There are a number of communications packages available for
Linux. Many of these packages are terminal
programs, which allow a user to dial in to another computer
as if she were sitting in front of a simple terminal. The traditional
terminal program for Unix-like environments is
kermit. It is, however, fairly ancient now, and
would probably be considered difficult to use. There are more
comfortable programs available that support features, like
telephone-dialing dictionaries, script languages to automate dialing
and logging in to remote computer systems, and a variety of file
exchange protocols. One of these programs is minicom,
which was modeled after some of the most popular DOS terminal
programs. X11 users are accommodated, too. seyon is
a fully featured X11-based communications program.
Terminal programs aren't the only type of serial communication
programs available. Other programs let you connect to a host and
download news and email in a single bundle, to read and reply later at
your leisure. This can save a lot of time, and is especially useful if
you are unfortunate enough to live in an area where your local calls
are time-charged. All of the reading and replying time can be spent
offline, and when you are ready, you can redial and upload your
responses in a single bundle. This all consumes a bit more hard disk
because all of the messages have to be stored to your disk before you
can read them, but this could be a reasonable trade-off at today's
hard drive prices.
UUCP epitomizes this
communication software style. It is a program suite that copies files
from one host to another and executes programs on a remote host. It is
frequently used to transport mail or news in private networks. Ian
Taylor's UUCP package, which also runs under Linux, is described in
detail in Chapter 16. Other noninteractive
communications software is used throughout networks such as
Fidonet. Fidonet application ports like ifmail are
also available, although we expect that not many people still use
them.
PPP and SLIP are in between, allowing both interactive and
noninteractive use. Many people use PPP or SLIP to dial in to their
campus network or other Internet Service Provider to run FTP and read
web pages. PPP and SLIP are also, however, commonly used over
permanent or semipermanent connections for LAN-to-LAN coupling,
although this is really only interesting with ISDN or other high-speed
network connections.
