In a HQ-BO case, users would like to interconnect PBXs in two sites to achieve internal calling between headquarter and branch office, or route external calls from headquarter to branch. By traditional solution, it's high possible to open ports in both firewalls to allow remotely connections while this would exposure attacked risk by hackers.
- Applied Devices
With yeastar FQDN feature, yeastar PBX will work as FQDN server to allow client's registration, so the other pbx can be yeastar pbx or other brand. Here is detailed configuration for p-series PBX, it is similar with s-series PBX.