Hello list, In my set up Freeswitch acts as fax originator, so an image is being processed and sent by FS. I do not receive any fax, so all my questions/issues are related to sending it. All fax is over IP. First a question - how to understand if Freeswitch is sending in T.38? Why do I always see T.30 FLOW in log even if in SDP is mentioned T.38? I do see some "T.38 rxfax set to 0/txfax set to N", I understand that rx is receive and tx is transmit, but why any other log strings shows T.30 FLOW? And the issue - sometimes when I initiate fax I get ----------------- Codec RAW Signed Linear (16 bit) encoder error mod_g729.c:102 This codec is only usable in passthrough mode! ----------------- I can't understand why it's happening as it occurs from time to time, but it always happens before Freeswitch makes re-invite to initiate a T.38 session. I suppose that's because I have no license for g729, but the supplier side negotiates it before FS has chance to re-invite. But why does it work with same SDP in other times? Does it have sense to exclude g729 for the initial codec negotiation, or g729 is essential to keep T.38 working? What shall I do in case of Asia where everything is on g729,? Maybe it has sense to purchase a license - but why then it works unstable right now, I mean, why does it even work if it requires mod_g729_com? Or it doesn't? I'm really confused on all that. Thanks in advance!