I'm not even sure if this is possible, but here goes. All I have right now is two 3CX systems set up, one each in two offices. I've succesfully created a bridge and can make calls between offices, pass CID, etc. Eventually I'm going to add a PRI for service, but we're just in testing phase right now. I want to see if our IPhone and Droid device users can make and take internal calls. I don't need them to leave them phone system at all. I installed SipDroid on my own phone, and I've succesfully got it to register by opening SIP_UDP port on my router and pointed it to my 3CX machine. I am able to make calls to the Droid from inside, but when I dial to an internal extension (email@example.com), nothing happens. Nothing shows up in the event log on the server either. Is there another port I need to open, or do I have some kind of netork issue or what? Oh, the default gateway of the 3CX is the same IP as the internal interface of the router that I'm using as well. Any ideas?