Specifying dial-up parameters with the Devices file
The Devices file (/usr/lib/uucp/Devices) contains
information for all the devices that can be used to
establish a link to a remote computer.
Devices are Automatic Call Units, direct links, or network connections.
This file works closely with the Dialers, Systems,
and Dialcodes files.
Before you make changes in any of these files,
you should be familiar with them all.
A change to an entry in one file may require
a change to a related entry in another file.
Each entry in the Devices file has the following format:
type ttyline dialerline speed dialer-token
This field usually contains one of two keywords (Direct or ACU) the name of a Local Area Network switch, or a system name.
tty1a - 1200 direct
1200 - ogin: nuucp ssword: DontLook
You can designate a protocol to use for a device within this field. For more information, see ``Defining a communications protocol''.
In most cases, this is simply the speed of the device,
if the keyword ACU or Direct is used in the type field.
can contain a letter and a speed
(for example, C1200, D1200) to differentiate between
classes of dialers (Centrex or Dimension PBX).
This is necessary because many larger offices
may have more than one type of telephone network:
one network may be dedicated to serving only
internal office communications, while another handles the external
It is necessary to distinguish which lines
are used for internal communications and
which are used for
external communications. The keyword used in the
speed field of the Devices file
is matched against the fourth field of the Systems file entries,
ACU tty1A -
gorgon Any ACU
3251 ogin: nuucp ssword: DontLook
Some devices can be used at any speed, so the keyword Any can be used in the speed field. If Any is used, the line matches any speed requested in a Systems file entry. If this field is Any and the Systems file speed field is Any, the speed defaults to 1200bps. If a device can be used at a range of speeds, then the speed field can specify this range (for example, 1200--9600 or D1200--9600). This is preferable to the use of Any.
This field has the following format:
dialer [ token dialer token ... ]
For a direct line, this field contains simply the word direct, and no token is required.
For a simple connection to a dialer, this field contains the name of the dialer, and the token is omitted; by default it is taken from the phone number field of the Systems file entry.
For a dialer or a network dataswitch, this field contains the name of an entry found in the Dialers file (develcon and micom are examples of network data switches). Other dialer types are supported by binaries instead of Dialers entries. (Support for 801-type dialers is provided through use of separate lines for data and the dialer. See the Devices file for details.) UUCP recognizes a dialer as a binary if the name begins with a ``/'' or if there is an executable file by that name in /usr/lib/uucp.
For more information on Dialers entries and binaries, see ``Using dialers'' in the SCO OpenServer Handbook.
The dialer-token can be structured four different ways, depending on the device associated with the entry:
If an automatic dialing modem is connected directly to
a port on your computer, the dialer-token field of the associated
Devices file entry only has one pair.
This pair would normally be the name of the modem.
This name matches the particular Devices
file entry with an entry in the Dialers file.
Therefore, the dialer field must match the first field of
the following Dialers file entry:
ACU tty1A - 1200
=&-% "" \r\p\r\c $ <K\T%%\r>\c ONLINE!
Notice that only the dialer portion (ventel) is present in the dialer-token field of the Devices file entry. This means that the token to be passed on to the dialer (in this case the phone number) is taken from the Phone field of a Systems file entry. ``\D'' is implied; see Modems used with a local network switch . Backslash sequences are described later.
If a direct-link is established to a particular computer, the dialer-token field of the associated entry contains the keyword direct. This is true for both types of direct link entries, direct and sysname (refer to discussion on the type field).
If a computer that you wish to communicate with is
on the same local network switch as your
computer, your computer must first access the switch
and the switch can then make the connection to the other
In this type of entry, there is only one pair.
The dialer portion matches a Dialers file entry, as
shown in the following example:
develcon tty13 -
1200 develcon \D
develcon "" ""
\pr\ps\c est:\007 \E\D\e \007
obie develcon ACU 1200 obie --ogin:-BREAK-ogin:
nuucp ssword: mavra
The token portion is ``\D'', which indicates that it is retrieved from the Systems file without translation. The Systems file entry for this particular computer contains the token in the phone field, which is normally reserved for the phone number of the computer (refer to Systems file, phone field). The ``\D'' ensures that the contents of the phone field is not interpreted as a valid entry in the Dialcodes file.
If an automatic dialing modem is connected to a switch,
your computer must first access the switch and the
switch makes the connection to the automatic dialing modem.
This type of entry requires two dialer-token pairs.
The following dialer
portion of each pair (fifth and seventh fields of entry)
are used to match entries in the Dialers file:
ACU tty14 - 1200
develcon vent ventel
"" "" \pr\ps\c est:\007 \E\D\e \007
ventel =&-% "" \r\p\r\c $ <K\T%%\r>\c ONLINE!
In the first pair, develcon is the switch and vent is the token that is passed to the develcon switch to tell it which device to connect to your computer. This token would be unique for each LAN switch because each switch can be set up differently. Once the modem is connected, the second pair is accessed, where ventel is the dialer and the token is retrieved from the Systems file.