Honghuang, I am engaged in science and technology in the Wuzu

A month later, Mo sent Fang Hao two computer samples, and the two computers had a feature, that is, they could receive each other’s high or low levels.

Moreover, this function is integrated into the CPU chip, which can display on the software whether the voltage on another computer is connected by press.

“Mo, you guys did a very good job, and it exceeded my expectations, let’s build two more according to this drawing!” Fang Hao looked at the data sheet in his hand and was very satisfied in his heart.

More people is good, if you have to do everything yourself as before, I don’t know how long it will take to build these two computers, now Fang Hao only needs to send out a research plan, there will be thousands of researchers to act immediately, and the results can be obtained soon.

The physical layer scheme given by Fang Hao is only the simplest one, not to mention efficiency and reliability, but the research team of the institute has designed a more complex schematic according to Fang Hao’s schematic, Fang Hao requires only one wire communication, but now the machine given to Fang Hao can communicate 8 lines at the same time.

“Dean, Dr. Wang, they are trying to use these eight wires for dual-machine communication, they want to ask your opinion, this is the schematic diagram of the dual-computer communication they designed.” Amo said, handing him another document.

“I’ll take a look.” Fang Hao took the drawing and looked at the drawing and thought.

The scheme in the drawing is similar to the first generation of network communication on Earth, using data lines to gather long-distance information into a computer for centralized processing, and then sending the processed data back through the data line.

This is a network structure centered on a single computer and oriented to other computers, strictly speaking, an online system, just the prototype of a computer network.

Fang Hao pondered, it seems that the technological development is similar, this network structure is the LAN of the Internet café later, this stage can think of the LAN, and it is designed out, it is already very remarkable.

“The design is very good, let them continue to work on it, and I also designed another network and let them study it.” Fang Hao read the document enough and said to Amo.

“Yes, Dean.” Ah Mo didn’t talk nonsense, took the documents handed by Fang Hao and left.

The network designed by Fang Hao is the data link layer of the future market, which is a hardware protocol and no host communication.

The simple electrical signals 0 and 1 on the physical layer have no meaning, and it is necessary to specify how many bits of the electrical signal are in one group and what each group means.

The data link layer is to group these data, sample the data on the physical layer, and then store it, and then translate it through computer software, so that the communication is successful.

It can be easily deduced that this network structure has no host, and any computer can communicate with each other.

This communication method is achieved by specifying the grouping of electrical signals, which is the origin of Ethernet.

In the early days on Earth, various companies discovered this hostless communication method, but the data of each company was grouped differently and incompatible with each other.

Later, a unified standard, the Ethernet protocol Ethernet protocol, has been used, which is a technology that has undergone various tests, and Fang Hao intends to use it directly, so as not to spend a lot of time exploring in Redstone City.

In Fang Hao’s design, eight bits of data are a byte, and a set of electrical signals form a data packet, which is called a frame on Earth.

The name frame sounds very strange, and it is also a boring translator to make it, after all, the network technology on the earth is to translate foreign laboratory data tables, which is actually a piece of data.

The Chinese interpretation of the frame is the meaning of a picture, a painting of silk fabrics, and the translation is too outrageous.

Not to mention the translation of garbage, each frame is divided into several parts, the head, the tail, the sender address, the receiver address, the data type, and the last middle paragraph is the data to be transmitted.

In order, the first is the header, followed by the recipient’s address, followed by the sender’s address, followed by the data type, then the data to be transmitted, and the tail at the bottom.

Header: 18 bytes

Sender: 6 bytes

Recipient: 6 bytes

Data type: 6 bytes

Data: 46~1500 bytes

Tail: Four bytes

Such a packet is 64 bytes short and 1518 bytes long, and if the network data exceeds the maximum 1518 bytes, it needs to be sent in segments.

In fact, the above design is very simple, only need the computer to identify the data type and tail, through the software to extract the data.

But there is a question, how to identify the sender and receiver? This involves network cards.

A network card is a device that identifies the sender’s address and the receiver’s address, and each computer has only one address, so each computer needs a network card to manage its identity.

If there are sender and receiver addresses that do not meet the requirements of the network card, then network communication cannot take place, and the network card masks the packet.

This is the way the network charges, you only need to control the network card, you can let others pay, and if you don’t pay, you won’t be allowed to go online.

This is the initial version of the network, as long as the network card is good and it seems that it is possible to surf the Internet without problems, but why is the network divided into many generations later?

This is another story, every time the network technology is upgraded, the hardware part will improve a little efficiency, and the user will find that the network speed is faster.

At the same time, one thing cannot be ignored, that is, the part of the network packet outside the useful data is lengthened, what is the use of this lengthened part?

Monitor, block, harmonize, this longer part can be used to capture keywords in the data.

If a keyword is detected, the NIC will automatically extract the keyword and send it to the host of the network monitoring center.

However, if the sender is a hacker, it will not send data so directly, but will encrypt the sent data, so that the network card cannot detect those keywords and can freely go to various bad websites.

This is the origin of the smuggling technology, where the user first encrypts the request data to be sent with software, such as some action movies, and sends it to the offending server.

The offending server then translates the encrypted content through the translation software, then calls the data of Mr. Cang according to the user’s request, and then encrypts it with the smuggling software and sends it to the user.

Hacking technology sounds tall, but in fact it is what it is, of course, this is only the core principle, those network security companies and hackers will continue to create through this principle, forming a prosperous hacker world.

With the network card, there will be a network card address, the network card address is the MAC address, this address is the network company to manage the computer network card things, the network company can use the Mac address to remotely control the computer’s network card, thereby prohibiting users in arrears from surfing the Internet.

Each network card leaves the factory with a world-only MAC address, six bytes long, the first three bytes are the manufacturer number, the last three bytes are the pipeline number, of course, the network card will definitely not be so simple.

With a MAC address, with a network card, two hosts in the same network can communicate, but Ethernet is the most primitive network, although it can allow many computers to communicate at the same time, but it is very slow.