Introduction to TCP and IP protocols

I believe you have heard of the word "TCP/IP", which seems to be everywhere and always jumps out in front of you. What does TCP/IP mean? TCP/IP is actually a combination of two basic network protocols: IP protocol and TCP protocol name. Let's take a look at these two ubiquitous protocols.
The IP Protocol (Internet Protocol) is an Internet Protocol. From this name, we can know the importance of the IP protocol. In real life, we pack the goods into cartons or containers before transportation. in the online world, all kinds of information are transmitted in a similar way. The IP protocol specifies the basic unit and format for data transmission. If compared to shipping goods, the IP protocol specifies the packing box size and packaging procedures during packaging. In addition, the IP protocol also defines the packet delivery method and route selection. In the same way, the IP protocol defines the transportation methods and routes of goods. Www.2cto.com we already know that the IP Protocol is very important. The IP Protocol already specifies the main content of data Transmission. What does the TCP (Transmission Control Protocol) Protocol do? I don't know if it is found that the transmission defined in the IP protocol is one-way. That is to say, we don't know whether the other party has received the delivered goods. It's like a normal credit with 8 cents. What should we do if we send a registered letter to an important letter? TCP is used to send a "registered email" to us. TCP provides reliable rules and conventions for object-oriented data stream transmission services. Simply put, in TCP mode, the other Party sends you a packet, and you need to send a confirmation packet to the other party. This validation provides reliability. TCP/IP (short for Transmission Control Protocol/Internet Protocol) is the most basic Internet Protocol, is composed of the underlying IP protocol and TCP protocol. The development of TCP/IP protocol started in 1970s and is the first protocol for the Internet. 1.1 TCP/IP Reference Model developers of TCP/IP protocol divide the Internet into five layers for ease of understanding. It is also called an Internet layered model or an Internet layered reference model, as shown in the following table: www.2cto.com application layer (layer 5) transmission layer (Layer 4) Internet layer (Layer 3) network interface layer (Layer 2) Physical Layer (Layer 1) physical layer: corresponds to the basic hardware of the network, this is also the physical structure of the Internet, that is, we can see hard devices, such as PCs, Internet servers, network devices, etc., the electrical characteristics of these hard devices must be standardized, these devices are connected to each other and compatible with each other. Network Interface Layer: it defines the rules for composing data into correct frames and transmitting frames in the network. A frame refers to a series of data, which is the unit of data transmission over the network. Internet layer: This layer defines the "information packet" format transmitted over the Internet, as well as the "information packet" forwarding mechanism from one or more routers to the final target. Transport Layer: establishes, manages, and removes reliable and effective end-to-end connections between two user processes. Application Layer: defines the procedure for applications to use the Internet. 1. 2. A key underlying protocol used by the IP address on the Internet is the Internet protocol, which is usually called the IP protocol. We use a common communication protocol to make the Internet a network that allows connections to different types of computers and different operating systems. To allow two computers to communicate with each other, the two computers must use the same language ". The communication protocol is just like the common language used by two computers to exchange information. It specifies the agreement that both parties shall abide by in the communication.
The computer's communication protocol precisely defines all the details of the computer's communication process. For example, the format and meaning of the information sent by each computer, the specific special information to be sent, and the answers to the recipient's computer. Www.2cto.com
The Internet Protocol IP protocol provides the flexibility to adapt to a variety of network hardware and has almost no requirements for the underlying network hardware. Any network can transmit binary data from one location to another, you can use the IP protocol to join the Internet. If you want to communicate and communicate over the Internet, each computer connected to the Internet must comply with the IP protocol. For this reason, each computer that uses the Internet must run the IP software to always prepare to send or receive information. The IP protocol is of great significance to network communication: by installing IP software on computers in the network, many local networks constitute a large and strict communication system. In this way, the Internet seems to actually exist, but it is actually a non-existent virtual network, except that it uses the IP protocol to connect all the local computer networks that are willing to access the Internet in the world, so that they can communicate with each other. 1.3 Transport Control Protocol (TCP) although the computer can send and receive data between computers by installing IP software, the IP protocol cannot solve the possible problems of data groups during transmission. Therefore, to solve possible problems, a computer connected to the Internet also needs to install the TCP protocol to provide reliable and error-free communication services. TCP is called an end-to-end protocol. This is because it plays an important role in connecting two computers: when one computer needs to be connected to another remote computer, TCP enables them to establish a connection, send and receive data, and terminate the connection. The Transport Control Protocol (TCP) uses the resend technology and congestion control mechanism to provide reliable communication connections to applications so that they can automatically adapt to various changes on the Internet. TCP ensures reliable communication even when the Internet is temporarily blocked. Www.2cto.com
As we all know, Internet is a huge international network, and the congestion and free time on the network are always changing. In addition, the distance between transmission and transmission is also different, so the time used for data transmission will also change. The TCP protocol can automatically adjust the "timeout value" to adapt to various changes on the Internet and ensure that the transmitted values are correct. Therefore, we can learn from the above that the IP protocol only ensures that computers can send and receive group data, the TCP protocol provides a reliable, flow-controlled, and full-duplex information stream transmission service. To sum up, although the functions of the IP and TCP Protocols are different, they can be used separately, but they are designed as a protocol in the same period, in addition, the functions are complementary. Only the combination of the two can ensure that the Internet runs normally in a complex environment. All computers connected to the Internet must install and use these two protocols at the same time. Therefore, in practice, these two protocols are collectively referred to as TCP/IP. IP addresses and all computers connected to the Internet, from the mainframe to the microcomputer, are displayed in an independent identity. We call it a host. Each host must have a unique network address for communication between hosts. It's like every house has a unique portal card, so it won't be in disorder during data transmission. The Internet address refers to the address number of the computer connected to the Internet. Therefore, in an Internet network, a network address uniquely identifies a computer. We all know that the Internet is made up of tens of millions of computers. We need to confirm that each computer on the network depends on the network address that uniquely identifies the computer. This address is called an IP address (short for Internet Protocol, that is, the address in the Internet Protocol language. Currently, IP addresses in the Internet are a 32-bit binary address. To facilitate memory, they are divided into four groups, each group of eight digits separated by the decimal point, represented in four bytes, in addition, the value range of each byte separated by vertices is 0 ~ 255, such as 202.116.0.1. This writing method is called the point representation. The IP address can identify any network and computer in the network. To identify other networks or computers in the network, it is determined by the classification of these IP addresses. Generally, the IP addresses are divided into three types based on the network size of the node computer. The default network shielding is determined by the first field in the IP address.