PBX stands for Private Branch Exchange, which is a private telephone network used within a company or organization. The users of the PBX phone system can communicate within their company or organization and the outside world, using different communication channels like Voice over IP, ISDN, or analog.
Attack Warning – A 3 to 5-minute wavering tone on sirens or a series of short blasts on horns or other devices. The Attack Warning signal means the detection of an actual attack or accidental missile launch. … A third distinctive signal may be used for other purposes, such as a local fire signal.
Shatter Resistant Film’ (SRF) is widely used in the industry to describe the polyester laminate film that provides protection against blasts. … The most simple form of SRF application is called ‘Daylight Application’; when the film is cut to the size of the glass and adhered to it.