Patent ID: 7349383

Claim:
A communication method for use by a first gateway device in communication with a second gateway device over a packet network, the first gateway device further in communication with an originating modem over a first telephone line and the second gateway device further in communication with an answering modem over a second telephone line, the method comprising: receiving a first message from the second gateway device, wherein the first message is indicative of a first answer tone classification by the second gateway device based on a first answer tone generated by the answering modem; determining whether the first message is indicative of either a modulated answer tone or a non-modulated answer tone; generating a second answer tone based on the determining; transmitting the second answer tone to the originating modem; receiving a second message from the second gateway device after the generating the second answer tone based on the determining and during the transmitting the second answer tone, wherein the second message is indicative of a second answer tone classification by the second gateway device based on the first answer tone generated by the answering modem; determining whether the second message is indicative of the first answer tone being with a phase reversal or without a phase reversal; and causing a phase reversal for the second answer tone during the transmitting the second answer tone if the second message is indicative of the first answer being with the phase reversal.