10. Communications Programs And Utilities

PPP is by far the most widely used. It's used for Internet access. For dialing out to public libraries, bulletin boards, etc. minicom is the most popular followed by Seyon (X-Windows only) and Kermit.

10.1 Minicom vs. Kermit

Minicom is only a communications program while Kermit is both a communications program and a file transfer protocol. But one may use the Kermit protocol from within Minicom (provided one has Kermit installed on one's PC) . Minicom is menu based while Kermit is command line based (interactive at the special Kermit prompt). While the Kermit program is free software, the documentation is not all free. There is no detailed manual supplied and it is suggested that you purchase a book as the manual. However Kermit has interactive online help which tells all but lacks tutorial explanations for the beginner. Commands may be put in a script file so you don't have to type them over again each time. Kermit (as a communications program) is more powerful than Minicom.

Although all Minicom documentation is free, it's not as extensive as Kermit's. Since permission is required to include Kermit in a commercial distribution, and since the documentation is not entirely free, some distributions don't include Kermit. In my opinion it's easier to set up Minicom and there is less to learn.

10.2 Lists of Programs

Here is a list of some communication software you can choose from, available via FTP, if they didn't come with your distribution. I would like comparative comments on the dialout programs. Are the least popular ones obsolete?

Least Popular Dialout:

• ecu - a communications program
• pcomm - procomm-like communications program with zmodem
• xc - xcomm communication package

Most Popular Dialout:

• minicom - telix-like communications program. Supports scripts, zmodem, kermit
• C-Kermit - portable, scriptable, serial and TCP/IP communications including file transfer, character-set translation, and zmodem support
• seyon - X based communication program

Fax

• efax a small fax program
• hylafax a large fax program based on the client-server model.
• mgetty+fax handles fax stuff and login for dial-ins

Voicemail

• mvm is a Minimal VoiceMail for Linux
• vgetty is an extension to mgetty that handles voicemail for some modems. It should come with recent releases of mgetty.

Dial-in (uses getty)

• mgetty+fax is for modems and is well documented. It also handles fax stuff and provides an alternative to uugetty. It's incorporating callback and voicemail (using vgetty) features. See About mgetty
• uugetty is for modems. It comes as a part of the ps_getty package. See About getty_ps

Other

• callback is where you dial out to a remote modem and then that modem hangs up and calls you back (to save on phone bills).
• SLiRP and term provide a PPP-like service that you can run in user space on a remote computer with a shell account. See term and SLiRP for more details
• ZyXEL is a control program for ZyXEL U-1496 modems. It handles dialin, dialout, dial back security, FAXing, and voice mailbox functions.
• SLIP and PPP software can be found at ftp://sunsite.unc.edu/pub/Linux/system/network/serial.
• Other things can be found on ftp://sunsite.unc.edu/pub/Linux/system/serial and ftp://sunsite.unc.edu/pub/Linux/apps/serialcomm or one of the many mirrors. These are the directories where serial programs are kept.

10.3 SLiRP and term

SLiRP and term are programs which are of use if you only have a dial-up shell account on a Unix-like machine and want to get the equivalent of a PPP account (or the like) without being authorized to have it (possibly because you don't want to pay extra for it, etc.). SLiRP is more popular than term which is almost obsolete.

To use SLiRP you install it in your shell account on the remote computer. Then you dial up the account and run SLiRP on the remote and PPP on your local PC. You now have a PPP connection over which you may run a web browser on your local PC such as Netscape, etc. There may be some problems as SLiRP is not as good as a real PPP account. Some accounts may provide SLiRP since it saves on IP addresses (You have no IP address while using SLiRP).

term is something like SLiRP only you need to run term on both the local and remote computer. There is no PPP on the phone line since term uses its own protocol. To use term from your PC you need to use a term-aware version of ftp to do ftp, etc. Thus it's easier to use SLiRP since the ordinary version of ftp works fine with SLiRP. There is an unmaintained Term HOWTO.