Terminal servers still exist in the technological
backwaters of the world, and are handy little buggers for low-tech
internet connection sharing.
The terminal servers I support at work are made by Xylogics; they allow 8-32 dumb terminals and/or modems to share one IP address. The terminals can telnet to the server, and the modems allow (depending on the password provided) the user to telnet to a specific machine or to get full PPP access. In hardware terms, a terminal server lets many serial devices share one Ethernet port.
Unfortunately, a terminal server usually is connected to many modems and phone lines, and to many terminals, each of which has its own connection to lightning-friendly wires. In an area so prone to T-storms as metro Tampa, too often these handy boxes literally become terminal servers.