I'm currently testing the 3CX 'Free' edition v15.5. On my 'site' the IP range is 10.0.*.* with a sub net of 255.255.0.0 this site is where the 3CX server runs from. Any Phone / Softphone client has connected / authorised with no problems. On my other site IP range is 10.10.*.* with the same sub net does not connect / authorise for the softphone client I added there. On my current Asterisk based PBX I have to have 'NAT' turned on for the extension so that it will use the sites gateway / router to find the PBX on the other site. I can of course ping the server and the gateway does not filter any traffic by port etc. as its a 1gb link bandwidth is not an issue. How can I get the softphone (then phones when I come to that part of testing) to authorise across my link? Thanks in advance!