Hi, I'm in the UAE (Dubai) at the moment. UAE are notorious for blocking SIP calls, so I am trying to setup the 3CX tunnel app on an iPhone. The tunnel connects fine, and the 3CX phone app registers, but I can only achieve oneway audio. I have tried connecting using various port combinations 5090, 8000 etc. but with the same results. I am able to use a program called Teamviewer (control a remote PC over a secure connection) perfectly. I assume that Teamviewer requires an encrypted two way connection much the same as 3cx tunnel? Any ideas anyone? Thanks in advance.