초록 ▼

A subscriber line control device utilizes a scan input table and a last look table. The scan input table stores respective current line states of a plurality of analog subscriber lines. The last look table stores respective preceding line states of the plurality of analog subscriber lines and inform

A subscriber line control device utilizes a scan input table and a last look table. The scan input table stores respective current line states of a plurality of analog subscriber lines. The last look table stores respective preceding line states of the plurality of analog subscriber lines and information for validating or invalidating a timer device. A valid timer device corresponds to when a monitoring process is required. The scan input table is compared with the last look table at every predetermined cycle. When they do not match, it is judged whether the line state has changed or if the timer device is validated. Based on the judging result, an analog subscriber line control is performed according to an instruction specified by a call processing unit. The analog subscriber control is any of a call origination monitor, a dial pulse monitor, and an on-hook and off-hook (HIT) monitor.

대표청구항 ▼

A switching system including a subscriber line control device and a call processing device for accommodating a plurality of analog subscriber lines, said subscriber line control device comprising: memory means: a) for storing present on-hook and off-hook information indicating present line states fo

A switching system including a subscriber line control device and a call processing device for accommodating a plurality of analog subscriber lines, said subscriber line control device comprising: memory means: a) for storing present on-hook and off-hook information indicating present line states for a plurality of subscriber lines, b) for storing previous on-hook and off-hook information indicating previous line states for said plurality of subscriber lines obtained in a previous scanning period, and c) for storing present timer information of a plurality of bits each respectively corresponding to the present on-hook and off hook information for each of said plurality of subscriber lines and previous timer information of a plurality of bits each respectively corresponding to the previous on-hook and off-hook information for each of said plurality of subscriber lines, each of said plurality of bits of said present and previous timer information indicating a validity of a timer device for monitoring one of a) on-hook time for a monitoring process of each of said plurality of subscriber lines, b) off-hook time for a monitoring process of each of said plurality of subscriber lines and c) on and off time of dial pulses for a monitoring process of each of said plurality of subscriber lines, said validity of the timer device indicating a state wherein the timer device counts time when one of said monitoring processes is required; detecting means for simultaneously detecting a change in each of the present and previous line states of each of said plurality of subscriber lines and for determining a validity of said timer device by comparing the present on-hook and off-hook information with the previous on-hook and off-hook information at predetermined intervals the previous and present timer information included in the previous and present on-hook and off-hook information, respectively; control means for a) validating said timer device using the present and previous timer information from said memory means corresponding to each of the plurality of subscriber lines if an instruction is issued via a subscriber line to require monitoring any of off-hook states, on-hook states, and dial pulses, and for b) counting one of the on-hook and off-hook time and the on and off time of dial pulses of the subscriber line through which the instruction is sent using said validated timer device if said detecting means detects a change in one of the states of the subscriber line through which the instruction is sent; and congestion control means for setting a maximum first number of events associated with call processes in the subscriber line control device, a maximum second number of events associated with call processes between the subscriber control device and the call processing device, and a maximum number of subscriber lines for monitoring dial pulses, and for managing a first number of events, a second number of events, and a number of subscriber lines requesting monitoring to be equal to or smaller than the set maximum numbers, respectively, by executing selected call processes if the first number of events, the second number of events and the number of subscriber lines for monitoring dial pulses reach the maximum first number of events, the maximum second number of events and the maximum number of subscriber lines, respectively.