For a couple weeks I’ve been trying to get Clearly Anywhere working on my on-site FreePBX 15.x system.
I got to the point where it registered, and I could dial in our out, but there was no audio.
I had UDP Ports 10000 to 20000 open as this is the recommendation I see everywhere. I was going to throw in the towel but then I noticed in FreePBX, under Aseterisk SIP Settings, the port range there is set to 10000 to 38000. I changed the rule on my firewall and behold, it works now.
I have seen a lot of security theater and recommendations by “experts” There is a solid chance someone followed a blog somewhere and thought they were smarter than an attacker.
FreePBX has always defaulted 10000-20000. There are platforms like PIAF that would add things like webmin so the port range would be something like 10001-20000