Custom FQDN mapping means that the backend resource or server is mapped to an external fully qualified domain name (host and domain). The resource should be accessed with the FQDN name rather than with the IP address. The FQDN name should be resolvable to an IP address in the public domain. The application listens on port 443 at this IP address. All HTTPS traffic is terminated at this socket. A new HTTP request is made to retrieve the mapped backend resource. The HTTP reply is transmitted using plain text to facilitate translation of absolute URLs. URL rewriting is not used.