Abstract: A network interface device includes a first interface operable to receive at least two incoming calls over a subscriber line, and a second interface operable to facilitate communication between the first interface and a first telephone line and between the first interface and a second telephone line. The second interface is also operable to generate one or more first ring voltages on the first telephone line and one or more second ring voltages on the second telephone line. The network interface device also includes a processor coupled to the first interface and the second interface. The processor is operable to instruct the second interface to generate the first and second ring voltages in response to receiving the incoming calls. The processor is also operable to allocate the first and second ring voltages among the first and second telephone lines to ensure that a total instantaneous load placed on the second interface does not exceed a determined threshold level.

Abstract: A communication apparatus includes circuitry operable to facilitate communication over a digital subscriber line. The apparatus also includes a filter operable to be coupled between the circuitry and the digital subscriber line. The filter has a corner frequency and is operable to attenuate transients associated with the circuitry when the apparatus is in use. The filter is tuned to an impedance of the circuitry.

Abstract: In a system including a plurality of telephones coupled to an asymmetric digital subscriber line, a circuit operable to facilitate communication using the asymmetric digital subscriber line includes a filter having a corner frequency and being operable to be coupled between one of the plurality of telephones and the asymmetric digital subscriber line. The filter is also operable to attenuate transients associated with the telephone operating in an off-hook state. The circuit also includes a switch coupled to the filter. The switch is operable to effect a change in the corner frequency of the associated filter depending on whether the telephone coupled to the filter is operating in an on-hook or an off-hook state, the change in the corner frequency operating to attenuate parasitic interference associated with telephones in an on-hook state.