ppp.Devices(4)ppp.Devices(4)NAME
ppp.Devices - PPP physical device description file format
DESCRIPTION
The file associates dialer types with physical devices and speeds.
examines it when placing a call to a neighboring machine. If no suit‐
able speed is found, or if all devices associated with that speed are
busy, will try again later.
Format
Entries are one to a line; blank lines are ignored. Comments begin
with a and extend to the end of the line. Upper/lower case distinc‐
tions are significant. Fields on a line are separated by horizontal
white space (blanks or tabs).
Each entry must contain three or more fields, in this order:
dialer Either the string or the name of the modem dialing chat
script (found in to use with this device, or the name of an
external dialer program.
device The name of the device in the directory etc.). Device
names for SnapLink connections are followed by a slash and
the port number in use etc.).
speed The baud rate of the synchronous connection, or a string to
be matched against the speed field of entries in when the
device field is set to ACU. Speeds must either be valid
async baud-rate numbers (as found in or must begin with
them (2400, 38400, 19200-PEP, etc.), or must be speeds of
which the SnapLink hardware is capable (9600, 56000, 64000,
1536000, etc.)
optional parameters
Any special handling for this device. Currently supported
values include:
Specifies that the line be conditioned for in-band (soft‐
ware)
flow control, using the characters DC3
(^S, XOFF, ASCII 0x13) to stop the flow
and DC1 (^Q, XON, ASCII 0x11) to resume.
The default is to use no flow control.
For an outbound connection, this may be
specified either in or on the command
line.
The SnapLink will provide the synchronous clock sig‐
nal. By default, it expects the modem,
CSU/DSU or modem eliminator to provide
the clock signal. Internal-clocking can‐
not be used with RS-232 cables on the
SnapLink.
The SnapLink will calculate 32-bit FCS values for
transmitted frames, and check received
frames with 32-bit FCS calculations.
This is not negotiable at connection
establishment time. 32-bit FCS is only
available when running synchronous PPP on
the SnapLink.
The number of additional HDLC flag characters the SnapLink
should
insert between data frames. The default
and minimum is 2; the maximum is 16.
Ignore the state of the CD (Carrier Detect, also called
DCD, Data
Carrier Detect) signal. This is useful
for systems that don't support CD but
want to run PPP over a dedicated line.
External Dailer
The external dialer program is run with the following arguments:
device name The contents of the Device field from the Devices
entry.
speed The contents of the Speed field of the Systems and
Devices entries.
telephone number The contents of the Phone Number field of the Sys‐
tems entry.
optional parameters Copied from the Optional Parameters section of the
Devices entry.
If the external dialer program exits with status 0, then the dial
attempt is considered to have succeeded. Any other exit status indi‐
cates a failure.
EXAMPLES
#
# Devices - PPP devices file
#
#Dialer device speed Optional parameters
T2500-PEP cua 19200-PEP rtscts
T1600 cub 38400 rtscts
Direct rsd0a/0 1536000 internal-clocking
Oddball rsd0a/1 64000 cua 9600 5551212
In the last line of this example, the 64Kb synchronous modem on the
SnapLink's port 1 has an asynchronous dialer interface attached to the
workstation's port The Systems line would look like
host Oddball rsd0a/1 64000 0
There must be a program (or an executable shell script) called that
dials the modem when invoked as
Oddball rsd0a/1 64000 0 cua 9600 5551212
A warning message will be printed for each unrecognized optional param‐
eter if the debug level is 2 or more.
The external dialer is invoked as so you should take appropriate secu‐
rity precautions with its content and file protection.
AUTHOR
was developed by the Progressive Systems.
SEE ALSOpppd(1), ppp.Auth(4), ppp.Dialers(4), ppp.Filter(4), ppp.Keys(4),
ppp.Systems(4).
RFC 1548, RFC 1332, RFC 1144, RFC 1055.
ppp.Devices(4)
