mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-22 11:17:19 +00:00
134 lines
4.1 KiB
Groff
134 lines
4.1 KiB
Groff
.\"
|
|
.\" Copyright (c) 1997, 2002 Hellmuth Michaelis. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.\" last edit-date: [Sun Jul 28 14:14:06 2002]
|
|
.\"
|
|
.Dd July 28, 2002
|
|
.Dt I4BTEL 4
|
|
.Os
|
|
.Sh NAME
|
|
.Nm i4btel
|
|
.Nd isdn4bsd ISDN B-channel telephony interface driver
|
|
.Sh SYNOPSIS
|
|
.Cd device \&"i4btel\&" Op count
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Nm
|
|
driver provides an interface to the ISDN B-channel for telephony applications
|
|
and is currently used by the
|
|
.Xr isdnd 8
|
|
for answering machine support.
|
|
The driver is part of the isdn4bsd package.
|
|
.Pp
|
|
The lower six bits of the drivers's minor number is used to specify a
|
|
unit number, whereas the upper two bits specify a functionality.
|
|
.Pp
|
|
Functionality zero is the usual telephony data stream i/o driver.
|
|
.Pp
|
|
Functionality one is used to enable commands to dial out and hang up and
|
|
receive responses about the state of the dial out progress and status.
|
|
This commands may change in the future, for details see the file
|
|
.Em i4b_tel_ioctl.h
|
|
and the
|
|
.Xr isdnphone 1
|
|
utility.
|
|
.Pp
|
|
The telephony data stream comes out of the line in a bit-reversed format,
|
|
so the
|
|
.Nm
|
|
driver does the bit-reversion process in any case.
|
|
.Pp
|
|
Additionally, the user can specify to do A-law to u-law, u-law to A-law
|
|
or no conversion at all in the i4btel driver by using the
|
|
.Xr isdntelctl 8
|
|
utility.
|
|
.Pp
|
|
The driver is able to process several ioctl's:
|
|
.Pp
|
|
.Bl -tag -width Ds -compact -offset indent
|
|
.It Ar I4B_TEL_GETAUDIOFMT
|
|
get currently used audio format conversion.
|
|
.It Ar I4B_TEL_SETAUDIOFMT
|
|
set currently used audio format conversion.
|
|
.It Ar I4B_TEL_EMPTYINPUTQUEUE
|
|
clear the input queue.
|
|
.El
|
|
.Pp
|
|
For the I4B_TEL_GETAUDIOFMT and I4B_TEL_SETAUDIOFMT, the following
|
|
parameters are available:
|
|
.Pp
|
|
.Bl -tag -width Ds -compact -offset indent
|
|
.It Ar CVT_NONE
|
|
do no A-law/u-law audio format conversion.
|
|
The conversion path looks like this:
|
|
.Pp
|
|
USER <--> bitreversing <--> ISDN-line
|
|
.Pp
|
|
.It Ar CVT_ALAW2ULAW
|
|
set set audio format conversion to do an audio conversion from A-law
|
|
(on the ISDN line) to u-law (in the userland).
|
|
The
|
|
.Xr read 2
|
|
conversion path looks like this:
|
|
.Pp
|
|
USER <-- u-law/A-law <-- bitreversing <-- ISDN-line
|
|
.Pp
|
|
and the
|
|
.Xr write 2
|
|
conversion path looks like this:
|
|
.Pp
|
|
USER --> u-law/A-law --> bitreversing --> ISDN-line
|
|
.Pp
|
|
.It Ar CVT_ULAW2ALAW
|
|
set set audio format conversion to do an audio conversion from u-law
|
|
(on the ISDN line) to A-law (in the userland).
|
|
The
|
|
.Xr read 2
|
|
conversion path looks like this:
|
|
.Pp
|
|
USER <-- A-law/u-law <-- bitreversing <-- ISDN-line
|
|
.Pp
|
|
and the
|
|
.Xr write 2
|
|
conversion path looks like this:
|
|
.Pp
|
|
USER --> A-law/u-law --> bitreversing --> ISDN-line
|
|
.Pp
|
|
.El
|
|
.Sh STANDARDS
|
|
A-Law and u-Law are specified in ITU Recommendation G.711.
|
|
.Sh SEE ALSO
|
|
.Xr g711conv 1 ,
|
|
.Xr isdnphone 1 ,
|
|
.Xr isdnd.rc 5 ,
|
|
.Xr isdnd 8 ,
|
|
.Xr isdntelctl 8
|
|
.Sh AUTHORS
|
|
The
|
|
.Nm
|
|
device driver and this manpage were written by
|
|
.An Hellmuth Michaelis Aq hm@FreeBSD.org .
|