History

SLIP has its origins in the 3COM UNET TCP/IP implementation from the early 1980's. It is merely a packet framing protocol: SLIP defines a sequence of characters that frame IP packets on a serial line, and nothing more. It provides no addressing, packet type identification, error detection/correction or compression mechanisms. Because the protocol does so little, though, it is usually very easy to implement.

Around 1984, Rick Adams implemented SLIP for 4.2 Berkeley Unix and Sun Microsystems workstations and released it to the world. It quickly caught on as an easy reliable way to connect TCP/IP hosts and routers with serial lines.

SLIP is commonly used on dedicated serial links and sometimes for dialup purposes, and is usually used with line speeds between 1200bps and 19.2Kbps. It is useful for allowing mixes of hosts and routers to communicate with one another (host-host, host-router and router- router are all common SLIP network configurations).