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MelwareDE c02af7806f Added patch from Michael Gernoth to fix bridging by removing codec 'none'. 4 years ago
divastatus Original idea was to use L1/L2 state to manage mapping of outgoing calls to available hardware resources for E.1/T.1 only. This functionality is not availeble for BRI: the state of L2 is newer known: even if we know local L2 activation policy we do not know the remote on and do not know if L2 activation works without problems. But now it is requested to show the state of BRI interfaces. The code is modified to maintain two states: functional and visual one. Functional is used for E.1/T.1 only. Visual is used for every one. 11 years ago
divastreaming Add support for tx stream counter polling 11 years ago
divaverbose Add copyright 12 years ago
libcapi20 Use Diva QSIG CAPI extensions for processing of Calling Party Name 12 years ago
CHANGES Added patch from Michael Gernoth to fix bridging by removing codec 'none'. 4 years ago
INSTALL Reviewed by doc control 14 years ago
LICENSE Initial import of new chan_capi. 18 years ago
Makefile Hide error output if version.h of Asterisk is not found. 6 years ago
README CAPI specs (5th edition diagrams in section A.5) say that early B3 should 6 years ago
README.Diva.HDAudio Diva Hight Definition (WB, Wide Band) Audio 12 years ago
README.Diva.fax Allow "," as capicommand option separator (needed from asterisk 1.6) 12 years ago
README.Diva.qsig Formatting 12 years ago
README.Diva.streaming Description of Diva streaming 12 years ago
README.ami Spelling 12 years ago
README.media Use codecs for resource PLCI 12 years ago
README.mwi Add MWI Client 12 years ago
README.qsig Allow "," as capicommand option separator (needed from asterisk 1.6) 12 years ago
capi.conf Better call distribution algorithm 12 years ago
chan_capi.c Added patch from Michael Gernoth to fix bridging by removing codec 'none'. 4 years ago
chan_capi.h Added patch to support Asterisk 13 from Michael Kuron. 6 years ago
chan_capi20.h Added header file capiutils.h 17 years ago
chan_capi_ami.c Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_ami.h Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_chat.c Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_chat.h Add 'capi show bridges' to show used by group based conference resources. Add information about state of tx stream to 'capi show resources' 12 years ago
chan_capi_cli.c Add module to write traces to Diva trace driver. Restore compilation with version 1.2 12 years ago
chan_capi_cli.h Add/Update copyright 12 years ago
chan_capi_command.c Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_command.h Use received from IP tone events for VC command 14 years ago
chan_capi_devstate.c - Adapt to new cache argument for ast_devstate_changed() 10 years ago
chan_capi_devstate.h Add/Update copyright 12 years ago
chan_capi_fmt.h Added patch from Michael Gernoth to fix bridging by removing codec 'none'. 4 years ago
chan_capi_management_common.c Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_management_common.h Add/Update copyright 12 years ago
chan_capi_mwi.c Add module to write traces to Diva trace driver. Restore compilation with version 1.2 12 years ago
chan_capi_mwi.h Add/Update copyright 12 years ago
chan_capi_platform.h Add/Update copyright 12 years ago
chan_capi_qsig.h Customer reported unexpected behavior after incoming call with redirection number information element. The problem is caused by destruction of internal structures of libc and arrives not on every system but 12 years ago
chan_capi_qsig_asn197ade.c Customer reported unexpected behavior after incoming call with redirection number information element. The problem is caused by destruction of internal structures of libc and arrives not on every system but 12 years ago
chan_capi_qsig_asn197ade.h updated copyright 15 years ago
chan_capi_qsig_asn197no.c Runtime optimization 14 years ago
chan_capi_qsig_asn197no.h updated copyright 15 years ago
chan_capi_qsig_core.c Added patch to support Asterisk 13 from Michael Kuron. 6 years ago
chan_capi_qsig_ecma.c Added changes from https://github.com/Ionic/chan_capi 8 years ago
chan_capi_qsig_ecma.h Asterissk 1.8 12 years ago
chan_capi_rtp.c Clean up 11 years ago
chan_capi_rtp.h Update copyright years. 14 years ago
chan_capi_supplementary.c Added patch to support Asterisk 13 from Michael Kuron. 6 years ago
chan_capi_supplementary.h From CAPI thread locks are taken in the wrong order. The right ordr is ast_channel_lock followed by i->lock. But from CAPI thread 12 years ago
chan_capi_utils.c Added patch to support Asterisk 13 from Michael Kuron. 6 years ago
chan_capi_utils.h Added changes from https://github.com/Ionic/chan_capi 8 years ago
create_config.sh - fixed check of asterisk version with asterisk binary if another install path is used. 6 years ago
dlist.c source code is not executable 14 years ago
dlist.h source code is not executable 14 years ago
xlaw.c - more restructuring 16 years ago
xlaw.h - more restructuring 16 years ago

README

chan_capi a Common ISDN API 2.0 implementation for Asterisk

Copyright (C) 2005-2010 Cytronics & Melware
Armin Schindler <armin@melware.de>

Reworked, but based on the work of
Copyright (C) 2002-2005 Junghanns.NET GmbH
Klaus-Peter Junghanns <kpj@junghanns.net>

This program is free software and may be modified and distributed under
the terms of the GNU Public License. There is _NO_ warranty for this!

Thanks go to the debuggers, bugfixers and contributors :)
===========================================================================
Lele Forzani <lele@windmill.it>
Florian Overkamp <florian@obsimref.com>
Gareth Watts <gareth@omnipotent.net>
Jeff Noxon <jeff@planetfall.com>
Petr Michalek <petr.michalek@aca.cz>
Jan Stocker
Frank Sautter, levigo group
Hans Petter Selasky
Simon Peter <dn.tlp@gmx.net>
Mario Goegel <m.goegel@gmx.de>

(...and all the others that have been forgotten...) :-)

No support for Asterisk 1.0.x any more, you need at least
Asterisk 1.2.x , 1.4.x or 1.6.x.

Note:
Eicon DIVA Server cards are now named Dialogic(R) Diva(R) Media Boards.

This chan_capi version includes:
=====================================================
- Multiple controller support
- CID,DNID (callling party, called party)
- CLIR/CLIP
- Supplementary services: CD (deflect/reroute),HOLD,RETRIEVE,ECT,3PTY
- DTMF (dependend on card) + software DTMF support
- Early B3 connects (always,success,never)
- Digital audio (what did you think?)
- Incoming/outgoing calls
- Overlap sending (dialtone and additional digits)
- E(xplicit) C(all) T(ransfer) (...although it's done implicit-but don't tell!)
- Use asterisks internal DSP functions for DTMF
- a-Law support
- u-Law support!
- Dialogic(R) Diva(R) software DSP echo cancellation (echocancel=1)
- Reject call waiting (ACO)
- DID for Point to Point mode (a.k.a overlap receiving)
- Rx/Tx gains using positive linar value (rxgain=1.0, txgain=1.0 means no change)
- (Inter)national/subscriber dialing prefix (for callerid) configurable in capi.conf
- CLI command "capi info" shows B channel status of chan_capi
- Catch all MSN (incomingmsn=*)
- Some configuration enhancements (msn=123,124,125)
- Added accountcode=
- Echo squelching (echosquelch=1)
- Callgroup support
- report correct DIALSTATUS and HANGUPCAUSE.
- Updated to support the new frame->delivery field
- Compiles with different Asterisk versions (automatic build configuration)
- receive/send faxes for CAPI (see below)
- Fixes and compatibility for BSD (Jan Stocker and Hans Petter Selasky)
- Support 'type of number'.
- ISDN hold.
- CAPI Line Interconnect.
- CAPI VoIP/RTP
- CLI command "capi show channels" shows details on channel status.
- Asterisk 1.4 jitterbuffer configuration.
- some QSIG extensions (see README.qsig)
- CCBS (call completion on busy subscriber)
- CAPI CHAT (CAPI MeetMe using onboard DSPs)
- KEYPAD digits detection
- provide DATE/TIME in NT-mode.


The Dial string
===============

Example: Dial(CAPI/g<group>/[<callerid>:]<destination>[/<params>])
Or: Dial(CAPI/contr<controller>/[<callerid>:]<destination>[/<params>])
Or: Dial(CAPI/<interface-name>/[<callerid>:]<destination>[/<params>])

'group' can be a value, comma separated list of values or a range
using '-'. The according interface is found by searching a match with
the 'group' specified in the capi.conf for each interface.

The optional <callerid> followed by an ':' can be used to set a caller ID
for this dial() command, without changing the original channel's caller ID.

'params' is an optional part to set special settings for this call.
The string consists of a list of characters with the following meaning:
'b' : early B3 always.
'B' : early B3 on successful calls only.
't' : enable B3 only on in-band tones available indication as Q.931 (05/98)
recommends (without this option it will be enabled on "PROGRESS" or
"ALERTING" messages, any "Progress" indication or channel identification).
'd' : use the default caller ID that is set by defaultcid= in capi.conf
'o' : use overlap sending of number.
(Useful if additional digits should be send afterwards or together
with 'b' to get the dialtone and then send the number, e.g., if
no progress tones are available)
'c' : do not send sending complete
's' : activate 'stay-online': do not disconnect CAPI connection on hangup.
This is needed to give additional commands like CCBS after hangup.
To really hang up the CAPI connection, use either capicommand(hangup)
or wait for chan_capi/network timeout (about 20 seconds).
'G' : early Line-Interconnect / bridge: Use Line-Interconnect as soon as
both B-channels are up. Both channels must be of type the CAPI and
the incoming call may need 'capicommand(progress)' to enable Early B3
on it as well as the dial option 'b' for the outgoing channel.
Before Dial(), the capicommand(peerlink) must be used to signal the
dialed channel its peer.

If the <interface-name> is used in dialstring, be sure the name (specified
in capi.conf) does not start with 'contr' or 'g'.

CLIP/CLIR uses the calling presentation of the calling channel, which can
be modified using the SetCallerPres() application. Use
SetCallerPres(prohib_not_screened) for CLIR. That is why the msn= param in
capi.conf has been removed. The callerID is also taken from the calling channel.


CLI commands
============

capi info:
Show chan_capi version info.
Show status of available B-channels.

capi debug:
Enable CAPI message verbosity.

capi no debug:
Disable CAPI message verbosity.

capi show channels:
Display detailed information on CAPI B-channels.
(Description see below)

capi chatinfo:
Show status of CAPI CHAT.

capi ifcstate:
Show state of interfaces. (Diva only, chan_capi
compiled with 'make DIVA_STATUS=1')

capi show resources:
Show resources in use.

capi exec:
'capi exec CHANNEL command,parameter1,parameter2,....,parameterN'
Exec capicommand 'command' for selected channel.

CAPI command application
========================================
chan_capi provides an additional Asterisk application
capicommand()
With this application, special CAPI commands and features can be used.

Call Deflection:
Forwards an unanswered call to another number.
Example:
exten => s,1,capicommand(deflect,12345678)

Fax receive:
Receives a fax using CAPI.
Example:
exten => s,1,capicommand(receivefax,/tmp/${UNIQUEID},+49 6137 555123,Asterisk,kX)
(more see below)

Fax send:
Sends a fax using CAPI.
Example:
exten => s,1,capicommand(sendfax,/path/to/faxfile.sff,+49 6137 555123,Asterisk)
(more see below)

Enable/Disable echosquelch:
Enables or disable a very primitive echo suppressor.
Disable this option before you start recording voicemail or your files may get choppy.
Example:
exten => s,1,capicommand(echosquelch,yes)
or
exten => s,1,capicommand(echosquelch,no)

Enable/Disable echocancel:
Enables or disables echo-cancel provided by CAPI driver/hardware.
You might need to disable echo-cancel when the data/fax transmission is handled
by a non-CAPI application. After hangup, this setting is restored to the value
set in capi.conf.
Example:
exten => s,1,capicommand(echocancel,yes)
or
exten => s,1,capicommand(echocancel,no)

By default chan_capi deactivates echo-cancel for transit connections
(Dial command called from existing call). You can use 'econtransitconn'
configurations parameter (capi.conf) to change this behavior:
econtransitconn=0 ; Deactivate EC on transit connections
econtransitconn=1 ; Deactivate EC on secondary call of transit connection only
econtransitconn=2 ; Deactivate EC on primary call of transit connection only
econtransitconn=3 ; Do not deactivate EC on transit connections

Send Keypad Facility:
Send Keypad Faciliaty information.
Example:
exten => s,1,capicommand(keypad,<digits>)

Malicious Call Identification:
Reports a call of malicious nature.
Example:
exten => s,1,capicommand(malicious)

Hold:
Puts an answered call on hold, this has nothing to do with Asterisk's onhold
(music et al).
An optional parameter is the name of the variable, which should be set with
the reference ID of the call on hold.
Example:
exten => s,1,capicommand(hold)
or
exten => s,1,capicommand(hold,MYHOLDVAR)

Holdtype:
Sets the type of 'hold'. When Asterisk wants to put the call on hold, the specified method
will be used.
Example:
exten => s,1,capicommand(holdtype,local) ;no hold, Asterisk can play MOH
or
exten => s,1,capicommand(holdtype,hold) ;ISDN-HOLD
or
; not yet implemented
exten => s,1,capicommand(holdtype,notify) ;notify the peer only, Asterisk can play MOH


Retrieve:
Gets back the holded call. An optional parameter is the reference ID of the call
on hold.
Example:
exten => s,1,capicommand(retrieve)
or
exten => s,1,capicommand(retrieve,${MYHOLDVAR})

ECT:
Explicit Call Transfer of the call on hold (must put call on hold first!)
Example:
exten => s,1,capicommand(ect,${MYHOLDVAR})
or
[macro-capiect]
exten => s,1,capicommand(ect)
[default]
exten => s,1,capicommand(hold)
exten => s,2,Wait(1)
exten => s,3,Dial(CAPI/contr1/1234,60,M(capiect))
Note: Normaly a PBX needs 'implicit call transfer', which is done by default
with this command. But if the line needs real 'explicit call transfer', use
exten => s,1,capicommand(ect,x)
instead.

3PTY:
Initiates a Three-Party Conference (must have one call on hold and one active call!).
Example:
exten => s,1,capicommand(3pty_begin,${MYHOLDVAR})
or
[macro-capi3pty]
exten => s,1,capicommand(3pty_begin)
[default]
exten => s,1,capicommand(hold)
exten => s,2,Dial(CAPI/contr1/1234,,M(capi3pty))

Peer link creation:
Creates a reference for chan_capi to know who is the calling channel on Dial().
This is needed if you want to use CCBS/CCNR afterwards.
Example:
exten => s,1,capicommand(peerlink)

Hangup in mode 'stay-online':
After hangup in 'stay-online' mode, the line is not really disconnected
until timeout or command:
exten => s,1,capicommand(hangup)
This works after capicommand(peerlink) only.

Set local party to 'busy' or 'free':
Sets the local phone to the status 'busy' or 'free' when
awaiting a callback for CCBS/CCNR. If the network wants to
call you back for CCBS/CCNR, chan_capi normaly does not know
about the status of the extension who started the callback.
By default, chan_capi assumes 'free', but you can change that
with:
exten => s,1,capicommand(ccpartybusy,${CCLINKAGEID},yes)
or
exten => s,1,capicommand(ccpartybusy,${CCLINKAGEID},no)

Call completion on subscriber busy (CCBS):
To receive a callback when the dialed and busy party becomes free, aka
call completion on subscriber busy, you can do the following:
Example:
exten => s,1,capicommand(peerlink) ;to let chan_capi know who is the calling channel.
exten => s,2,Dial(CAPI/contr1/123456,60,g) ;'g' to go-on with the dialplan on busy.
exten => s,3,NoOp(${CCLINKAGEID}) ;if this variable now contains a number, CCBS is possible.
;here you can ask the caller if CCBS shall be activated...
exten => s,4,capicommand(ccbs,${CCLINKAGEID},<context>,<exten>,<priority>)
exten => s,5,NoOp(${CCBSSTATUS}) ;if CCBS was successfully enabled, it is set to "ACTIVATED".
If the remote party becomes 'non-busy', the network initiates the callback that will be
sent to the provided context/exten/priority. Of course, this only happens if your local
phone is set to 'free' with capicommand(ccpartybusy), which is the default.
In this context/exten/priority you should just setup a callfile to initiate an outgoing
call from your extension to
exten => s,1,Dial(CAPI/ccbs/${CCLINKAGEID}/)

Deactivate CCBS:
To deactivate a previously activated CCBS, use the following command:
Example:
exten => s,1,capicommand(ccbsstop,${CCLINKAGEID})

Chat (MeetMe/Conference):
See also README.media for details!
If the CAPI card/driver supports it, the caller can be put into a chat-room:
(This uses the DSPs onboard a Dialogic(R) Diva(R) Rev.2 Media Board.)
exten => s,1,capicommand(chat,<roomname>,<options>,controller)
Example:
exten => s,1,capicommand(chat,salesmeeting,m,1,3-6)
Possible options:
'm' = The first caller will get music-on-hold until second caller arrives.
'h<sec>' = Hangup after <sec> seconds if caller is alone in conference.
'o' = The caller is operator
'l' = The caller is listener

Progress / Early-B3 on incoming calls:
Activate Early-B3 on incoming channels to signal progress tones
when in NT-mode or if the Telco-line supports this.
Example:
exten => s,1,capicommand(progress)

Get CAPI application ID:
To store the CAPI application ID in an Asterisk dialplan variable, use:
Example:
exten => s,1,capicommand(getid,CAPI_ID)
exten => s,2,NoOp(CAPI appl-id is ${CAPI_ID})

Using CLIR
==========
Use the SetCallerPres() application before you dial:
exten => _X.,1,SetCallerPres(prohib_not_screened)
exten => _X.,2,Dial(CAPI/contr1/${EXTEN})


Enjoying Early B3 connects (inband call progress, tones and announcements)
==========================================================================
Early B3 is configurable in the dialstring parameters.
If you set a 'b', early B3 will always be used, also if the call fails,
because the number is unprovisioned, etc ...
If you set a 'B', early B3 will only be used on successful calls,
giving you ring indication,etc...

Do not use indications in the Dial command, your local exchange will do that for
you:
exten => _X.,1,Dial(CAPI/contr1/${EXTEN}/B,30)
(early B3 on success)

exten => _X.,1,Dial(CAPI/contr1/${EXTEN}/b,30)
(always early B3)

exten => _X.,1,Dial(CAPI/contr1/${EXTEN},30,r)
(no early B3, fake ring indication)

exten => _X.,1,Dial(CAPI/contr1/${EXTEN}/b,30,r)
(always early B3, fake indicatons if the exchange does not give us
indications)

exten => _X.,1,Dial(CAPI/contr1/${EXTEN}/B,30,r)
(early B3 on success, fake indicatons if the exchange does not give us
indications)

For normal PBX usage, you would use the "b" option, always Early B3.
You can also add "t" option so B3 will be enabled only on in-band tones available
indication as Q.931 (05/98) recommends.

Overlap sending (a.k.a. real dialtone)
======================================
When you dial an empty number and have early B3 enabled, with:
Dial(CAPI/g1//b)
the channel will come up at once and give you the dialtone it gets from the
local exchange.
At this point the channel is like a legacy phone, now you can send DTMF digits
to dial.


Example context for incoming calls on MSN 12345678:
===================================================

[capi-in]
exten => 12345678,1,Dial(SIP/phone1)
exten => 12345678,2,Hangup


Short HOWTO of capicommand(receivefax...) and capicommand(sendfax...):
========================================================================================
For those of you who have a CAPI card with an on-board DSP (like Dialogic(R) Diva(R) Media Boards),
this allows you to receive/send faxes.

capicommand(receivefax,<filename>[,<stationid>,<headline>,<options>]):
-------------------------------------------------------------------------
If you want to answer a channel in fax mode, use capicommand(receivefax,...)
instead of Answer(). If you use Answer(), you will be in voice mode.
If the hardware DSP detects fax tone, you can switch from voice to fax mode
by calling capicommand(receivefax,...).
The parameter <filename> is mandatory and the parameters <stationid>,
<headline> and <options> are optional.
By default, if fax reception was not successful, the file is deleted. If you want even
partly received or broken fax files, use 'k' for "keep bad fax" in the <options>:
capicommand(receivefax,/tmp/${UNIQUEID},+123456789,,k)
You can activate extended fax support by 'X' in the <options>:
capicommand(receivefax,/tmp/${UNIQUEID},+123456789,X)
Please read details on extended fax options in README.Diva.fax.

To enable fax tone detection and redirect to extension 'fax', use config variable
'faxdetect' in capi.conf. This can be limited to the first 'n' seconds of a connection
using the setting 'faxdetecttime' in capi.conf.

Example of use :
line number 123, play something, if a fax tone is detected, handle it
line number 124, answer directly in fax mode

[incoming]
exten => 123,1,Answer()
exten => 123,2,BackGround(jpop)
exten => 124,1,Goto(handle_fax,s,1)
exten => fax,1,Goto(handle_fax,s,1)

[handle_fax]
exten => s,1,capicommand(receivefax,/tmp/${UNIQUEID}[,<stationid>,<headline>,<options>])
exten => s,2,Hangup()
exten => h,1,deadagi,fax.php // Run sfftobmp and mail it.

The output of capicommand(receivefax,...) is a SFF file.
Use sfftobmp to convert it.
With a Dialogic(R) Diva(R) Media Board, the following features are provided:
- fax up to 33600
- high resolution
- Color Fax
- JPEG Compression is disabled (not tested yet)
See README.Diva.fax for more details and description of all options.

capicommand(sendfax,<filename>[,<stationid>,<headline>,<options>]):
------------------------------------------------------------
To send a fax, you can use the same mechanism like with receivefax.
Just replace the <filename> with the path to the .SFF file to send.
You can activate extended fax support by 'X' in the <options>:
capicommand(sendfax,/tmp/${UNIQUEID},+123456789,,X)
Please read details on extended fax options in README.Diva.fax.

After disconnect of a fax connection, the following variables
will be set for that channel:
FAXSTATUS : 0 = OK, 1 = Error.
FAXREASON : Value of B3 disconnect reason.
FAXREASONTEXT : Decoded text of FAXREASON value.
FAXRATE : The baud rate of the fax connection.
FAXRESOLUTION : 0 = standard, 1 = high.
FAXFORMAT : 0 = SFF.
FAXPAGES : Number of pages received.
FAXID : The ID of the remote fax maschine.

KEYPAD digits in NT-mode
========================
If the device connected to a NT-mode port sends KEYPAD digits
instead of normal digits, this call is then send to extension
'Kxxx'. Where 'xxx' stands for the KEYPAD digits sent.

CLI command "capi show channels"
==============================================
This CLI command shows detailed info on all CAPI channels.
Column description:
Line-Name : the name of the interface as defined in capi.conf
NTmode : is the line in NT-mode instead fo TE-mode
state : the state of the channel, like 'Conn', 'Disc', 'Dial', ...
i/o : incoming or outgoing line
bproto : protocol on CAPI ('fax', 'trans' or 'rtp')
isdnstate : a string which may consists of the following characters
* = PBX is active
G = Line-Interconnect (CAPI bridge) active
B = B-channel is up
b = B-channel is requested
P = Progress was signaled
H = this line is on hold
T = this line is in transfer (ECT) mode
S = SETUP[_ACK] was signaled
ton : type of number value
number : the caller number and destination number


Asterisk variables used/set by chan_capi
==========================================================

BCHANNELINFO
On incomming calls, this variable is set with the B-channel information value:
'0' : B-channel is used (default)
'1' : D-channel is used (not implemented yet)
'2' : neither B nor D-channel is used (e.g., call waiting)
Call-Waiting: an incoming call with BCHANNELINFO not '0' cannot be accepted.
Another connection must be dropped before accepting or use
capicommand(deflect,<number>) to initiate call deflection to another destination.

CALLEDTON
Incoming calls: 'type of number' value of the called number is saved in this variable on
incomming call.
Outgoing calls: Allows to specity the 'ETS 300 102-1' called party number octet 3
(0x80 is used by default)

exten => _X.,1,Answer
exten => _X.,n,Set(_CALLEDTON=${CALLEDTON}) ; Use value of incoming call for outgoing call
exten => _X.,n,Dial(CAPI/ISDN3/100,10)

exten => _X.,1,Answer
exten => _X.,n,Set(_CALLEDTON=1) ; Use new value
exten => _X.,n,Dial(CAPI/ISDN3/100,10)


CALLERTON
The 'type of number' value to overwrite for the caller number on outgoing call.

_CALLERHOLDID
If a call is put on hold (ISDN-HOLD), the reference ID is saved in this variable.
This variable is inherited as CALLERHOLDID to the dialed channel and will be used
if e.g., capicommand(ect) is used to transfer the held call.

CALLINGSUBADDRESS
If set on dial(), the calling subaddress will be set to the content.

CALLEDSUBADDRESS
If set on dial(), the called subaddress will be set to the content.

CAPI_CIP
The real CIP value, not the transformed 'transfercapability'.
Set on incoming call automatically. If set on outgoing call, it is used
instead of transfercapability.

CCBSSTATUS
When using capicommand(ccbs,....), this variable is set to either "ERROR" or
"ACTIVATED".

CCLINKAGEID
If a Call-Linkage-Id is received for CCBS/CCNR, this variable contains this ID.
But you need to use capicommand(peerlink) before dialing a CAPI channel, because
of a design problem in Asterisk, chan_capi is not able to set channel variables
of the calling channel.

CONNECTEDNUMBER
Can be set before answering and if set, the content is used for
IE 'Connected Number' on answering.

DISCONNECT_IND_REASON
When CAPI reports DISCONNECT_IND, some CAPI reason codes are not set
in HANGUPCAUSE, because they are not valid cause codes. To also
get those CAPI reason codes, you can check this variable on hangup.
This is e.g. useful for reason 0x3301, which tells that the ISDN
connection is physically broken (cable).

FAXEXTEN
If chan_capi sends the call to configured fax extension, the original extension number
is saved in this variable.

PRI_CAUSE
If set, this value will be used as hangup cause on hangup.

REDIRECTINGNUMBER
On incoming calls, if the call was redirected to you by someone, the
number of the redirecting party is saved in this variable.
RDNIS is set as well.

REDIRECTREASON
If the incoming call was redirected to you, this variable is set
with the reason value.

REDIRECTIONNUMBER
If an outgoing call is redirected, this variable may be set to the
new destination.

ISDNPI1 and ISDNPI2
The two values of the information element PI (Progress Indicator).

Asterisk outgoing calls
==========================================================

Distribution of outgoing calls is controlled by two
configuration variables (capi.conf, controller specific).

hlimit - Number of reserved channels. If number of free
channels is below the one specified by 'hlimit' value then
no new outgoing calls are delivered to this controller.

slimit - If value is set for multiple belonging to same dialout group
controllers then the outgoing calls are distributd as follows:
Calls are delivered to the controller with smalest (in group)
number and the amount of free channels bigger then or equal to
one speciefied by 'slimit'. After amount of free channels for all
included in the group controllers is decreased below one specified
by 'slimit' value calls are distributed in rount robin fashion
between all (in group) controllers.