our new small business office has got a PBX in a Flash installed on a virtual box in the cloud(which is Auckland Data center). And our office are using VDSL(Changing to UFB in a few weeks) with Spark.
Our phone system is playing up. It rings when there is a incoming call, but we just could not pick up. even between extensions would be the same situation. But we can call out no problem. I've tried using my mobile with SIP phone APP through 4G data(which is not in our LAN), it works perfect every single time.
I guess it's the router problem, it doesn't route properly (but the internet is working fine), I've disabled SIP ALG on the router already.
Can i do something with the firewall setting or other settings to fix this issue?
Thanks Guys.