Abstract: The preferred embodiments of the present invention generally provide improved communications over a subscriber loop that is loaded with at least one and potentially a plurality of load coils. The preferred embodiments of the present invention will work over loaded subscriber loops that also support a native POTS interface as well as over loaded subscriber loops that are not providing a native POTS interface. Furthermore, although the preferred embodiments of the present invention are intended to address the technical and business problems of service providers delivering digital subscriber line service over loaded loops, the preferred embodiments will also work over unloaded loops.

Abstract: A system and method for modulation on demand in a computing device, such as a personal computer, allows a central processor located in a computing device to perform the processing necessary to accomplish data communications without the need for an external processor. The system and method uses a novel modulation and accomplishes that modulation on the processor of a general purpose computing device.

Abstract: The preferred embodiments of the present invention generally provide improved communications over a subscriber loop that is loaded with at least one and potentially a plurality of load coils. The preferred embodiments of the present invention will work over loaded subscriber loops that also support a native POTS interface as well as over loaded subscriber loops that are not providing a native POTS interface. Furthermore, although the preferred embodiments of the present invention are intended to address the technical and business problems of service providers delivering digital subscriber line service over loaded loops, the preferred embodiments will also work over unloaded loops.

Abstract: The present invention provides a method and apparatus for multi-protocol, point-to-point communications which allocates processing tasks between a processor of an end point device and a processor of a communication device. The processor of the end point device performs all higher level protocol processing and the processor of the communication device performs lower level protocol processing. Internet service providers usually have several modems connected to each host computer for providing simultaneous point-to-point communication with a plurality of end users. The modems normally are located on cards which reside inside of the host computer, which may be a personal computer. To prevent the host processor from having to perform all of the protocol processing tasks for each session, the present invention provides for off-loading at least a portion of the Point-to-Point Protocol processing onto the modem processors. The host and the communication device or devices are interfaced via a shared memory device.

Abstract: In a multidrop data communication system operating at a first bit rate using the High-Level Data Link Control (HDLC) protocol, dial restoral of communications with a particular tributary at a second, lower bit rate is accomplished without requiring the system as a whole to back down to that lower bit rate. Specifically, the outgoing data is buffered in the dial restoral modem, which discards the data stored in the buffer upon receipt of the HDLC frame which follows any frame in which the so-called "poll" bit is set.