8.8 Remote Connectivity
8.8.1 The distinction between PPP and SLIP
Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) allow users to log on remotely to a network using a device such as a modem (a dial-up connection through an analog telephone line). Although it is available for Windows 95 and NT desktops, SLIP was originally designed to connect UNIX platforms to a remote network. SLIP was one of the first remote connectivity protocols. However, with new technology and better security, SLIP is being replaced by PPP.

PPP was designed to replace all the older technology SLIP. It provides asynchronous and bit-oriented synchronous encapsulation, network protocol multiplexing, session negotiating, and data-compression negotiation, while supporting protocols such as IPX/SPX, DECnet, and TCP/IP. PPP uses the High-Level Data-Link Control (HDLC) protocol for data encapsulation during transmission and establishes and maintains connections using the Link Control Protocol (LCP). Using the Network Control Protocol (NCP) with PPP, an administrator is enabled to run different protocols simultaneously on the same line.

Advantages of PPP over SLIP include the fact that SLIP can only be used with TCP/IP, while PPP can use multi-network protocols and can use these protocols simultaneously during one session. PPP also uses DHCP to resolve IP addresses with the server, and can handle a faster speed connection than SLIP. PPP supports data compression and IP address negotiation, neither of which SLIP does.