I'm seeing a few problems with audio in certain directions on calls made from or to extensions over a VPN. Running 3CX version 12 with Yealink T46G on both ends. VPN is setup using a Draytek Vigor 2860 at the server end and Vigor 2830 at the remote end, both are on 50-70MB cable broadband connections with average/low usage. I've enabled the 'PBX delivers Audio' option in the 3CX 'Other' options on the Extension Capabilities section of the phone extension. Generally the problem will be we can hear the caller at the server end but the remote user cannot hear us. Would this be a QoS issue or something else (QoS is not enabled).