PPP.DEVICES(MST

PPP.DEVICES(MST_PPP)

NAME

ppp.Devices - PPP physical device description file format

The file /usr/lib/mstppp/Devices on SCO systems associates dialer types with physical devices and speeds. Pppd examines it when placing a call to a neighboring machine. If no suitable speed is found, or if all dev ices associated with that speed are busy, pppd 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 distinctions are significant
Fields on a line are separated by horizontal white space created by blanks or tabs
Each entry must contain three or more fields, in this order:

dialer: Contains either the string `Direct, the name of the modem dialing chat script in Dialers to use with this device, or the name of an external dialer program.
Device: The name of the device in the /dev directory ( tty1a, tty1A , etc.). Device names for SnapLink connections are followed by a slash and the port number in use ( rfd0, rfd1 , etc.).
speed: The baud rate of the synchronous connection, or a string to be matched against the speed field of entries in Systems when the Systems device field is set to ACU (Any Call Unit).

There is also a fourth field for describing options:

optional parameters: Any special handling for this device. Currently supported values are shown in the table below.
rtscts: Specifies that the line be conditioned for out-of-band EIA RS-232-D `hardware (RTS/CTS) flow control. The default is to use no flow control. For an outbound connection, this may be specified either in Devices or on the pppd command line.
Crtscts: A synonym for rtscts
xonxoff: 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 Devices or on the pppd command line.
internal-clocking: 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.
32-bit-fcs: A 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.
min-flags=min flags: The number of additional HDLC flag characters a SnapLink should insert between data frames. The default and minimum is 2; the maximum is 16.
ignore-cd: 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 DIALER

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.

This program also allows for optional parameters:

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.

EXAMPLE

# # 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 SnapLinks port 1 has an asynchronous dialer interface attached to the workstations port `a' The Systems line would look like

host Oddball rsd0a/1 64000 0

There must be a program (or an executable shell script) called /usr/lib/mstppp/Oddball 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.

CAVEATS

The external dialer is invoked as root , so you should take appropriate security precautions with its content and file protection.

PPP.DEVICES(MST_PPP)

NAME

DESCRIPTION

FORMAT

EXTERNAL DIALER

EXAMPLE

CAVEATS

SEE ALSO

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