Hi, thanks for reading. I have set up a hardware VPN between two locations using a pair of DrayTek 2820's. VPN is fine with a constant connection. Head office has a Dell box running a 3CX server (latest version) I'm using SNOM 821's and 870's as phone of choice. Within the head office ip range (192.168.30.0) all extensions work fine, call groups and everything. Remote office (192.168.1.0) 821 registers and shows a green light with the 3cx but only ring after 3 or 4 attemps. This is not just for call to the remote office but when that extension ring an extension at head office. I have also used a different extension number and a SIP .app on an iphone with same results. Any help would be great. Jeremy.