Why exactly do you want to use telnet to IRC ?
Can you not use the online thing found on the site or something like mIrc ?

You don't have to reply to pings sent by other users, but if you don't reply to pings sent by the server you'll get dropped out (usually after 60 or 90 seconds, depending on the server's configuration) with a ping timeout message. Reply with pong :ip_address or pong :sequence_number.

(taken from a tut by Raven)
here is the full tut.