| 摘要 |
PURPOSE: A low capacity switching system for an ISDN(Integrated Services Digital Network) is provided to extend a subscriber capacity, and to supply various ISDN services. CONSTITUTION: An S connector(10) temporally stores a message when each subscriber terminal attempts connection, and stores the message in a RAM(Random Access Memory) again, then performs interfaces of many ISDN(Integrated Services Digital Network) subscriber terminals. An R connector(20) reads a message received through an SLIC(Subscriber Line Interface Circuit) from an analog subscriber, and converts the message into an ISDN message to transmit the converted ISDN message to a main controller(30), then performs interfaces of analog subscriber terminals. The main controller(30) performs a most significant control in order to supply synchronous clocks to each function. A U connector(40) extracts an only D channel message from a received signal to temporally store the extracted message, and notifies an interrupt of a message reception. Then, the U connector(40) reads the message to add necessary information, and transmits the message to the main controller(30), finally supplies many central office interfaces. PRI(Primary Rate Interface) connector(50) equips a D channel control function for controlling a D channel, and supplies an interface with the main controller(30) by using a mounted SDLC(Synchronous Data Link Control) function.
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