ppp.Devices(4) Kernel Interfaces Manual 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 num-
ber 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 (software)
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 signal. By default, it expects the modem, CSU/DSU or modem eliminator to
provide the clock signal. Internal-clocking cannot 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 calcula-
tions. 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 dedi-
cated 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 Systems 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 indicates
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 parameter if the debug level is 2 or more.
The external dialer is invoked as so you should take appropriate security precautions with its content and file protection.
AUTHOR
was developed by the Progressive Systems.
SEE ALSO
pppd(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)