PPP

The Point-to-Point Protocol is a data link protocol that provides dial-up access over serial lines. It can run on any full-duplex link from POTS to ISDN to high-speed lines (T1, T3, etc.). Developed by the Internet Engineering Task Force (IETF) in 1991, it has become popular for Internet access, as well as a method for carrying higher level protocols.

PPP encapsulates protocols in specialized Network Control Protocol packets; for example, IPCP (IP over PPP) and IPXCP (IPX over PPP). It can be used to replace a network adapter driver, allowing remote users to log on to the network as if they were in-house. PPP can hang up and redial on a low-quality call.

PPP also provides password protection using the Password Authentication Protocol (PAP) and the more rigorous Challenge Handshake Authentication Protocol (CHAP).