@Criggn Solution: Reconfiguration of 3CX. Instead of a direct TCP/IP connection between the Phones the 3CX provides a channel via SSL. Works fine.

@Tedd404 Sorry for the delay, we are in the middle of the last turnarounds for this year. I hadn't configurated anything. It was litteraly Plug and Play. I also had a testrun for a few weeks now with...

@MR.S tried, didnt help. Still nothing to hear.

@MR.S was never enabled. Normally it should allow all outgoing connections therefore i didnt change anything

Moin, as i work through my built (ER8411, TL-SG3452XP, TL-SG3452, 2xEAP650 Outdoor, 2xEAP265HD, OC300) i run into an issue with my phones. I use SNOM D385 VoIP desk Phones wich come with 3CX as...

@Criggn Antwort für Interessierte: Ich hab dazu einen Versuch gestartet, das funktioniert. Wenn das Endgerät die Phantomspeisung akzeptiert versorgt der Switch es via 4 Draht/Pin anstelle der 8....