One Way Silence to Zaptel FXS phones


#1

I have a Astribank, a 8 port FXS interface.
When i phone to any of the lines and pick up, then the receiving phone stay’s silent while the calling party can hear the POTS phone OK.
If I phone from this POTS phone to whatever other phone like SIP IAX or ISDN, then it works OK.
Anybody an idea why this could be happening?