[asterisk-users] Data transfer

[Tilghman Lesher]

On Wednesday 27 January 2010 15:18:41 thorsten.stoffregen at gmx.de wrote:
> Hi,
>
> im a student and we are devloping a training sytem for
> radio operators (for ships, police, ...) at our university.
> So far we are using a simple own protocol for speech and data
> transmission, works well at a Lan. Now we are looking for a way to
> connect the devices over the internet.
>
> I did some very quick testing with Asterisk and PJSIP [1] and it looks very
> promising. Apart from the voice transmission we need to sent some Data
> too (like used frequency, GPS position, very small data, about 5 kByte a
> minute).
>
> So my first thougt was to use SIP/Messages but some time of searching shows
> that asterisk doesn't handle this. We could of course use an extra tcp
> connection but this seems not very elegant to me ;-) because SIP should
> handle that...
>
> The Asterisk Console shows that asterisk drops the message:
>  WARNING[15294]: chan_sip.c:9769 receive_message: Received message to
> <sip:test.user2 at 192.168.1.104> from
> <sip:192.168.1.101>;tag=yNOCnaUdAjHob7Gmpl-5tjCuNmQDeGJp, dropped it...
> Content-Type:text/plain
>   Message: gnaaa
>
> Is there a way to get this message out of the server - to the AMI Interface
> for example? This would enough for us, because only our server needs to
> read the messages and maybe sent an answer. Or someone has an even better
> idee how to achive this?

That's not exactly true.  Asterisk merely requires that a call be up in order
to pass text messages.  It does not, however, allow text messages to be passed
stateless.

-- 
Tilghman Lesher
Digium, Inc. | Senior Software Developer
twitter: Corydon76 | IRC: Corydon76-dig (Freenode)
Check us out at: www.digium.com & www.asterisk.org