asterisk users - Dec 2009 - ReceiveFAX G.711 + Realtime

Hello,

We're trying to receive G.711 (aLaw) faxes on the asterisk and convert 
them to tif. With T.38, we have several issues, so we are trying to use 
G.711, since the gateway is located in the same LAN, so there's no 
bandwidth/packet-lose issue.

We also use on the same Asterisk Real-Time process for the extensions.conf

My question:

Is the following syntax for disabling T.38 support correct?
vm*CLI>     -- Executing Set("SIP/Proxy-00000000",
"t38pt_udptl=no")
vm*CLI>     -- Executing Set("SIP/Proxy-00000000",
"SIP_CODEC=aLaw")
vm*CLI>     -- Executing Answer("SIP/Proxy-00000000", "")

The aLaw Set command is taken into consideration, because the SDP of the 
OK that follows these lines includes only codec 8, but when the 
ReceiveFAX command is executed, Asterisk immediately sends a T.38 reINVITE:
vm*CLI>     -- Executing ReceiveFAX("SIP/Proxy-00000000", 
"/var/spool/asterisk/fax/3/1261993891.0.tif")

I must be doing something wrong, but I'm not sure what :-(

Your help would be highly appreciated.

Thanks,

Andreas

Cyprus VoIP wrote:
> My question:
> 
> Is the following syntax for disabling T.38 support correct?
> vm*CLI>     -- Executing Set("SIP/Proxy-00000000",
"t38pt_udptl=no")
> vm*CLI>     -- Executing Set("SIP/Proxy-00000000",
"SIP_CODEC=aLaw")
> vm*CLI>     -- Executing Answer("SIP/Proxy-00000000",
"")
I have no idea where you got the idea that such a thing is possible...
it's not. sip.conf settings for SIP endpoints are not channel variables,
and cannot be modified from the dialplan unless the CHANNEL() dialplan
function has been specifically extended to support them. If you don't
want T.38 support for a SIP endpoint, don't configure it that way in
sip.conf or in your Realtime SIP peers table.

-- 
Kevin P. Fleming
Digium, Inc. | Director of Software Technologies
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
skype: kpfleming | jabber: kpfleming at digium.com
Check us out at www.digium.com & www.asterisk.org