Hi all, We are having some diffuclties getting our virtual multitenant 3CX install working. I followed this guide: http://www.3cx.com/docs/virtual-pbx-firewall-setup/ https://doc.pfsense.org/index.php/PBX_VoIP_NAT_How-to Our Setup: A Pfsense 2.3-1 that has the PPOE session Transit VLAN a pfsense connected to the transit vlan each pfsense that is connected has a virtual external static ip. With a 1:1 NAT mapping. so I'll try to give an example: 188.8.131.52 --> 192.168.1.1 pfsense 1 192.168.1.2 --> 192.168.0.1 pfsense 2 (has 184.108.40.206 as Virtual IP - NAT mapping) 192.168.0.100 --> 3CX 3CX instance 9 (yeah somehow this is the first? ) Sip port: 13060 Sip Tunnel: 13090 Now the problem: Every phonecall got disconnected after 32 seconds. A second try: I moved the 3CX into the transit VLAN. 220.127.116.11 --> 192.168.1.1 pfsense 1 192.168.1.100 --> 3CX (has 18.104.22.168 as Virtual IP - NAT mapping) The problem with this is: The phonecall keeps connected now, but I have no sound. Logs keep telling me: 31-mei-2016 14:03:30.506 NAT/ALG check:L:5.1[Extn] REQUEST 'INVITE' - some of SIP/SDP headers may contain inconsistent information or modified by intermediate hop SIP contact header is not equal to the SIP packet source(IPort): Contact address:192.168.1.2:37587 Received from :192.168.1.2:57977 'audio' media IP is not equal to the IP specified in contact header: 'audio' media IP is not equal to the SIP packet source(IPort): So obviously I am doing something wrong. I just don't know what. I checked over and over for settings. Need more info? Please ask!