06141341 is referenced by 403 patents and cites 3 patents.

An Internet Protocol telephone system and method uses a telephone (26) to place and receive voice over Internet Protocol (VoIP)-based telephone calls and public switched telephone network (PSTN)-based telephone calls. An off-hook condition with the telephone (26) is detected and a sequence of signals generated by the telephone (26) is received. At least a first signal generated by the telephone (26) is buffered while the system attempts to detect a predetermined signal that signifies a VoIP-based call. Upon detection of the predetermined signal, the system intercepts subsequent signals in the sequence, absent the at least first signal that was buffered, and places the VoIP-based call via an internet (12). Otherwise, the system places the PSTN-based call via a PSTN (16).

Title
Voice over internet protocol telephone system and method
Application Number
9/150427
Publication Number
6141341
Application Date
September 9, 1998
Publication Date
October 31, 2000
Inventor
Robert Victor Holland
Madison
AL, US
Timothy Cotton
Huntsville
AL, US
Wesley Stuart Jones
Palatine
IL, US
Agent
Heather L Creps
Assignee
Motorola
IL, US
IPC
H04L 12/66
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