminal 11, the terminal 21, and the terminal 51 is stored in the connection information storage unit 43 of the relay server 4. ing. In FIG. 7A, the terminal 11, the terminal 21, the terminal 51,
An example in which the terminal 61 logs in to the relay server 4 and a TCP / IP connection is provided is shown.

In this state, for example, the connection when the terminal 11 sends a search request for past connection information to the relay server 4 and as a result of the search, communication is performed in a group including the terminal 11, the terminal 21, and the terminal 51. Suppose you have obtained information. The terminal 11 specifies the acquired connection information and requests the relay server 4 to reproduce the communication. In the relay server 4, the control unit 42 retrieves the specified connection information from the connection information storage unit 43, and the member of communication at that time is the terminal 1
It is recognized that it was 1, terminal 21, and terminal 51. Then, with respect to the terminals 21 and 51, the terminal 11
In response to the request, the relay server 4 sends a connection request to start communication with a network device permitted to communicate and relay with a network device of another member. As a result, as shown in FIG. 7B, communication can be performed in a group including the terminal 11, the terminal 21, and the terminal 51. In this way, it is possible to reproduce communication that has been performed between a plurality of network devices in the past. Of course, terminal 61
For network devices that are not registered in the past connection information as described above, relay is not performed even if logged on.

If the network device that is a member of the group identified from the past connection information is not logged in to the relay server 4, the relay server 4 cannot make a connection request. The same applies when there is no free TCP / IP connection due to communication with another network device. Furthermore, even if the network device side rejects the connection request from the relay server 4, the communication cannot be started. In such a case, the communication according to the past connection information cannot be reproduced. In such a case, it is advisable to notify the requester of the reproduction that the reproduction cannot be completed completely. Alternatively, the communication may be reproduced only when it is completely reproducible, or these may be selectable.

As described above, the relay server 4 can relay communication with a large number of network devices and realize communication between network devices, but the communication band in the communication unit 41 and the processing capability of the control unit 42. Depending on the situation, there may be a delay in relaying the transferred data. In such a case, for example, communication with a specific network device may be prioritized, and communication with a higher priority may be relayed with priority over other communication. By setting a high priority for application communication that requires real-time processing, such as video communication, a wide communication band can be secured and communication can be performed without impairing real-time processing. is there.

In the above description, the communication between the network devices logged in one relay server 4 has been described as an example. However, the present invention is not limited to this. For example, a plurality of relay servers exist, and communication can be similarly performed between network devices that log in to different relay servers. As a matter of course, a plurality of network devices logged in to a plurality of different relay servers can form a group to communicate with each other, join the group, disconnect communication, merge groups, divide groups, and the like. In addition, the connection information is stored in each relay server, and other relay servers are configured to be queried at the time of search. In addition, the connection information is transferred between relay servers so that the connection information is always consistent. It may be configured to take. Alternatively, a server for holding and searching connection information may be separately provided, and the connection information may be stored in the server, and a connection information search request may be made to the server. It is possible.

[0055]

As is apparent from the above description, according to the present invention, it becomes possible to communicate between a plurality of network devices via the relay server, and the connection status of such communication can be determined by other networks. It can be retrieved from the device. By using the connection information retrieved in this way, it is possible to join a group of network devices communicating with each other or to merge a plurality of groups. further,
By using the connection information at the time of the communication performed in the past, it is possible to reproduce the communication at that time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a communication system including an embodiment of a relay server of the present invention.

FIG. 2 is an explanatory diagram of an example of a procedure for performing communication between a plurality of network devices in an example of a communication system including an embodiment of the relay server of the present invention.

FIG. 3 is an explanatory diagram of an example of a procedure for joining a group in an example of a communication system including the embodiment of the relay server of the present invention.

FIG. 4 is an explanatory diagram of a procedure example when merging between groups in an example of a communication system including an embodiment of a relay server of the present invention.

FIG. 5 is an explanatory diagram of a procedure example when terminating communication with a group in an example of a communication system including an embodiment of a relay server of the present invention.

FIG. 6 is an explanatory diagram of an example of a procedure for dividing a group in an example of a communication system including the relay server according to the embodiment of the present invention.

FIG. 7 is an explanatory diagram of a procedure example when reproducing communication in an example of a communication system including an embodiment of the relay server of the present invention.

FIG. 8 is an explanatory diagram showing an example of a general system using the Internet.

[Explanation of symbols]

1, 2, 5 ... Local system, 3 ... Internet,
4 ... Relay server, 11, 12, 21, 22, 51, 6
1, 71, 81 ... Terminal, 13, 23, 52 ... Gateway, 14, 24, 53 ... LAN, 41 ... Communication unit, 42 ...
Control unit 43 ... Connection information storage unit.

Claims (12)

[Claims] 1. A communication means capable of communicating with a plurality of network devices, a control means for relaying communication between the plurality of network devices via the communication means, and a connection relating to the network device relayed by the control means. A relay server having storage means for storing information, wherein the control means responds to the inquiry about the connection status received via the communication means with the connection information in the storage means. 2. The relay server according to claim 1, wherein the control unit accepts a connection status inquiry specifying a network device as the connection status inquiry. 3. The relay server according to claim 1, wherein the storage unit stores, as the connection information, information indicating a group of a plurality of network devices through which the control unit relays communication. 4. The control unit according to claim 1, wherein the control unit receives a search request for the connection information, searches for the connection information stored in the storage unit, and responds. Relay server. 5. The control means receives instruction information for an inquiry about the connection status from the network device in advance, and determines whether to reply the connection information according to the instruction information when inquiring about the connection status. Any one of claims 1 to 4
The relay server described in the section. 6. The control means accepts a participation request from another network device for a group of a plurality of network devices relaying communication, and communicates with the other network device in a plurality of network devices of the group. The relay server according to any one of claims 1 to 5, wherein the relay server relays between the relay server and the relay server. 7. The control means merges a plurality of groups, each of which is composed of a plurality of network devices relaying communication in response to a request, into one group, and between the plurality of network devices belonging to the group after the merger. The relay server according to any one of claims 1 to 6, wherein the relay server relays the communication. 8. The relay server according to claim 6, wherein the control unit can limit the number of network devices belonging to the group. 9. The control means separates the relay of communication for one or a plurality of network devices in a group composed of a plurality of network devices relaying the communication in response to a request. The relay server according to any one of claims 1 to 8. 10. The storage means retains the connection information even after the relay of communication by the control means is completed, and the control means is based on the connection information retained in the storage means in response to a request. The relay server according to claim 1, wherein the relay of communication is reproduced. 11. The control unit accepts a request to reproduce the relay of communication according to the specific connection information, and reproduces the relay of communication based on the specific connection information. Relay server. 12. The control unit according to claim 1, wherein the control unit gives priority to communication with the network device, and guarantees a bandwidth as necessary. Relay server.