how to configure Linux for incomming connections

I have two computers running red hat, but when i use telnet command in a shell from one to another, it works. but from the other , it does not, it said: refused. i sent the security for incoming connecting, but it still not work . anyone have experience ?
thanks

vh

See if telnet is listening - look for a process listening on port 23.

netstat -an | grep LISTEN