hey, is it possible at all to just use IPs with 3CX 15.5 and not have a publicly available DNS entry at all? What would happen if I just release the FQDN in the customer portal and leave it like that? And on another subject: Do I really need to open port 5001 on the firewall if I want outside clients to use core features like presence? Shouldn't that be possible over the tunnel? Thanks in advance.