What is Internet Relay Chat

Internet Relay Chat (Internet Relay Chat), commonly known as Internet Relay Chat, referred to as IRC. It is a web chat protocol pioneered by Finnish Jarkko Oikarinen in 1988. After ten years of development, more than 60 countries in the world now provide IRC services. The working principle of IRC is very simple. You only need to run the client software on your PC, and then connect to an IRC server through the Internet using the IRC protocol. Its characteristics are very fast, there is almost no delay in chatting, and it only takes up a small amount of bandwidth resources. All users can talk or secretly talk about a topic in a place called a "Channel". Every IRC user has a Nickname.

IRC (InternetRelayChat) originated in 1988

Let s make a comparative explanation. Suppose A and B want to talk. If no transit is used, then A directly establishes a communication tunnel to B, and the two exchange information through this communication tunnel. The direction of information flow is: A- > B and B-> A; if transit is used, a third party is required to assume the transit role. Set to C, A establishes a communication tunnel to C, B also establishes a communication tunnel to C, and then A and B Indirectly through C

In the above example, there is only one relayer C to undertake the service. When there are a large number of chatters, C will be overwhelmed. The solution is to use multiple servers, which are connected to each other to form a network, and the chatters are dispersed. To each server. The server network is connected to each other in a tree structure. Chatpers can choose any server to connect to. For example, in

The essence of a channel is a broadcast group. A user can enter a channel or leave a channel. When a user speaks to the channel, other users in the channel can receive his words (relayed by the server). When the first user enters When a channel is created, the channel is cancelled when the last user leaves the channel. Therefore, from the user s point of view, the channel is the chat room. Let s talk about the reason why a channel is called a channel. If a chat There are multiple servers on the network, and the channel must be maintained by the server. For example, there are three servers, the connection method is ABC. On server A, the first user enters the #IRC channel. At this time, the channel is created on server A "#IRC", A sends the creation message of channel "IRC" to B and C. Since there are no users on B and C on the #IRC channel, no action is taken. After that, a user on server C enters #IRC channel, at this time server C also creates channel "#IRC", and C sends "#IRC" creation message to A and B. After that, you need to do the following: Create channel "#IRC" on B and send A With C "#IRC" channels are connected to form a unified #IRC. At present, although there are no users on B in the #IRC channel, the #IRC channel is also opened on B. It can be seen that the channel is like a communication channel that opens all The server of this channel runs through, and the information flow flows through this channel.

The information exchange on IRC adopts the model of request and response. A request is issued by a server or client, and its purpose is to request (another) server to perform an operation or provide some information; a response is a server's response to a request Requests are often called commands; since each response is specified with a three-digit number, the response is also called a numeric reply.