isdninfo

isdninfo(4)			Special files			  isdninfo(4)



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	 sub-
       system 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 val-
       ues 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	 pro-
       cess.   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, avail-
		     able 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>

SEE ALSO
       isdnctrl(4), icnctrl(4).



ISDN 4 Linux 3.3		  1999/09/06			  isdninfo(4)