We have a Asterisk server at work, and if i phone my cell from my work extension, it shows "private number". Does anyone know why
it is not showing the number?
You using a SIP trunk right? You probably didnt specify the fromuser as its unlikely your provider is removing it.
You can specify what you want so for example we ported our old number to the SIP trunk, so our ID goes out as legacy 1111111 as thats what clients were used to, even though our SIP trunk is 2222222
Check you didnt miss a field in your config, and maybe state what GUI you are using so somebody can tell you where to look