Virtual terminal control device for switching system

A virtual terminal control device for a switching system, said virtual terminal control device provided between a protocol control section and a basic call control section, said protocol section performing a process control according to protocols where a number of simultaneously connectable call references differs depending on a terminal to be employed, said basic call control section performing a basic call connecting process relative to said terminal and further performing an added service control through a plurality of call references attendant upon said call connecting process, said protocol control section and said basic call control section forming a hierarchical structure and mutually sending and receiving signals each being an event of a call reference correspondence so as to achieve a call process in said switching system, said virtual terminal control device comprising:

• call reference managing data including terminal identifying data indicating that a plurality of the call references processed by said basic call control section and said protocol control section, respectively, are for said terminal, call reference correspondence data indicative of a connectable correspondence between each of the call references processed by said basic call control section and each of the call references processed by said protocol control section based on the number of the simultaneously connectable call references depending on a classification of the protocol processed by said protocol control section, and terminal classification data for classifying each of the call references of said basic call control section into an actual terminal call reference corresponding to the call reference of said protocol control section or into a virtual terminal call reference not corresponding thereto;
• distributing means responsive to a signal from said basic call control section for referring to said call reference managing data based on the call reference of the signal to classify the signal and to distribute the signal as one of said actual terminal call reference and said virtual terminal call reference;
• actual terminal processing means having means for determining and executing an operation per state while shifting the state in response to receipt of a signal, said actual terminal processing means, when detecting the signal of said actual terminal call reference from said basic call control section via said distributing means, looking up said call reference managing data so as to convert the call reference of the received signal into the corresponding call reference of said protocol control section and sending the corresponding call reference to said protocol control section, said actual terminal processing means, when receiving the signal from said protocol control section, looking up said call reference managing data so as to convert the call reference of the received signal into the corresponding call reference of said basic call control section and sending the corresponding call references to said basic call control section, said actual terminal processing means, when receiving a control signal inside said device, carrying out a designated process and a signal sending to said basic call control section, said actual terminal processing means, when detecting a changing trigger for said call reference correspondence data and said terminal classification data in said call reference managing data, changing said call reference correspondence data and said terminal classification data;
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• virtual terminal processing means for reading out a state of said actual terminal processing means in response to receipt of the signal of said virtual terminal call reference from said basic call control section via said distributing means, said virtual terminal processing means, depending on the received signal and the state of said actual terminal processing means, executing a process and a signal sending to said basic call control section and outputting said control signal designating an operation of said actual terminal processing means, said virtual terminal processing means, when detecting a changing trigger for said call reference correspondence data and said terminal classification data in said call reference managing data, changing said call reference correspondence data and said terminal classification data.