Opening a port in your firewall is not enough. There must be something listening on that port, so you can get an answer.
To see what ports are listening on your box, run:
netstat -tan|grep LISTEN
telnet: 127.0.0.1:8080: Name or service not known
is not correct. To telnet to a port different than the default port 23 you need to use:
telnet: 127.0.0.1 8080
telnet: connect to address 127.0.0.1: Connection refused
That means that there is no telnend running on localhost. You have to install/start the telnet service in order to use it. For security reasons it's always better to keep telnet disabled and use ssh to connect to a remote host