Curiously I have a question about… why IT DOES work
I have an Asterisk server (based on Debian Linux) running in my office. It is connected to a standard Netgear router with some opened ports, but not 5060 or others that belong to the PBX.
Everything works well: I can place phone calls from the two HW phones we have at our desks and receive them from both the SIP provider I configured as inbound.
How can it work? And… what’s the point to open these ports in the router, if everything can work flawlessy without additional configurations?
Thank you in advance for your answers