[asterisk-users] Asterisk 1.6.1.13 and T.38 faxing

[Kevin P. Fleming]

Vinícius Fontes wrote:

> I've put it on pastebin because is was a lot of text. Here's the link: http://pastebin.com/m7467cea1. That's all the information on the CLI with verbose=3 and "sip set debug peer voxip". 

OK, with the complete capture we can see that the problem is actually
quite different. In this call, Asterisk sent a re-INVITE to T.38 mode
from audio mode, the provider accepted it, and then Asterisk
acknowledged it. Immediately afterwards, Asterisk sent a re-INVITE
*back* to audio mode, which the provider accepted (and included T.38
capabilities in their response). Because of this, the FAX reception
process failed since the T.38 session was destroyed.

The most likely cause of this problem is a bug in chan_sip, but it has
been fixed for quite some time now, and the fix is included in 1.6.1.13.
This would also fit with your statement about not having this issue with
Fax For Asterisk, as it does not generate any audio frames while
negotiating T.38 as the receiver of a FAX.

I would suggest opening an issue in the issue tracker at
issues.asterisk.org and uploading your console trace there; there is
clearly a bug here that needs to be found and fixed.

-- 
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