Point-to-point protocol framework having link control protocol layer operates in OS kernal space and informs upper/lower layers of established communication path and LCP characteristics

摘要

It is an object of the invention to minimize the efforts required to integrate a new communication media and network service into an operating system. These and other objects are accomplished by implementing the link control protocol layer as an operating system service multiplexing a set of network protocol connections to a set of communication media connections routing messages between respective connections. The LCP function is isolated by a set of network interfaces and a set of communication media interfaces. The invention allows the NCP and datagram support to be independent of the LCP support so long as the NCP and datagram implementations conform to the interfaces provided by the LCP operating system service that allow exchanges of state information. Also, the LCP operating system service allows the addition of new types of physical communication media support to the PPP subsystem of the present invention with knowledge only of the interfaces to the LCP layer and the framing characteristics of the communications medium. Further, because the LCP layer is now isolated by the interfaces, enhancements to the LCP layer become accessible to all communications media as well as to the NCP and datagram protocols without impact to the media or network layers.