Listening to the Voice menu, either self-recorded or built-in, it seems to be weaker than expected. Users are complaining that they have to speak louder because they sound far away.
It has been experienced on different phone models (budgetone, aastra 480i, ata) and I'm using g729 codec. I remember that sound level is adjustable for zaptel, but what about SIP?
Is this under my control?