Abstract:
A telecommunications service control unit within which a plurality of controllers classified for service items are included makes quite easy to add a new telecommunications device under the same service control unit. Each control procedure of a controller corresponding to respective telecommunications device is standardized and also encoded as a result of classification of standardized procedure. Designating another code for calling out controller corresponding to the control procedure code, a conversion table between control procedure codes and call out code is provided for service control interface of corresponding classified service item. Service control controller which instructs all classified controllers applies the procedure codes to instruct corresponding service control interface and the instructed service control interfaces apply the call out code for call out the instructed specific controller. Accordingly, addition of new telecommunications device requires only to arrange controller for the new device and to modify the contents of the conversion table at the corresponding service control interfaces.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a telecommunications service control unit within a telecommunications switching network and method of operation of the telecommunications service control unit, and more particularly, to controlling a call processing between a call originating terminal and called terminal including switching operations. 
     2. Description of the Related Art 
     The conventional service control unit of this type described above uses a plurality of specific controls corresponding to user&#39;s requests, in addition to effecting the operation of a standard communication control system prepared in advance, as described in Japanese Patent Application Laid-Open No. 216568/87. 
     FIG. 1 is a block diagram illustrating an example of a conventional telecommunication service system configuration. 
     Service controller  801  is provided for corresponding to every connection services, contains a descriptive operating procedure, calls service common management/control means  821  for implementation and controls a requested telecommunications service, and as service control unit  101 , controls service implementation device  251  thereby to implement the communication service according to the instruction of the service controller  801 . 
     Service common management/controller  821  has a data library for control procedures necessary for all telecommunications services, from which the procedures of implementing a requested service are called out by service controller  801 , the procedures are referred to control such telecommunications apparatus as subscriber circuit controller  211  and switching controller  221 ; and the control procedures are executed through implementation device  251  upon called from service control means  801 . 
     Terminals  241  and  242  connected to each other via subscriber circuit controller  211 , switching controller  221  and subscriber circuit controller  212 . A service implementation processing involved in this connection, is executed by service control unit  101  which drives service controller  801  and service common management/controller  821 , so that subscriber circuit controller  211 , switching controller  221 , media controller  231  and subscriber circuit controller  212  are controlled through apparatus control interface  261 . 
     In executing this processing, service implementation device  251  is controlled by service controller  801  which applies service control-use memory  811  as a storage, causing each terminal controller to implement a requested service via service common management/controller  821  which applies service common management/controller-use memory  831  as a storage. 
     It is noted here that media controller  231  is a voice storage and/or a voice synthesizer unit, etc. 
     Next, referring to FIG. 1, this conventional technique is described in accordance with its functional aspect. 
     Terminal  241  requests service control unit  101  for a service through subscriber circuit controller  211 . In response to this request, service control unit  101  judges the service required, selecting the control procedure corresponding to the requested service through service controller  801 , and instructing service implementation device  251  to execute the control procedure selected by service controller  801 . 
     Service controller  801  is defined to call service common management/controller  821  which holds feasible processing procedures as the library within service control unit  101  and implementation device  251  undertakes a service implementation processing, under the control of service controller  801 . 
     The information, which is temporarily required during the operation of service controller  801  is written into and read out from service controller-use memory  811  according to the procedure built-in service controller  801 . 
     Service common management/controller  821  starts functioning in response to a call from service controller  801 . 
     Service common management/controller  821  has calling procedures to call each of such functions of subscriber circuit controller  211 , media controller  231 , switching controller  221 , subscriber circuit controller  212 , etc. which are driveable by service control unit  101  and in response to a request from service controller  801 , operates such telecommunications apparatus as subscriber circuit controller  211 , and so forth, via apparatus control interface  261 . 
     The information, which is temporarily required while service common management/controller  821  is proceeding with its processing, is stored into and read out from service common management/control-use memory  831 , following the procedure contained in service common management/control means  821 . 
     FIG. 2 is a block diagram illustrating one example of the conventional telecommunications service control system, wherein the principle of the invention disclosed in above Japanese Patent Application Laid-Open Publication No. 216568/87 is described. In the conventional telecommunications control system disclosed in the Japanese Patent Application Laid-Open Publication, controller (CC)  911  controls switching/connection-use communication path  901  according to a given procedure. 
     Logic node  922  includes therein data  951  related to service users, processing procedure  961 , etc. for satisfying a service user request. A detail of internal configuration  931  of node  922  is denoted in FIG.  2 . 
     Next, referring to FIG. 2, the conventional communication service control system is described with regard to its functioning. User A sends out a request a call with B to controller  911  through communication path  901 . Controller  911  starts node  921  corresponding to user A and then transfers an incoming call information to node  922  corresponding to user B. 
     Node  922  keeps information  931  concerning user B, as shown in the figure, and executes a judgment whether the incoming call is accepted or transferred to elsewhere. 
     The result of the judgment at node  922  is reported to controller  911 , and following this reported information, controller  911  controls communication path  901  for a connection processing. 
     However, the conventional technique confronts with the problems which will be referred to hereunder: 
     The first problem lies in that to enable controlling a newly added communication apparatus from service control unit  101 , it is needed to modify, over a great extent, the operational contents stored in the service common management/controller. 
     The reason thereof is that in the conventional service control unit  101 , respective telecommunications apparatus operating procedures are integrally contained in the service common management/controller in wholly configuration thereto, thus not allowing to renew the telecommunications apparatus operating procedures alone. 
     The second problem consists in that when a service controller and service common management/controller defined to operate within a service control unit are forced to implement across a plurality of service control unit, it is necessary to greatly modify the operational contents included in the service common management/controller. 
     The reason thereof is that to implement a service which needs to operate across a plurality of service control units, it is required to simultaneously control the telecommunications devices associated with this service from plural service controllers, because in spite of the requirement that an arbitration processing must be undertaken among service control units, for each telecommunications apparatus in a manner that respective controls of individual communication apparatus may not conflict with one another, as pointed out regarding the reason of the first problem, the communication apparatus operating procedures are stored in the service common management/controller, resulting in necessity to contain a required arbitration processing procedure in the service common management/controller. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention, which is achieved in consideration of the problems described above, to provide a service controller and a service control system allowing to reduce the amount of rewriting the operational contents of a control means, which rewriting becomes necessary not only for commissioning of new telecommunications apparatus with a service controller but also for adaptability thereof to the configuration of a different service controller. 
     In a telecommunications service control system configured to implement a telecommunications service through the control of a telecommunications apparatus, the service control unit of the present invention to achieve said object comprises control means for controlling telecommunications apparatus and software respectively, control-use memories which are used by the respective control means as a temporary storage, a control interface means for converting from call code representing a standardized control procedure to another code designating a corresponding controller, a service control means so programmed previously to utilize the control interface means for calling requested controller, a service control-use memory which the service control means applies as a temporary storage, and a service implementation device to actuate each of means described above. 
     Further, the present invention provides a control means, corresponding to one terminal, which comprises a control means for an actual terminal such as an originating call, a control means for a virtual terminal which is to be defined by connection environmental conditions, control-use memories corresponding to the control means respectively for the actual and virtual terminal, and control interfaces respectively for said actual and virtual terminal. 
     Further, the present invention has a service control library which stores all necessary standardized control procedures with respective represented codes classified for each control stage, a service control library-use memory which the service control library applies as a temporary storage, and owns a configuration, wherein the service control means calls the service control library while the service control library calls a group of said control interface means. 
     The present invention not only makes feasible a plurality of said telecommunications service control units to communicate with each other via an inter-telecommunications service control units path but also enables to implement telecommunications service across said plurality of telecommunications service control units. 
     Outlining the present invention, it is summarized that in the present invention, telecommunications service control is effected according to the control procedures included in a service controller. More precisely, service implementation device  251  illustrated in FIG. 3 implements a communication service, following the control procedures stored in service controller  111  in FIG.  3 . The service controller has a service implementation procedure stored therein previously, which is put into practice, using each of respective control interfaces  271 ,  272 ,  273 ,  274  and  275 , each holds the interface to standardized procedure for each of respective telecommunications apparatus and a software means, subscriber circuit controllers  211  and  212 , switching controller  221 , media controller  231  and address resolution controller  151 . 
     These control interfaces are each provided with a table of correspondence between the standardized control procedure for each communication apparatus, and the mode of calling by code which represents each of the control procedures respectively of controllers  121 ,  122 ,  131 ,  141 , and  151  corresponding to respective telecommunications apparatus. The controller corresponding to each of respective communication apparatus has a function to control actual communication apparatus  211 ,  212 ,  221 ,  231 ,  241  and  242 . 
     Service implementation device  251  transmits an instruction code representing requested control procedures operating instruction to a control interface according to the instruction of service controller  111 . Using a table of correspondence held with, the control interface converts a received instruction into a mode of calling a control means which control the corresponding actual telecommunications apparatus, executing the calling. Upon receiving a call, the control means actuate controlling of corresponding apparatus according to the contents of the instruction. 
     In the present invention, in case where the service control unit adds a new telecommunications apparatus under the same service control means, a new control means and a new control interface corresponding to the new telecommunications apparatus are provided; the service implementation device transmits the same operating code instruction as described above to the new control interface; and upon receiving the operating code instruction, the new control interface converts said operating code instruction into the mode of calling said new control means, subsequently executing the mode of calling. In response to a received call, the new control means actuate controlling of the corresponding apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a block diagram illustrating the configuration of a conventional system. 
     FIG. 2 is an illustrative figure presenting a configurational example of another conventional service control system. 
     FIG. 3 is a block diagram illustrating a functional configuration and an operating environment of the first embodiment according to the present invention. 
     FIG. 4 is a flowchart illustrating the processing by a service controller in this embodiment. 
     FIG. 5 is a block diagram showing a functional configuration and an operating environment into which different communication apparatus are introduced, in the first embodiment of the present invention. 
     FIG. 6 is a block diagram illustrating the second embodiment of the present invention and also showing a functional configuration and an operating environment in which a virtual terminal function is implemented. 
     FIG. 7 is a block diagram illustrating the third embodiment of the present invention and also showing a functional configuration and an operating environment, wherein a service control library is applied. 
     FIG. 8 is a block diagram illustrating the fourth embodiment of the present invention and also showing a functional configuration and an operating environment, wherein communication services are implemented across a plurality of service controllers. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, each embodiment of the present invention is described in detail. 
     FIG. 3 is a block diagram illustrating the configuration of the first embodiment according to the present invention. Referring to FIG. 3, the first embodiment of the present invention comprises program-controlled service control unit  101 , terminals  241  and  242 —the parties concerned in communication, subscriber circuit controller  211  for coupling these terminals with each other, switching controller  221 , subscriber circuit controller  212 , and media control unit  231  for transforming the contents of communication from one to another, or elsewhere. 
     Service control unit  101  comprises service implementation device  251  to implement communication services, apparatus control interface  261  controlling signal exchange between service control unit  101  and a telecommunications apparatus such as subscriber circuit controller  211 , etc., service control-use memory  161  serviceable as a temporary storage when service controller  111  operates, terminal control-use memory  171  serviceable as a temporary storage when terminal controller  121  is actuated, terminal control-use memory  172  serviceable as a temporary storage when terminal controller  122  is actuated, connection control-use memory  181  serviceable as a temporary storage when connection controller  131  is in operation, media control-use memory  191  serviceable as a temporary storage when media controller  141  operates, and address resolution control-use memory  201  serviceable as a temporary storage when address resolution controller  151  operates. 
     Service implementation device  251  executes corresponding service control, following the control procedure shown by service controller  111 , using service control-use memory  161  as a temporary storage. 
     Service controller  111  has functions as follows: 
     (a) a function to call terminal controller  121  through terminal control interface  271 ; 
     (b) a function to call terminal controller  122  through terminal control interface  272 ; 
     (c) a function to call connection controller  131  through connection control interface  273 ; 
     (d) a function to call media controller  141  through media control interface  274 ; and 
     (e) a function to call address resolution controller  151  through address resolution control interface  275 . 
     Service controller  111  provides necessary control procedures for a requested service, using these functions. 
     Terminal control interface  271  is caused to correspond to terminal controller  121  and keeps a conversion table between the information required to call respective control procedures selectively which is actually provided in terminal controller  121 , and the terminal control procedure discriminating information obtainable as a result of encoding discriminative by classifying a plurality of standardized control procedure groups of different type terminal controllers preliminary. 
     Further, in case where another controller such as service controller  111 , etc. calls the function of terminal controller  121 , another controller does not directly call terminal controller  121  but requests to execute a specific control method of terminal controller  121  by showing the discriminating information representing the requesting terminal control procedures to terminal control interface  271  corresponding to terminal controller  121 . 
     Terminal control interface  271 , receiving information of discriminating mode of terminal control, decides which control procedure is called from procedures provided in terminal controller  121  by detecting the conversion table held within and calls the decided procedure. 
     Terminal controller  121  is provided with a function to be called externally the standardized grouped control procedures of subscriber circuit controller  211  and terminal  241  which is controlled by terminal controller  121  through subscriber circuit controller  211 , and is controlled by service controller  111  via terminal control interface  271 , also controls subscriber circuit controller  211  through apparatus control interface  261 , and further controlling terminal  241  by way of subscriber circuit controller  211 . Furthermore, terminal controller  121  stores the temporary storage information necessary for the operation thereof in terminal control exclusive-use memory  171 . 
     Terminal control interface  272  is caused to correspond to terminal controller  122  and keeps a conversion table between the information required to call respective control procedures selectively which is actually provided in terminal controller  122 , and the terminal control procedure discriminating information obtainable as a result of encoding discriminative by classifying a plurality of standardized control procedure groups of different type terminal controllers preliminary. 
     Further, in case where another controller such as service controller  111 , etc. calls the function of terminal controller  122 , another controller does not directly call terminal controller  122  but requests to execute a specific control method of terminal controller  121  by showing the discriminating information representing the requesting terminal control procedures to terminal control interface  272  corresponding to terminal controller  122 . 
     Terminal control interface  272  receives the specific terminal controlling method discriminating information and then, using the table of relation of procedures held therein, decides which procedures of the controlling method actually contained in terminal controller  122  is to be called, then calling the controlling mode concerned. 
     Terminal controller  122  is provided with a function to be called externally the standardized grouped control procedures of subscriber circuit controller  212  and terminal  242  which is controlled by terminal controller  122  through subscriber circuit controller  212 , and is controlled by service controller  111  via terminal control interface  272 , also controls subscriber circuit controller  212  through apparatus control interface  261  and further controlling terminal  242  by way of subscriber circuit controller  212 . Furthermore, terminal controller  122  stores the temporary storage information necessary for the operation thereof in terminal control exclusive-use memory  172 . 
     Connection control interface  273  is caused to correspond to connection controller  131  and keeps a conversion table between the information required to call respective control procedures selectively which is actually provided in connection controller  131 , and the terminal control procedure discriminating information obtainable as a result of encoding discriminative by classifying a plurality of standardized control procedure groups of different type terminal controllers preliminary. 
     Further, in case where another controller such as service controller  111 , etc. calls the function of connection controller  131 , another controller does not directly call connection controller  131  but requests to execute a specific control method of connection controller  131  by showing the discriminating information representing the requesting terminal control procedures to connection control interface  273  corresponding to connection controller  131 . 
     Connection control interface  273  receives the specific connection controlling method discriminating information and then, using the table of relation of procedures held therein, decides which procedures of the controlling method actually contained in connection controller  131  is to be called, then calling the controlling mode concerned. 
     Connection controller  131  is provided with a function to be called externally the standardized grouped control procedures of switching controller  221 , and controlled by service controller  111  via terminal control interface  273 , also controls switching controller  221  through apparatus control interface  261 . Furthermore, connection controller  131  stores necessary data into a connection controller use buffer memory  181 . 
     Media control interface  274  is caused to correspond to media controller  141  and keeps a conversion table between the information required to call control procedures selectively which is actually provided in media controller  141 , and the media control procedure discriminating information obtainable as a result of encoding discriminative by classifying a plurality of standardized control procedure groups of different type terminal controllers preliminary. 
     Further, in case where another controller such as service controller  111 , etc. calls the function of media controller  141 , another controller does not directly call media controller  141  but requests to execute a specific control method of media controller  141  by showing the discriminating information representing the requesting specific media control procedures to terminal control interface  274  corresponding to media controller  141 . 
     Media control interface  274 , receiving information of discriminating mode of media control, decides which control procedure is called from procedures provided in media controller  141  by detecting the conversion table held within and calls the decided procedure. 
     Media controller  141  is provided with a function to be called externally the standardized grouped control procedures of media control device  231  and is controlled by service controller  111  via media control interface  274 , also controls media control device  231  through apparatus control interface  261 . Furthermore, media controller  141  stores the temporary storage information necessary for the operation thereof in media control exclusive-use memory  191 . 
     Address resolution control interface  275  is caused to correspond to address resolution controller  151  and keeps a conversion table between the information required to call respective control procedures selectively which is actually provided in address resolution controller  151 , and the address resolution control procedure discriminating information obtainable as a result of encoding discriminative by classifying a plurality of standardized control procedure groups of different type address resolution controllers preliminary. 
     Further, in case where another controller such as service controller  111 , etc. calls the function of address resolution controller  151 , another controller does not directly call address resolution controller  151  but requests to execute a specific control method of address resolution controller  151  by showing the discriminating information representing the requesting address resolution control procedures to address resolution control interface  275  corresponding to address resolution controller  151 . 
     Address resolution control interface  275 , receiving information of discriminating mode of address resolution control, decides which control procedure is called from procedures provided in address resolution controller  151  by detecting the conversion table held within and calls the decided procedure. 
     Address resolution controller  151  is provided with a function to be called externally the standardized grouped control procedures and is controlled by service controller  111  via address resolution control interface  275 , also controls address resolution use memory  201 . 
     Address resolution memory  201  stores previously the terminal logical name and terminal physical number which are necessary for address resolution, so that the memory  201  is referred by other controllers through address resolution controller  151 . 
     Apparatus control interface  261  is a device to provide a operative coupling between service control unit  101  and each of subscriber circuit controller  211 , switching controller  221 , subscriber circuit controller  212  and media control unit  231  and has a function not only to transfer the contents instructed to a corresponding telecommunications apparatus but also to show the information transferred from each telecommunications apparatus to a corresponding controller in response to each of the instructions received respectively from terminal controller  121 , connection controller  131 , terminal controller  122  and media controller  141 . 
     Subscriber circuit controller  211  has respective functions, one for monitoring the state of terminal  241  and the communication path which terminal  241  uses, and for informing terminal controller  121  of a state change thereof through apparatus control interface  261 , and another for receiving an instruction from terminal controller  121  through apparatus control interface  261  and in response the instruction received, for controlling terminal  241  and the communication paths which terminal  241  uses. 
     Subscriber circuit controller  212  has respective functions, one for monitoring the state of terminal  242  and the communication path which terminal  242  uses, another one for informing terminal controller  122  of a change of said state through apparatus control interface  261 , and another for receiving an instruction from terminal controller  122  through apparatus control interface  261  and in response the instruction received, for controlling terminal  242  and the communication paths which terminals  242  uses. 
     Switching controller  221  has respective functions, the first for monitoring the states respectively of a group of communication paths connected thereto, the second for informing connection controller  131  about changes of these states through apparatus control interface  261 , and the third for receiving an instruction from connection controller  131  through apparatus control interface  261  and in response the instruction received, changing the relation of a coupling among said group of communication paths, and switching among said group of communication paths. 
     Referring to FIGS. 3 and 4, the first embodiment of the present invention is described with regards to its functioning. FIG. 4 is a flowchart illustrating one functional example of the first embodiment and showing the basic connection processing of a communication service. 
     Before the start of a communication service, service control unit  101  drives service implementation device  251  and thereafter keeps on the initialized state, which is one of the states available from terminal controller  121 , through terminal control interface  271 . Through this process, subscriber circuit controller  211  is initialized and subsequently goes into a state of monitoring of terminal  241  (steps  301  and  302 ). At this stage, terminal controller  121  is fed with the information concerning terminal  241  by way of subscriber circuit controller  211  and then stores this information into terminal control-use memory  171 , while at the same time being allowed to register the information about terminal  241  in address resolution controller  151  via address resolution control interface  275  as occasion demands. 
     When terminal  241  sends out a certain service start request, subscriber circuit controller  211  detects this request and then informs arrival of this request to terminal controller  121  through apparatus control interface  261 . Upon reception of this information, terminal controller  121  reads the contents of the request according to its internal processing procedure stored therein, and subsequently writes necessary information into terminal control-use memory  171 , while at the same time effecting an examination processing as to what action is to be made for the request (step  303 ). 
     In this embodiment, as a result of this examination processing, a decision is made to actuate service controller  111 . 
     Service control unit  101  receives the result from the examination processing by terminal controller  121  and then instructs service implementation device  251  to actuate service controller  111  (step  304 ). 
     With reference to FIG. 4, the scope of operation started from step  304  is marked within dotted line  314 , and the scope of operation surrounded by dotted line  314  coincides with the operating procedure stored in service controller  111 . 
     Next, service controller  111  requests terminal controller  121 , through terminal control interface  271 , to read a call incoming terminal address, and in response to this request, terminal controller  121  then reads out the call incoming terminal address from the information stored in terminal control-use memory  171 , then reports this read-out address information back to service controller  111  in reply to the request. 
     Service controller  111  shows this address information reported back from terminal controller  121  to address resolution controller  151  through address resolution control interface  275 , requesting not only to examine whether or not this address is resolvable, but also to resolve the address when this address is judged resolvable (step  305 ). 
     Address resolution controller  151  refers to the address resolution logic stored therein and the contents of address resolution control-use memory  201  to judge whether or not this address is resolvable, and if judged not resolvable, a finding “null” is sent back to service controller  111  while in case where the address is confirmed resolvable, a further address resolution processing is proceeded to follow by answering to service controller  111  about the result of address resolution. 
     In case where the result from the address resolution processing by address resolution controller  151  turns out “null,” service controller  111  starts a service implementation to terminate the processing (step  306 ). To terminate service implementation, it is necessary at this stage to release the devices reserved in use for service implementation; the reserved devices are a part of terminal control-use memory  171  and subscriber circuit controller  211 . 
     Service controller  111  instructs terminal controller  121 , through terminal control interface  271 , to release the devices, and in response to this instruction, terminal controller  121  not only releases the used region of the terminal control-use memory  171  but also instructs the service implementation termination and re-initialization to subscriber circuit controller  211  through apparatus control interface  261 . 
     When subscriber circuit controller  211  executes initialization, terminal controller  121  informs service controller  111  about completion of the service implementation termination processing. In response to this information, service controller  111  completes its processing while terminal controller  121  returns to an initial state (namely, back to step  302 ). 
     In case the address resolution processing is turned out effective, in response to the answer from address resolution controller  151 , service controller  111  requests terminal controller  122  corresponding to terminal  242 , to execute inquiry whether the called terminal is allowable or not through terminal control interface  272 , (step  307 ). 
     Upon reception of the inquiry, terminal controller  122  reads terminal control-use memory  172 , then starts an acceptance control processing to examine whether or not the incoming call is acceptable, and sends back a finding of the examination together with the reason of a consequential judgment to service controller  111 . 
     Service controller  111  receives an answer from terminal controller  122 , and reads the answer from terminal controller  122  over the reason of this refusal if the received answer is an incoming call refusal, then starts a service implementation termination processing according to the reason of the refusal. 
     As this service implementation termination processing varies in procedure according to request originating-side terminal controller  121  how to present the reason of an incoming call refusal to terminal  241 , so after a judgment by service controller  111  and terminal controller  121 , via terminal control interface  271 , the method necessary to undertake the service implementation terminative processing, subsequently executing thereof. 
     In case where service controller  111  has received an answer of incoming call acceptable from terminal controller  122 , service controller  111  not only informs call originating-side terminal controller  121 , through terminal control interface  271 , of a fact that a call processing is in progress, but also requests called terminal side terminal controller,  122 , through terminal control interface  272 , to start ringing to the called terminal (step  308 ). 
     Terminal controller  121  requests subscriber circuit controller  211  to inform terminal  241  of a fact that the call processing is in progress while in response to this request, subscriber circuit controller  211  informs terminal  241  of that fact. Terminal controller  122  requests subscriber circuit controller  212  to inform terminal  242  of a fact that there is an incoming call request addressing to terminal  242 , and in response to this request, subscriber circuit controller  212  informs terminal  242  of that fact. 
     Service controller  111  next instructs terminal controller  122 , through terminal control interface  272 , to wait until the commencement of a speech is allowed, and to answer by sending out the information that the speech is get through (step  310 ). 
     Terminal controller  122  starts a speech standby control processing functioned therein and instructs subscriber circuit controller  212  to monitor terminal  242  over an off-hook (taking-up of the handset) condition. 
     Subscriber circuit controller  212  monitors terminal  242  and transfers the information of a change of state thereof to terminal controller  122  as required. 
     Following the information received, terminal controller  122  and service controller  111  selects which one of the steps is to be taken next. In the example shown in FIG. 4, the step to be taken when being no off-hook in step  310  is so defined as to go back to step  308 ; therefore, the change of state other than off-hook is ignored. 
     When terminal  242  goes into the state of off-hook, and service controller  111  is informed subsequently thereof through subscriber circuit controller  212  and terminal controller  122 , service controller  111  then starts the processing for coupling terminals  241  and  242  with one another (step  311 ). 
     This processing involves the steps as follows: 
     (a) a step of selecting connection controller  131 , noting the physical positional relation between subscriber circuit controllers  211  and  212 ; 
     (b) a step of instructing connection controller  131 , upon requesting thereto via connection control interface  273  to secure an actual switching device (resource) such as a switching capacity source, etc. and undertake an initialization, to provide necessary information by way of connection control interface  273 , so that the processing for coupling subscriber circuit controllers  211  and  212  together may be executed; 
     (c) a step of selecting media controller  141  to put it into use as occasion demands so that there may be provided matching between the communication media and the signaling speeds which both terminals  241  and  242  can apply; 
     (d) a step of instructing media controller  141 , via media control interface  274 , to execute the processing for securing a device (resource) which becomes necessary; and 
     (e) a step of calling connection controller  131  through connection control interface  273  to control switching controller  221  so that the function of a media controller may be used as occasion demands. 
     Upon completing this processing, service controller  111  informs not only terminal controller  121 , via terminal control interface  271 , but also terminal  122 , through terminal control interface  272 , of readiness of a speech. 
     Upon receiving the information about readiness of a speech, these terminal controllers  121  and  122  advise their counterpart subscriber circuit controllers  211  and  212  respectively of the processing required to commence a speech. 
     Next, service controller  111  not only instructs terminal controller  121 , via terminal control interface  271 , and terminal controller  122 , by way of terminal control interface  272 , to monitor the terminal concerned over a change of state to on-hook (hanging-up of a handset) but also gathers the information regarding a call originating party from terminal controller  121  through terminal control interface  271  to charge the call originating party so as to write the information about the call originating party and the speech start time into service control-use memory  161  (step  312 ). 
     When either terminal  241  or  242  goes into an on-hook state, the terminal controller corresponding to the terminal, whichever has gone into the state of on-hook, detects the change of state, sending out the information thereof to service controller  111 . Upon reception of this information, service controller  111  starts the service implementation terminative processing (step  313 ). 
     First, service controller  111  instructs terminal controllers  121  and  122 , respectively via terminal control interfaces  271  and  272 , to execute the service implementation termination processing, and waits until being informed about completion of the service implementation termination processing. 
     Terminal controller  121  detects the condition of subscriber circuit controller  211 , and if an off-hook state is found, it executes the service implementation termination processing to release terminal control use memory  171 , then upon re-initializing said subscriber circuit controller  211  and thereafter informs service controller  111  that the service implementation terminative processing is over. 
     If terminal controller  121  detects that subscriber circuit controller  211  is still monitoring remaining in the state other than on-hook, subscriber circuit controller  211  is instructed, via apparatus control interface  261 , to inform terminal  241  about completion of the call processing service, and then after subscriber circuit controller  211  keeps monitoring until terminal  241  changes the state to on-hook, the service termination processing is executed for releasing terminal control-use memory  171 , then upon the re-initialization of subscriber circuit controller  211 , then informing service controller  111  of the service implementation terminative processing being over. 
     Terminal controller  122  detects the condition of subscriber circuit controller  212 , and if the on-hook state is detected prevailing therein, the former executes the service implementation terminative processing for releasing terminal control-use memory  172  then upon re-initializing subscriber circuit controller  212 , then the completion of the service termination processing is informed to service controller  111 . 
     If the on-hook state is not detected in subscriber circuit controller  212  yet, subscriber circuit controller  212  is instructed, via apparatus control interface  261 , to inform terminal  242  of service implementation is over, and then after subscriber circuit controller  212  keeps standing by until a conditional change into the on-hook state, the service implementation termination processing is executed for releasing terminal control-use memory  172 , or else otherwise upon the re-initialization of subscriber circuit controller  212 , followed by informing service controller  111  of the service implementation termination processing being over. 
     Then, upon receiving from both terminals the information about completion of the service implementation termination processing, service controller  111  releases other devices which have been secured to implement the service concerned, and subsequently executes the processing for charging, based on the information of a call originating terminal and the time of service commencement stored in service control-use memory  161 , subsequently storing the result of this processing into terminal control-use memory  161  and returning to its initial state. 
     A case, wherein a communication apparatus with the operating procedure contained therein is introduced which is different from that of the communication apparatus in the first embodiment of the present invention, is referred to as a modified example of the first embodiment. 
     With reference to FIG. 5, terminal controller  123 , subscriber circuit controller  213  and terminal  243  are the communication apparatus different from those in FIG.  3 . 
     Subscriber circuit controller  213  is operated according to a control procedure different from that of subscriber circuit controller  211 . Likewise, terminal  243  goes, following the control procedure different from that of terminal  241 . Therefore to match a operating procedural difference, the respective components such as terminal control interface  273 , terminal controller  123  and terminal control-use memory  173  are varied from those illustrated in FIG. 
     Though subscriber circuit controller  213  and terminal  243  are different from those in said first embodiment shown in FIG. 3, the logical roles of these respective devices have similarity respectively between subscriber circuit controllers  213  and  211  and between terminals  243  and  241 ; in view of this, terminal controller  123  is provided with the function capable of encoding the functions controllable for a group of communication apparatus and externally calling a group of encoded functions, thus being equal terminal controller  121  over the identity of its functional type. 
     The difference in this case lie in the type of internal circuitry installation between terminal controllers  121  and  123  and also in the terminal control system discriminating information between them, which information each denotes a request of calling of respective functions. 
     The difference in the type of internal circuitry installation of terminal controller exists in the internal construction of each terminal controller. Further, the difference in the terminal control system discriminating information of request to call of respective functions consists in the difference in a table of relation (conversion table) which is provided in the terminal control interface. Accordingly, the effects of installing terminal  243  and subscriber circuit controller  213  serviceability in the existing system are limited to system internal additional installation of terminal control interface  273 , and the modification of terminal controller  123  and terminal control-use memory  173 , not requiring to modify external controllers such as service controller  111 , etc. 
     Next, the effect and the result of the first embodiment according to the present invention are described hereunder. In the first embodiment of the present invention, the operating procedure of communication apparatus is separate from that of service controller  111 , whereby even in case that the telecommunications apparatus different from existing telecommunications apparatus are controlled from service control unit  101 , controlling is allowed by modifying only the controller which is in charge of controlling the communicating apparatus concerned, and its interface, without modifying other parts. Therefore, the result is that the amount of a change in the operating procedure stored in the controller in charge is greatly reduced when new telecommunications apparatus are connected to the service controller unit. 
     Furthermore, since a preliminary processing to call control procedures of telecommunications apparatus from service controller  111  occurs at the time of each, execution, the task to enable service implementation to control the new telecommunications apparatus different from the existing service control unit is practicable without compiling new configuration by service controller  251  while service implementation is under way. 
     Next, to illustrate the first embodiment of the present invention in further detail, the operation thereof is described hereunder in detail with direct reference thereto. 
     With reference to FIG. 3, it is assumed that terminal number “123-4567” is allocated to terminal  241  and terminal number “123-4568” to terminal  241 . At the point prior to the start of a telecommunications service, service control unit  101  drives service implementation device  251  and keeps on, via terminal control interface  271 , an initializing function which is one of those available from terminal controller  121 . With this step taken, subscriber circuit controller  211  is initialized, getting into a state of monitoring the condition of terminal  241  (steps  301  and  302  in FIG.  4 ). 
     At this stage, terminal controller  121  gets the information regarding terminal  241  through subscriber circuit controller  211 , then loads the received information into terminal control-use memory  171 , while at the same time registering the information about terminal  241  in address resolution controller  151  via address resolution control interface  275 . 
     Since the terminal coupled to subscriber circuit controller  211  has had its terminal number “1213-4567” registered previously in address resolution control-use memory  201 , address resolution controller  151  at this stage newly registers the correspondence between terminal number “123-4567” and terminal controller  121  in resolution control-use memory  201 . Terminal controller  121  is reported back with the result of this registration and identifies the terminal number of terminal  241  of which terminal controller  121  takes charge, and writes it into terminal control-use memory  171  for storage therein. 
     Likewise, as regards terminal  242 , address resolution controller  151  newly registers the correspondence between terminal number “123-4568” of terminal  242  and terminal controller  122  in address resolution control-use memory. Terminal controller  122  is fed back with the result of this registration and identifies the terminal number of terminal  242  of which terminal controller  122  takes charge, and writes it into terminal control-use memory  172  for storage therein. 
     When terminal  241  sends out a regular telephone service start request specifying terminal number “123-4568” as a called terminal number, subscriber circuit controller  211  detects this request, and informs terminal controller  121 , via apparatus control interface  261 , of arrival of this request. 
     Upon reception of this request (a regular telephone service start request), terminal controller  121  reads the contents of said request according to the processing procedure contained therein, then writing the necessary information such as a called terminal number “123-4568”, etc. into terminal control-use memory  171 , subsequently examining which one of operational steps is required to be taken for said request (step  303  in FIG.  4 ), and deciding to actuate regular telephone service controller  111 . 
     Upon receiving the examination result from terminal controller  121 , service control unit  101  instructs service implementation device  251  to drive service controller  111  (step  304 ). 
     Subsequently, service controller  111  requests terminal controller  121 , via terminal control interface  271 , to read the call incoming terminal address while terminal controller  121  reads out called terminal address “123-4568” from the information stored in terminal control-use memory  171  in response to said request and then feeds back this terminal address information to service controller  111  in reply to said request. Service controller  111  shows the terminal address information fed back from terminal controller  121  to address resolution controller  151  through address resolution control interface  275 , requesting to examine whether or not the terminal address concerned is resolvable and to resolve said terminal address concerned in case where said address is found resolvable (step  305 ). 
     Address resolution controller  151 , referring to the address resolution logic contained therein and the contents of address resolution control-use memory  201 , judges that call incoming terminal address “123-4568” is resolvable; the consequence of this address resolution is terminal  242 ; and the terminal controller corresponding to this terminal is terminal controller  122 , subsequently answers to the consequence of the address resolution to service controller  111 . 
     Following the answer from address resolution controller  151 , service controller  111  requests terminal controller  122 , which corresponds to terminal  242 , a call incoming terminal, via terminal control interface  272 , to execute an inquiry processing as regards whether or not an incoming call is acceptable (step  307  in FIG.  4 ). 
     Upon receiving this request, terminal controller  122  reads terminal control-use memory  172  and starts a request acceptance control processing contained therein, wherein for example, by judging, referring to the table provided inside, whether or not the call originating-side terminal number “123-4567” is connectable, a judgment processing of whether said incoming call is connectable or not is effected, answering to service controller  111  the result of judgment together with the reason for attainment of this judgment. 
     In case where service controller  111  has received an answer that the incoming call connectable from terminal controller  122 , service controller  111  informs call originating-side terminal controller  121 , via terminal control interface  271 , of a fact that a call processing is in progress upon reception of a call request, while at the same time requesting call incoming-side terminal controller  122 , via terminal control interface  272 , to start a ringing processing (step  308  in FIG.  4 ). 
     Terminal controller  121  requests subscriber circuit controller  211  to inform terminal  241  of the call processing being under way, while upon receiving this request, subscriber circuit controller  211  informs terminal  241  that the call processing is in progress by sending a ring-back tone. 
     Terminal controller  122  requests subscriber circuit controller  212  to inform terminal  242  of a fact that there is an incoming call, while upon receiving this call, subscriber circuit controller  212  then informs terminal  242  of this fact by ringing Service controller  111  next instructs terminal controller  122 , through terminal control interface  272 , to wait until the speech path is ready to get through and to inform that the line is ready to get through (step  310  in FIG.  4 ). Terminal controller  122  then starts a speech path connection standby control processing contained therein, and subsequently instructs subscriber circuit controller  212  to monitor terminal  242  over its state transference to an off-hook state. 
     When terminal  242  goes into the off-hook state, with this state transference informed to service controller  111  via subscriber circuit controller  212  and terminal controller  122 , service controller  111  then starts a connection processing for connecting terminals  241  and  242  one another (step  311 ). Precisely, service controller  111  starts a routine processing contained therein, with the result from this routing processing in this embodiment corresponding connection controller is concluded to connection controller  131 , since subscriber circuit controllers  211  and  212  are connected directly to one switching controller  221 . 
     Connection controller  131  is requested to execute a processing for circuit-switching of terminals  241  and  242  represented by terminal controllers  121  and  122  according to the regular voice band transmission circuits. In response to this request, connection controller  131  inquires terminal controllers  121  and  122 , via respective terminal control interfaces  271  and  272 , how subscriber circuit controllers  211  and  212  are connected physically to switching controller  221 , and controls switching controller  221 , following the answers by terminal controllers  121  and  122  to the inquiry, and the setting information of switching controller  221  which is stored in connection control-use memory  181 . 
     Assuming in this embodiment that subscriber circuit controller  211  for example is connected to the first port of switching controller  221  while subscriber circuit controller  212  is connected to the second port of switching controller  221 , connection controller  131  controls switching controller  221 , through apparatus control interface  261 , to couple the first and second port with each other. 
     Next, service controller  111  informs terminal controllers  121  and  122  respectively via terminal control interface  271  and terminal control interface  272  of readiness of a speech. Upon receiving this information, terminal controllers  121  and  122  advise each of subscriber circuit controllers  221  and  212 , of which they take charge respectively, of the processing necessary for the speech path connection. In this embodiment, lighting of the busy indication lamp provided on each terminal for example corresponds to this advice. 
     Subsequently, service controller  111  instructs terminal controllers  121  and  122 , respectively via terminal control interfaces  271  and  272  to monitor terminals  241  and  242  state transition to the on-hook state, then gathers the call subscriber information from terminal controller  1211  through terminal control interface  271  so as to charge the call subscriber for the communication service, and writes the call subscriber information and the time of speech commencement in service control-use memory  161  for storage therein (step  312  in FIG.  4 ). 
     Next, supposing that terminal  241  has gone into the on-hook state, terminal controller  121  corresponding to terminal  241  detects this conditional change, subsequently sending out the conditional change information to service controller  111 . Upon receiving this information, service controller  111  starts the service implementation terminative processing (step  313  in FIG.  4 ). 
     First, service controller  111  instructs terminal controllers  121  and  122 , respectively via terminal control interfaces  271  and  272 , to execute the service implementation termination processing, then stands by until informed of a fact that both terminal controllers  121  and  122  are finished said termination processing. As terminal controller  121  detects the condition of subscriber circuit controller  211 , detecting the on-hook state, it next executes the service implementation termination processing to release terminal control-use memory  171 , then upon reinitializing subscriber circuit controller  211 , informing service controller  111  about completion of the service implementation termination processing. 
     Meanwhile, when terminal controller  122  detects that the subscriber circuit controller  212  detects no on-hook state, then instructs subscriber circuit controller  212 , via apparatus control interface  261 , to inform terminal  242  of completion of the service implementation, subsequently standing by until the subscriber circuit controller concerned changes into its state to the on-hook state. Upon reception of this instruction, subscriber circuit controller  212  transmits a speech path cut-off tone to terminal  242 , and then keeps standing by until terminal  242  goes into the on-hook state. Then, when terminal  242  turns into the on-hook state, the condition of subscriber circuit controller  212  likewise goes into the on-hook state, informing terminal controller  122  of its conditional shift to the on-hook state. In response to this information, terminal controller  122  gets out of a standby state and executes the service implementation termination processing to release terminal control-use memory  172 , etc., subsequently informing service controller  111  about completion of the service termination processing. 
     Service controller  111 , when being informed about completion of the service implementation termination processing, then releases other devices which have been secured for service implementation, thereafter executes a charge processing, based on the calling subscriber information and the time of service commencement stored in service control-use memory  161 , and gets back to the initial condition after writing the charge processing data into service control-use memory  161  for storage therein. 
     Next, referring to the drawings, the second embodiment of the present invention is described hereunder in detail. FIG. 6 is a block diagram illustrating the configuration of the second embodiment of the present invention. 
     Referring to FIG. 6, the second embodiment of the present invention different from said first embodiment in that the controller corresponding to terminal  24  land subscriber circuit controller comprises actual terminal controller  401  and virtual terminal controllers  411  and  412  (which are confirmed as actual terminal when they are resolved actual address terminals), and also in that each controller is provided with a control interface and a control-use memory. 
     Virtual terminal control interface  441  is caused to correspond to virtual terminal controller  401  and keeps a table of relation between the information required to call a control procedure which is actually provided in virtual terminal controller  401 , and the terminal control procedure discriminating information obtainable as a result of previous encodement of the control procedures by classifying as a plurality of groups of practicable standardized control procedures. 
     Further, actual terminal control interface  441  is associated with virtual terminal control interfaces  442  and  443  corresponding respectively to the virtual terminal controller derived from actual terminal controller  401 , thus being controllable with each other. 
     Actual terminal controller  401  is provided encoding functions of subscriber circuit controller  211  and terminal  241  which is controlled by actual terminal controller  121  through  211  so that the encoded functions are set to be called out from other controllers as a group, and further to control subscriber circuit controller  211  through apparatus control interface  261  and also terminal  241  via subscriber circuit controller  211 . Further, actual terminal controller  401  keeps the temporary storage information necessary to drive actual terminal controller  401  in actual terminal control exclusive-use memory  421 . Besides, actual terminal controller  401  is associated with virtual terminal controllers  411  and  412  derived from said actual terminal controller  401 , thus being controllable with each other by way of each respective virtual terminal control interfaces. 
     Virtual terminal control interface  442  is caused to correspond to virtual terminal controller  411  and keeps a table of relation between the information required to call a control procedure which is actually provided in virtual terminal controller  411 , and the terminal control procedure discriminating information obtainable as a result of previous encodement of the control procedures by classifying as a plurality of groups of practicable standardized control procedures. 
     Virtual terminal controller  411  is a device having such a function to encode the function of subscriber circuit controller  211  and groups of functions integrating respective services as a virtual terminal out of those of terminal  241  that are controllable from actual terminal controller  121  via subscriber circuit controller  211 , and to set all encoded grouped functions allowed to be called out externally, and to execute actual control via actual terminal controller  401 . 
     Further, actual terminal controller  411  keeps the temporary storage information necessary to drive actual terminal controller  411  in virtual terminal control exclusive-use memory  431 . 
     Virtual terminal control interface  443  is caused to correspond to virtual terminal controller  412  and keeps a table of relation between the information required to call a control procedure which is actually provided in virtual terminal controller  412 , and the terminal control procedure discriminating information obtainable as a result of previous encodement of the control procedures by classifying as a plurality of groups of practicable standardized control procedures. 
     Virtual terminal controller  412  is a device having a function to encode the function of subscriber circuit controller  211  and group of functions integrating respective service as a virtual terminal out of those of terminal  241  that are controllable from actual terminal controller  401  via subscriber circuit controller  211 , and set all encoded group of functions allowed to be called out externally, and to execute actual control via actual terminal controller  401 . Further, virtual terminal controller  412  stores the temporary information necessary to drive virtual terminal controller  412  in virtual terminal control-use memory  432 . 
     The second embodiment of the present invention is described hereunder in detail over its function. With reference to FIG. 6, except of  401 ˜ 443  which are associated with terminal  241  and subscriber circuit controller  211  are omitted to describe because rest portions are the same to the first embodiment shown in FIG.  3 . In view of this, the description of the same portion is omitted here. 
     In said first embodiment, as terminal  241  corresponds to terminal controller  121 , so the first embodiment cannot correspond to a virtual terminal which is physically counted an existing terminal but is possible to be treated a plurality of terminals of ISDN (Integrated Services Digital Network) or the ATM (Asynchronous Transfer Mode). 
     In this embodiment, there is provided a configuration capable of meeting the case wherein a virtual terminal controller is allocated to each one of virtual terminals, whereby a terminal which is physical one, is nevertheless virtually workable as a plurality of terminals. In other words, actual terminal controller  401 , actual terminal control-use memory  421  and actual terminal control interface  441  are provided in consideration of the correspondence to such physical entities as terminal  241  and subscriber circuit controller  211 , while virtual terminal controllers  411 ˜ 412 , virtual terminal control-use memories  431 ˜ 432  and virtual terminal control interfaces  442 ˜ 443  are prepared in views of that they may correspond to virtual terminals. 
     Actual terminal control interface  441  and virtual terminal control interfaces  442 ˜ 443  operate identically to the exterior. Therefore, as regards the means to call each of these interfaces, it is unnecessary to discriminates whether an called entity is an interface corresponding to an actual terminal or to a virtual terminal. The operation to be undertaken in the case where an interface has been called, is carried out by exchanging requested specific operational control procedures which are assigned to each respective controllers at every stage of implementation, after the operation request has once been handed over to each of corresponding actual terminal controller  401  and virtual terminal controllers  411 ˜ 412 . 
     Actual implementation of the operation described above is shared by actual terminal controller  401  for the processing of terminal  241  and subscriber circuit controller  211  and shared by virtual terminal controller  411  to  412  for the processing of virtual terminals. But in order to avoid the contradiction of issuance of instructions, virtual terminal controller  411  to  412  send control instructions through actual terminal controller  401  indirectly to telecommunications devices. 
     Said second embodiment of the present invention is further described hereunder in detail. 
     With reference to FIG. 6, it is assumed that terminal  241  is an ATM terminal and the signaling system of said terminal  241  is of a ATM Forum&#39;s UN13.1. As an initializing step at the point prior to starting to implement the communication service, actual terminal controller  401  drives subscriber circuit controller  211  via apparatus control interface  261  for due setting so that actual terminal controller  401  may read and write the virtual path for use in the communication with terminal  241  over UNI signaling information. Then, it is assumed that as an operational instance of this embodiment, a via-UNI (Use Network Interface) regular connections would be undertaken as communication service implementations. 
     First, an operating example of the case where terminal  241  transmits a call request, is illustrated here. When terminal  241  sends out a call request (a setup message), actual terminal controller  401  receives this request through the initial setting referred to in the foregoing. Actual terminal controller  401  analyzes the contents of a call request message, discriminating that this request is a call request, and makes ready for subsequent control by generating virtual terminal controller  411 , virtual terminal control-use memory  431  and virtual terminal control interface  442  and then writing the identifier of virtual terminal controller  411  into actual terminal control-use memory  421 . 
     Next, actual terminal controller  401  shows the call request message to virtual terminal controller  411  and then instructs thereto to execute an call operation. In views of the fact that excepting the call operation which will be described later, subsequent operations are the same as those with the case of said first embodiment, so the description thereof is omitted. 
     Here, a description is given of the operation for the case of accepting an incoming call request. The relation between an ATM address which is the terminal number of terminal  241 , and the actual terminal controller is written previously into address resolution control-use memory  201 , similarly to the case of said first embodiment. It is assumed here that the service controller completed of deciding the ATM address of a called terminal. Next, it is further assumed that the service controller showed address resolution controller  151  the ATM address of the called terminal through address resolution control interface  275  to request for address resolution, and that in reply to this request, actual terminal controller  401  is reported the result of address resolution. 
     This service controller requests actual terminal controller  401 , via actual terminal control interface  441 , to execute an inquiry processing whether an incoming call is accepted or not. Upon receiving this request, actual terminal controller  401  first generates virtual terminal controller  412 , virtual terminal control-use memory  432  and virtual terminal control interface  443 , and thereafter transfers the call incoming request to virtual terminal control interface  443 , requesting to execute an examination processing whether the incoming call request is acceptable or not. 
     Upon receiving an examination processing request, virtual terminal controller  412  reads virtual terminal control-use memory  432 , then starts a built-in request acceptance processing or occasionally, calling actual terminal control-use memory  421  through actual terminal controller  401 , or else calling built-in acceptance control processing of actual terminal controller  401  to execute a judgment processing finally as to whether or not the incoming call request is accepted, and then reports the result thereof together with the reason of the judgment to the service controller. 
     Thereafter, as regards implementation of the telecommunication service concerned, the terminal controller continues implementing said service, with virtual terminal controller  412  communicating with the exterior, and calling actual terminal controller  401  occasionally. 
     Describing the effect and the result of said second embodiment of the present invention, in the second embodiment, even in case where the actual terminal has a virtual terminal function, it is not required to modify other portions than the internal circuitry installation portion of a group of controllers associated with said terminal by properly dividing and installing the terminal control interface, terminal controller and terminal control-use memory. 
     This enables to reduce the amount of a change in the built-in operating procedure contained in the controller is greatly cut even when a new additional telecommunications apparatus (telecommunications terminal devices, each with a virtual terminal function in this instance) are connected to the existing service controller. 
     Next, referring to the drawings, the third embodiment of the present invention is described hereunder in detail. FIG. 7 is a block diagram illustrating the third embodiment of the present invention. 
     In contrast to said first embodiment illustrated in FIG. 3, wherein service controller  111  is configured to directly call controllers having the encoded function of each communication apparatus, referring to FIG. 7, the third embodiment of the present invention is found showing a difference in that service controller  501  effects an indirect call via service control library  511 . 
     Service controller  501  implementing telecommunications services each by controlling telecommunications apparatus applies service control library  511  in combination with service control-use memory  521  which is a temporary storage serving to actuate service controller  501 . While using service control library-use memory  531  as a temporary storage, service control library  511  in the first embodiment of the present invention calls the functions respectively of terminal controllers  121  to  122 , connection controller  131 , media controller  141  and address resolution controller  151  via terminal control interfaces  271  to  272 , connection control interface  273 , media control interface  274 , address resolution interface  275 , etc. according to the procedure similar to that which service controller applies for calling each telecommunications apparatus control means. 
     The third embodiment of the present invention is described hereunder in detail over its functioning. 
     With reference to FIG. 7, excepting service controller  501 , service control-use memory  521 , service control library  511  and service control library-use memory  531 , the third embodiment according the present invention is identical with the embodiment shown in FIG. 1, so the description of functions of them are omitted. In said first embodiment, service controller  111  is observed to directly call such interfaces as terminal control interface  271 , etc. Further, in FIG. 1 which presents one example of the conventional communication service control system, it is observed that service controller  801  calls the function of service common management/controller  821 . Therefore, even though service controllers  801  and  111  are described to implement the same service, the contents of these descriptions differ completely. 
     In the third embodiment of the present invention, service control library  511  having the same function as that of the conventional service common management/controller  821  is so installed to call the functions respectively of terminal controllers  121  to  122 , connection controller  131 , media controller  141  and address resolution controller  151  through terminal control interfaces  271  to  272 , connection control interface  273 , media control interface  274 , address resolution control interface  275 , etc. while service controller  501  is adapted to call the function of service control library  511 . 
     In other words, while using service control-use memory  521  as a temporary storage according to the operating procedure previously defined, service controller  501  call the function of service control library  511 . To execute the called function, using service control library-use memory  531 , as occasion demands, according to the controller defined previously for each service implementing function, service control library  511  calls the functions respectively of terminal controllers  121  to  122 , connection controller  131 , media controller  141  and address resolution controller  151  via terminal control interfaces  271  to  272 , connection control interface  273 , media control interface  274 , address resolution control interface  275 , etc. 
     The third embodiment of the present invention referred to above is further described in detail. It is noted here that in FIG. 7, though subscriber circuit controller  211  to  212 , switching controller  221 , media controller  231  and terminals  241  to  242  are omitted of presentation, these devices are assumed to be connected together likewise in FIG.  3 . 
     Referring to FIG. 7, it is assumed that terminals  241  and  242  have terminal numbers “123-4567” and “123-4568” allocated respectively. At a time preceding to the start of a telecommunications service, service control unit  101  drives service implementation device  251  and keeps on, via terminal control interface  271 , the function of initialization which is one of function available from terminal controller  121 . This step takes place, not only initializing subscriber circuit controller  211  but also driving subscriber circuit controller into a state of monitoring the state of terminal  241  (steps  301  and  302  in FIG.  4 ). 
     At this stage, terminal controller  121  receives the information regarding terminal  241  through subscriber circuit controller  211 , and then stores the received information into terminal control-use memory  171  while at the same time registers the information about terminal  241  in address resolution controller  151  via address resolution control interface  275 . Since in address resolution control-use memory  201 , the terminal coupled to subscriber circuit controller  211  has its terminal number “1213-4567” registered previously, address resolution controller  151  at this stage newly registers the correspondence between terminal number “123-4567” and terminal controller  121  in resolution control-use memory  201 . 
     Upon receiving the result of this registration, terminal controller  121  identifies the terminal number of terminal  241  of which terminal controller  121  takes charge, and then writes it in terminal control-use memory  171  for storage therein. Further likewise, as regards terminal  242 , address resolution controller  151  newly registers the correspondence between terminal number “123-4568” and terminal controller  122  in address resolution control-use memory  201 . Upon receiving the result of this registration, terminal controller  122  identifies the terminal number of terminal  242  of which terminal controller  122  controls, and then writes it in terminal control-use memory  172  for storage therein. 
     When terminal  241  sends a request of start of a regular telephone call origination service addressing called terminal number “123-4568”, subscriber circuit controller  211  detects the request, and informs it to terminal controller  121 , via apparatus control interface  261 , of arrival of this request. Upon reception of this received request, terminal controller  121  reads the contents of said request according to the processing procedure contained therein, then writing the necessary information such as called terminal number “123-4568,” etc. into terminal control-use memory  171 , examining operational steps which are required to be executed for said request (step  303  in FIG.  2 ), and deciding to actuate service controller  501  for the regular telephone call origination service. Upon receiving the result of the examination of processing from terminal controller  121 , service control unit  101  instructs service implementation device  251  to drive service controller  501  (step  304 ). 
     Next, service controller  501  instructs service control library  511  to get the details of a call request. 
     Upon receiving this request, service control library  511  requests terminal controller  121 , through terminal control interface  271 , to read out the telephone numbers as addresses of call originating terminal and the call incoming terminal while in response to this request, terminal controller  121  then reads out from the information stored in terminal control-use memory  171  own terminal address “123-4567” as a call originating terminal address and “123-4568” which has been specified, in the service start request, as a call incoming terminal address, then answers these to service control library  511 . 
     Service control library  511  not only writes the received information in service control library-use memory  531  but also answers said information to service controller  501 . Upon receiving these address information, service controller  501  then shows the called terminal address to service control library  511 , instructing to examine whether or not the terminal corresponding to said address and the calling terminal are physically allowed to go into the state for a speech. 
     Upon receiving this instruction, service control library  511  requests address resolution controller  151  via address resolution control interface  275  with a view to retrieving the terminal controller corresponding to the called terminal address to examine whether or not said address is resolvable, and resolve said address when said address is found resolvable. Address resolution controller  151  judges, referring to the address resolution logic which is provided as a proper function, and the contents of address resolution control-use memory  201 , that called terminal address “123-4568” is resolvable; the consequence of address resolution is terminal  242 ; and the terminal controller corresponding to the terminal  242  is terminal controller  122 , and then answers the consequence of address resolution to service control library  511 . 
     Service control library  511  receives, via address resolution control interface  275 , the result of the examination which address resolution controller  151  conducted, and checks the received examination result. 
     In this case, as the received examination result indicates that the address resolution is possible, the relation among called terminal address “123-4568,” terminal controller  122  and terminal  242  is written into service control library-use memory  531  as address resolution consequent information, and answers to service controller  501  about the result of address examination according to the answering procedure prescribed in the procedure of calling service control library  511 . Service controller  501  reads out the address examination result (step  305  in FIG.  2 ). 
     In response to the address examination which results physical connectivity, service controller  501  specifies the call originating terminal number and the called terminal number to service control library  511 , requesting to execute the inquiry processing as regards whether or not the called terminal is ready to accept an incoming call (step  307  in FIG.  4 ). It is noted here that since at this stage, service control library  511  keeps in service control library-use memory  531  the received answer to an address resolution request which is made previously to address resolution controller  151 , it is unnecessary to re-retrieve the relation between called terminal number “123-4568” and terminal controller  122 . 
     Upon receiving this request, service control library  511  shows the call originating terminal number to terminal controller  122  through terminal control interface  272 , requesting to inquire whether or not the incoming call is accepted. Upon receiving said request, terminal controller  122  not only reads terminal control-use memory  172  but also starts an acceptance control processing stored therein, wherein by judging, based on the table provided inside, whether or not call originating side terminal number “123-4567” is connectable, an incoming call acceptance examination processing is executed, followed by the answered result of judgment together with the reason thereof to service control library  511 . Upon receiving the result of judgment from the terminal controller  122 , service control library  511  feeds back said result to service controller  501  according to the answering system prescribed in the calling procedure of service control library  511 . In this embodiment, it is assumed that the answered result shows acceptability of the incoming call. 
     Judging at this stage that the logical judgment required to implement the service which service controller  501  provides has been completed, service controller  501  instructs service control library  511  to undertake remaining tasks (from step  308  to  313  in FIG.  4 ), specifying such information as call originating terminal number “123-4567,” called terminal “1123-4568”, etc. necessary to execute the remaining tasks. 
     Depending on the category of a service to be implemented, it is also practicable to execute the tasks from step  308  (to ring to the called terminal) to step  313  in FIG. 4 or an another appropriate processing in a manner that the service controller calls service control library  511  separately, without leaving whole tasks to service control library  511 . 
     As service controller  501  completes its role at this stage, service control memory  521 , a device which service controller  501  has secured for service implementation, will be released, with said service implementation processing ending up. 
     Thereafter, service control library  511  executes the steps from  308  to  313  by undertaking the processing similar to that of service controller  111  in said first embodiment. 
     Describing the effects and the result of the above-remarked third embodiment of to the present invention, it is said that in this third embodiment, the existing service controller is rendered available when the service control library provides the service controller with the function similar to that of the conventional service common management/controller. 
     Furthermore, as regards internal circuitry installation of service control library, since telecommunications apparatus control procedures are separated from the service control library, similarly to the first embodiment, the service control library is rendered to enable to control different telecommunications apparatus merely by modifying the telecommunications apparatus controller and its interface, with other parts left unaltered. The result is that the amount of a change in the operating procedure included in the service control library can be cut in an attempt to make practicable to control new telecommunications apparatus from the service control library. 
     The two effects described above enable to cut the amount of a change in the operating procedure included in the existing service controller when new telecommunications apparatus is rendered to put in service under the existing service control system. 
     Next, referring to the drawings, the fourth embodiment of the present invention is described in detail. FIG. 8 is a block diagram illustrating the configuration of the fourth embodiment of the present invention. 
     Referring to FIG. 8, the fourth embodiment of the present invention is different from said first embodiment in respect of items as follows:: 
     (a) a plurality of service control units  701 ˜ 703  are provided as an independent service control unit respectively; 
     (b) a plurality of switching controllers  222 ˜ 224  are provided under control of respective service control units; 
     (c) in conformance to the existence of plural service control units, there is increased in the number of controllers; 
     (d) service control units  701  and  702  are connected together via inter-service control unit communication path  761 ; and 
     (e) service control units  702  and  703  are connected to each other through inter-service control unit communication path  762 . 
     Service control unit  701  including service implementation device  252  not only controls subscriber circuit controller  211  via apparatus control interface  262  and terminal  241  through subscriber circuit controller, but also controls switching controller  222 . 
     Service control unit  702  provided with service implementation device  253  controls switching controller  223  and media controller  231  via apparatus control interface  263  Service controller furnished with service implementation device  253  not only controls subscriber circuit controller  212  by way of apparatus control interface  263  and terminal  242  via subscriber circuit controller  212 , but also controls switching controller  224 . 
     Service control units  701  and  702  are allowed, by respective service implementation devices  252  and  253  controlling inter-service control unit communication path  761 , to call respective control interfaces such as terminal control interface  271 , connection control interface  732 , etc. Meanwhile, service controller units  702  and  703  are likewise allowed, by respective service implementation devices  253  and  254  controlling inter-service control unit communication path  762 , to call respective control interfaces such as terminal control interface  272 , connection control interface  732 , etc. 
     It is noted here that with reference to the fourth embodiment of the present invention, a description is made of a configurational example wherein three service control units are provided but said embodiment of the present invention is easily applicable to the case where a plurality of service control units more than two are installed. 
     Next, the fourth embodiment of the present invention is described over its functioning. With reference to FIG. 8, at the time each of respective control interfaces is called, at the time when service implementation device  253  actuates service controller  741 , service implementation device  253  examines the information of a called terminal concerned, and then calls the control interface on a called terminal side service controller via the inter-service control unit communication path in the event the called terminal side control interface is provided on the service control unit other than the call originating-side service control unit. 
     The operation in the foregoing is generally referred to as a remote procedure call (RPC) and is effected by a general type device serving to call a specific function between information processors which can communicate with each other. In FIG. 8, although there is presented such a case, only for the convenience of preparing the drawings, where service controller  741  is actuated to effect the RPC, the RPC is practicable with another controller such as each of connection control interfaces  731 ˜ 733 . Effecting the RPC by each of service implementation devices  252 ˜ 254  enables to call from each controller the function of another controller via another control interface, no matter which is the service control unit that actuates said call-originating-side controller and said call-incoming controller. 
     This enables to implement the services defined in respective service controllers, using plural service controllers, without modifying the operating procedural contents defined in various controllers including the service controllers. 
     To effect the operation in the fourth embodiment of the present invention, which is similar to that in said first embodiment, namely for the case where service controller  111  in said first embodiment is desired to be applied straight as service controller  741 , it is possible that a pair of connection control interface and a connection controller are such configured as being a representative connection control interface and connection controller as if they represent a plurality of connection control interfaces and connection controllers. In this case, the representative connection controller writes the entities of other connection controllers into the connection control-use memory corresponding thereto, and when a request is directed from another controller via the connection control interface to the representative connection controller, the representative connection controller calls the function of another connection controller through another connection control interface, in addition to controlling, via the apparatus control interface, the switching controller of which the representative connection controller concerned takes charge. 
     In case it is allowed that service controller  741  is different from service controller  111 , though the operating procedural contents included in service controller  741  are identical, in respect of the sequence of operation, as compared with the contents stored in service controller  111  in said first embodiment, in view of the fact that there is an increased number of switching controllers of which service controller  741  takes charge, the step required to control the communication path between terminals  241  and  242  used to be to call connection controller  131  via connection control interface  273  in said first embodiment while in contrast with this, the step to be taken likewise in the fourth embodiment of the present invention is altered to call connection controllers  711 ˜ 713  through connection control interfaces  731 ˜ 734 . 
     Adding this alteration to service controller  741  enables to include a detailed control procedure in service controller  741  for switching controller  222 ˜ 224 . 
     Next, the fourth embodiment of the present invention is described in detail about its functioning. With reference to FIG. 8, it is assumed that terminals  241  and  242  have terminal numbers “124-4567” and “123-4568” allocated respectively. At the time preceding to the start of a telecommunications service, service controller  701  drives service implementation device  252  and keeps on, via terminal control interface  271 , the function of initialization which is available from terminal controller  121 . This step takes place, not only initializing subscriber circuit controller  211  but also driving subscriber circuit controller  211  into a state of monitoring the state of terminal  241  (steps  301  and  302  in FIG.  4 ). At this stage, terminal controller  121  receives the information regarding terminal  241  through subscriber circuit controller  211 , then stores the received information into terminal control-use memory  171  while at the same time registers the information about terminal  241  in address resolution controller  151  via address resolution control interface  275 , using the remote procedure call. 
     Since terminal number “123-4567” of the terminal connected to subscriber circuit controller  211  has been registered previously in address resolution control-use memory  201 , address resolution controller  151  newly registers the correspondence between terminal number “123-4567” and terminal controller  121  in address resolution control-use memory  201  at this stage. Terminal controller  121  receives the result of this registration and identifies the terminal number of terminal  241  of which terminal controller  121  takes charge, and keeps it stored in terminal control-use memory  171 . Further likewise, as regards terminal  242 , address resolution controller  151  newly registers the correspondence between terminal number “123-4568” and terminal controller  122  in address resolution control-use memory. Terminal controller  122  is fed back with the result of this registration and identifies the terminal number of terminal  242  of which terminal controller  122  takes charge, and keeps it stored in terminal control-use memory  172 . 
     When terminal  241  sends out a request for the start of a regular call origination telephone service together with terminal number “123-4568” which is identified as a called terminal number, subscriber circuit controller  211  detects the request, and informs terminal controller  121 , via apparatus control interface  262 , of arrival of this request. Upon reception of this request, terminal controller  121  reads the contents of said request according to the processing procedure which is provided as a proper function, then writing the necessary information such as called terminal number “123-4568”, etc. into terminal control-use memory  171 , examining which one of operational steps is required to be executed for said request (step  303  in FIG.  4 ), and deciding to actuate regular telephone service controller  741 . 
     Upon receiving the examination result from terminal controller  121 , service controller  701  examines which service control units is to be applied to actuate service controller  741 . 
     The contents of this examination may include the methods as follows:: 
     (a) a method to select service control unit  701  from which a request has originated; 
     (b) a method to choose a low load service control unit out of plural service control units; and 
     (c) a method to request terminal controller  121  to undertake a selection processing. 
     In this embodiment, it is assumed that service control unit  702  has been selected to actuate service controller  741 . Depending on the result of this selection, service controller unit  701  instructs service implementation device  253 , via the remote procedure call, to actuate service controller  741  (step  304  in FIG.  2 ). 
     Next, using the RPC, service controller  741  requests terminal controller  121 , via terminal control interface  271 , to read out the called terminal address while in response to this request, terminal controller  121  reads out called terminal address “123-4568” from the information stored in terminal control-use memory  171 , answering the information of this address to service controller  741  to said request. 
     Service controller  741  shows this address to address resolution controller  151  through address resolution control interface  275 , requesting to examine whether or not this address is resolvable and resolve said address when said address is found resolvable (step  305  in FIG.  4 ). 
     Address resolution controller  151  judges, referring to address resolution logic which is provided as a proper function and the contents of address resolution control-use memory  201 , that call incoming terminal address “123-4568” is resolvable; the consequence of this resolution is terminal  242 ; and the terminal controller corresponding to said terminal is terminal controller  122  of which service control unit  703  takes charges, then reporting the consequence of the address resolution to service controller  741 . 
     Based on the report from address resolution controller  151 , and using the RPC, service controller  741  requests execution of an inquiry processing whether the incoming call is connectable or not to terminal controller  122  corresponding to called terminal  242  (step  307  in FIG.  4 ). 
     Upon receiving this request, terminal controller  122  reads terminal control-use memory  172  and starts the acceptance control processing which is it&#39;s proper function, then by judging, based on the table provided therein, whether or not call originating terminal number “123-4567” is connectable technically, and reports the judged result together with the reason thereof to service controller  741 . 
     When receiving the answer that the incoming call is acceptable from terminal controller  122 , using the RPC, service controller  741  informs call originating-side terminal controller  121 , via terminal control interface  271 , of a call processing is under way in response to the acceptance of the call request, and using the RPC, requests called terminal side terminal controller  122 , via terminal control interface  272 , to starts a ringing processing step ( 308  in FIG.  4 ). 
     Terminal controller  121  requests subscriber circuit controller  211  to inform terminal  241  of the call processing being in progress while in response to this request, subscriber circuit controller  211  transmits dial tone to terminal  241 , thereby informing that the call processing is under way. On the other hand, terminal controller  122  requests subscriber circuit controller device  212  to inform terminal  242  that there is a call incoming request, while in response to this request, subscriber circuit controller  212  rings the bell of terminal  242  informing the presence of said request. 
     Subsequently, through the RPC, service controller  741  instructs terminal controller  122 , via terminal control interface  272 , to wait until the speech path is ready to get through, and to report at the time when speech path is ready to get through (step  310  in FIG.  4 ). Terminal controller  122  starts a speech path standby control processing which is provided as a proper function, and instructs subscriber circuit controller  212  to monitor terminal  242  over the off-hook state. 
     When terminal  242  goes into the off-hook state, and receiving the state change via subscriber circuit controller  212  and terminal controller  122 , service controller  741  then sets about a connection processing to couple terminals  241  and  242  together (step  311  in FIG.  4 ). To be more precise, in this embodiment, since subscriber circuit controllers  211  and  212  are connected respectively to separated switching controllers  222  and  224 , unlike the case of said first embodiment, a straight decision as to which telecommunications apparatus is to undertake coupling terminals  241  and  242  together is not practicable, whereby the routing processing becomes significant. 
     Service controller  741  starts the routing processing which is provided as a proper function and receives the consequential information of practicability to connect terminals  241  and  242  each other by relaying switching controllers  222  and  224 , using switching controller  223 . Next, via the routine processing, the connection controllers  711 ˜ 713  corresponding respectively to switching controllers  222 ˜ 224  are identified; one of the group connection controllers is selected as a representative; and the information regarding other connection controllers is delivered to the representative connection controller which corresponds to the result of selection, and the representative connection controller is accepted as a coincidence with a routine processing consequence. 
     In this embodiment, it is assumed that connection controller  712  has been selected as a representative connection controller. Thus, in connection control-use memory  722  which connection controller  712  uses as a temporary storage, said connection controller  712  records the information re connection controllers  711  and  713  that correspond to other connection controllers making up a group of connection controllers represented by connection controller  712 . 
     It is noted here that as regards the routing processing, this embodiment may be of such a configuration, wherein this routing processing is included in the connection controllers; in such a case, service controller  741  first generates an optional connection controller newly without undertaking routing calculations; showing terminal controllers  121 ˜ 122  to said new connection controller as respective communication terminal points; rendering the connection controller executes the routing processing; becoming a representative connection controller; and putting connection controllers  711 ˜ 723  under the control thereof. In this configuration, service controller  741  is allowed to operate with no respect of how many connection controllers are actually working. 
     Next, service controller  741  requests connection controller  712  to execute a processing of circuit-switching for regular voice transmission system, between terminals  241  and  242  under control respectively of terminal controllers  121  and  122 . Connection controller  712  reads out from connection control-use memory  722  the information of connection controllers  711 ˜ 713  which are derived as the related connection controllers by the routing processing. Then, connection controller  712  delivers the information respectively of the neighboring connection controllers and terminal controllers requesting to decide and execute the control procedures for each switching controller under their control through connection control interfaces by way of RPC. 
     Upon receiving the request from connection controller  712  through connection control interface  731 , connection controller  711  inquires, how subscriber circuit controller  211  and switching controller  223  are coupled physically to switching controller  222 , of terminal controller  121  and connection controller  712  by way of terminal control interface  271 , RPC, and connection control interface  732 , and then controls switching controller  222 , following the answer to the inquiry and setting information of switching controller  222  stored in connection control-use memory  721 . 
     Assuming in this embodiment that subscriber circuit controller  211 , for example, is connected to the first port of switching controller  222  and switching controller  223  to the second port of thereof, connection controller  711  controls switching controller  222 , via apparatus control interface  262 , to couple the first and second port with each other. 
     Upon receiving the request from connection controller  712  via connection control interface  732 , connection controller  712  inquires, how switching controller  222  is connected physically to switching controller  223 , of connection controller  711  through the RPC and connection control interface  731 , also inquires, how switching controller  224  is connected physically to switching controller  223 , of connection controller  731  via the RPC and connection control interface  733 , and then controls switching controller  223  according to the answer to the inquiries and the setting information of switching controller stored in connection control-use memory  722 . 
     Assuming in this embodiment that switching controllers  222  and  224  for example are connected respectively to the second and third port of switching controller  223 , connection controller  712  controls switching controller  223 , via apparatus control interface  263 , to connect the second and third port each other. 
     Upon receiving the request from connection controller  712  through connection control interface  733 , connection controller  713  inquires, how subscriber circuit controller  212  and switching controller  223  are coupled physically to switching controller  224 , of terminal controller  122  and connection controller  712  by way of terminal control interface  272 , RPC, and connection control interface  732 , and then controls switching controller  224 , following the answer to the inquiry and the setting information of switching controller  224  stored in connection control-use memory  723 . 
     Assuming in this embodiment that subscriber circuit controllers  212  and  223  for example are connected respectively to the fifth and second port of switching controller  224 , connection controller  713  controls switching controller  224 , via apparatus control interface  264 , to couple the fifth and second port with each other. 
     Next, using the RPC, service controller  741  informs terminal controllers  121  and  122  respectively via terminal control interfaces  271  and  272  of speech path is ready for get through. Upon receiving the notice of the speech path is ready for get through, terminal controllers  121  and  122  inform respective subscriber circuit controllers  211  and  212  which are in charge of processing a necessary control for the speech path commissioning. In this embodiment, lighting of the busy indication lamp provided on each terminal corresponds to this noticing. 
     Next, using the RPC, service controller  741  instructs terminal controllers  121  and  122  respectively via terminal control interfaces  271  and  272  to monitor the respective terminals concerned over their state change into the on-hook state, and obtains the information regarding the calling party from terminal controller  121  through the RPC and terminal control interface  271  to record the time of off-hook in service control-use memory  751  (step  312  in FIG.  2 ). 
     Next, supposing that terminal  241  has gone into the on-hook state, terminal controller  121  corresponding thereto detects this state change, reporting this information to service controller  741 . Upon receiving this information, service controller  741  starts the service implementation termination processing (step  313 ). Then, service controller  741  advises terminal controllers  121  and  122  respectively via terminal control interfaces  271  and  272  to execute the service implementation termination processing, thereafter keeps waiting until when the report that terminal controllers  121  and  122  complete the service implementation termination processing. 
     Terminal controller  121  detects the state of subscriber circuit controller  211 , wherein since the on-hook state is already detected, the terminal controller executes the service implementation termination processing to release terminal control-use memory  171  after re-initializing subscriber circuit controller  211 , then informs service controller  741  about completion of the service implementation termination processing. Meanwhile, terminal controller  122  detects the state of subscriber circuit controller  212 , finding the state without on-hook, instructs subscriber circuit controller  212 , through apparatus control interface  261 , to inform terminal  242  about completion of service implementation, thereafter keeping to wait until the subscriber circuit controller indicates the on-hook state. In response to this instruction, subscriber circuit controller  212  transmits a call cut-off tone to terminal  242 , then keeps waiting until terminal  242  turns into the on-hook state. 
     Then, when terminal  242  turns to the on-hook state, subscriber circuit controller  212  also turns into the on-hook state, informing terminal controller  122  that the sate is changed into the on-hook state. In response to this notice, terminal controller  122  releases the condition of waiting, executing the service implementation termination processing for releasing terminal control-use memory  172 , after re-initializing subscriber circuit controller  212 , and informs service controller  741  about completion of the service implementation termination processing. 
     Upon receiving the notice about completion of the service implementation termination processing respectively from terminal controllers  121  and  122 , service controller  741  releases the devices, namely operation sates of switching controllers  222  to  224  thus those are secured to during implement this service, subsequently executing the charge processing, following the calling party information stored in service control-use memory  751  and the time of service commencement, then writing the charge processing result in service control-use memory  751  and finally returning to the initial state. 
     Describing the effect and the result of the fourth embodiment of the present invention, it is said that in this embodiment, by rendering the RPC adaptable to the call from each of respective controllers, it becomes possible to minimize a change of each service controller aimed to undertake the service implementation processing across plural service controller units. 
     In the service common management/controller-applied conventional system, since controllers to control a plurality of devices are installed all together one buy one in said service common management/controller, free from complying with a certain rule, in case where the service controller arrangement or the arrangement of such telecommunications apparatus as a switching controller, etc. is changed, it used to be necessary to modify to execute calling up processing of RPC etc. and to review the contents of procedures of implementation of the service common management/controller. 
     In the fourth embodiment of the present invention, since encoding each controller which controls functions of telecommunications apparatus such as a switching controller etc. as a calling unit of the commonly usable function, resulting in that the timing of a RPC processing is definite and regular, thereby allowing availability of the effect and the result described above. 
     Further, in the fourth embodiment according to the present invention, in case where the routing processing is included in one connection controller, the connection controller which contains the routing processing is allowed to supervise other all connection controllers, whereby the service controller may behave as if functioning under one service control unit, thus resulting in availability of the unnecessariness to modify the service controller. 
     A further embodiment of the present invention is described hereunder. In said third embodiment, though the service controller is of such a configuration to call each control interface only via the service control library, the service controller is allowed to call each control interface in addition to calling the service control library, likewise in other embodiments. Further reversely to the above, in said first, second and fourth embodiment, it is practicable to utilize the service control library. 
     In the third embodiment, although a standard run is undertaken by letting service control library  511  takes charge of steps from  308  to  313 , starting this run is feasible otherwise, not following the method in which the service controller calls the service control library. Namely, the service controller sets necessary information such as controller information denoting called terminal address to which the connection is to be made to each controller for telecommunications apparatus, instructing to start the standard execution for the controllers through control interface. Receiving the instruction from service controller, the controllers execute a judging control to judge how to call the standard control procedures defined in the service control library. Followed by calling the service control library according to the result of executing the judging control, the controllers execute the requested control according to the control procedures read out from the called service control library. 
     Further in this embodiment, it is practicable to reduce the amount of controller&#39;s procedures to be stored in the service controller by previously containing the method of calling the service control library in the controller of each telecommunications apparatus. Further, a similar method is applicable to such a controller which is merely a logical entity like an address resolution controller, etc. which does not take direct control on telecommunications apparatus. In this regard, a case where the address resolution controller requested to undertake an address resolution processing calls the service control library so as to control a terminal controller or a connection controller is a typical case. 
     Describing a practical embodiment hereunder, such a configuration is quoted, wherein in response to a request calling for the address resolution of terminal telephone number “999,” the address resolution controller refers to the contents of an address resolution control-use memory owned thereby, and when the information relate plural terminal controllers and the information instructing to choose one which is not busy, the selection of a terminal controller which is not busy is executed by the way of calling service control library. 
     Also in the case of the fourth embodiment, to prevent the decline of an operation rate due to frequent application of the RPC, it is possible to attempt to reduce the subsequent communication quantity by the way of selecting one service control unit to actuate the service controller and choosing a representative connection controller. Enumerated below are the respective methods applicable for the selection and choice remarked above: 
     (a) a method to use a pre-selected rule 
     (b) a method to refer the load conditions of each service control unit as a basis of judgment. 
     Further, to accelerate speeds of a RPC processing, it is also allowed to provide proxy interfaces each of which represents control interface of other service control unit respectively within each service control unit and a processing which can not be managed by the proxy interface is only transferred to the proper control interface via RPC. 
     With reference to FIG. 8, although an inter-service control unit communication path is provided separately from the communication path via the switching controller, etc., the communication among the service control units may also be conducted through the communication path via switching controllers, etc. 
     Although in the present invention, each control interface and controller are generally handled as individual processing units, in view of the fact that they are closely related each other, a plurality of individual processing related together can also handled as an identical processing unit. The grouped processing unit will result in easiness in keeping consistency between each control interface and each controller when a new controller is developed or an existing controller is altered. 
     Further, in the embodiment of the present invention, although the processing of conversion—in the control interface—of an encoded identifier and a method of calling each of controller corresponding to every one of telecommunications apparatus, is implemented while service control is under way, previous computations for processing of conversion enables to increase the service implementation rate. 
     It is noted here that the program codes and the data for use in installing each controller of said telecommunications apparatus, address resolution controller, control interface, service controller, service control library, etc. can be stored in a recording medium, and executing these programs enables these controllers function as described above. 
     As described above, as regards the present invention, even when the telecommunications apparatus different from existing ones are controlled through the service control unit, a modification is required only on a control means in charge of the telecommunications apparatus concerned and its interface without altering other parts. This will result, according to the present invention, in practicability of reducing the amount of a change in the operating procedure stored in controllers in connecting new additional telecommunications apparatus to the service control unit. 
     As regards the present invention, the reason of this lies in feasibility to functionally define the service controller without affecting the method of implementing each controller of actual telecommunications apparatus by introducing a rule functionally defining the service controller, using a control interface of the telecommunications apparatus with its function encoded. 
     Further, as regards the present invention, even if such telecommunications apparatus with the method of operation different from that of existing telecommunications apparatus, are controlled through the service control unit, modification is required only for a group of interfaces corresponding respectively to a plurality of control means in charge of those different telecommunications devices concerned and other controllers are not required altering. This will result, according to the present invention, to reduce the amount of operating procedures to be stored in respective controller when those telecommunications apparatus having a different new method of operation are connected to the service controller. 
     In the present invention, the reason of this consists in availability of freedom from necessity to alter those function-encoded telecommunications apparatus control instructions, which the service controller applies, by appropriately dividing and installing a group of communication apparatus controllers and a group of control interfaces corresponding thereto. 
     Further as regards the present invention, it is possible that the task to enable the service control unit to control the telecommunications apparatus other than existing ones is achieved without compiling by the service controller while telecommunications service implementation is progressing. 
     The reason is that in the present invention, an adaptive processing at the time of calling a telecommunications apparatus controller from the service controller is executed along with communication service implementation. 
     Further as regards the present invention, the amount of a change in the operating procedure contained in the service controller is reduced comparing with a case applying the service controller defined for the conventional service common management/controller to the telecommunications apparatus other than existing ones. 
     The reason is that the present invention is available for provide the service control library having the same interface as that of the conventional service common management/control means, and practicability to define the service control library without affecting the method of implementing actual telecommunications apparatus control means by introducing a rule of defining the service control library, using the control interface of such a telecommunications apparatus with its function encoded. 
     Further as regards the present invention, the amount of alterations to the service controllers can be minimized in undertaking a service implementation processing across a plurality of service control units. 
     The reason is that in the present invention, the control means such as a switching controller, etc. since regarding its communicating function encoded as a function calling unit, the timing of a remote procedural call processing becomes definite and regular, and by letting one connection control means supervise all other connection control means, the service controller is allowed to behave as if functioning under one service control unit.