Integrated ringing circuit and a ring trip circuit for the same
Intelligent multimode message alerts
Intelligent phone cord apparatus
Intelligent telephone system
Intelligent telephone system and method for determining dialing
Interface circuit to quickly establish a loop current
Interference attenuation for acoustic-dialers
International call prefix identification and formatting
Interrupted tone converter
Interswitch line circuit
Intrinsically safe telephone
IP telephone apparatus and IP telephone system
ISDN interface unit with separate ring generator
Key input device
Key input device
Key top attachment structure
Key unit
Key-in sound-generating circuit
Keypad device
Keypad monitor with keypad activity-based activation