v15: VPS, behind SBC in our office. So I set up an extension under FXS/DECT and pointed the ATA registration over to the SBC on that extension. Dropped in a DID to route inbound to that.. inbound fax from external source rings/answers/receives/prints fine to some HP MFP. However.. outbound fax dials.. but then just goes quiet. I put a phone on the end of it.. can make/receive voice calls on it internal or external just fine. Almost seems that it detects signal or something, but from there I hear nothing. Rather strange. The call logs on 3CX and Flowroute (my SIP provider) show the outbound call as fine. I don't have another fax and line to "hear" the other end directly.. but if I call from 3CX or some handset I get fax tone. Strange that receiving on it would be fine but sending would not. So.. I tried a new extension instead, pointed it and registered. I heard the other end pick up.. but the handshake failed (almost expected..). Is there a clear picture of how to use an ATA for T38 outbound fax on v15?.. there are plenty of examples et al for older versions.. but things have changed.