TCP/IP Introduction
TCP/IP is the communication protocol used for the Internet.
Computer Communication Protocol
Computer communication protocols describe the rules that computers must follow in order to communicate with each other.
What is TCP/IP?
TCP/IP is a communication protocol for computers connected to the Internet to communicate.
TCP/IP stands for Transmission Control Protocol/Internet Protocol (Transmission Control Protocol / Internet Protocol）。
TCP/IP defines the standards for how electronic devices (such as computers) connect to the Internet and how data is transmitted between them.
Inside TCP/IP
TCP/IP includes a series of protocols used to handle data communication:
- TCP (Transmission Control Protocol) - communication between applications
- UDP (User Datagram Protocol) - simple communication between applications
- IP (Internet Protocol) - communication between computers
- ICMP (Internet Control Message Protocol) - for errors and status
- DHCP (Dynamic Host Configuration Protocol) - for dynamic addressing
TCP Uses Fixed Connections
TCP is used for communication between applications.
When an application wants to communicate with another application over TCP, it sends a communication request. This request must be sent to a specific address. After the two parties "handshake", TCP will establish a full-duplex communication between the two applications.
This full-duplex communication will occupy the communication line between the two computers until it is closed by one or both parties.
UDP is very similar to TCP, but it is simpler and less reliable than TCP.
IP Is Connectionless
IP is used for communication between computers.
IP is a connectionless communication protocol. It does not occupy the communication line between two communicating computers. In this way, IP reduces the demand for network lines. Each line can simultaneously meet the communication needs of many different computers.
Through IP, messages (or other data) are divided into small independent packets and transmitted between computers over the Internet.
IP is responsible for routing each packet to its destination.
IP Routers
When an IP packet is sent from a computer, it reaches an IP router.
The IP router is responsible for routing the packet to its destination, either directly or through other routers.
In the same communication, the path taken by one packet may differ from other packets. The router is responsible for correctly routing based on traffic, network errors, or other parameters.
TCP/IP
TCP/IP means TCP and IP work together.
TCP is responsible for communication between application software (such as your browser) and network software.
IP is responsible for communication between computers.
TCP is responsible for dividing data and packaging it into IP packets, then reassembling them when they arrive.
IP is responsible for sending packets to the receiver.
Other Extensions