HI folks, and many thanks to anyone that can assist here. We have purchased a Patton SN4114 FXS gateway and installed this using the following guide: https://www.3cx.com/voip-gateways/patton-smartnode-sn4112-fxs/ At this stage we're using the free trial of 3CX, and planning to purchase an 8SC license once we get this bedded in place. I am wondering if the problems we're seeing below are because it's a free trial? It seems that we have a couple issues here: (1) When I create the fax extension, I am being asked for a Fax Extension Authentication ID, which defaults to the extension number I am using. What should be entered here please? (2) I am then creating the entry in FSX/DECT and selecting the gateway, entering MAC address etc. and then entering the extension created above. All good here. (3) We have a block of 10 DID's in one trunk, which I have set up and calls are working perfectly. I have an existing inbound rule for the main number - i.e. the first of the 10 incoming numbers. We don't want extensions having a DID, so no need to assign numbers further. I assume I must now make an inbound rule for calls coming in on the number we wish to use for fax (second sequential number in the block of 10) and I am then selecting the option "Send fax to" and choosing the Fax extension I created above. When I then call this number, I am getting a reply from 3CX saying "Called number does not exist" - would anyone know why this might be? Many thanks for any advice that folks may have to offer!