#1 I assume you have spandsp installed
#2 I’m guessing you got some hints from this thread –
I was not aware you needed SpanDSP for T.38 passthrough.. How will that work with the UDPTL packets not going through Asterisk.
Not certain that you actually do. I do know that T.38 can be a “dental”
experience with Asterisk, but some folks have succeeded with it.
We process a lot of t.38 with Level 3 and our Asterisk servers. We do not prefer Adtran end points for t.38.
Bryant Zimmerman (ZK Tech Inc.)
616-855-1030 Ext. 2003
Do you use faxdetect at all? I’m wondering if faxdetect is required for Asterisk to set CHANNEL(t38passthrough) to 1. It is set to zero on fax calls passing through Asterisk.
Use “tcpdump” utility, capture all udp packets for the faulty t38 fax call.