Ubuntu Manpage: isdninfo - ISDN status device

Provided by: isdnutils-base_3.25+dfsg1-9ubuntu2_amd64

NAME

       isdninfo - ISDN status device

SYNOPSIS

       #include <linux/isdn.h>

DESCRIPTION

       /dev/isdninfo  is  a  character  device  with  major  number  45 and minor number 255.  It
       delivers status information from the Linux ISDN subsystem to user level.

DATA FORMAT

When reading from this device, the current status of the Linux ISDN subsystem is delivered
in 6 lines of text. Each line starts with a tag string followed by a colon and whitespace.
After that the status values are appended separated by whitespace.

idmap is the tag of the first line. In this line for every virtual channel, the Id-string
of the corresponding lowlevel driver is shown. If no driver is loaded, a - (hyphen)
is shown.

chmap is the tag of line 2. In this line for every virtual channel, the channel number of
the corresponding lowlevel driver is shown. If no driver is loaded, -1 is shown.

drmap is the tag of line 3. In this line for every virtual channel, the index number of
the corresponding lowlevel driver is shown. If no driver is loaded, -1 is shown.

usage is the tag of line 4. In this line for every virtual channel, the current usage is
shown. The following usage constants are defined:

ISDN_USAGE_NONE (0)
Unused channel

ISDN_USAGE_RAW (1)
Channel used by raw device (currently unsupported)

ISDN_USAGE_MODEM (2)
Channel used by some ttyI

ISDN_USAGE_NET (3)
Channel used by an ISDN net-interface

ISDN_USAGE_VOICE (4)
Channel used by some ttyI in voice mode.

ISDN_USAGE_EXCLUSIVE (64)
Channel exclusively preserved for a net-interface. This value is logically
or'ed with one of the other codes.

ISDN_USAGE_OUTGOING (128)
Channel is used outgoing. This value is logically or'ed with one of the
other codes. It is set, when dialling is started and reset, when either
dialling failed or after hangup. Therefore, it is not always an indicator
for an established connection. To get a reliable indicator for an
established connection, the driver flags (see below) have to be inspected
also.

flags is the tag of line 5. In this line for every driver slot, it's B-Channel status is
shown. If no driver is registered in a slot, a ? is shown. For every established
B-Channel of the driver, a bit is set in the shown value. The driver's first
channel is mapped to bit 0, the second channel to bit 1 and so on.

phone is the tag of line 6. In this line for every virtual channel, the remote phone
number is shown if the channel is active. A ??? is shown, if the channel is
inactive.

BLOCKING BEHAVIOUR

       After opening the device, at most 6 lines can be read by a user process.  After that,  the
       user  process is blocked. Whenever a status change happens, the process is allowed to read
       6 more lines, starting with line one.

IOCTL FUNCTIONS

       Currently, there are two ioctl calls supported:

       IIOCGETDVR
              Get Revision information.
              Returns an unsigned  long  value  v,  representing  various  user  level  interface
              revisions, where

              (v & 0xff)
                     is  the  revision  of  the  modem-register  info,  available  via  ioctl  on
                     /dev/isdnctrl.

              ((v >> 8) & 0xff)
                     is the revision of the net-interface config data,  available  via  ioctl  on
                     /dev/isdnctrl.  and

              ((v >> 16) & 0xff)
                     is the revision of the data delivered via /dev/isdninfo itself.

       IIOCGETCPS
              Get transfer statistics.
              Returns  the number of bytes transferred so far for all virtual channels. The third
              parameter  should  be  a  pointer  to  an  array   of   unsigned   long   of   size
              ISDN_MAX_CHANNELS  *  2.  This  array  is  filled with the byte counter values upon
              return.

OTHER CONSTANTS

       There are some more useful constants defined in /usr/include/linux/isdn.h:

       ISDN_TTY_MAJOR
              The major device number of /dev/ttyI.

       ISDN_TTYAUX_MAJOR
              The major device number of /dev/cui.

       ISDN_MAJOR
              The major device number of /dev/isdnctrl, /dev/isdninfo, /dev/ippp and /dev/isdn

       ISDN_MAX_DRIVERS
              The number of driver slots.

       ISDN_MAX_CHANNELS
              The number of virtual channels.

       ISDN_MINOR_CTRL
              The minor device number of /dev/isdnctrl0.

       ISDN_MINOR_CTRLMAX
              The minor device number of /dev/isdnctrl63.

       ISDN_MINOR_PPP
              The minor device number of /dev/ippp0.

       ISDN_MINOR_PPPMAX
              The minor device number of /dev/ippp64.

       ISDN_MINOR_STATUS
              The minor device number of /dev/isdninfo.

       Other constants, necessary for ioctl's on /dev/isdnctrl are listed in isdnctrl(4).

AUTHOR

       Fritz Elfert <fritz@isdn4linux.de>