isdn: remove isdn4linux

$Id: INTERFACE.fax,v 1.2 2000/08/06 09:22:50 armin Exp $

Description of the fax-subinterface between linklevel and hardwarelevel of 

  isdn4linux. 

  The communication between linklevel (LL) and hardwarelevel (HL) for fax

  is based on the struct T30_s (defined in isdnif.h).

  This struct is allocated in the LL.  

  In order to use fax, the LL provides the pointer to this struct with the 

  command ISDN_CMD_SETL3 (parm.fax). This pointer expires in case of hangup 

  and when a new channel to a new connection is assigned. 

Data handling:

  In send-mode the HL-driver has to handle the <DLE> codes and the bit-order 

  conversion by itself. 

  In receive-mode the LL-driver takes care of the bit-order conversion

  (specified by +FBOR)

Structure T30_s description:

  This structure stores the values (set by AT-commands), the remote-

  capability-values and the command-codes between LL and HL.

  If the HL-driver receives ISDN_CMD_FAXCMD, all needed information

  is in this struct set by the LL.

  To signal information to the LL, the HL-driver has to set the 

  parameters and use ISDN_STAT_FAXIND.

  (Please refer to INTERFACE)

Structure T30_s:

  All members are 8-bit unsigned (__u8)

  -  resolution     

  -  rate

  -  width

  -  length

  -  compression

  -  ecm

  -  binary

  -  scantime

  -  id[]

  Local faxmachine's parameters, set by +FDIS, +FDCS, +FLID, ...

  -  r_resolution

  -  r_rate

  -  r_width

  -  r_length

  -  r_compression

  -  r_ecm

  -  r_binary

  -  r_scantime

  -  r_id[]

  Remote faxmachine's parameters. To be set by HL-driver.

  -  phase      

  Defines the actual state of fax connection. Set by HL or LL

  depending on progress and type of connection.

  If the phase changes because of an AT command, the LL driver

  changes this value. Otherwise the HL-driver takes care of it, but

  only necessary on call establishment (from IDLE to PHASE_A).

  (one of the constants ISDN_FAX_PHASE_[IDLE,A,B,C,D,E])

  -  direction

  Defines outgoing/send or incoming/receive connection.

  (ISDN_TTY_FAX_CONN_[IN,OUT])

  -  code

  Commands from LL to HL; possible constants : 

      ISDN_TTY_FAX_DR        signals +FDR command to HL

      ISDN_TTY_FAX_DT        signals +FDT command to HL 

      ISDN_TTY_FAX_ET        signals +FET command to HL

  Other than that the "code" is set with the hangup-code value at

  the end of connection for the +FHNG message.

  -  r_code 

  Commands from HL to LL; possible constants :

      ISDN_TTY_FAX_CFR       output of +FCFR message. 

      ISDN_TTY_FAX_RID       output of remote ID set in r_id[]

                             (+FCSI/+FTSI on send/receive)

      ISDN_TTY_FAX_DCS       output of +FDCS and CONNECT message,

                             switching to phase C.

      ISDN_TTY_FAX_ET        signals end of data,

                             switching to phase D.

      ISDN_TTY_FAX_FCON      signals the established, outgoing connection,

                             switching to phase B.

      ISDN_TTY_FAX_FCON_I    signals the established, incoming connection,

                             switching to phase B.

      ISDN_TTY_FAX_DIS       output of +FDIS message and values.

      ISDN_TTY_FAX_SENT      signals that all data has been sent 

                             and <DLE><ETX> is acknowledged,

                             OK message will be sent.

      ISDN_TTY_FAX_PTS       signals a msg-confirmation (page sent successful),

                             depending on fet value:

                             0: output OK message (more pages follow)

                             1: switching to phase B (next document)

      ISDN_TTY_FAX_TRAIN_OK  output of +FDCS and OK message (for receive mode).

      ISDN_TTY_FAX_EOP       signals end of data in receive mode,

                             switching to phase D.

      ISDN_TTY_FAX_HNG       output of the +FHNG and value set by code and

                             OK message, switching to phase E.

  -  badlin

  Value of +FBADLIN  

  -  badmul

  Value of +FBADMUL

  -  bor

  Value of +FBOR

  -  fet

  Value of +FET command in send-mode.

  Set by HL in receive-mode for +FET message.

  -  pollid[]  

  ID-string, set by +FCIG

  -  cq

  Value of +FCQ

  -  cr

  Value of +FCR

  -  ctcrty

  Value of +FCTCRTY

  -  minsp

  Value of +FMINSP

  -  phcto

  Value of +FPHCTO

  -  rel

  Value of +FREL

  -  nbc

  Value of +FNBC (0,1)

  (+FNBC is not a known class 2 fax command, I added this to change the

   automatic "best capabilities" connection in the eicon HL-driver)

Armin

mac@melware.de

The FAQ for isdn4linux

======================

Please note that there is a big FAQ available in the isdn4k-utils.

You find it in:

 isdn4k-utils/FAQ/i4lfaq.sgml

In case you just want to see the FAQ online, or download the newest version,

you can have a look at my website:

https://www.mhessler.de/i4lfaq/ (view + download)

or:

https://www.isdn4linux.de/faq/4lfaq.html (view)

As the extension tells, the FAQ is in SGML format, and you can convert it

into text/html/... format by using the sgml2txt/sgml2html/... tools.

Alternatively, you can also do a 'configure; make all' in the FAQ directory.

Please have a look at the FAQ before posting anything in the Mailinglist,

or the newsgroup!

Matthias Hessler

hessler@isdn4linux.de

$Id: README.audio,v 1.8 1999/07/11 17:17:29 armin Exp $

ISDN subsystem for Linux.

  Description of audio mode.

When enabled during kernel configuration, the tty emulator of the ISDN

subsystem is capable of a reduced set of commands to support audio.

This document describes the commands supported and the format of

audio data.

Commands for enabling/disabling audio mode:

        AT+FCLASS=8      Enable audio mode.

                         This affects the following registers:

                           S18: Bits 0 and 2 are set.

                           S16: Set to 48 and any further change to

                                larger values is blocked.

        AT+FCLASS=0      Disable audio mode.

                         Register 18 is set to 4.

        AT+FCLASS=?      Show possible modes.

        AT+FCLASS?       Report current mode (0 or 8).

Commands supported in audio mode:

All audio mode commands have one of the following forms:

        AT+Vxx?          Show current setting.

        AT+Vxx=?         Show possible settings.

        AT+Vxx=v         Set simple parameter.

        AT+Vxx=v,v ...   Set complex parameter.

where xx is a two-character code and v are alphanumerical parameters.

The following commands are supported:

        AT+VNH=x         Auto hangup setting. NO EFFECT, supported

                         for compatibility only.

        AT+VNH?          Always reporting "1"

        AT+VNH=?         Always reporting "1"

        AT+VIP           Reset all audio parameters.

        AT+VLS=x         Line select. x is one of the following:

                           0 = No device.

                           2 = Phone line.

        AT+VLS=?         Always reporting "0,2"

        AT+VLS?          Show current line.

        AT+VRX           Start recording. Emulator responds with

                         CONNECT and starts sending audio data to

                         the application. See below for data format

        AT+VSD=x,y       Set silence-detection parameters.

                         Possible parameters:

                           x = 0 ... 31  sensitivity threshold level.

                                         (default 0 , deactivated)

                           y = 0 ... 255 range of interval in units

                                         of 0.1 second. (default 70)

        AT+VSD=?         Report possible parameters.

        AT+VSD?          Show current parameters.

        AT+VDD=x,y       Set DTMF-detection parameters.

                         Only possible if online and during this connection.

                         Possible parameters:

                           x = 0 ... 15  sensitivity threshold level.

                                         (default 0 , I4L soft-decode)

                                         (1-15 soft-decode off, hardware on)

                           y = 0 ... 255 tone duration in units of 5ms.

                                         Not for I4L soft decode (default 8, 40ms)

        AT+VDD=?         Report possible parameters.

        AT+VDD?          Show current parameters.

        AT+VSM=x         Select audio data format.

                         Possible parameters:

                           2 = ADPCM-2

                           3 = ADPCM-3

                           4 = ADPCM-4

                           5 = aLAW

                           6 = uLAW

        AT+VSM=?         Show possible audio formats.

        AT+VTX           Start audio playback. Emulator responds

                         with CONNECT and starts sending audio data

                         received from the application via phone line.

General behavior and description of data formats/protocol.

    when a connection is made:

      On incoming calls, if the application responds to a RING

      with ATA, depending on the calling service, the emulator

      responds with either CONNECT (data call) or VCON (voice call).

      On outgoing voice calls, the emulator responds with VCON

      upon connection setup.

  Audio recording.

    When receiving audio data, a kind of bisync protocol is used.

    Upon AT+VRX command, the emulator responds with CONNECT, and

    starts sending audio data to the application. There are several

    escape sequences defined, all using DLE (0x10) as Escape char:

    <DLE><ETX>              End of audio data. (i.e. caused by a

                            hangup of the remote side) Emulator stops

                            recording, responding with VCON.

    <DLE><DC4>		    Abort recording, (send by appl.) Emulator

			    stops recording, sends DLE,ETX.

    <DLE><DLE>              Escape sequence for DLE in data stream.

    <DLE>0                  Touchtone "0" received.

         ...

    <DLE>9                  Touchtone "9" received.

    <DLE>#                  Touchtone "#" received.

    <DLE>*                  Touchtone "*" received.

    <DLE>A                  Touchtone "A" received.

    <DLE>B                  Touchtone "B" received.

    <DLE>C                  Touchtone "C" received.

    <DLE>D                  Touchtone "D" received.

    <DLE>q                  quiet. Silence detected after non-silence.

    <DLE>s                  silence. Silence detected from the

                            start of recording.

    Currently unsupported DLE sequences:

    <DLE>c                  FAX calling tone received.

    <DLE>b                  busy tone received.

  Audio playback.

    When sending audio data, upon AT+VTX command, emulator responds with

    CONNECT, and starts transferring data from application to the phone line.

    The same DLE sequences apply to this mode.

  Full-Duplex-Audio:

    When _both_ commands for recording and playback are given in _one_

    AT-command-line (i.e.: "AT+VTX+VRX"), full-duplex-mode is selected.

	In this mode, the only way to stop recording is sending <DLE><DC4>

    and the only way to stop playback is to send <DLE><ETX>.