Patent ID: 7933295

Claim:
A cable modem, comprising: a network port configured to interface with a cable head end; a telephony port configured to interface with a telephony device; a data port configured to interface with a data terminal; and a processor, coupled to each of the ports, configured to: differentiate between a voice signal associated with a voice call and a voice signal associated with a machine call, determine whether a voice signal received from the network port is destined for the data port or the telephony port based on whether the voice signal received from the network port is associated with the voice call or the machine call, and send the voice signal received from the network port to one of the data port and the telephony port based on such determination, wherein the processor comprises: an echo canceller operable to cancel a cable head end echo on a voice signal received from the telephony port, wherein the echo canceller comprises: a filter operable to adaptively filter the voice signal received from the network port, based on adaptation coefficients, to determine the cable head end echo, a speech detector operable to detect whether speech is present on the voice signal received from the telephony port, wherein the adaptation coefficients are held constant when the speech is detected to be present, and wherein the adaptation coefficients are adapted when the speech is not detected to be present, and a subtractor operable to subtract the cable head end echo from the voice signal received from the telephony port after the adaptation coefficients are held constant.