[asterisk-users] How to send DTMF down a channel

Frank Church voipfc at googlemail.com
Thu Sep 14 22:38:34 MST 2006


The program in question is an adaptation an AGI calling card program.
It is adapted for callback by setting by channelling the callback call
into the context used for the normal inbound leg.

When used that way entering the PIN and destination number via DTMF
works normally.

I tried to implement sms/web callback simply by passing the
destination number and the callerid in call file's parameters, so that
the script can go straight to dialling the destination number without
prompting the caller for it.

This method results in dead air when the call is answered at the
destination and it seems that the absence of DTMF tones for generating
the call is the cause.

Logically it should work, why the call should result in dead air
because the destination number was not obtained through DTMF is what I
can't understand.

It appears that the absence of DTMF stops the RTP from being
established to the destination number  or prevents the calls from
being joined. When I dial back to the calling  number I get the busy
voice prompt okay.

Injecting the DTMF tones on the call channel is a really a kludge to
simulate actual key presses in the hope that the dead air problem will
go away and it .

On 9/15/06, Moises Silva <moises.silva at gmail.com> wrote:
> Frank. PlayDTMF and SendDTMF is the same as pressing keys at the
> phone. Im not understanding well, can you please explain a practical
> scenario of how do you expect it to work, and how actually works? :)
> Thanks
>
> Regards
>
> On 9/14/06, Frank Church <voipfc at googlemail.com> wrote:
> > How do you specify the channel the SendDTMF is sent on, as it has to
> > be variable? I am able to use PlayDTMF  to send tones using the
> > manager interface - the tones come up okay but it doesn't work.
> >
> > My problem comes from a working callback script that I am trying to
> > adapt to web/SMS callback.
> >
> > The script is unchanged only that in the web/sms callback the
> > destination number is passed in the call file variables to allow it be
> > dialled after the callback is answered rather than being obtained via
> > DTMF.
> >
> > The destination call is made alright, but the called party only gets
> > dead air after the call is answered. It seems that the fact of
> > pressing the DTMF keys activates the sound channel in way that the
> > direct call back does not, which is why I am going through all these
> > hoops. I just hoped that sending some DTMF tones programmatically
> > would simulate the actual key presses.
> >
> > Do you have any ideas of what the problem might be?
> >
> >
> >
> > On 9/14/06, Moises Silva <moises.silva at gmail.com> wrote:
> > > http://www.voip-info.org/wiki-Asterisk+cmd+SendDTMF
> > >
> > > Regards
> > >
> > > On 9/14/06, Frank Church <voipfc at googlemail.com> wrote:
> > > > How can DTMF  be sent down a channel?
> > > >
> > > > I am thinking of method where say a channel id can be grabbed from
> > > > Asterisk Manager events and a DTMF signal sent down that channel,
> > > > through AGI, Asterisk Manager Interface or whatever?
> > > >
> > > > Is it possible to have a command in extensions.conf which can take
> > > > both the channel and the dtmf numbers as parameters and send the DTMF
> > > > signals?
> > > >
> > > > Frank Church
> > > > _______________________________________________
> > > > --Bandwidth and Colocation provided by Easynews.com --
> > > >
> > > > asterisk-users mailing list
> > > > To UNSUBSCRIBE or update options visit:
> > > >    http://lists.digium.com/mailman/listinfo/asterisk-users
> > > >
> > >
> > >
> > > --
> > > "Su nombre es GNU/Linux, no solamente Linux, mas info en http://www.gnu.org"
> > > _______________________________________________
> > > --Bandwidth and Colocation provided by Easynews.com --
> > >
> > > asterisk-users mailing list
> > > To UNSUBSCRIBE or update options visit:
> > >    http://lists.digium.com/mailman/listinfo/asterisk-users
> > >
> > _______________________________________________
> > --Bandwidth and Colocation provided by Easynews.com --
> >
> > asterisk-users mailing list
> > To UNSUBSCRIBE or update options visit:
> >    http://lists.digium.com/mailman/listinfo/asterisk-users
> >
>
>
> --
> "Su nombre es GNU/Linux, no solamente Linux, mas info en http://www.gnu.org"
> _______________________________________________
> --Bandwidth and Colocation provided by Easynews.com --
>
> asterisk-users mailing list
> To UNSUBSCRIBE or update options visit:
>    http://lists.digium.com/mailman/listinfo/asterisk-users
>


More information about the asterisk-users mailing list