We have multiple virtual PBX setup (4 servers). For minimizing configuration on firewall / ports etc. we use a 3rd SBC (Audiocodes Mediant VE) in between. All works well on every device except the 3CX Phone, the SBC trips over an un-escaped " This issue is already discussed about with support (Ticket ID: 25188) and opted back to here. With this we would like to have an adjustable auto provisioning. (for all phones and 3CX phone) Reason for this: The SBC uses the FQDN for routing all SIP traffic. By default the IP address is used and not the FQDN. We would like to, Disable the tunnel, remove STUN, Change intern / extern to FQDN and proxy address (for 3CX PHone only) With this changes 3CX applies to all SIP standards. We would like a discussion about this subject. This in order to let 3CX compete to ITSP grade options like Broadworks / Broadsoft.