Emergency interrupt technique

Abstract

A user on a data call, e.g., to the Internet, is prevented from establishing a data call immediately after an emergency interrupt has been initiated, and the fact that the emergency interrupt took place is brought to his attention. This is necessary because otherwise the emergency interrupt is likely to be perceived by a user connected to the Internet as simply a dropped line, in response thereto the user is likely to simply originate a new call to the ISP, and so may never become aware that there has been an attempt to bring to his attention, via the emergency interrupts, an extraordinary circumstance. The invention achieves this by transmitting from the telephone network a signal which is recognizable by the user's modem and which indicates that an emergency interrupt took place. Such an emergency-interrupt-occurred signal may be transmitted upon the occurrence of the emergency interrupt or after the line next goes off-hook. Such a signal may be in addition to or in lieu of dial tone. In response to detection thereof the user's modem may take appropriate action. For example, the modem will not initiate the dialing out for the next attempt to connect the ISP, but instead, the modem will hang up, so that an incoming call can be received. Furthermore, the auto answer mode of the modem may be disabled temporarily.