SOLVED: Last night i updated to the latest Version. But now, when i call out, there is NO Audio. All incomming calls are redirected to my Trunk-Backup Number. After asking my Trunk Provider, they told me, that SIP Invites are not answered by the 3CX (hosted, Debian) Any Ideas? Edit: Thanks to the great support on the Forums, we found out, that it was an DNS Problem. Some sort of IPv4 vs IPv6 thing... SOLUTION: In the Trunk settings the outbound Proxy must be set to an IP, not a FQDN.