[asterisk-users] FAX using T38

[Ricardo Carvalho]

Dear all,

I'm trying to enable Asterisk to work with FAX using T38. I've tried 
Asterisk 1.2.4 with the available patch found at URL 
http://bugs.digium.com/view.php?id=5090 and also with the new 1.4 Beta3 
that is announced to support it too.

With both Asterisk versions, I've sent with success FAXes between two 
FAX machines each one attached to an ATA interface, both registered in 
Asterisk. Although I can't send FAXes to PSTN using T38. The problem, as 
far as I know, might be assigned with the "Content-Length" shown in the 
message header of every SIP message negotiating T38 parameters. I've 
observed that after leaving Asterisk, the Content-Length of every 
message carrying T38 parameters gets shorter than truly is, and 
contrarily to my ATAs that seem to don't care about this, my Telco 
analyses the packet length written in this messages and truncates them, 
aborting the call.

Does anyone experienced this too? Any ideas besides editing the 
chan_sip.c code to fix this problem?

Thanks,
Ricardo.