HK1117312A - Relay server and client terminal - Google Patents

Description

Relay server and client terminal

Technical Field

The present invention relates to a relay communication system capable of communicating with a communication device in another Local Area Network (LAN) across a Wide Area Network (WAN). In particular, the present invention relates to a technique for operating a resource held by a communication device in a certain LAN, on the basis of a communication device in another LAN.

This application claims priority from japanese patent application No. 2006-341066, filed 2006, 12, 19, and is hereby incorporated by reference in its entirety.

Background

There is a communication technology called vpn (virtual Private network). With this communication technology, another LAN located at a remote site can be used as in a directly connected network. For example, communication can be performed across the internet between terminals connected to LANs of a plurality of branch offices installed by regions.

However, this system is likely to become a rigid system due to the relationship of virtually constructing a network. Therefore, it is not easy to construct a system having expandability and flexibility, and the systems proposed so far have respective merits and demerits in terms of functions, costs, and the like.

For example, if resources are managed by the same protocol in the same LAN in general, the system configuration is not so complicated, and thus resources and the like can be easily shared among a plurality of terminals, but when a communication system involves a plurality of LANs over a WAN, it is not easy to deal with such situations even if it is desired to share resources such as folders and files among a plurality of terminals or to delete files held by other terminals from a certain terminal. It is even more difficult when the protocols employed in the various LANs are different.

In addition, although the resources held by each terminal are constantly changing due to deletion, movement, or the like, it is not easy to dynamically respond to these changes. And, there is no provision for providing such dynamically changing information to the user using a more widely used format.

Disclosure of Invention

In view of these problems, it is an object of the present invention to provide a relay communication system that can be easily operated, even between communication apparatuses connected to different LANs and managed by different protocols, and that can share or operate resources with a desired partner when each communication apparatus needs the resources. It is also an object of the present invention to provide a technique that can provide information held by these relay communication systems to users in a format that is widely used.

The present invention relates to a relay server connected to a LAN and capable of communicating with a relay server of another LAN. The server has: an account information registering unit that stores account information including information of client terminals connected to the same LAN; the relay group information registering unit stores relay group information including information on a group of relay servers permitted to be connected to each other. The server further includes: a shared resource information registration unit that stores shared resource information including resource information and information of a client terminal that shares the resource; and a relay processing unit configured to, when receiving an operation instruction for a resource that can be operated by a client terminal connected to another LAN based on the shared resource information, relay an operation for the resource based on the relay group information. The server system may further include a resource information providing unit that registers, in the shared resource information registration unit, an external client terminal other than the client terminal stored in the account information registration unit, and when receiving an access according to a predetermined protocol from the external client terminal, converts the shared resource information into a format of the predetermined protocol and provides the converted format to the external client terminal.

In the relay server, information as to whether or not access based on the predetermined protocol is permitted is set for each resource registered in the shared resource information, and the resource information providing unit extracts information on a resource for which access based on the predetermined protocol is permitted, from among the resources included in the shared resource information, and provides the information to the external client terminal.

In the relay server, information on an operation permitted to the external client terminal is set for each resource registered in the shared resource information, and the resource information providing unit embeds a command module related to the permitted operation in the information on the resource to which access based on the predetermined protocol is permitted and provides the information to the external client terminal.

The relay server may be configured to register the external client terminal in the shared resource information registration unit.

The relay server may be configured to set whether or not to permit access based on the predetermined protocol for each resource registered in the shared resource information registration unit.

Further, the present invention is a client terminal stored in the account information registration unit by a relay server, wherein the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

The client terminal according to the present invention is a client terminal stored in the account information registration unit by the relay server, and is characterized in that whether or not access based on the predetermined protocol is permitted can be set for each resource managed by the shared resource information registration unit.

By using the relay server of the present invention, a communication device can operate resources held by other communication devices over a WAN. The HTTP client terminal connected to the LAN or the WAN can refer to the shared resource information held in the relay communication system by HTTP access. Since the shared resource information is provided in a format that is widely used, the user can access the shared resource using a variety of terminals such as a mobile phone and a PDA.

Other features, components, processes, steps, characteristics and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the present invention with reference to the attached drawings.

Drawings

Fig. 1 is a network configuration diagram of a relay communication system according to an embodiment of the present invention.

Fig. 2 is a functional block diagram of an external server according to an embodiment of the present invention.

Fig. 3 is a functional block diagram of a communication device according to an embodiment of the present invention.

Fig. 4 is a functional block diagram of a relay server according to an embodiment of the present invention.

Fig. 5 is a diagram showing the contents of relay group information according to an embodiment of the present invention.

Fig. 6 is a diagram showing the contents of shared resource information according to an embodiment of the present invention.

Fig. 7 is a flowchart showing a process flow of resource operation according to an embodiment of the present invention.

Fig. 8 is a flowchart showing a process flow of resource operation according to an embodiment of the present invention.

Fig. 9 is a diagram showing the contents of shared resource information after addition of an HTTP account according to an embodiment of the present invention.

Fig. 10 is a diagram showing the contents of an HTML file output from shared resource information after the HTTP account is traced according to an embodiment of the present invention.

Fig. 11 is a diagram showing a WEB screen displayed on the display of the HTTP client according to the embodiment of the present invention.

Fig. 12 is a diagram showing the contents of shared resource information after a resource operation according to an embodiment of the present invention.

Fig. 13 is a diagram showing the contents of an HTML file output from shared resource information after a resource operation according to an embodiment of the present invention.

Fig. 14 is a diagram showing a WEB screen displayed on the display of the HTTP client according to the embodiment of the present invention.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is an exemplary diagram of the overall configuration of a relay communication system according to the present invention. As shown in fig. 1, the relay communication system is configured by a plurality of LANs connected to a WAN. The relay communication system includes an external server S, a relay server R, a communication device T, a file server F, an HTTP client terminal HC, and the like. Here, although the embodiment using the external server S is illustrated, the communication may be performed directly between the relay servers R without using the external server S. As a communication protocol, sip (session initiation protocol) can be used as appropriate, and this will be described in the present embodiment.

WAN (Wide Area network) is a network connecting different LANs. In the present embodiment, the internet is exemplified as the WAN, but the present invention is not limited thereto, and may be applied to other networks similar thereto.

Lan (local Area network) is a relatively small-scale network constructed in a limited place. LANs are constructed at a plurality of and physically separated places, respectively. For example, in the present embodiment, LAN1 is constructed in division a of tokyo, and LANs 2, 3, and 4 are constructed in divisions B, C, D of osaka, celebrity, and foggan, respectively. Also, the four LANs 1, 2, 3, 4 are connected to the internet as a global network, respectively. Of course, the number of LANs may be plural, and is not limited to four.

The external server S is a device for performing communication between the relay servers R arranged in the respective LANs, and is provided on the internet. The external server S has a function as a SIP server. Specifically, the external server S has a function as a SIP proxy (ProxyServer) that relays a SIP method (method), a response (response), or the like, and a function as a SIP registrar (registry server) that registers an account of the relay server R. The external server S is not limited to one, and may function in a plurality of distributed ways. In the case of using a protocol other than SIP, if it is sufficient that direct communication between the relay servers R can be controlled based on the protocol, it is not necessarily necessary to provide the external server S functioning as a SIP server.

Fig. 2 shows a functional block diagram of the external server S. As shown in fig. 2, the external server S includes a WAN interface 201, a control unit 202, a relay server account information Database (DB)203, and the like.

The WAN interface 201 is an interface for communicating with each device such as the relay server R connected to the internet by using a global IP address. The relay server account information DB203 is a database that manages the account of the relay server R having received the registration request in association with the global IP address. The control unit 202 is a processing unit that controls various communications performed through the WAN interface 201, and controls communication processing based on a protocol such as TCP/IP, UDP, or SIP. For example, the control section 202 executes the following processing: a process of receiving an account of each relay server R transmitted from each relay server R and registering in the relay server account information DB 203; and a process of relaying communication data such as various SIP methods and responses transmitted from the relay server R to another relay server R.

The communication device T is a client terminal (hereinafter, simply referred to as client terminal T) which can be directly operated by a user. For example, a Personal Computer (PC) or the like used by a user in daily business belongs to the client terminal T. In the present embodiment, the client terminals 1A and 1B are connected to the LAN1, the client terminals 2A and 2B are connected to the LAN2, the client terminals 3A and 3B are connected to the LAN3, and the client terminals 4A and 4B are connected to the LAN 4. Each client terminal T is assigned a private IP address uniquely managed only in the same LAN.

Fig. 3 shows a functional block diagram of the client terminal T. As shown in fig. 3, the client terminal T includes: a LAN interface 601, a control unit 602, a resource storage unit 603, a shared resource information Database (DB)604, a display unit 605, and the like.

The LAN interface 601 is an interface for communicating with each device such as the relay server R and the file server F connected to the same LAN by using a private IP address. The resource storage unit 603 stores resource entities such as files and folders that can be operated by the client terminal T. The shared resource information Database (DB)604 stores the shared resource information 120, and the shared resource information 120 includes the resource information held by the client terminal T and the account information of the client terminal T sharing the resource, and describes the shared resource information held by each client terminal T. The display unit 605 visually displays the content of the relay group information 100 or the shared resource information 120. The control unit 602 is a processing unit that controls various communications performed through the LAN interface 601. The control unit 602 controls communication processing based on a protocol such as TCP/IP, UDP, or SIP.

For example, the control section 602 executes the following processing: a process of controlling movement, change, deletion, and the like of the resource stored in the resource storage unit 603; a process of receiving the shared resource information 120 from the relay server R; a process of displaying the content of the shared resource information 120 in cooperation with the display unit 605; receiving the instruction of operating the resource and judging whether the resource can be directly operated; the shared resource information 120 is registered in the relay server R.

(relay server) one relay server R is disposed in each LAN. Here, the relay server R1 is disposed in the LAN1, the relay server R2 is disposed in the LAN2, the relay server R3 is disposed in the LAN3, and the relay server R4 is disposed in the LAN 4.

The relay server R is connected not only to the LAN but also to the internet, and can communicate with each client terminal T connected to the same LAN and, at the same time, can communicate with the relay server R connected to another LAN via the external server S. Therefore, each relay server R is given a global IP address in addition to a private IP address.

Fig. 4 is a functional block diagram of each relay server R. As shown in fig. 4, the relay server R includes: a LAN interface 501, a WAN interface 502, a control section 503, an account information Database (DB)504, a relay group information Database (DB)505, a shared resource information Database (DB)506, and the like.

The LAN interface 501 is an interface for communicating with a client terminal T or the like connected to the LAN by using a private IP address. For example, the relay server R1 communicates with the client terminals 1A and 1B via the LAN interface 501 in the LAN 1. The WAN interface 502 is an interface for communicating with each device such as an external server S connected to the internet by using a global IP address. In the present embodiment, the relay server R is configured to have the WAN interface 502, but a router may be used to connect to the internet and provide the relay server R thereunder.

The account information DB504 is a database for managing the account of the client terminal T having requested registration in association with the private IP address. The relay group information DB505 is a database for managing the relay group information 100 associated with the client terminal T registered in the account information DB. The shared resource information DB506 is a database for managing the shared resource information 120 associated with the client terminal T registered in the account information DB.

The control unit 503 is a processing unit that controls various communications performed through the LAN interface 501 and the WAN interface 502, and controls various communication processes based on protocols such as TCP/IP, UDP, and SIP. For example, the control section 503 executes the following processing: sending the account of the device to an external server S, and processing a registration request; a process of registering an account transmitted from a client terminal T connected in the same LAN in the account information DB 504; a process of creating relay group information 100 and storing it in the relay group information DB 505; the shared resource information 120 is created and stored in the shared resource information DB 506.

Next, the relay group information 100 and the shared resource information 120, which are information handled in the present relay communication system, will be described.

(relay group information) the relay group information 100 records information of the relay servers R permitted to connect to each other, and is stored in the relay group information DB505 of each relay server.

The relay group information 100 is normally initially set in the relay communication system. When a change occurs in any of the relay group information 100, the relay group information 100 automatically performs a change notification setting for updating the content, and can dynamically respond to the change even if the account of the relay server R or the client terminal T changes.

Fig. 5 shows an example of the relay group information 100. Fig. 5 shows relay group information 100, and the relay group information 100 is created by exchanging information among three relay servers R1, R2, and R3 with the relay server R1 as a base point, and is stored in the respective relay group information DBs 505. The relay group information 100 includes one group identification information 101 and information (relay account information) 102 of three relay servers R1, R2, and R3 that permit connection to each other. In fig. 1, the LAN4 (relay server R4) is not connected to the network because no account is registered, and cannot participate in the communication service described here.

The group identification information 101 is information for identifying the relay group information 100, and is given a different ID every time relay group information is created so as to be uniquely identifiable. Therefore, the operator or the like can specify the relay group using the identification information 101 and can easily change the group configuration or the like.

The relay account information 102 is composed of information such as an account of the relay server R and an account of the client terminal T connected to the same LAN as the relay server R and registered in the relay server R. The account of the relay server R is given a specific name, and user identification is facilitated. Similarly, each account of the client terminal T is given a specific name. For example, the Relay account information 102 of the Relay server R1(Relay-server1) is assigned a name (branch a)104 to the account (Relay-server1@ net) of the Relay server R1. Further, the account (for example, User1A @ account) of each client terminal T connected to the relay server R1 and each name (for example, User1A)105 thereof are stored in association with (in a lower position) the account information of the relay server R1. Reference numeral 103 denotes identification data to which the client terminal T belongs, such as "business department" and "development department".

As described above, the relay group information 100 is created so as to be uniquely identifiable for each relay group information, and includes the relay account information 102 of a group permitted to be connectable to each other. Since the relay account information 102 includes the account of each relay server R and the account of the registered client terminal T arranged in the same LAN as the relay server R, it is possible to know which LAN and which LAN form a group and which relay server R or client terminal T is registered in these LANs if the relay group information 100 is referred to.

The shared resource information 120 (shared resource information) includes information on a plurality of client terminals T that share resources such as files and folders with each other and information on resources to be shared, and is stored in the shared resource information DB506 of the relay server or the shared resource information DB604 of the client terminals T.

Fig. 6 shows an example of the shared resource information 120. Fig. 6 illustrates the shared resource information 120 stored in the shared resource information DB604 of the client terminal 1A. The shared resource information 120 includes: account identification information 121 indicating that the shared resource information 120 is related to the client terminal 1A; the individual shared resource information 122 is information related to the client terminal 1A. The individual shared resource information 122 includes shared resource identification information 123, family account information 124, family resource information 125, and the like. In this example, since a resource sharing group associated with one client terminal 1A is formed, the shared resource information 120 includes one individual shared resource information 122. If a resource sharing group associated with a plurality of client terminals 1A is formed, the shared resource information 120 includes a plurality of individual shared resource information 122 in response to this. For example, in the example of fig. 6, the client terminals 1A, 2A, and 3A form a resource shared group, but when another resource shared group is formed by the client terminals 1A, 2B, and 3B, the individual shared resource information 122 corresponding thereto is generated.

Shared resource identification information 123 is information for identifying the individual shared resource information 122, and is given a different ID so as to be uniquely identifiable each time the individual shared resource information 122 is created. Therefore, the user or the like can specify the individual shared resource 122 using the shared resource identification information 123 and can easily edit the content thereof or the like.

The family resource information 125 is an aggregate of resource information 126 indicating resource entities such as files and folders held by the client terminal T. Each resource information 126 includes: information of a name of a shared resource entity (e.g., resource name ═ folderA); account information of a client terminal T (owner client terminal) that can operate the resource entity (e.g., owner ═ user1A @ account "); and address information (e.g., value ═ c:/folderA) indicating the location of the resource entity.

The family account information 124 is an aggregate of accounts (for example, user1A @ account) of the client terminals T sharing the resource entity indicated in the family resource information 125. Homogeneous account information 124, including: an owner client terminal T; the client terminal T (user client terminal) of the resource entity can be operated indirectly through the owner client terminal. The user client terminal T is a client terminal T that cannot directly operate a resource entity, but can indirectly operate a resource through the owner client terminal T.

By referring to the shared resource information 120 configured as described above, the client terminal T that shares the resource can be identified, and the type and location of the resource can be known.

The shared resource information 120 is, for example, registered by the client terminal T. That is, the client terminal T has means for registering, in the relay server R, information: the information (resource information 126) of the resource that the client terminal T can directly or indirectly operate, or the information of the account of another client terminal T that shares the resource. Therefore, the operator can easily create and change the shared resource information 120 on the display unit 605 of the client terminal T.

The relay communication system according to the present embodiment described above can perform HTTP access (access by HTTP client terminal) via a LAN or a WAN. In this embodiment, as shown in fig. 1, a case where an HTTP client terminal HC (hereinafter, simply referred to as a terminal HC) connected to a WAN performs HTTP access to a relay communication system will be described as an example. As the HC, for example, a PDA (personal digital assistant) or a cellular phone can be used.

Fig. 7 and 8 are sequence diagrams showing a process in which the terminal HC participates in the relay communication system and a process in which the resource operation is actually performed. First, the client terminal 1A performs an operation (AddAccount) of adding an account of the terminal HC. The client terminal 1A transmits account information and authentication information of the terminal HC to the relay server R1. The relay server R1 registers the account information and the authentication information of the terminal HC in a predetermined storage unit, and also transfers the account information and the authentication information of the terminal HC to the relay servers R2 and R3 related to the shared resource information 120.

Further, the client terminal 1A updates the shared resource information 120. The updated shared resource information 120 is shown in fig. 9. As shown in the figure, the family account information 124 is added with an account (http-account1) of the terminal HC.

The client terminal 1A performs an account addition process for the terminal HC with respect to the family account information 124 and additionally stores information for HTTP access to the family resource information 125. Specifically, as shown in fig. 9, access permission information 127 indicating whether or not to permit HTTP access is set for each resource. In addition, as the permission operation information 128, the contents of the operation permitted for the terminal to which HTTP access is to be performed are set for each resource.

Among the shared resources, HTTP ═ enable is set as the access permission information 127 for the resource to which HTTP access is permitted, and HTTP ═ disable is set for the resource to which HTTP access is denied. In the legend, a shared resource other than "file 002. wrd" is set to permit HTTP access.

In addition, when the permitted operation is a read operation, http-act is set to "r" as the permitted operation information 128. Note that http-act is set to "w" when the write operation is permitted, and http-act is set to "d" when the erase operation is permitted. In the figure, for example, http-act is set to "rw" for folderA, and therefore, reading of a file in folderA and writing of a file to folderA are permitted.

The access permission information 127 and the permission operation information 128 may be set individually for each resource when the HTTP client follows. In addition, if a default value is determined in advance, particularly if no designation is made, the default setting may be used. In the present embodiment, the client terminal T performs registration of the HTTP client terminal with respect to the shared resource information 120, registration processing of the access permission information 127 and the permission operation information 128, and the like, but these processes may be performed by the relay server R by an operation of an operator.

Refer to the sequence diagram of fig. 7. The client terminal 1A makes an update request (updateshared resource) for the shared resource information 120 to the relay server R1 (step S1). In response to this, the relay server R1 notifies the relay servers R2 and R3 of a change (NOTIFY) of the shared resource information 120 (step S1.1 and step S1.2). The relay servers R2 and R3 transmit update requests of the shared resource information 120 to the client terminals 2A and 3A, respectively (step s1.1.1 and step s 1.2.1). In this way, the updated content of the shared resource information 120 is notified to the client terminals 2A, 3A listed in the family account information 124 of the shared resource information 120.

Next, the terminal HC transmits an account via the WAN, and makes an HTTP access to the relay server R3 (step S2). After the Authentication process (Authentication), the relay server R3 responds to the terminal HC. Then, the terminal HC makes a request (HTTP-GET) to the relay server R3 to acquire the shared resource information 120 (step S3).

The relay server R3 receives the acquisition request from the terminal HC, reads the shared resource information 120(LoadResourceData), and performs HTML conversion (convertmhtml) on the read shared resource information 120. Then, the relay server R3 transmits the converted HTML file 130 to the terminal HC as a response.

Fig. 10 shows the contents of the HTML file 130 transmitted from the relay server R3 to the terminal HC. The WEB browser is started in the terminal HC, and the WEB screen 140 generated based on the received HTML file 130 is displayed on the display. Fig. 11 shows a WEB screen 140 displayed on the display of the terminal HC. In this way, the shared resource information 120 after HTML conversion is displayed on the display of the terminal HC.

The content of the HTML file 130 shown in fig. 10 is basically content for visually displaying the shared resource information 120 on the WEB browser. The title information 131 is an expression showing the title 141 displayed in the window column of the WEB screen 140 shown in fig. 11.

The link information 132 contains the resource name and link information. In the WEB screen 140 shown in fig. 11, the name of the resource is displayed as a resource name 142. According to the link information 132, the access path for the resource entity is linked with the resource name 142. When an operation of selecting the resource name 142 is performed on the WEB screen 140, a process of accessing the resource entity is executed. Listed as the resource information 132 is a resource for which "enable" is set as the access permission information 127. That is, only the shared resource permitted to be accessed by HTTP among the resources included in the shared resource information 120 is extracted and included in the HTML file 130. Only the extracted shared resources are displayed on the WEB screen 140 shown in fig. 11.

Further, the command embedding section 133 expresses an operation command for the resource subsequent to the "INPUT" flag. I.e. a command module that embeds resource operations. On the WEB screen 140 shown in fig. 11, the operation buttons 143 are displayed in accordance with the expression of the command embedding unit 133. When the selection operation button 143 is operated on the WEB screen 140, the process described by the command embedding unit 133 is executed in response thereto.

In the display of the terminal HC, the user of the terminal HC operates to select the resource name 142 ("file 001. xls") in a state displayed on the WEB screen 140. In response to this operation, the terminal HC makes an acquisition request (HTTP-GET) for "file 001. xls" to the relay server R3 (step S4). The relay server R3 determines that the owner client terminal of "file 001. xls" is the client terminal 1A based on the shared resource information 120, and determines that the relay is to be performed to the relay server R1 based on the relay group information 100.

Then, the relay server R3 transmits the INVITE method to the relay server R1 through the SIP server S, and makes a file open request of "file 001. xls" (step S4.1). The relay server R1 that has received the request transmits a file open request to the client terminal 1A (step s4.1.1). If "file 001. xls" can be operated, the client terminal 1A returns an OK response to the relay server R1. The relay server R1 returns an OK response to the relay server R3.

The relay server R3 that has received the OK response makes a file acquisition request by using the media session (Mediasession) established with the relay server R1 (step S4.2). Then, the relay server R1 makes a file acquisition request to the client terminal 1A (step S4.2.1). In response to this, the client terminal 1A transmits "file 001. xls" (FileTransfer) to the relay server R3 via the relay server R1. Relay server R3 transmits "file 001. xls" to terminal HC as a response. Thus, the terminal HC can refer to "file 001. xls".

Transition is made to the sequence of fig. 8. Next, the user of the terminal HC uploads "pic000. jpg". The user of the terminal HC selects the operation button 143 displayed on the right side of the "folder a" displayed on the WEB screen 140 shown in fig. 11. That is, the operation button 143 displayed as "FILEUPLOAD" is selected. Then, on a predetermined screen displayed following this operation, an operation of designating "pic000. jpg" located in the hard disk of the terminal HC is performed.

In response to this operation, the terminal HC makes an update request (HTTP-PUT) of "pic000. jpg" to the relay server R3 (step S5). The relay server R3 determines that the owner client terminal of "folderA" is the client terminal 1A based on the shared resource information 120, and determines that the relay is to be performed to the relay server R1 based on the relay group information 100.

Then, the relay server R3 transmits the INVITE method to the relay server R1, and makes an update request to add "pic000. jpg" to "folderA" (step S5.1). The relay server R1 that has received the request transmits an update request to the client terminal 1A (step s5.1.1). If "folderA" is operable, the client terminal 1A returns an OK response to the relay server R1. The relay server R1 returns an OK response to the relay server R3.

The relay server R3 that has received the OK response transmits an update request of "pic000. jpg" by using Mediasession established with the relay server R1 (step S5.2). Then, the relay server R1 makes a file update request to the client terminal 1A (step s 5.2.1). Accordingly, the client terminal 1A writes "pic000. jpg" into "folderA". When the write processing is completed, the client terminal 1A transmits an OK response to the relay server R3 via the relay server R1. Next, the relay server R3 transmits the BYE method to the relay server R1 (step S5.3), and disconnects Mediasession between the relay servers. Then, an OK response is returned to the terminal HC.

When the update process of the file "pic000. jpg" is completed, the relay server R3 updates the shared resource information 120. Fig. 12 shows the updated shared resource information 120. It is known that "pic000. jpg" is added as a shared resource. Then, the owner client terminal is designated as the client terminal 1A of the owner of "folderA". Further, "enable" is set as the access permission information 127 and "r/d" is set as the permission operation information 128, with respect to the added "pic000. jpg". These settings may be made based on default settings or may be specified by the user of the terminal HC.

When the shared resource information 120 is updated, the relay server R3 notifies the relay servers R1 and R2 of a change (NOTIFY) of the shared resource information 120 (step S6 and step S8). Further, the client terminal 3A makes an update request (UpdateSharedResource) for the shared resource information 120 (step S7). The relay servers R1 and R2 then request the client terminals 1A and 2A to update the shared resource information 120 (step S6.1 and step S8.1). In this way, the shared resource information 120 is updated in the client terminals 1A, 2A, and 3A listed in the family account information 124.

Fig. 13 shows an HTML file 130 generated based on the updated shared resource information 120. It is understood that "pic000. jpg" is added as the link information 132 a. Further, the resource "pic000. jpg" has a command embedding unit 133a that specifies a delete command based on the updated shared resource information 120.

Fig. 14 is a diagram showing a WEB screen 140 generated based on the HTML file 130 shown in fig. 13. It is understood that "pic000. jpg" is added as resource information. In addition, a "DELETE" button is displayed on the right side of the resource information of "pic000. jpg". Thus, the terminal HC or another HTTP client terminal registered in the family account information 124 can perform an operation of referring to or deleting the file "pic000. jpg" added by the terminal HC.

In this way, by using the relay communication system of the present embodiment, the client terminal T connected to the LAN can operate the shared resource existing in another LAN. Further, since the information on the shared resources is dynamically reflected in the entire system, the system is highly convenient. Also, according to the present embodiment, the HTTP client terminal HC can refer to the shared resource information 120 through the LAN or the WAN. When the shared resource information 120 is provided to the HTTP client terminal HC, the information is HTML-converted. Therefore, the HTTP client terminal HC can access the latest information of the shared resource by using a general WEB browser.

While the invention has been described with reference to preferred embodiments, it will be apparent to those skilled in the art that the invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, it is intended by the appended claims to cover all modifications of the invention which fall within the true spirit and scope of the invention.

Claims (13)

1. A relay server connected to a LAN and capable of communicating with a relay server of another LAN, comprising:

an account information registering unit that stores client information including information of client terminals connected to the same LAN;

a relay group information registering unit that stores relay group information including information on a group of relay servers that permit connection to each other;

a shared resource information registration unit that stores shared resource information including resource information and information of a client terminal that shares the resource;

a relay processing unit configured to relay, based on the relay group information, an operation of a resource that can be operated by a client terminal connected to another LAN based on the shared resource information, when an operation instruction for the resource is received from the client terminal stored in the account information registration unit;

and a resource information providing unit that is capable of registering, in the shared resource information registering unit, an external client terminal other than the client terminal stored in the account information registering unit, and, when an access based on a predetermined protocol is received from the external client terminal, converting the shared resource information into a format of the predetermined protocol and providing the converted format to the external client terminal.

2. The relay server according to claim 1,

the resource information providing unit extracts information on a resource to which access based on the predetermined protocol is permitted, from among the resources included in the shared resource information, and provides the information to the external client terminal.

3. The relay server according to claim 2,

the resource information providing unit sets information on an operation permitted to the external client terminal for each resource registered in the shared resource information, and embeds a command module related to the permitted operation in the information on the resource to which access based on the predetermined protocol is permitted, and provides the information to the external client terminal.

4. The relay server according to claim 1,

the external client terminal may be registered in the shared resource information registration unit.

5. The relay server according to claim 2,

the external client terminal may be registered in the shared resource information registration unit.

6. The relay server according to claim 3,

the external client terminal may be registered in the shared resource information registration unit.

7. The relay server according to claim 2,

the relay server may set whether or not to permit access based on the predetermined protocol to each resource registered in the shared resource information registration unit.

8. A client terminal stored in the account information registration unit by the relay server according to claim 1, wherein the client terminal is further configured to store the account information registration unit in the account information registration unit,

the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

9. A client terminal stored in the account information registration unit by the relay server according to claim 2, wherein the client terminal is further configured to store the account information registration unit in the account information registration unit,

the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

10. A client terminal stored in the account information registration unit by the relay server according to claim 3, wherein the client terminal is further characterized in that the account information registration unit is configured to register the account information in the account information registration unit,

the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

11. A client terminal stored in the account information registration unit by the relay server according to claim 4, wherein the client terminal is further characterized in that the account information registration unit is configured to register the account information in the account information registration unit,

the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

12. A client terminal stored in the account information registration unit by the relay server according to claim 7, wherein the client terminal is further configured to store the account information registration unit in the account information registration unit,

the external client terminal can be registered in the shared resource information managed by the shared resource information registration unit.

13. A client terminal stored in the account information registration unit by the relay server according to claim 2, wherein the client terminal is further configured to store the account information registration unit in the account information registration unit,

whether or not to permit access based on the predetermined protocol can be set for each resource managed by the shared resource information registration unit.