I need serious help. I have a Brekeke SIP Server that is handling the integration at a facility to the Nurse Call system. I need to forward calls from Brekeke to the 3CX Phone System (v.11). Whenever I do I get the following: First INVITE from Brekeke, 3CX gives 407 Proxy Authentication Required. Brekeke Sends ACK Second INVITE attempt from Brekeke, gives 403 Forbidden from 3CX. I have set up Brekeke to use both Thru and Upper Registration so that the phone on Brekeke also registers on 3CX. I have used the same extension on 3CX that is on Brekeke to represent the Nurse Call System. 3CX shows that it registers. I can actually call from a phone on 3CX to the phone that is on Brekeke and 3CX, I just can't receive calls from Brekeke on a 3CX only phone. I can't figure out how to let my call through in 3CX, I thought that a call from a registered active extension would be allowed. Anyone done this before or have any experience with Brekeke? Their Dial Plan is kind of unwieldy compared to 3CX so any help is appreciated with that. I am trying to do it currently with two Xlite soft phones on two different computers (the Brekeke Server and the 3CX Server). I have also tried to set up a Generic Gateway to represent Brekeke but I don't think I'm doing that correctly or maybe that's just the wrong way all around. Has anybody out there ever used a third party SIP Server with 3CX? Thanks!