You need the telnet server, however telnet is NOT secure. For that you should use ssh (man sshd and man sshd). you can access ssh from a Linux box aand from windows you will need a software called putty You can download it from here
. If you still want to use telnet, then you have to install the telnet server it is comething like telnet-server-version.architecture.rpm I think that should do it. Though, telnet is a xinetd service, ssh not, it is different the way you configura it... Still I think that you can configure sshd to be a inetd service, but it would be better if yu keep it apart.
Hope I helped.