Hi, I myself needed a FXS gateway, to be able to use my analogue fax, dialing out using my VoIP Provider. I do not have PSTN lines anymore. I had a spare Linksys (Cisco) SPA9000, which I now use for this purpose. I thought sharing how I did this, so you can use this as well. There is now real gateway configuration necessary. I created an new Extension (200). On the webinterface of the SPA9000, configured tab Line 1 to use my 3CX Phone System as the Proxy and used the User ID (200) and password I have set. In the Contact field I set 299. This way it is also possible to receive faxes on the physical fax, instead of the build in FaxServer. On the FXS 1 tab, I set the Display Name to 299 and the User ID to 299 as well. These fields to not relate to 3CX, but I are used on the SPA9000 only. I set a Dial Plan to using a 1 for an outside line to distinguished from voice calls, which use a 0. On the SIP tab, I therefor had to change Call Routing Rule to (<:L1,2,3,4>1xx.). The created Fax extension should now show 'Registered (Idle)'. To use the physcal fax to receive faxes I set the fax phone number in the VOIP Provider settings to Connect to extension 200, within 3CX Management Console.