mirror of
https://github.com/asterisk/asterisk.git
synced 2025-10-31 10:47:18 +00:00
8a71ea8aa3
https://origsvn.digium.com/svn/asterisk/trunk ........ r228499 | file | 2009-11-06 13:52:00 -0400 (Fri, 06 Nov 2009) | 2 lines Fix the localchannel.tex file. ........ git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.6.1@228502 65c4cc65-6c06-0410-ace0-fbb531ad65f3
85 lines
3.5 KiB
TeX
85 lines
3.5 KiB
TeX
\subsection{Introduction}
|
|
|
|
chan\_local is a pseudo-channel. Use of this channel simply loops calls back
|
|
into the dialplan in a different context. Useful for recursive routing.
|
|
|
|
\subsection{Syntax}
|
|
\begin{verbatim}
|
|
Local/extension@context[/{n|j}]
|
|
\end{verbatim}
|
|
|
|
Adding "/n" at the end of the string will make the Local channel not do a
|
|
native transfer (the "n" stands for "n"o release) upon the remote end answering
|
|
the line. This is an esoteric, but important feature if you expect the Local
|
|
channel to handle calls exactly like a normal channel. If you do not have the
|
|
"no release" feature set, then as soon as the destination (inside of the Local
|
|
channel) answers the line and one audio frame passes, the variables and dial plan
|
|
will revert back to that of the original call, and the Local channel will become a
|
|
zombie and be removed from the active channels list. This is desirable in some
|
|
circumstances, but can result in unexpected dialplan behavior if you are doing
|
|
fancy things with variables in your call handling.
|
|
|
|
There is another option that can be used with local channels, which is the "j"
|
|
option. The "j" option must be used with the "n" option to make sure that the
|
|
local channel does not get optimized out of the call. This option will enable
|
|
a jitterbuffer on the local channel. The jitterbuffer will be used to de-jitter
|
|
audio that it receives from the channel that called the local channel. This is
|
|
especially in the case of putting chan\_local in between an incoming SIP call
|
|
and Asterisk applications, so that the incoming audio will be de-jittered.
|
|
|
|
Using the "m" option will cause chan\_local to forward music on hold start and stop
|
|
requests. Normally chan\_local acts on them and it is started or stopped on the
|
|
Local channel itself.
|
|
|
|
\subsection{Purpose}
|
|
|
|
The Local channel construct can be used to establish dialing into any part of
|
|
the dialplan.
|
|
|
|
Imagine you have a TE410P in your box. You want to do something for which you
|
|
must use a Dial statement (for instance when dropping files in
|
|
\path{/var/spool/outgoing}) but you do want to be able to use your dialplans
|
|
least-cost-routes or other intelligent stuff. What you could do before we had
|
|
chan\_local was create a cross-link between two ports of the TE410P and then
|
|
Dial out one port and in the other. This way you could control where the call
|
|
was going.
|
|
|
|
Of course, this was a nasty hack, and to make it more sensible, chan\_local was
|
|
built.
|
|
|
|
The "Local" channel driver allows you to convert an arbitrary extension into a
|
|
channel. It is used in a variety of places, including agents, etc.
|
|
|
|
This also allows us to hop to contexts like a GoSub routine; See examples below.
|
|
|
|
\subsection{Examples}
|
|
\begin{astlisting}
|
|
\begin{verbatim}
|
|
[inbound] ; here falls all incoming calls
|
|
exten => s,1,Answer
|
|
exten => s,2,Dial(local/200@internal,30,r)
|
|
exten => s,3,Playback(sorrynoanswer)
|
|
exten => s,4,Hangup
|
|
|
|
[internal] ; here where our phones falls for default
|
|
exten => 200,1,Dial(sip/blah)
|
|
exten => 200,102,VoiceMail(${EXTEN}@default)
|
|
|
|
exten => 201,1,Dial(DAHDI/1)
|
|
exten => 201,102,VoiceMail(${EXTEN}@default)
|
|
|
|
exten => _0.,1,Dial(DAHDI/g1/${EXTEN:1}) ; outgoing calls with 0+number
|
|
\end{verbatim}
|
|
\end{astlisting}
|
|
|
|
\subsection{Caveats}
|
|
|
|
If you use chan\_local from a call-file and you want to pass channel variables
|
|
into your context, make sure you append the '/n', because otherwise
|
|
chan\_local will 'optimize' itself out of the call-path, and the variables will
|
|
get lost. i.e.
|
|
|
|
\begin{verbatim}
|
|
Local/00531234567@pbx becomes Local/00531234567@pbx/n
|
|
\end{verbatim}
|