what could be causing the issue of poor sound quality ? Some calls, certainly not all of them, sound like if the caller is standing next to a very busy road with lots of cars passing.
To be clear : the person calling is not standing next to a highway.
But there seems to be a noise “on the line” of busy highroad that makes that the caller can not be understood.
What can be causing this kind of “poor quality” ?
Is it lack of resources on the Asterisk-server (codec translation ?) Is it lack of bandwith ? Is it a problem of CentOS (the underlying OS) ? Is it a physical problem of the server components (network interface ?) ?
Kind regards, Jonas.