Point to Point Protocol (PPP) is a form of serial line data encapsulation that is an improvement over SLIP. PPP provides serial bi-directional communication. When using Point to Point Protocol (PPP) packets are delivered in the order they were sent. PPP is much like SLIP but can support AppleTalk, IPX, TCP/IP, and NetBEUI along with TCP/IP which is supported by SLIP. PPP can negociate connection parameters such as speed, transport protocol, and selection of PAP or CHAP user authentication method.