Operator's guide
command
pppd
to establish these links.
pppd
is a versatile program, which
uses command-line options to specify the type of PPP link required. These
options are fully described in the Linux documentation for
pppd
.
The serial.x.ppp box allows you to specify
pppd
options to use on this serial
port. Options which you wish to apply to all serial ports running the ppp service
should be placed in the
/etc/ppp/options
file (see
“options” in Section
4.4
.)
serial.x.service : How the DCM will use each serial port. There are five options:
•
getty : The module will use this port to listen for logins from a
connected computer. Once logged in, the user will have direct
command-line access to the DCM's Linux operating system.
•
mgetty : The module will use this port to listen for logins over a
connected serial modem. Again, a logged-in user will be presented with
the DCM's Linux command line.
•
mgetty-r : The module will use this port to listen for logins over a
connected serial modem which is operating in raw mode (i.e. which does
not support the standard AT modem commands.) This option in runs the
Linux command
mgetty -r
. A port running the mgetty-r service will
also listen for incoming PPP frames, and if it detects one will configure
the
PPP
link
according
to
the
/
etc/sendfax/login.config
file (see
“login.config”
in Section 4.4
.)
•
ppp : The module will use this port to provide a PPP link to a connected
computer. Once set up on the computer, the DCM will appear as if on a
local TCP/IP network. You can then log in to it using ssh or use its
Web-based administration system, as well as receiving data.
Before a PPP link will function, you will need to specify the PPP options
and (if using CHAP) provide a
chap-secrets
file. This can be done
through the DCM configuration interface: see
“options” in Section 4.4
and
“chap-secrets” in Section 4.4
. Also see the Linux manual page for
pppd(8)
for an explanation of how PPP is implemented.
•
gcf_in : The module will use this port to communicate with a GCF-
compatible digitizer.
•
gcf_out : The module will use this port to send GCF data directly to the
connected device as it is received. A number of programs are available
for PCs which handle incoming GCF data streams, such as Scream!,
Antelope, and Earthworm. The DCM transparently merges all incoming
data streams, so if you are using Scream!, you can also configure and
December 2005
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