I tried using the FTP for the backup and my service is running on a non standard port of 50021.
The paramters for the host: ftp://ftp.***.com:50021/
When I test the connection, it gave the error:
Warning: ftp_connect() [function.ftp-connect]: php_network_getaddresses: getaddrinfo failed: Name or service not known in /home/***/***.com/wp-content/plugins/backup-scheduler/backup-scheduler.php on line 1256
The host ftp.***.com:50021 cannot be resolved!
The FTP server is running and I have managed to log in to the server using 2 different FTP client.