The Internet Relay Chat protocol (IRC) is similar to a SMS Text Message, in that it provides near-real-time text communication between a group of "nicknames" (users) connected to the same "channel" (chatroom) in an interconnected IRC server network. Server access requires using an IRC client. IRC uses the URI "irc://". There is never a chatroom delay or disconnect between users attached to the same IRC server, due to connections between users taking place internally (a slow external connection between users attached to different servers will cause a chatroom condition known as "lag", while a severed external connection between users attached to different servers causes a chatroom condition known as "netsplit"). Because IRC has a short packet size, and because messages can't span packets, users should keep each message under about 400 characters to prevent truncation. Below is a list of public IRC server networks, with an associated address of their suggested round-robin pool server.
[IANA Port assignment = 6667]

IRC Networks