Problem with CHANUNAVAIL

I have Asterisk with Sangoma card ( A104d ).
Asterisk is connected to Ericsson Business Phone 250 ( 2 spans )
and 2 telco’s (PRA).
There is a problem with CHANUNAVAIL Dial Status.
I have daily 1400 calls throw this spans. About 10% have CHANUNAVAIL
I do not know why ?
Can You tell me ?
What does it mean ?

Hi przemek, I have also the problem.
Have you fix your problem? any update? any solutions?

Thanks :smile: