Abstract:
When a first service providing device and a second service providing device located on a network have a dependent relationship, services can be disclosed and provided, with the dependent relationship held. A service utilizing device inquires of a service disclosing device regarding available services. The service disclosing device refers to service information and sends back, to the service utilizing device, an address of the first service providing device for providing a first service. The service providing device accepts a service request from the service utilizing device, refers to manageable target information, and issues a service request to the second service providing device by use of an address of the second service providing device being under non-disclosure. The second service providing device executes services and sends back requested information to the service utilizing device via the first service providing device.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to service disclosing and providing technologies suitable for use in network systems, and particularly to a service disclosing and providing technology having a dependent relationship between services. 
   It is common practice that the services of a network system comprising a service utilizing device, a service disclosing device, and one or more service providing devices have heretofore been provided to disclose all of those existing on a network. 
   A conventional typical service disclosing method will be explained with reference to  FIGS. 18 through 24 .  FIG. 18  is a diagram showing one configuration example of a conventional system for disclosing services existing on a network. In  FIG. 18 , reference numeral  10  denotes a service utilizing device,  30  denotes a service disclosing device,  100  denotes a first service providing device, and  120  denotes a second service providing device. The service utilizing device  10 , the service disclosing device  30 , the first service providing device  100 , and the second service providing device  120  are connected to one another via a network  90 . 
   The service utilizing device  10  includes an input unit  11 , an output unit  12 , a CPU  13 , a memory  14 , a communications unit  15 , and storage  16 . A service utilizing program  25  and a service inquiry program  23  are programs stored in the storage  16  and executed by the CPU  13  after they have been read into the memory  14 . 
   The service disclosing device  30  includes an input unit  31 , an output unit  32 , a CPU  33 , a memory  34 , a communications unit  35 , and storage  36 . A service inquiry processing program  41  and a service detection program  42  are programs stored in the storage  36  and executed by the CPU  33  after they have been read into the memory  34 . 
   The first service providing device  100  includes an input unit  101 , an output unit  102 , a CPU  103 , a memory  104 , a communications unit  105 , and a storage  106 . A first service program  111  and a service registration program  112  are programs stored in the storage  106  and executed by the CPU  103  after they have been read into the memory  104 . 
   The second service providing device  120  includes an input unit  121 , an output unit  122 , a CPU  123 , a memory  124 , a communications unit  125 , and storage  126 . A second service program  131  and a service registration program  132  are respectively programs stored in the storage  126  and executed by the CPU  123  after they have been read into the memory  124 . 
     FIG. 19  shows service information  44  stored in the storage  36  of the service disclosing device  30 . The service information  44  has, as data, a service ID  44 - 1  for identifying each service, a type  44 - 2  representing the type of service, and an address  44 - 3  representing the position of each service on a network. In the conventional service disclosing method, the services that have been registered in the service information  44  are all disclosed. 
   The flow of a process up to the registration of the services in the service information  44  will next be explained using  FIGS. 20 and 21 . 
     FIG. 20  is a diagram showing the flow of a process for registering the first service program  111  of the first service providing device  100  with the service information  44 . When the first service program  111  is executed, the service registration program  112  is first started up to execute its registration. The service registration program  112  performs broadcast transmission of a service registration request to the network  90  via the communications unit  105 . In doing so, the service detection program  42  being executed on the service disclosing device  30  receives the service registration request via the communications unit  35  and registers the registration-requested services with the service information  44 . 
     FIG. 21  is a diagram showing a process for registering the second service program  131  of the second service providing device  120  in the service information  44 . When the second service program  131  is executed, the service registration program  132  is started up to execute its registration in a manner similar to  FIG. 20 . The service registration program  132  performs broadcast transmission of a service registration request, and the service detection program  42  registers services requested for registration with the service information  44  after it has received the registration request. 
   The flow of a process up to the utilization of services by the service utilizing device  10  will finally be explained using  FIGS. 22 through 24 . 
     FIG. 22  is a diagram showing the flow of a process for allowing the service utilizing program  25  of the service utilizing device  10  to make an inquiry about services on the network. When the service utilizing program  25  is executed, the service inquiry program  23  is started up to make an inquiry about information of available services. The service inquiry program  23  performs broadcast transmission of a service inquiry request to the network  90  via the communications unit  15 . In doing so, the service inquiry processing program  41  being executed on the service disclosing device  30  receives a registration request through the communications unit  35  and sends back a list of services that satisfy an inquiry condition of the services registered with the service information  44 , as a response message. 
   The inquiry condition contains the type of service. Thus, in the case of an inquiry for a first type of service, the service inquiry processing program  41  sends back information about the first service program  111 . In the case of an inquiry for a second type of service, the service inquiry processing program  41  sends back information about the second service program  131 . When the first type and the second type are indicative of the same kind, the service inquiry processing program  41  sends back the information about the first service program  111  and the second service program  131 . 
     FIG. 23  is a diagram showing the flow of a process for allowing the service utilizing program  25  to be served by the first service program  111 . The service utilizing program  25  makes an inquiry about the first type of service under the flow of  FIG. 22  to thereby obtain the information about the first service program  111 . Thereafter, the service utilizing program  25  designates an address for the first service program  111  to request the first service program  111  to execute services and accepts a response obtained as the result of service execution by the first service program  111 . 
     FIG. 24  is a diagram showing the flow of a process for allowing the service program  25  to be served by the second service program  131 . The service utilizing program  25  makes an inquiry about the second type of service to thereby obtain address information on the second service program  131 . Thereafter, the service utilizing program  25  designates an address for the second service program  131  to request the second service program  131  to execute services and receives a response obtained as the result of service execution by the second service program  131 . 
   Non-Patent Document 1: 
   E. Guttman and three more inventors, &amp; quot; Service Location Protocol, Version 2 &amp; quot; [online], June 1996, IETF, [retrieved on Dec. 16, 2002], Internet: &amp;lt;URL:http://www.ietf.org/rfc/rfc2608.txt&amp;gt; 
   When a first service and a second service have a dependent relationship, e.g., when the first service has a security function and permits the provision of a second service only for a user having an access right, and the second service provides substantial service, it is desirable that users are not able to access the second service. According to the prior art, however, the users are able to directly make use of the second service because the service disclosing device discloses all services that meet conditions inquired by the users. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to make it possible to disclose and provide services in a state in which a dependent relationship between such services is being held. 
   The present invention provides a technology for disclosing and providing services where first service providing means and second service providing means located on a network have a dependent relationship. This technology is characterized by, responsive to an inquiry issued from service utilizing means, sending back by a service disclosing means a location of the first service providing means being under disclosure to the service utilizing means; receiving by the first service providing means a service request sent from the service utilizing means to request the second service providing means to provide services by using a location of the second service providing means being under non-disclosure; and sending back by the second service providing means the requested information to the service utilizing means via the first service providing means. 
   Incidentally, other features of the present invention become apparent from the descriptions of the present specification and the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a configuration diagram of a service disclosing system according to a first embodiment; 
       FIG. 2  is a diagram illustrating manageable target information of a service providing device employed in the first embodiment; 
       FIG. 3  is a flowchart showing a device status acquiring process of the first embodiment; 
       FIG. 4  is a flowchart depicting a device status monitoring process of the first embodiment; 
       FIG. 5  is a diagram showing service information of a service disclosing device employed in the first embodiment; 
       FIG. 6  is a flowchart illustrating a service registering process of the first embodiment; 
       FIG. 7  is a flowchart depicting a service hierarchy acquiring process of the first embodiment; 
       FIG. 8  is a flowchart showing a service inquiring process of the first embodiment; 
       FIG. 9  is a configuration diagram illustrating a service disclosing system according to a second embodiment; 
       FIG. 10  is a diagram depicting service information of a service disclosing device employed in the second embodiment; 
       FIG. 11  is a diagram showing user information of a service providing device employed in the second embodiment; 
       FIG. 12  is a diagram illustrating access right information of the service providing device employed in the second embodiment; 
       FIG. 13  is a diagram showing the format of a device status acquisition/setting message employed in the second embodiment; 
       FIG. 14  is a flowchart illustrating a device status acquisition/setting process employed in the second embodiment; 
       FIG. 15  is a configuration diagram showing a service disclosing system according to a third embodiment; 
       FIG. 16  is a diagram illustrating service information of a service disclosing device employed in the third embodiment; 
       FIG. 17  is a flowchart showing a device status report generating process employed in the third embodiment; 
       FIG. 18  is a diagram depicting one configuration example of a service disclosing system according to a prior art; 
       FIG. 19  is a diagram showing service information of a service disclosing device employed in the prior art; 
       FIG. 20  is a flowchart illustrating a service registering process employed in the prior art; 
       FIG. 21  is a flowchart depicting a service registering process employed in the prior art; 
       FIG. 22  is a flowchart showing a service inquiring process employed in the prior art; 
       FIG. 23  is a diagram illustrating a service utilizing process employed in the prior art; and 
       FIG. 24  is a flowchart showing a service utilizing/responding process employed in the prior art. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Preferred embodiments of the present invention will hereinafter be described with reference to the accompanying drawings. 
     FIG. 1  is a diagram showing a configuration of a first embodiment of the present invention, wherein services are disclosed over a network. In  FIG. 1 , reference numeral  10  denotes a service utilizing device,  30  denotes a service disclosing device,  50  denotes a first service providing device, and  70  denotes a second service providing device. The service utilizing device  10 , the service disclosing device  30 , the first service providing device  50 , and the second service providing device  70  are connected to one another via a network  90 . 
   The service utilizing device  10  includes an input unit  11 , an output unit  12 , a CPU  13 , a memory  14 , a communications unit  15 , and storage  16 . A device status acquisition/setting program  21 , a device status monitoring program  22 , and a service inquiry program  23  are programs stored in the storage  16 . After the programs have been read into the memory  14 , they are executed by the CPU  13 . 
   The device status acquisition/setting program  21  is a service utilizing program provided with a user interface for acquiring the statuses of hardware or software of devices constituting a computer system connected via a network  90  and setting these statuses. The device status monitoring program  22  is a service utilizing program provided with a user interface for detecting abnormalities of the hardware or software of the devices constituting the computer system connected via the network  90 . The service inquiry program  23  is a program for making inquiries about device status acquisition/setting and device status monitoring services existing on the network  90 , which program is started up by the device status acquisition/setting program  21  or the device status monitoring program  22 . 
   The service disclosing device  30  includes an input unit  31 , an output unit  32 , a CPU  33 , a memory  34 , a communications unit  35 , and storage  36 . A service inquiry processing program  41 , a service detection program  42 , and a service hierarchy acquisition program  43  are respectively programs stored in the storage  36 , which are executed by the CPU  33  after they have been read into the memory  34 . 
   The service inquiry processing program  41  is a program for providing information about services lying on the network  90  from information stored in service information  44  in response to an inquiry from a service utilizing program. The service detection program  42  is a program for detecting the services lying on the network  90  and storing the same in the service information  44 . The service hierarchy acquisition program  43  is a program for acquiring a dependent relationship between the services registered in the service information  44 . 
   The first service providing device  50  includes an input unit  51 , an output unit  52 , a CPU  53 , a memory  54 , a communications unit  55 , and storage  56 . A device status acquisition/setting service program  61 , a device status monitoring service program  62 , a service registration program  63 , and a manageable target detection program  64  are programs stored in the storage  56 , which are executed by the CPU  53  after they have been read into the memory  54 . 
   In response to a request for a service utilizing program, the device status acquisition/setting service program  61  starts up the corresponding service program registered with manageable target information  65 , thereby acquires the statuses of the hardware or software of the devices constituting the computer system, and sets these statuses. The device status monitoring service program  62  starts up the corresponding service program registered in the manageable target information  65 , and detects abnormalities of the hardware or software of the system-constituting devices. The service registration program  63  is a program for registering information about the device status acquisition/setting service program  61  and the device status monitoring service program  62  with the service disclosing device  30 . The manageable target detection program  64  is a program for detecting or registering service programs capable of providing services through the device status acquisition/setting service program  61  and the device status monitoring service program  62 . A list of the service programs capable of providing the services through the device status acquisition/setting service program  61  and the device status monitoring service program  62  is stored in the manageable target information  65 . 
   The second service providing device  70  is provided with an input unit  71 , an output unit  72 , a CPU  73 , a memory  74 , a communications unit  75 , storage  76 , a controller  77 , and a sensor  78 . The controller  77  is built in the corresponding device constituting the system and has a mechanism for reading or setting the status of the device. The sensor  78  is connected to an interface such as a bus in the device and detects the status of hardware/software of the device. A device status acquisition/setting service program  81 , a device status monitoring service program  82 , and a service registration program  83  are programs stored in the storage  76 , which are executed by the CPU  73  after they have been read into the memory  74 . 
   The device status acquisition/setting service program  81  is a program for, in response to a request from a service utilizing program, acquiring information about the hardware or software of the second service providing device  70  through the controller  77  and setting these information. The device status monitoring service program  82  is a program for monitoring the statuses of the hardware or software of the second service providing device  70  through the sensor  78  and notifying the registered service utilizing program of a fault upon detection of an abnormality. The service registration program  83  is a program for registering information about the device status acquisition/setting service program  81  and the device status monitoring service program  82  with the service disclosing device  30 . The second service providing device  70  can be provided for every target devices constituting the system. 
     FIG. 2  shows a data format of the manageable target information  65  stored in the storage  56  of the first service providing device  50 . The manageable target information  65  has, as data, a service ID  65 - 1  for identifying each service, a type  65 - 2  representing the type of service, and an address  65 - 3  representing the location of each service on the network. 
     FIG. 3  is a diagram showing the flow of a process for allowing the device status acquisition/setting program  21  of the service utilizing device  10  to acquire the information about the hardware or software of the second service providing device  70 . The device status acquisition/setting program  21  may acquire the information about the device&#39;s hardware or software provided by the second service providing device  70 . In this case, the device status acquisition/setting program  21  first transmits a request for device status acquisition to the device status acquisition/setting service program  61  of the first service providing device  50  without directly communicating with the device status acquisition/setting service program  81  of the second service providing device  70 . This device status acquisition request designates the type of device constituting the system. Thereafter, the device status acquisition/setting service program  61  transmits a request for device status acquisition to the device status acquisition/setting service program  81  and sends back its response to the device status acquisition/setting program  21 . Although a procedure for making a request for device status setting is similar to the above, the device status setting request contains the type of device and setting parameters. 
     FIG. 4  is a diagram showing the flow of a process for executing a fault notification from the device status monitoring service program  82  to the device status monitoring program  22  in case an abnormality occurs in the hardware or software of the second service providing device  70 . 
   First of all, the device status monitoring program  22  transmits a request for device status monitoring to the device status monitoring service program  62  of the first service providing device  50 . The device status monitoring request designates the type of device constituting the system. Thereafter, the device status monitoring service program  62  sends a request for device status monitoring to the device status monitoring service program  82 . When the device status monitoring service program  82  detects an abnormality of the hardware or software of the second service providing device  70  through the sensor  78 , it issues a fault notification to the registered service utilizing program in response to the device status monitoring request. 
     FIG. 5  shows a data format of the service information  44  stored in the storage  36  of the service disclosing device  30 . The service information  44  has, as data, a service ID  44 - 1  for identifying each service, a type  44 - 2  representing the type of service, an address  44 - 3  representing the location of each service on the network, and an upper service ID  44 - 4  for identifying services being in an mutual dependent relationship. 
   The service of ID 61  is a service for performing status acquisition/setting of the corresponding device being in operation at the first service providing device  50 . The service of ID 62  is a service for carrying out status monitoring of the device being in operation at the first service providing device  50 . The service of ID 61  and the service of ID 62  are disclosed because they have no upper services. 
   The service of ID 81  is a service for performing status acquisition or setting of the corresponding device being in operation at the second service providing device  70  and includes the service of ID 61  corresponding to the same type as an upper service. Thus, since the service utilizing program makes use of the service of ID 81  through the service of ID 61 , the service of ID 81  is not disclosed. 
   The service of ID 82  is a service for monitoring the status of the device being in operation at the second service providing device  70  and includes the service of ID 62  corresponding to the same type as an upper service. Thus, since the service utilizing program makes use of the service of ID 82  through the service of ID 62 , the service of ID 82  is not disclosed. 
     FIG. 6  is a diagram showing the flow of a process for registering the device status acquisition/setting service program  81  or device status monitoring service program  82  of the second service providing device  70  with the service information  44 . Incidentally, assume that the device status acquisition/setting service program  81  and the device status monitoring service program  82  have already been registered with the manageable target information  65  as shown in  FIG. 2 . 
   The device status acquisition/setting service program  81  or the device status monitoring service program  82  starts up or activates the service registration program  83  to make a request for service registration. This registration request is accompanied by the service ID  44 - 1 , type  44 - 2 , and address  44 - 3 . The service registration program  83  performs broadcast transmission of the service registration request to the network  90  via the communications unit  75 . In doing so, the service detection program  42  being in execution on the service disclosing device  30  receives the registration request via the communications unit  35 . When the service detection program  42  receives the registration request therein, it activates the service hierarchy acquisition program  43  to acquire service hierarchy information representing the relationship of mutual dependence between services from the first service providing device  50 . The service hierarchy information is accompanied by the service ID 44 - 1 , type  44 - 2  and address  44 - 3  of a registration-requested service, and the type  44 - 2  and address  44 - 3  of its upper service. When the service detection program  42  acquires the service hierarchy information, it sets the service ID  44 - 1  of the upper service and registers its service with the service information  44 . The dependent relationship between the services is registered with its corresponding upper service ID column  44 - 4  of the service information  44 . 
     FIG. 7  is a diagram showing the flow of a process for allowing the service hierarchy acquisition program  43  to acquire a service hierarchy. When the service hierarchy acquisition program  43  is started up by the service detection program  42 , it transmits a request for acquisition of a service hierarchy representing a dependent relationship between services to the manageable target detection program  64  of the first service providing device  50 . The present hierarchy acquisition request is accompanied by the service ID  44 - 1 , type  44 - 2  and address  44 - 3  of a registration-required service. When the manageable target detection program  64  receives the hierarchy acquisition request therein, it reads information about the service providing device to be managed from the manageable target information  65  stored in the storage  56 . Then the manageable target detection program  64  sets an upper service of the corresponding service program of the second service providing device  70  intended for the hierarchy acquisition request as its corresponding service program of the first service providing device  50 , and sends back service hierarchy information to the service hierarchy acquisition program  43 . 
     FIG. 8  is a diagram showing the flow of a process for allowing the device status acquisition/setting program  21  of the service utilizing device  10  to make an inquiry about each service on the network  90 . When the device status acquisition/setting program  21  is executed, the service inquiry program  23  is first started up to make an inquiry about information on device status acquisition/setting services. The service inquiry program  23  performs broadcast transmission of a service inquiry request to the network  90  via the communications unit  15 . In doing so, the service inquiry processing program  41  being executed on the service disclosing device  30  receives the service inquiry request via the communications unit  35  and sends back a list of disclosable services that satisfy an inquiry condition from within the services registered with the service information  44 . Here, the inquiry condition is to designate one or more types  44 - 2 . 
   The device status acquisition/setting program  21  acquires an address for the device status acquisition/setting service program  61  as an inquiry response. Next, the device status acquisition/setting program  21  issues a request for device status acquisition or a request for device status setting to the device status acquisition/setting service program  61 . The device status acquisition/setting service program  61  issues a request for device status acquisition or a request for device status setting to the device status acquisition/setting service program  81 , receives its response therein and sends it back to the device status acquisition/setting program  21 . A procedure for allowing the device status monitoring program  22  to obtain access to the device status monitoring service program  82  is similar to the above. The device status monitoring program  22  receives a fault notification from the device status monitoring service program  82  via the device status monitoring service program  62 . 
     FIG. 9  is a diagram showing a configuration of a second embodiment illustrative of a method of disclosing a service on a network in accordance with the present invention. The second embodiment illustrates an example in which a second service is worth executing a security management and has such a dependent relationship with a first service that the second service is utilized through the security management by the first service. 
   In  FIG. 9 , reference numeral  10  denotes a service utilizing device,  30  denotes a service disclosing device,  50  denotes a first service providing device, and  70  denotes a second service providing device. The service utilizing device  10 , the service disclosing device  30 , the first service providing device  50 , and the second service providing device  70  are connected to one another via a network  90 . The service utilizing device  10 , service disclosing device  30 , and second service providing device  70  are respectively identical in configuration to those shown in  FIG. 1 . 
   The first service providing device  50  includes an input unit  51 , an output unit  52 , a CPU  53 , a memory  54 , a communications unit  55 , and storage  56 . An access-to-device status acquisition/setting control service program  66 , a device status monitoring service program  62 , a service registration program  63 , and a manageable target detection program  64  are programs stored in the storage  56  and executed by the CPU  53  after they have been read into the memory  54 . The service registration program  63  and manageable target detection program  64  are programs identical, respectively, to those shown in  FIG. 1 . Only when a user has an access right, the access-to-device status acquisition/setting control service program  66  starts up or activates a corresponding service program registered with manageable target information  65  in response to a request from a service utilizing program to thereby acquire the statuses of hardware or software of the devices constituting a system and set these statuses. The type of its service corresponds to device status acquisition/setting of service information  44 . That is, the access-to-device status acquisition/setting control service program  66  exercises control on access rights in addition to acquisition/setting of each device status via an interface common to the device status acquisition/setting service program  61 . 
     FIG. 10  shows a data format of the service information  44  stored in the storage  36  of the service disclosing device  30 . In a manner similar to  FIG. 5 , the service information  44  has, as data, a service ID  44 - 1  for identifying each service, a type  44 - 2  representing the type of service, an address  44 - 3  representing the location of each service on a network, and an upper service ID  44 - 4  for identifying services being in a mutual dependent relationship. 
   The service of ID 66  is a service for performing status acquisition/setting of a device being in operation at the first service providing device  50  and is disclosed because it has no upper service. The service of ID 81  is a service for performing status acquisition or setting of a device being in operation at the second service providing device  70  and has the service of ID 66  corresponding to the same type as an upper service. Thus, since the device status acquisition/setting program  21  determines through the service of ID 66  whether or not to have an access right, and makes use of the service of ID 81  in this condition, the service of ID 81  is not disclosed. 
     FIG. 11  shows a data format of user information  67  stored in the storage  56  of the first service providing device  50 . The user information  67  has a user ID  67 - 1  for identifying each user, and a password  67 - 2  of each user as data. 
     FIG. 12  shows a data format of access right information  68  stored in the storage  56  of the first service providing device  50 . The access right information  68  includes, as data, a user ID  68 - 1  for identifying each user, a device ID  68 - 2  for identifying each system constituting device for executing an operation, a component ID  68 - 3  for identifying each component lying in the device for executing the operation, an acquisition operation  68 - 4  representing whether an acquisition operation is allowed or prohibited, and a setting operation  68 - 5  representing whether a setting operation is permitted or prohibited. 
     FIG. 13  is a diagram showing a data format of a request message P 13  transmitted from the device status acquisition/setting program  21  upon utilizing the service of the access-to-device status acquisition/setting control service program  66 . The request message P 13  contains a user ID for identifying each user who makes use of service, a password P 13 - 2 , a device ID P 13 - 3  for identifying a device defined as a target for performing acquisition or setting of a device status, a component ID P 13 - 4  for identifying each component, an operation name P 13 - 5  representing an acquisition or setting operation, and an operation parameter P 13 - 6 . 
     FIG. 14  is a diagram showing the flow of a process from the reception of a request for device status acquisition or setting from the device status acquisition/setting program  21  by the access-to-device status acquisition/setting control service program  66  to the sending-back of its response. The access-to-device status acquisition/setting control service program  66  receives a request for device status acquisition or setting from the device status acquisition/setting program  21  as a request message P 13  at Step  14 - 1  (S 14 - 1 ). At Step  14 - 2 , the access-to-device status acquisition/setting control service program  66  obtains a user ID and a password from the request message P 13 . At Step  14 - 3 , the access-to-device status acquisition/setting control service program  66  determines whether or not a set or pair of the user ID and password contained in the request message P 13  coincides with any row of the user information  67 . If the determination made in Step  14 - 3  is No, then the access-to-device status acquisition/setting control service program  66  proceeds to Step  14 - 8 , where it rejects execution of the operation and transmits an error message. 
   If the determination made in Step  14 - 3  is found to be Yes, then the access-to-device status acquisition/setting control service program  66  proceeds to Step  14 - 4 , where it acquires a device ID, a component ID and an operation name from the received request message P 13 . At Step  14 - 5 , the access-to-device status acquisition/setting control service program  66  determines using the access right information  68  whether or not the operation on each of the device ID and component ID contained in the corresponding request has been permitted. If the determination made in Step  14 - 5  is found to be No, then the access-to-device status acquisition/setting control service program  66  proceeds to Step  14 - 8 , where it rejects execution of the operation and transmits an error message. If the determination made in Step  14 - 5  is found to be Yes, then the access-to-device status acquisition/setting control service program  66  proceeds to Step  14 - 6 , where it acquires operation parameters from the request message P 13 . Next, at Step  14 - 7 , the access-to-device status acquisition/setting control service program  66  executes the requested operation. Further, the access-to-device status acquisition/setting control service program  66  transmits a response message containing a status code indicative of the success or unsuccess of the execution of the operation. 
     FIG. 15  is a diagram showing a configuration of a third embodiment illustrative of a method of disclosing a service on a network in accordance with the invention. The third embodiment is an example where a first service has a dependent relationship with a second service in utilizing the second service. 
   In  FIG. 15 , reference numeral  10  denotes a service utilizing device,  30  denotes a service disclosing device,  50  denotes a first service providing device, and  70  denotes a second service providing device. The service utilizing device  10 , the service disclosing device  30 , the first service providing device  50 , and the second service providing device  70  are connected to one another via a network  90 . The service disclosing device  30  and the second service providing device  70  are respectively identical in configuration to those shown in  FIG. 1 . 
   The first utilizing device  10  includes an input unit  11 , an output unit  12 , a CPU  13 , a memory  14 , a communications unit  15 , and storage  16 . A device status report generating program  24  and a service inquiry program  23  are programs stored in the storage  16  and are executed by the CPU  13  after they have been read into the memory  14 . The device status report generating program  24  is a service utilizing program provided with a user interface for generating a report of the statuses of hardware or software of devices constituting a system connected via a network  90 . 
   The first service providing device  50  includes an input unit  51 , an output unit  52 , a CPU  53 , memory  54 , a communications unit  55 , and storage  56 . A device status report generating service program  69 , a service registration program  63 , and a manageable target detection program  64  are programs stored in the storage  56  and are executed by the CPU  53  after they have been read into the memory  54 . The service registration program  63  and the manageable target detection program  64  are programs identical, respectively, to those shown in  FIG. 1 . The device status report generating service program  69  is a program for acquiring the statuses of the hardware or software of the system-constituting devices, registered with a manageable target information  65  and generating a report of the same. The manageable target information  65  is set so as to be able to identify each device constituting the computer system according to its type  65 - 2 . 
     FIG. 16  shows service information  44  stored in the storage  36  of the service disclosing device  30 . As is the case with  FIG. 5 , the service information  44  has, as data, a service ID  44 - 1  for identifying each service, a type  44 - 2  representing the type of service, an address  44 - 3  representing the location of each service on a network, and an upper service ID  44 - 4  for identifying services being in a mutual dependent relationship. The service of ID 69  is a service for generating a report of the status of the corresponding device being in operation at the first service providing device  50 , and is disclosed because it has no upper service. The service of ID 81  is a service for performing status acquisition/setting of the corresponding device being in operation at the second service providing device  70 , and has the service of ID 69  corresponding to a different type as an upper service. Thus, since the service utilizing program indirectly utilizes the service of ID 81  through the service of ID 69 , the service of ID 81  is not disclosed. 
     FIG. 17  is a diagram showing the flow of a process for allowing the device status report generating program  24  of the service utilizing device  10  to generate a report of the status of hardware or software of the second service providing device  70 . When the device status report generating program  24  acquires information about the hardware or software of the second service providing device  70 , it transmits a request for report generation to the device status report generating service program  69  of the first service providing device  50 . The report generation request designates one or more types  44 - 2 . Afterwards, the device status report generating service program  69  transmits a request for device status acquisition to a device status acquisition/setting service program  81  of the second service providing device  70 , generates a report from its response, and sends it back to the device status report generating program  24 . A data format of the device status acquisition request transmitted from the device status report generating service program  69  to the device status acquisition/setting service program  81  is identical to that of the device status acquisition request transmitted from the device status acquisition/setting service program  61  to the device status acquisition/setting service program  81 . 
   Incidentally, the aforementioned embodiment has described, as an example, the status acquisition/setting and status monitoring of each device constituting the computer system. However, the present invention is not limited to the embodiment but can be applied to the provision of services wherein a service utilizing device has a dependent relationship between a first service and a second service so that it may widely utilize the second service through the first service. 
   According to the present invention, when there is a dependent relationship between services, the services can be disclosed and provided with the dependent relationship held.