If you have a modem, you will be able to communicate with other machines using one of the telecommunications packages available for Linux. Many people use telecommunications software to access bulletin board systems (BBSs), as well as commercial online services such as Prodigy, CompuServe, and America On-Line. Other people use their modems to connect to a UNIX system at work or school. You can even use your modem and Linux system to send and receive facsimiles. Telecommunications software under Linux is very similar to that found under MS-DOS or other operating systems. Anyone who has ever used a telecommunications package will find the Linux equivalent familiar.
One of the most popular communications packages for Linux is Seyon, an X application providing a customizable, ergonomic interface, with built-in support for various file transfer protocols such as Kermit, ZModem, and so on. Other telecommunications programs include C-Kermit, pcomm, and minicom. These are similar to communications programs found on other operating systems, and are quite easy to use.
If you do not have access to a SLIP server (see the previous section), you can use term to multiplex your serial line. term will allow you to open multiple login sessions over the modem connection to a remote machine. term will also allow you to redirect X client connections to your local X server, through the serial line, allowing you to display remote X applications on your Linux system. Another software package, KA9Q, implements a similar SLIP-like interface.
Running a bulletin board system (BBS) is a favorite hobby (and means of income) for many people. Linux supports a wide range of BBS software, most of which is more powerful than what is available for other operating systems. With a phone line, a modem, and Linux, you can turn your system into a BBS, providing dial-in access to your system to users worldwide. BBS software for Linux includes XBBS and the UniBoard BBS packages.
Most BBS software locks the user into a menu-based system where only certain functions and applications are available. An alternative to BBS access is full UNIX access, which would allow users to dial into your system and login as a regular user. While this would require a fair amount of maintenance on the part of the system administrator, it can be done, and providing public UNIX access from your Linux system is not difficult to do. Along with a TCP/IP network, you can provide electronic mail and news access to users on your system.
If you do not have access to a TCP/IP network or UUCP feed, Linux will also allow you to communicate with a number of BBS networks, such as FidoNet, with which you can exchange electronic news and mail via the phone line. More information on telecommunications and BBS software under Linux can be found in Chapter 5.