Protocol--TCP/UDP on Transport layer in TCP/IP Reference Model

Tcp

Transmission Control Protocol (Transmission Control Protocol), which is an available to the user process
The full duplex byte stream is a connection-oriented protocol. TCP provides reliable and error-free data transfer between two computers.
When an application uses TCP for communication, a virtual connection is established between the source host and the destination host, which
Once a connection is established, data can be exchanged between two computers as a two-way byte stream;
If the connection is unsuccessful, the data is not sent. In addition, each message that is oriented to a connection transmission needs to be acknowledged by the receiving end,
An unconfirmed message is considered to be an error message.
The so-called flow is a correct data sequence without packet loss, repetition and disorder. Flow is equivalent to a pipe,
What you put from one end and what you can get out of the other end. Transport layer protocol for the realization of streaming transmission, paid a lot of
Overhead.

Udp
Subscriber Datagram Protocol (user Datagram Protocol), which is a connectionless protocol provided to the user process.
Used to transfer data without performing a correctness check.
In the communication process, UDP does not guarantee the transmission of reliable data, but can send data to several targets, receive
Data originating from several sources. Simply put, if a client sends data to the server, this data is immediately
Issued, regardless of whether the server is ready to receive data. If the server receives data from the client, it does not confirm
Received or not. Data transmission methods are based on datagrams.
In general, the TCP and UDP protocols coexist in one internet, which is equal in status, which provides
By service, the latter provides efficient services. If the transfer file is small and requires a high speed, you may consider using UDP
Protocol; If the quality of the transmission is high and the reliability of the physical network is poor, it is best to use the TCP protocol;
User needs, or you can use both protocols together in the same application.