I have setup an Asterisk 13.8 as a fax gateway between a SIP provider (providing service over a reliable fibre cable) and an ATA (connected to Asterisk over an LTE connection).
ITSP ==fibre==> Asterisk ==LTE==> ATA (IAX or SIP)
Now when the ATA uses SIP, then I can see udptl traffic flowing through Asterisk from ITSP to ATA and in the opposite direction (udptl set debug on).
But when the ATA uses IAX2, then no udptl traffic is being sent/received to/from the ATA, but only the ITSP.
I would know, does IAX2 support T38 udptl ? If yes, then how to debug udptl traffic?
I searched here in the community forums, found few un-answered similar questions.