无连接协议

无连接 Connectionless Protocol (Connectionless Protocol) is the ability to make Connectionless service in a network Protocol. This Internet protocol (IP) and user packet protocol (UDP) are the most popular non-connection protocols. Communication protocols are either oriented or disconnected. Depending on whether you need the sender and the receiver contact information and links to maintain a dialogue (connection-oriented), or send a message without any prior contact (no connection) and hope to receive order to order to receive all the content. These methods reveal two ways of communicating on the network. Connectionless protocol In a connection-oriented approach, the network is responsible for sending packets in order and detecting the loss and conflict in a reliable way. This approach is used by "reliable" transmission services. In an unconnected method, the network only needs to send the message packet to the receiving point, which is handled by the sender and receiver by the sender and receiver. This approach is called the "best effort" or "unacknowledged" transfer protocol. Suppose you want to send a series of letters to friends in another city, similar to those sent by computer networks. There are two ways of sending a letter to a trusted friend, which he sends by private and then confirms to you. In this approach, you maintain contact at both ends of the transmission, and your friends provide a connection-oriented service. Another is that you specify the address on the envelope and put them into the post office, you have not been assured that every letter will reach the destination, if arrive, they may arrive at different time and is not continuous, it's like a connectionless service. [editing this segment] for connection communication Connection - Oriented Communication communicates to the Connection In a connection-oriented approach, a data communication channel (circuit) is established between the two endpoints. This channel provides a predefined path to send packet messages in the order of the network, similar to the voice phone. The sender and the receiver keep in touch to coordinate the reception or failure of the session and message packet. But this does not mean that a connection-oriented channel USES more bandwidth than a connectionless channel, both of which use bandwidth only when the message is grouped. A communication channel built for a connection-oriented session is logically logical, often referred to as virtual circuit, which is concerned with endpoints. This channel is more concerned with maintaining the connection between two endpoints than finding an actual physical path on the web. Where there is more than one path of the destination network, the physical path during the session with the change of the data model and change, but the endpoint () and intermediate node has maintained the path tracking, Application is started on a computer to another computer connection-oriented session, it by visiting the basic communication protocol to request such a dialogue. In the transport control protocol/Internet protocol (TCP/IP) group, TCP provides a connection-oriented service, while IP (the lower level protocol) provides transport services. In the NetWare SPX/IPX protocol group, SPX provides a connection-oriented service. Because the packet is through virtual circuit transmission, so do not need to use the whole group address, this is because the network has already know the address of the sender and the receiver. Each node on the network path keeps track of virtual circuits and ports that need to be exchanged. The sequence number is used to ensure the sequential flow of groups. Build virtual circuit needs a process, but once the circuit is established, it is for a long time processing provides a effective path, such as the management procedure for continuous monitoring of the web sites and many large file transfer. In contrast, the unconnected method is designed for sudden, temporary communication, which is not very efficient in the form of virtual circuit building. [editing the section] process