Voice over internet protocol telephone system and method

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;
• and
• signaling, 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.