We have phones external to the network. They are connected via openvpn (epm and yealink). We have a blf button assigned to feature code *76 and their extension so that passing it turns the light red or green depending on their dnd status. However, it randomly doesn’t work, and it happens on random phones. The light will just always stay green no matter what their dnd status.
Is there anything that needs to be done in the firewall since these are external phones to ensure presence always works? I assumed the VPN would prevent things like this from happening vs doing direct sip connections from the phones to freepbx on the public ip.