Out of the box, most routers do not have any ports blocked that would impact VoIP traffic to our servers. However network and It managers sometimes block ports to increase network security. To ensure that your firewall does not interfere with your phone traffic:
Whitelist our PBX address and allow all traffic to this IP. We can supply this Ip on request.
Open up ports as follows:
FTP ports 21 and 21000-12100
UDP ports 5060 and 10000-20000