JP2003134152A - System and method for searching for node - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a node search system capable of searching in a wide range and searching for various objects. SOLUTION: If a client device 3 notifies a service searching device 5B of the position of a service searching device 5A, and on the contrary, a server device 4B notifies the service searching device 5A of the position of the service searching device 5B in a service detection area 10B, the service searching devices 5A and 5B can communicate with each other, and the connecting server device 4 can be searched for. When the client device 3 notifies the service searching device 5A of the position of a service searching device 5 of a different IP network 10 in this way each time the client device 3 uses a service of the server device 4 included in a different service detection area 10, the server device can finally be searched for over the entire network system 1 by accessing the service searching device 5A.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a node search system and method for searching a node that provides a service.

[0002]

2. Description of the Related Art Various services are provided by computers in a computer network. As a typical example of the service provided, WWW (Wo
rld Wide Web) system provides information service, server-client system print service, etc. When attempting to use a service on the network, the user may want to perform desired operations, desired service attributes (eg, functionality, performance), constraints (eg, supported communication protocols, billing types used),
Or have as minimum or maximum metric (eg, cost, quality) as a requirement. Based on this request, the user finds a server device satisfying the request from various server devices scattered on the network, and further,
Select one from among them, specify the server device by the identification information (network address, domain name, URL, etc., hereinafter referred to as service position) indicating the position of the server device on the network, and through the network. Communication is performed to execute desired processing.

In recent years, the generalization of the use of the Internet has made it possible for many users to use various services provided by computers at remote locations via a network. In addition, various devices and equipment such as vending machines and household appliances are being directly connected to a network, and it is expected that the content of services will further diversify in the future. Therefore, the importance of the system that provides the user and the client device with information regarding the service position and the service attribute of an unknown server device that satisfies the user's request is increasing. At the same time, a system that provides information such as a server device is required to have a wide searchable range and a wide variety of searchable objects.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to meet the above-mentioned demand, and it is possible to search a node suitable for a service desired by a user from unknown nodes included in a network. An object of the present invention is to provide a node search system and a method therefor.
It is another object of the present invention to provide a node search system and method having a wide searchable range and various searchable objects.

[0005]

[Means for Solving the Problems] [Node Search System]
In order to achieve the above object, a node search system according to the present invention is a node search system for a network including a plurality of areas, each of the plurality of areas includes at least one node and at least one search device. , Each of the first nodes of the nodes communicates with a search device in the same area to obtain the position of another node in the network, and the first search means and the search and other than the search. A communication unit that communicates with another node using the position of the node, and each of the nodes notifies a node or a search device in the other region of the position of the search device in each region. However, when the search device in the other area is notified of the position of the search device in the other area, the search device in the same area is notified of the notified position of the search device in the other area. Each uses the notified position of the search device in the other area, communicates with the search device in the other area, and notifies each other of the position of the search device held by the search device, and the same area. Second search means for communicating with a search device in another area using the notified position of the search device in another area in response to communication of a client device in the server Have and.

[0006] Preferably, the first node is a client device that receives a service, and the nodes other than the first node are server devices that provide a service.

[0007] Preferably, the search device is constructed integrally with the client device or the server device.

Preferably, the search device further includes a relay device for relaying between the first node and a node other than the first node.

[Searching Device] A searching device according to the present invention is a searching device for a network including a plurality of areas, and each of the plurality of areas includes one or more nodes and one searching device, respectively. Each of the first nodes among the nodes communicates with a search device in the same area to search the position of other nodes in the network, and using the position of the node obtained by the search and other than the search, Communicate with other nodes, and each of the nodes notifies the position of the search device in each area to the node or the search device in the other area, and notifies the position of the search device in the other area. When the notification is received, the position of the search device in the other area notified is notified to the search device in the same area, and the position of the search device in the other area notified is used to Within the area Notifying means for communicating with the search device and mutually notifying the position of the search device held by each, and in response to the communication of the client device in the same region, the position of the search device in the other notified region is used. And search means for communicating with a search device in another area to search for the position of the server device.

[Node Search Method] The node search method according to the present invention is a node search method for a network including a plurality of areas, and each of the plurality of areas has one or more nodes and a search device. And each of the first nodes of the nodes communicates with a search device in the same area to search for a position in the network of another node, and to search for the position of the node obtained by the search and other than the search. Using, communicate with other nodes, each of the nodes, to the node or search device in the other area, notifies the position of the search device in each area,
When receiving the notification of the position of the search device in the other area, notifies the position of the search device in the other area notified to the search device in the same area, each of the search device, the notification By using the position of the search device in the other area that has been set, it communicates with the search device in the other area, and notifies each other of the position of the search device held by each, and responds to the communication of the client device in the same area. By using the position of the search device in the other area notified, to communicate with the search device in the other area,
Search the position of the server device.

[Program] Further, the program according to the present invention is a program for realizing a node searching method for a network including a plurality of areas, wherein each of the plurality of areas has one or more nodes and a search device. Each of the first nodes among the nodes, the step of communicating with a search device in the same area to search the position of another node in the network, Using the position to cause the computer to perform a step of communicating with another node, and in each of the nodes, notify a node or a searching device in the other region of the position of the searching device in the respective region. , When the position of the search device in the other area is notified, the position of the search device in the other area notified is The computer is caused to execute the step of notifying the search device in the area, and in each of the search devices, using the notified position of the search device in the other area, communicate with the search device in the other area, respectively. Mutually notifying the position of the search device held by, and in response to the communication of the client device in the same region, using the notified position of the search device in the other region, search in the other region Causing the computer to communicate with the device and locate the location of the server device.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Background of the Invention] In order to help understanding of the embodiments of the present invention, first, a background of the present invention will be described. In order to meet the demand for widening the searchable range required for providing information such as a server device and the demand for diversifying the searchable target, the following technical approaches have been taken.

[First Technical Approach] The first technical approach is XML (eXtedable Markup Language).
It is to diversify the searchable target of the WWW robot search used in the WWW system by introducing the technology. WWW robot search technology is HTTP
(Hyper Text Transfer Protocol, Version 1.0; IETF
RFC1945) protocol and HTML (Hyper Text Marku)
p Language) is a dedicated text-based keyword search technology that depends on a WWW system such as a language, and is mainly applied to the Internet.

The WWW robot search technique uses a program called a search engine or search robot,
A hyperlink set between information contents provided on the WWW is automatically traced to discover information contents, a keyword is set, a database is created, and a user is provided with a keyword search function. Examples of this technology include "Lycos (Trademark of Carnegie Mellon University)" and "A
lta Vista (trademark of Alta Vista Company) ”and the like.

Since the WWW robot search technology is a text-based keyword search technology, the user must read the information content and determine what the text means from the contexts before and after the information content. It is impossible to search for a service other than the WWW information providing service because the logical operation necessary for performing the search based on the service attribute of the service cannot be performed. But XML
By introducing the technology, it is possible to give meaning to the text, so that it becomes possible to express service attributes, and it becomes possible to apply to services other than the WWW information providing service.

[Second Approach] The second approach is to widen the searchable range of the service search using the simultaneous broadcast communication. The service search technique using broadcast communication is applied to a local network, and uses the following method a and method b or any one of the methods.

[Method a] A message for a client device to search for a server device (hereinafter referred to as a search message) is broadcast to all computers on a network. Upon receiving the search message, the server device transmits a response message to the client device, so that the client device can detect the existence of the server device and its service position. The client device can acquire the service attribute by communicating with the detected server device.

[Method b] When the server device broadcasts a message (hereinafter referred to as a public announcement message) that advertises its existence at the time of activation or at regular intervals, the client device causes the server device to broadcast. Detects the presence of equipment. Alternatively, instead of the client device, the dedicated service search device acquires and holds the service positions and service attributes of all the server devices by the above method, and searches the client device for the service attributes of the server device. Provide the function to do. As an example of this method, SLP (Service Location Protocol, Version2; I
ETF RFC2608) can be mentioned.

However, in the service search technique using the broadcast communication, the detectable range of the server device (hereinafter referred to as the service detection area) is limited to the reachable range of the broadcast communication. The possible range is limited. This is because, due to management reasons based on the operation policy of each network, the broadcast communication may be blocked by a network relay device such as a router or a firewall, and the broadcast time of the broadcast packet (the router HOP It may be limited by the number).

Here, the service detection area depends on the positional relationship (distance) of the service on the network, does not necessarily reflect the geographical positional relationship of the server, and the network in which the management subject is the same in operation ( It is expected that one service detection area will be the management domain). As a result, there are numerous service discovery areas in wide area computer networks. Therefore,
In the service search technology using broadcast communication, a client device included in a certain service detection area can find a server device that provides a service in the service detection area in which the client device is included, but detects another service. It is not possible to find a server device located in the area. Even if the reachable range of the broadcast communication could be expanded, the search message and the announcement message would be broadcast to the entire network, increasing the load on the entire network and reducing the usage efficiency. It will be.

In order to deal with this point, by registering all the service search devices existing in each service detection area in one directory, a method of giving a wide area to the service search technique using the broadcast communication is provided. Can be considered. The service search device refers to the directory to discover another service search device, communicates with the service search device, and obtains information about the server device in the other service detection area, thereby enabling the server to search across multiple service detection areas. Search for device information. This method is disclosed, for example, in “Japanese Patent Application No. 2001-284485 (filing date 200
September 19, 1) ".

[Points to be improved] When the first approach is adopted, the user cannot use the keyword search function by the WWW robot search unless the user knows the position of the server device in the network in advance. Further, since the search robot updates the information stored in the database and used for the search irregularly, the server device cannot predict or control the update timing. Moreover, since the WWW information providing service must be provided in addition to the original service providing, the load on the server device increases.

If the second approach is adopted, the position of the database for registering the service search device in the network must be known in advance by the service search device itself, so that the operation of the system requires manpower and knowledge. . Also, in order to realize a database using a directory structure, it is necessary to systematically construct a directory structure over the entire network, so once a database is constructed, it is very difficult to change it.

[Outline of Node Search Method According to the Present Invention]
Of the terms included in the description of this part, those corresponding to the main terms in the claims are shown in parentheses, but this is not intended to help the understanding of the invention. Therefore, it is not intended to limit the technical scope of the present invention. The node search method according to the present invention basically allows a service search device (search device) to automatically discover another service search device (search device) without registration in a higher-level directory. The service search technique according to the second approach described above is improved. More specifically, in the service search method (node search method) according to the present invention, the client device (first node) is a server device existing in another service detection area (other area) to which the client apparatus does not belong. When communicating with (a node other than the first node) and receiving a service, the position of the service search device (search device) included in the service detection region (same region) in which the service search device is included in the network, Server device (first
(Nodes other than the above nodes).

On the contrary, the server device (nodes other than the first node) determines the position of the service search device (search device) existing in the service detection region (same region) in which the server device is included in the client device (first node). The service search area (search device) in the service detection area including the node (1). The service search device (search device) in the service detection area including the client device (first node) is connected to the service search device (search device) in the service detection region including the server device (node other than the first node). Between
The positions of the service search devices (search devices) acquired so far are notified to each other. As described above, the service search devices (search devices) included in the different service detection regions (areas) are notified of the positions of the service search devices (search devices), so that the different service detection regions (areas) are notified. ), The service search device is linked to the service search device, the client device (first
Node), the area where the service can be searched is widened, and the database can be flexibly constructed.

Further, the outline of the node searching method according to the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a network system 1 to which a node search method according to the present invention is applied. 2 and 3 are first and second diagrams for explaining the node search method according to the present invention. For example, as shown in FIG. 1, the node search method according to the present invention includes a plurality of service detection areas 10A to 10A including nodes that form a network such as a client device 3 and server devices 4A to 4C and service search devices 5A to 5B. 10C is applied to the network system 1 connected via the wide area network 12 or the like.

The user of the client device 3 in the service detection area 10A may discover an unknown server device 4B in another service detection area 10B by an empirical method. Here, the empirical method is, for example, by an electronic means such as the service searching device 5A, such as being taught by an acquaintance, knowing what is introduced in a publication such as a magazine, or seeing a commercial advertisement. Pointing to no way. The user uses the server device 4B thus discovered by using the client device 3, and further, as shown in FIG. 2, the information of the server device 4B is used as the service search device included in the same service detection area 10A. 5
Even if A is notified, the service search device 5A cannot know the existence of the service search device 5B in the service detection area 10B.

On the other hand, as shown in FIG. 3, the client device 3 has the service search device 5 in the service detection area 10A.
When the server device 4B notifies the service searching device 5B of the position of A and, conversely, the server device 4B notifies the service searching device 5A of the position of the service searching device 5B in the service detection area 10B, the service searching devices 5A and 5B are notified. It is possible to communicate with each other by using each other's position. In this way, when the service search devices 5A and 5B are set in the communicable state and the information of the server devices 4A and 4B included in the service detection areas 10A and 10B are searched for each other, the client device 3 By accessing the service search device 5A, not only the server device 4A included in the service detection area 10A but also the server device 4B included in the service detection area 10B can be searched.

As described above, each time the client device 3 communicates with the server devices 4B and 4C included in the other service detection regions 10B and 10C and uses the service, the server devices 4B and 4C cause the service detection regions 10B to be detected. , 10C
If the position of the service search devices 5B and 5C of the above is notified to the service search device 5A, the service search device 5A
The range in which the server device can be searched for gradually expands. Finally, by accessing the service searching device 5A, the server device can be searched over the entire network system 1. Become.

[First Embodiment] A first embodiment of the present invention will be described. FIG. 4 is a diagram illustrating a configuration of the network system 2 to which the node search method according to the present invention is applied. As shown in FIG. 4, the network system 2
Is configured by connecting IP networks 10A to 10C and a wide area network 12 such as the Internet via firewall devices 16A and 16B and a router device 14. IP network 10A-10
Each of the Cs is the above-described service detection area that depends on the mutual connection relationship and the management subject, and is the client device 3,
Server devices 4A-4C and service search devices 6A-6
Each includes one or more Cs (however, the client devices 3 of the IP networks 10B and 10C are omitted in FIG. 4).

Inside each of the IP networks 10, all the server devices 4 (server devices 4A to 4C.
Service search devices 6A to 6C / IP network 10A
10C to 10C without specifying any of them, simply server device 4, service search device 6, IP network 1
(Also referred to as 0) can advertise the information of the server device 4 to all the service search devices 6 by IP multicast (broadcast) communication. In addition, in the network system 2, communication other than IP multicast (broadcast) is performed by a message described in XML and an HTTP protocol. With these components, the network system 2 realizes the node searching method according to the present invention, the outline of which is described with reference to FIGS.

[Hardware Configuration] First, the hardware configurations of the client device 3, the server device 4, and the service search device 6 will be described.

[Client Device 3 / Service Search Device 6] FIG. 5 is a diagram illustrating the hardware configuration of the client device 3 and the service search device 6 shown in FIG. As shown in FIG. 5, the client device 3 and the service search device 6 include a main body 400 including a CPU 402 and a memory 404, a communication device 420 that communicates with other network nodes via the IP network 10, and an FD.
Device, CD device, HDD device, etc. recording device 440, C
The display / input device 460 includes an RT display device, a keyboard, a mouse, and the like, displays an image for a user interface (UI) to the user, and receives a user's operation. That is, the client device 3 and the service search device 6 include hardware as a general computer capable of communicating via a network.

[Server Device 4] FIG. 6 is a diagram illustrating a hardware configuration of the server device 4 shown in FIG. Note that, of the constituent parts shown in FIG. 6, those substantially the same as those in FIG. 5 are designated by the same reference numerals. As shown in FIG. 6, the server device 4 provides the same hardware as the client device 3 and the service search device 6 with the printer 480 when the server device 4 provides the print service, and the server device 4 provides the file service. In this case, the hardware necessary for the server device 4 to provide the service, such as the file system 482, is added.

[Software Configuration] Next, the software configurations of the client device 3, the server device 4 and the service searching device 6 will be described. The software (program) executed in the client device 3, the server device 4, and the service search device 6 is, for example, a recording medium 442.
It is supplied to each of the client device 3, the server device 4, and the service search device 6 via (FIGS. 5 and 6), and is loaded into the memory 404 and executed.

[Software Configuration of Client Device 3] FIG. 7 is a diagram showing the configuration of the client node program 30 executed in the client device 3 shown in FIG. As shown in FIG. 7, the client node program 30 includes the application client unit 30.
0, address acquisition unit 302 and service discovery unit 304
Composed of.

[Service Discovering Unit 304] The service discovering unit 304 in the client node program 30.
Is a position (IP address or the like) in the service search device 6A network system 2 which is set in advance,
In addition, as will be described later with reference to FIG. 8, the position (address) of the service search device 6A acquired by the address acquisition unit 302 is used, and the service search unit 600 of the service search device 6A (see FIG. 13, which will be described later with reference to FIG. 13,) and searches for the server devices 4A to 4C that provide the service desired by the user.

[Application Client Unit 300] In the application client unit 300, the user can display / input device 4
60 (FIG. 5), the position (IP address, etc.) of the server device 4 in the network system 2 and the position (address) of the server device 4 found as a result of the search using the service search device 6A. Via the IP networks 10A to 10C and the wide area network 12 to communicate with the application service unit 420 (described later with reference to FIG. 10) of the server devices 4A to 4C to provide the services provided by each. receive.

[Address Obtaining Unit 302] FIG. 8 is a flowchart showing the first process (S10) of the address obtaining unit 302 of the client node program 30 shown in FIG. FIG. 9 is a flowchart showing the second process (S12) of the address acquisition unit 302 of the client node program 30 shown in FIG. As shown in FIG. 8, the address acquisition unit 302 performs IP multicast (broadcast) communication and belongs to the same (same) IP network 10A in which the service search device 6A belongs.
(S100), and receives the response returned from the service search device 6A in response to this request (S10).
2). The response from the service search device 6A includes the position (address) of the service search device 6A, and the address acquisition unit 302 stores the position (address) of the service search device 6A included in this response (S104). ).

Further, as shown in FIG. 9, when the address acquisition unit 302 communicates with the server devices 4B and 4C of the (other) IP networks 10B and 10C not included therein, the application client unit 300. Receives a notification of the position (address) of the server device 4 that provides the service (S120). Next, the address acquisition unit 302 generates a message requesting acquisition of the position (address) of the service search device 6A included in the same IP network 10A as the client device 3 to the server devices 4B and 4C of the communication partner (S122). ), And transmits the generated message (S124).

Next, the server devices 4B and 4C of the communication partner
However, when the response message is returned in response to this request, the address acquisition unit 302 receives this response (S12).
6). Next, the address acquisition unit 302 sends the same IP network 10 to the server devices 4B and 4C of the communication partner.
Position (address) of the service search device 6A included in A
Is generated and the generated notification message is transmitted to the communication partner server devices 4B and 4C (S128). The server devices 4B and 4C access the service searching device 6A by using the position (address) of the service searching device 6A received from the client device 3, and the positions (address) of the service searching devices 6B and 6C.
To the service search device 6A (S130).

[Server Node Program 42] FIG. 10
FIG. 6 is a diagram showing a configuration of a server node program 42 executed in the server device 4 shown in FIG. Figure 1
As shown in 0, the server node program 42 includes an application service unit 422, an address acquisition unit 424, and a service information unit 426.

[Application Service Section 422] In the server node program 42 of the server devices 4A to 4A,
The application service unit 422 communicates with the application client unit 300 (FIG. 7) of the client device 3 to control the printer 480, the file system 482 (FIG. 6), and the like to request the requested service from the client. The device 3 is provided.

[Address Acquisition Unit 424] Server Device 4
In the server node programs 42 of B and 4C, when the address acquisition unit 424 communicates with the client device 3 of another IP network 10A, the address acquisition unit 302 (FIG. 7) of the client device 3
The notification of the position (address) of the service search device 6A of the IP network 10A is received. In addition, the server device 4B,
In the server node program 42 of each of the 4C, when the address acquisition unit 424 communicates with the client device 3, the address acquisition unit 424 uses the position (address) of the service searching device 6A notified from the client device 3 to communicate with the service searching device 6A. It communicates and notifies the service searching device 6A of the positions (addresses) of the service searching devices 6B and 6C included in the same IP networks 10B and 10C as the server devices 4B and 4C.

FIG. 11 is a flowchart showing the first process (S14) of the address acquisition unit 424 of the server node program 42 shown in FIG. FIG. 12 is a flowchart showing the second process (S16) of the address acquisition unit 424 of the server node program 42 shown in FIG. As shown in FIGS. 11 and 12, when the client device 3 requests the server devices 4B and 4C to notify the positions (addresses) of the service search devices 6B and 6C, the service search devices 6A and 6A are notified to the service search device 6A. 6B,
A response message including the position (address) of 6C is created, and the created response message is used as the service search device 6A.
Send to.

[Service Information Unit 426] The service information unit 426 uses the same IP network 1 at a fixed time interval, for example, by IP multicast (broadcast) communication.
For the service search device 6 included in 0, the server devices 4A to 4C are respectively present, positions (addresses), and
Information required for searching the server devices 4A to 4C, such as attributes of services provided by the server devices 4A to 4C, is announced, and a response from the service searching device 6 is requested (S1).
40). The service information unit 426 is used by the service search device 6
When the response from is received (S142), the position (address) of the service search device 6 is stored (S144).

[Search device program 60] FIG.
FIG. 5 is a diagram showing a configuration of a service search device program 60 executed by the service search device 6 shown in FIG. 4. As shown in FIG. 13, the service searching device program 60 includes a service searching unit 600 and an address receiving unit 60.
2, an address storage unit 604 and an information exchange unit 606.

[Service Search Unit 600] The service search unit 600 advertises information such as existence / location (address) and service attributes by IP multicast (broadcast) from the server devices 4 included in the same IP network 10. The received information of the server device 4 is stored. The service search unit 600 also receives a response request from the server device 4 by IP multicast (broadcast), and sends a response message including its own position (address),
It is returned to the server device 4.

Further, the service searching unit 600 of the IP network 10A responds to a request from the client device 3 included in the same IP network 10A, and the service searching devices 6B, 6 of the other IP networks 10B, 10C.
Information of the server devices 4A to 4C is searched in cooperation with C, and the client device 3 is notified of the information of the server device 4 obtained as a result of the search.

[Address Receiving Section 602] FIG.
6 is a flowchart showing a process of an address storage unit 604 of the service search device program 60 shown in FIG. The address reception unit 602 receives the position (address) of the service search device 6 included in the same IP network 10 as the server device 4 from the address acquisition unit 424 of the server device 4 included in another IP network 10, and The data is output to the storage unit 604 and the information exchange unit 606.

The processing of the address receiving unit 602 will be further described with reference to FIG. In the IP network 10A, the address receiving unit 602 of the service search device 6A
From the server devices 4B and 4C included in the other IP networks 10B and 10C to the other IP network 10
The message notifying the positions (addresses) of the service search devices 6B and 6C included in B and 10C is received (S1).
80). The address receiving unit 602 collates the received position (address) of the service search device 6B, 6C with another known service search device 6B, 6C already stored in the address storage unit 604 (S182).

As a result of the collation, the address receiving unit 602 finds that the newly received position (address) is already in the address storage unit 6.
If it is already registered in 04, the process is terminated, and in other cases, the process proceeds to S186 (S184). The address reception unit 602 outputs the positions (addresses) of the new service search devices 6B and 6C to the address storage unit 604 and registers them (S186). Address receiving unit 602
Notifies the information exchange unit 606 of the positions (addresses) of the new service search devices 6B and 6C.

[Address Storage Unit 604] The address storage unit 604 includes an address receiving unit 602 and an information exchanging unit 60.
6 stores and registers the position (address) of the service search device 6 included in another IP network 10 inputted from the IP network 6, and stores the stored (registered) position (address) of the service search device 6 in the address receiving unit 602 and the information exchange. Part 606
Output to.

[Information Exchange Unit 606] FIG. 15 is a flow chart showing the first process (S20) of the address storage unit 604 of the service search device program 60 shown in FIG. FIG. 16 is a flowchart showing the second process (S22) of the address storage unit 604 of the service search device program 60 shown in FIG. Information exchange section 6
06 is another IP input from the address receiving unit 602.
Known service search device 6 included in network 10
When the position (address) of a new service search device 6 which has been unknown until then is input using each position (address), the position (address) of this new service search device 6 is changed to another known position. The information exchange unit 606 of the service search device 6 of FIG. In addition, the information exchange unit 60
6 receives a notification of the position (address) of the new service searching device 6 from the information exchange unit 606 of another known service searching device 6, and notifies the notified position (address) of the new service searching device 6. Is output to the address storage unit 604.

Referring to FIGS. 15 and 16, the information exchange section 6
The processing of 06 will be further described. As shown in FIG. 15, when the information exchange unit 606 receives a notification of the position (address) of the new service search device 6 from the address reception unit 602 (S200), the information exchange unit 606 of the new service search device 6 is performed. A request message for requesting information exchange of the position (address) of the known service searching device 6 is generated (S202), and the generated request message is transmitted to the new service searching device 6 (S204). .

The information exchanging unit 606 determines whether or not a response message has been received from the new service search device 6 within a fixed time. If no response message is received, the process is terminated, and in other cases. Advances to the processing of S208 (S206). The information exchange unit 606 generates an address request message requesting the position (address) of the known service search device 6 acquired by the new service search device 6 (S208), and the generated address request message,
It is transmitted to the information exchange unit 606 of the known service search device 6 (S210).

The information exchange unit 606 receives a response message including the position (address) of the service searching device 6 newly acquired by the service searching device 6 from the new service searching device 6 (S212), and receives the received response message. Locations (addresses) of all service search devices 6 included in
And the position (address) of the service search device 6 stored / registered in the address storage unit 604 are compared (S2).
14).

The information exchanging unit 606 proceeds to the process of S218 if the address of the service searching device 6 in the received response message is not registered in the address storing unit 604, and ends the process otherwise. Yes (S21
6). The information exchange unit 606 uses the address of the service search device 6 in the received response message as the position (address) of the new service search device 6 which was unknown until then.
The address is registered in the address storage unit 604 (S218). Also,
The service search unit 600 periodically exchanges information with respect to the known service search device 6 by transmitting a message requesting information exchange to the known service search device 6. .

As shown in FIG. 16, the information exchange unit 606.
Receives a message requesting information exchange from the information exchange unit 606 of the known service search device 6 (S22).
0), generate a response message in response to this (S2
22), the generated response message is transmitted to the information exchange unit 606 of the known service search device 6 of the communication partner (S).
224). When the information exchange unit 606 receives a request message requesting verification of the position (address) of the known service search device 6 from the information exchange unit 606 of the other service search device 6 (S226), the information exchange unit 606 The positions (addresses) of all the service search devices 6 and all the service search devices 6 stored in the address storage unit 604.
Is compared with the position (address) (S228). In addition,
The information of the known service search device 6 is sent from the communication partner to the service search device 6 in the form of a list. Therefore, “the positions of all the service searching devices 6” mean the addresses of all the service searching devices 6 included in this list. The information exchanging unit 606 proceeds to the process of S232 when all the addresses are not registered in the address storing unit 604, and ends the process otherwise (S230).

The information exchanging unit 606 registers the position (address) of the service searching device 6 which has been unknown until then in the address storing unit 604 (S232). Information exchange unit 606
Generates a response message including the newly acquired address (matching result) of the service search device 6 (S234),
The generated message is sent to the service search device 6 of the communication partner.
To the information exchange unit 606.

[Overall Operation of Network System 2] The overall operation of the first embodiment of the network system 2 for executing the node search method according to the present invention will be described below with reference to FIGS. FIG. 17 is a first diagram showing the overall operation of the network system 2 according to the first embodiment, and shows a service announcement process performed by the server device 4 at startup and periodically. As shown in FIG. 17, the server apparatus 4 (for example, the server apparatus 4A) performs IP multicast (broadcast) communication with the same IP network 10B at the time of startup and at a fixed period after startup. , Announce one's existence (1).
The service search device 6B is waiting for the IP multicast (broadcast) communication from the server device 4B, and the new server device 4B is notified by the announcement from the server device 4B.
18 is detected, the server device 4B is requested for service information as shown in FIG. 18 (2). The server device 4B notifies the service information held therein in response to the request from the service search device 6B (3).

FIG. 18 shows the first part of the network system 2.
2 is a second diagram showing the overall operation in the embodiment of FIG.
Indicates service information. As shown in FIG. 18, the service information includes service type, network information, geographical information, license information, and service attributes. The service type indicates the type of service provided by the server device 4, and examples of the service type include a print service and a scan service. The network information uniquely identifies the server device 4B in the network system 2. As an example of the network information, the IP address and FQDN (Full DN) are used.
y Qualified Domain Name), URI (Universal Resou
rce Identifier).

The geographical information is information indicating the geographical position of the server, and must always include latitude and longitude coordinates, for example. The license information defines the range in which the service is open to the public, and may be unlimited or network limited.

The service attributes are composed of general attributes and service-dependent attributes. The general attributes include, for example, billing information, transfer protocol information, operating organization information and service dependent attributes. The billing information indicates the usage fee of the service and the payment method. Security information is
Contains a list of security protocols supported by the service. The transfer protocol information is a communication protocol or API (Applicatio) for using the service.
n Program Interface).

The operating organization information indicates the names and contact methods of companies, departments, groups, individuals, etc. who are the operators of the service. The service-dependent attribute is defined for each service type, and includes quality, performance, additional functions, a list of supported document formats, a list of supported languages, a list of supported character sets, driver acquisition information, and the like.

FIG. 19 shows the first part of the network system 2.
FIG. 6 is a third diagram showing the overall operation in the embodiment of
The service detection processing which the service search device 6 performs at the time of starting is shown. Further, as shown in FIG. 19, the service search device 6
(For example, the service search device 6B) announces its own existence by performing IP multicast (broadcast) communication at the time of activation (1). The server device 4B uses the IP multicast (broadcast) from the service search device 6B.
When waiting for communication, the server device 4B, upon detecting the advertisement of the service search device 6B, notifies the service search device 6B of the service information as shown in FIG. 18 (2).

The service search device 6B is the server device 4B.
Holds the service information notified from the server device 4B
If you do not receive the service announcement from the company for a certain period of time, discard it. The period from newly holding the service information to discarding the service information is set by the administrator of the IP network 10B, etc. Normally, by setting it to about 2 days, the power of the server device 4B is turned on and off on a daily basis. It is possible to avoid unnecessary discarding due to turning off. The service search device 6B is the IP network 10B.
The service information notified from the server device 4B in the above is stored.

FIG. 20 shows the first part of the network system 2.
FIG. 4B is a fourth diagram showing the overall operation in the embodiment of
The communication sequence when notifying the position (address) of the service searching device 6B on the server device 4 (for example, the server device 4B) side to the service searching device 6A on the client device 3 side is shown. As shown in FIG. 20, the client device 3 uses the service of the server device 4 (for example, the server device 4B) (1).

The server device 4B receives the notification of the position (address) of the service searching device 6A from the client device 3 (2). The server device 4B is replaced by the service search device 6A.
To the service search device 6B (3), and the service search device 6A uses the position (address) notified from the server device 4B to communicate with the service search device 6B. (4).

FIG. 21 shows the first part of the network system 2.
5 is a fifth diagram showing the overall operation in the embodiment of FIG.
A process in which the client device 3 searches for the server device 4 by using the service searching device 6A is shown. As shown in FIG. 21, the client device 3 is connected to the IP network 10A.
By performing IP multicast (broadcast) communication to the inside, a response is requested from the service search device 6A in the IP network 10A (1). The service search device 6A waits for an IP multicast (simultaneous same) communication from the client device 3 to the IP network 10A, and when this is received, the IP network 10A
It announces its own existence by responding to the inside by IP multicast (broadcast) communication (2).

The client device 3 notifies the service search device 6A of the query describing the search conditions and makes a service search request (3). Service search device 6A
When receiving the service search request from the client device 3, the server device 4A in the IP network 10A
At the same time as searching the service information of (1), another service searching device 6 (for example, the service searching device 6B) is requested to search (4). The service search request result is received from the other service search device 6B (5), and the own IP network 10 is received.
The search result of the server device 4A in A is merged and the client device 3 is notified as a service search result.

[Modification] In the first embodiment, for simplification of description, the IP networks 10A to 10A.
Although the case where each of 10C is one service detection area is illustrated, each of the IP networks 10A to 10C may include a plurality of service detection areas.
Plural of the IP networks 10A to 10C may configure one service detection area. Further, the service search device 6B uses the network management protocol SNMP.
It is also possible to collect service information from the server device 4B by (Simple Network Management Protocol).

The client device 3 has the network address of the service searching device 6A normally used by the user registered in advance by the user, and is registered in response to the service searching device address acquisition request from the server device 4B. It may be configured to respond with the position (address) of the service search device 6A. In addition, the service search device 6A sends W to the client device 3.
The eb page may provide a dedicated search function.
Further, the server devices 4B and 4C directly connect the service search device 6 to the service search device 6A of the IP network 10A.
Instead of notifying the positions (addresses) of B and 6C, the server devices 4B and 4C notify the service searching device 6A via the client device 3 of the positions (addresses) of the service searching devices 6B and 6C. Good.

FIG. 22 shows the first part of the network system 2.
FIG. 6 is a sixth diagram showing the overall operation in the embodiment of
The communication sequence when notifying the position (address) of the service searching device 6A on the client device 3 side to the service searching device 6 on the server device 4 side is shown. Note that the notification of the position between the service search devices 6A and 6B is shown in FIG.
It can be modified as shown in FIG. As shown in FIG. 22, the client device 3 is a server device 4 (for example, a server device 4B) included in another IP network 10.
When the above service is used (1), the server device 4 acquires the position (address) of the service search device 6A included in the same IP network 10A as the client device 3 (2).

The server device 4B communicates with the service searching device 6A using the acquired position (address) of the service searching device 6A, and the position (address) of the service searching device 6B included in the same IP network 10 as the server device 4B. To the service search device 6A (3). The service search device 6A uses the position (address) of the service search device 6B notified from the server device 4B to exchange information on the known position (address) of the service search device 6 (4).

[Second Embodiment] The second embodiment of the present invention will be described below. FIG. 23 shows the network system 2.
FIG. 10 is a diagram showing a first operation in the second exemplary embodiment.
FIG. 24 is a diagram showing a second operation of the network system 2 according to the second embodiment.

The node searching method according to the present invention shown in FIGS. 23 and 24 is a modification of the method of notifying the position between the service searching devices 6A to 6C in the network system 2. As shown in FIG. 23, when notifying the position (address) of the service searching device 6A to the service searching device 6 on the server device 4 side, the client device 3 uses the service of the server device 4 (for example, the server device 4B) ( 1), the server device 4B receives the notification of the position (address) of the service searching device 6A from the client device 3 (2), and the server device 4B sends the position (address) of the service searching device 6A to the service searching device 6B. And the service search device 6B uses the position (address) notified from the server device 4B.
It is also possible to communicate with (4).

It is also possible to change the operation as shown in FIG. That is, when notifying the position (address) of the service searching device 6 on the server device 4 side to the service searching device 6A on the client device 3 side,
When the client device 3 uses a service on a certain server device 4 (for example, the server device 4B), the server device 4
B is requested of the position (address) of the service search device 6B existing in the IP network 10B including the server device 4B, and this is acquired. The client device 3 notifies the service searching device 6A of the acquired position (address) of the service searching device 6B.

When the service searching device 6A is notified of the position (address) of the other service searching device 6B, the service searching device 6A communicates with the other service searching device 6B using the notified position (address). , Notify each other of a list of positions (addresses) of known service search devices 6 held by each other. The service search devices 6A and 6B respectively
The list of positions (addresses) of the known service searching device 6 notified from the service searching devices 6B and 6A of the communication partner and the list of positions (addresses) of the known service searching device 6 of its own are collated and registered. The unknown service search device address that has not been registered is added to the list of known service search device addresses.

[Third Embodiment] The third embodiment of the present invention will be described below. FIG. 25 is a diagram showing the configuration of the service search device program 70 shown as the third embodiment of the present invention. As shown in FIG. 25, the service search device program 70 executed in the service search device 6A has a configuration in which an application relay service unit 700 is added to the service search device program 60 shown in FIG. In the service search device program 70,
The application relay service unit 700 is the IP network 1
Client device 3 included in 0A and server devices 4B and 4C included in other IP networks 10B and 10C.
Relay communication with.

FIG. 26 shows a third network system 2.
FIG. 6 is a diagram showing a first operation in the exemplary embodiment. FIG. 27
FIG. 8 is a diagram showing a second operation of the network system 2 according to the third embodiment. As shown in FIG. 26, the service search device 6A on the client device 3 side moves from the server device 4 (for example, the server device 4B) to the service search device 6
When acquiring the position (address) of B, the client device 3 uses the service of the server device 4B via the service searching device 6A that executes the service searching device program 70 (1), and the service searching device 6A It is also possible to obtain the position (address) of the service search device 6B from the server device 4B (2), and the service search device 6A accesses the service search device 6B to perform communication (3).

Further, as shown in FIG. 27, the client device 3 has the server device 4 via the service searching device 6A.
(1) using the service of (for example, the server device 4B),
The server device 4B acquires the position (address) of the service searching device 6A (2), the server device 4B notifies the service searching device 6B of the acquired address, and the service searching device 6B accesses the service searching device 6A. It is also possible to communicate (4).

[Fourth Embodiment] The fourth embodiment of the present invention will be described below. FIG. 28 is a diagram showing the operation of the network system 2 according to the fourth embodiment. As shown in FIG. 28, the client device 3 uses the service of the server device 4 (for example, the server device 4B) (1), and the client device 3 notifies the position (address) of the server device 4B to the service search device 6A ( 2), the service search device 6A acquires the position (address) of the service search device 6B from the server device 4B (3), and the service search device 6A accesses the service search device 6B to perform communication (4).
It is also possible.

[Fifth Embodiment] The fifth embodiment of the present invention will be described below. FIG. 29 shows the network system 2
It is a figure which shows the operation | movement in 5th Embodiment of this. In the fifth embodiment, the service search device 6 and the client device 3
It is applied when and are integrally configured. As shown in FIG. 29, the client device 3 also serving as the service searching device 6A uses the service of the server device 4 (for example, the server device 4B) (1) and acquires the position (address) of the service searching device 6B (2). , The acquired position (address) of the service search device 6B to the other IP network 1
The client device 3 that also serves as the service search device 6C of 0 (for example, the IP network 10C) is notified (3).
In this way, the service search device 6 and the client device 3
Can be integrally configured, and the service search device 6 and the server device 4 can also be integrally configured.

[Effect] As described above, according to the network system 2 to which the node searching method according to the present invention is applied, another service searching device existing outside the reach range of the simultaneous broadcast communication is automatically detected. It is discoverable, flexible, and does not generate excessive traffic. Further, according to the network system 2, it takes a very long time to search for a service over the entire network, but since the service usage information of the user is used, the range of the usage behavior of the user can be found in a short time. . Therefore, according to the present invention,
To provide a flexible service search system and device that does not require manual operation or knowledge while achieving both (1) wide range of searchable range and (2) diversity of searchable objects at the same time. Is possible.

[0086]

As described above, according to the node search system and method according to the present invention, a node suitable for a service desired by a user can be searched from unknown nodes included in the network. it can. Further, the node search system and method according to the present invention have a wide searchable range and various searchable objects.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a network system to which a node search method according to the present invention is applied.

FIG. 2 is a first diagram for explaining a node search method according to the present invention.
FIG.

FIG. 3 is a second diagram for explaining the node search method according to the present invention.
FIG.

FIG. 4 is a diagram illustrating a configuration of a network system to which a node search method according to the present invention is applied.

5 is a diagram illustrating a hardware configuration of a client device and a service search device illustrated in FIG.

FIG. 6 is a diagram illustrating a hardware configuration of the server device illustrated in FIG.

7 is a diagram showing a configuration of a client node program executed in the client device shown in FIG.

8 is a flowchart showing a first process (S10) of the address acquisition unit of the client node program shown in FIG.

9 is a flowchart showing a second process (S12) of the address acquisition unit of the client node program shown in FIG.

10 is a diagram showing a configuration of a server node program executed in the server device shown in FIG.

11 is a flowchart showing a first process (S14) of the service information section of the server node program shown in FIG.

12 is a flowchart showing a second process (S16) of the service information section of the server node program shown in FIG.

13 is a diagram showing a configuration of a service search device program executed in the service search device shown in FIG.

FIG. 14 is a flowchart showing processing of an address storage unit of the service search device program shown in FIG.

FIG. 15 is a flowchart showing a first process (S20) of the address storage unit of the service search device program shown in FIG.

16 is a flowchart showing a second process (S22) of the address storage unit of the service search device program shown in FIG.

FIG. 17 is a first diagram showing the overall operation of the network system according to the first embodiment, and shows service announcement processing performed by the server device at startup and periodically.

FIG. 18 is a second diagram showing the overall operation of the first embodiment of the network system, showing service information.

FIG. 19 is a third diagram showing the overall operation of the first embodiment of the network system, showing the service detection processing performed by the service search device at the time of startup.

FIG. 20 is a fourth diagram showing the overall operation in the first embodiment of the network system, in which the service search device on the server device (for example, server device 4B) side is different from the service search device on the client device 3 side; The communication sequence when notifying a position (address) is shown.

FIG. 21 is a fifth diagram showing the overall operation in the first embodiment of the network system, showing the processing in which the client device searches for the server device using the service searching device.

FIG. 22 is a sixth diagram showing the overall operation of the first embodiment of the network system, in which the position (address) of the service search device on the client device side is notified to the service search device on the server device side. The communication sequence when performing is shown.

FIG. 23 is a diagram showing a first operation in the second embodiment of the network system.

FIG. 24 is a diagram showing a second operation in the second embodiment of the network system.

FIG. 25 is a diagram showing a configuration of a service search device program shown as a third embodiment of the present invention.

FIG. 26 is a diagram showing a first operation in the third embodiment of the network system.

FIG. 27 is a diagram showing a second operation in the third embodiment of the network system.

FIG. 28 is a diagram showing an operation in the fourth embodiment of the network system.

FIG. 29 is a diagram showing operations in the fifth embodiment of the network system.

[Explanation of symbols]

1, 2 ... Network system 10 ... IP network (service detection area) 12 ... Wide area network 3 ... Client device 400 ... Main body 402 ... CPU 404 ... Memory 420 ... communication device 440 ... Recording device 442 ... Recording medium 460 ... Display / input device 30 ... Client node program 300 ... Application client section 302: Address acquisition unit 304 ... Service Discovery Department 4 ... Server device 480 ... Printer 482 ... File system 42 ... Server node program 422 ... Application Service Department 424 ... Address acquisition unit 426 ... Service information section 5, 6 ... Service search device 60, 70 ... Program for service search device 600 ... Service search unit 602 ... Address receiving unit 604 ... Address storage unit 606 ... Information exchange section 700 ... Application relay service department

Claims (7)

[Claims] 1. A node search system for a network including a plurality of areas, wherein each of the plurality of areas includes at least one node and at least one search device, and each of the first nodes of the nodes is , A first searching unit that communicates with a searching device in the same area to search the position of another node in the network, and communicates with another node using the position of the node obtained by the searching and other than the searching. Each of the nodes notifies the position of the search device in each area to the node or the search device in the other area, and the position of the search device in the other area. When the notification of the search device is received, the search device in the other region is notified of the position of the search device in the other notified region, and each of the search devices is searched for in the other notified region. By using the position,
A notification means for communicating with a search device in another area and mutually notifying the position of the search device held by each, and a search in the other area notified in response to the communication of the client device in the same area. A node search system having a second search means for searching the position of a server device by communicating with a search device in another area using the position of the device. 2. The node search system according to claim 1, wherein the first node is a client device that receives a service, and the nodes other than the first node are server devices that provide a service. . 3. The node search system according to claim 2, wherein the search device is configured integrally with the client device or the server device. 4. The node search system according to claim 1, wherein the search device further includes a relay device that relays between the first node and a node other than the first node. . 5. A network search device including a plurality of areas, wherein each of the plurality of areas includes at least one node and at least one search device, and each of the first nodes of the nodes includes: Communicates with search devices in the same area to find the position of other nodes in the network,
Using the position of the node obtained by the search and other than the search, communicate with other nodes, each of the nodes,
To a node or a search device in the other area, the position of the search device in each area is notified, and when the notification of the position of the search device in the other area is received, the other notified The position of the search device in the area, notifies the search device in the same area, using the position of the search device in the other notified region,
A notification means for communicating with a search device in another area and mutually notifying the position of the search device held by each, and a search in the other area notified in response to the communication of the client device in the same area. A search device having a search means for communicating with a search device in another area using the position of the device and searching the position of the server device. 6. A node search method for a network including a plurality of areas, wherein each of the plurality of areas includes at least one node and at least one search device, and each of the first nodes of the nodes is , Communicating with a search device in the same area to search the position of the other node in the network, using the position of the node obtained by the search and other than the communication, communicate with other nodes, each of the nodes , The node or the search device in the other area is notified of the position of the search device in each area, and when the notification of the position of the search device in the other area is received, the other notified The position of the search device in the area of, notifies the search device in the same area, each of the search device, by using the position of the search device in the other notified region,
It communicates with the search devices in other areas, notifies each other of the positions of the search devices held by them, and responds to the communication of the client devices in the same area, and the notified position of the search devices in the other area. A node search method for communicating with a search device in another area to search the position of the server device using. 7. A program for realizing a node search method for a network including a plurality of areas, wherein each of the plurality of areas includes at least one node and at least one search device, respectively. In each of the nodes, the step of communicating with the search device in the same area to search the position of the other node in the network, and communicating with the other node by using the position of the node obtained by the search and other than the search. The step of performing a computer, in each of the nodes, to the node or search device in the other area, notifies the position of the search device in each area, the search device in the other area When a location notification is received, the step of notifying the location of the search device in the other area notified to the search device in the same area is compiled. Is performed over data, in each of the searching device, using the position of the search device the notified other regions,
Communicating with a search device in another area and mutually notifying the position of the search device held by each, and responding to the communication of the client device in the same area, the search device in the other area notified. A program that causes the computer to execute the step of searching for the position of the server device by communicating with the search device in another area using the position of.