Patent ID: 6141341
Filing Date: 2000-10-31
Classification: H04M

Abstract:
In an Internet Protocol telephone system using a telephone to place and receive voice over Internet Protocol (VoIP)-based and public switched telephone network (PSTN)-based telephone calls, a method comprising:detecting a presence of an incoming telephone call;detecting an off-hook condition from the telephone;receiving a sequence of signals generated by the telephone;buffering at least a first signal generated by the telephone;attempting to detect a predetermined signal that signifies a VoIP-based call;intercepting subsequent signals in the sequence, absent the at least first signal that was buffered, and facilitating the VoIP-based call via an internet when the predetermined signal is detected; andsignaling, via and audible tone, a user of the telephone during the VoIP-based call of the presence of a telephone call, the audible tone having a first ringing cadence when the telephone call is a VoIP-based call and the audible tone having a second ringling cadence when the telephone call is a PSTN-based call.