Remote Register

1.Pls port forward on your router if your ippbx is back of router

RTP port range 10000-10500 (UDP)
SIP port          5060(UDP&TCP)   our coocall of iphone is with tcp transport

2.Config the relation NAT

Advanced---->Options--->SIP Settings---->NAT Support

External IP: 
External Host: 
External Refresh(sec): 

  Local Network Address

 External IP:it is your router wan port ip,that through to internet
 Local Network Address :it is your IPPBX IP segment

3.Create one extension,then enable NAT  in the extension

4.Then you can register and call each other.