Actually TCP is a problem for IRC because there's no (standard) way to query how much data has been received (well, acknowledged) by the other end. This is why if you're unexpectedly disconnected from an IRC bouncer while in a busy channel, the replay can still be incomplete.
Lag is also a pig sometimes.
Datagram protocols are just more natural for message-oriented communication.
Lag is also a pig sometimes.
Datagram protocols are just more natural for message-oriented communication.