Reborn Tech Maniac

Chapter 242 Client Server Architecture
First, send a special blocking message and stop sending data immediately.The special blocking information is an all-1 signal of several consecutive bytes, which is intended to strengthen the collision so that other computers can detect the collision as soon as possible.

To put it more vividly, it is broken and smashed, so that everyone can see the heavy traffic and don't go on the road.

Secondly, wait for a random time within a fixed period of time and send again.

Finally, if there is still a collision, the "truncated binary exponential backoff algorithm" is used to send.That is, within ten times, stop random resending within twice the previous "fixed time", and after ten times, stop random resending within the previous "fixed time".After 16 attempts, if it still fails, give up the teleportation.

This method is like a metropolis with congested traffic, and the relevant departments arrange odd and even number restrictions according to the license plate number.

Obviously, collisions during Ethernet operation will cause a certain degree of waste of resources and lack advantages in execution efficiency.

In sharp contrast to this, a 4M Token Ring network is equivalent to a 10M Ethernet data transfer rate, and a 16M Token Ring network has a data transfer rate close to a 100M Ethernet.

The reason why there is such an obvious gap is, of course, because the basic operating principles of each other are completely different.

Token Ring networks use tokens, which represent permissions for signaling, to avoid conflicts in the network.

The computer that gets the token is like a police car that pulls the alarm and has the exclusive lane, monopolizing the network to send data. Compared with the operation mechanism of the computers on the Ethernet that are constantly probing and looking for blocking opportunities, the data transmission rate of the network is naturally increased.

Moreover, the priority of transmission can also be set through tokens to meet high-level network resource requirements.

Theoretically, the token ring network is impeccable, but in practice, because the network cannot be reused, the utilization rate of the token ring network is low.

When a computer in the network gets the token and starts using the network, no matter how much bandwidth the computer uses, even if it only uses 4M of the 1M, other computers must wait for it to finish using the network and give up the token before they have a chance Apply for a token and use the network.

It's like passing privileged cars on a road without interruption. Even if there are eight lanes, other ordinary vehicles can only stare blankly and cannot get on the road.

Especially when the network becomes complex, the programs running in each computer are written by humans, and the faint desire to monopolize the network makes the theoretical smoothness of token circulation impossible to obtain the expected guarantee. Correspondingly, There is also a clear gap between the network resource utilization and the theoretical value.

Overall, Token Ring, which is similar to a planned economy, is not as dynamic as Ethernet, which is similar to a market economy.

The benefits of using the network through spontaneous coordination between computers on the Ethernet outweigh the losses caused by the collision phenomenon.

However, the correct understanding of this point is far from being popularized. The theoretical school and big companies like IBM are favoring token ring networks.

Renowned computer scientist Jerry Saltzer, in an influential paper he co-authored, argued that Token Ring is theoretically superior to Ethernet.

In 1964, before Ken Thompson and Dennis Ritchie developed UNIX based on the C language, Bell Labs, MIT, and General Electric jointly developed a set of The multi-tasking operating system - Multiplexed Information and Computing Service is Multics. At that time, Jerry Saltzer was one of the leaders of the team.

Therefore, Jerry Saltzer's status in the world is not low, and his views are very influential. Affected by this conclusion, many computer manufacturers either hesitate, or simply decide not to use the Ethernet interface as the standard configuration of the machine.

However, the advantages of the simple structure of Ethernet in actual use cannot be ignored. In the original time and space, 3Com, which was neglected in time and space, was a blessing in disguise. It made a lot of money by selling separate Ethernet network cards, and quickly grew into a large international company, and then appeared An almost joking statement - "Ethernet is not suitable for research in theory, but only for practical application."

However, 3Com's brilliance will have to wait several years later, and now the company, which has been established for more than a year, is lobbying other manufacturers everywhere to accept its own technology.

So far, Robert Metcalfe, who has been running around, has made some progress, such as cooperating with DEC, Intel, and Xerox to standardize Ethernet, launch a standard, and develop a commercial version for Unix .

And Tang Huan's goal is to come up with a personal computer version with 3Com and occupy the commanding heights of the industry first.

Because of Simeone's relationship, Tang Huan had already had some contact with Robert Metcalf earlier, so the process of this meeting and various verbal temptations can be directly omitted.

Accompanying me here are another man and a woman, two philosophical engineers in their 30s: David Boggs and Radia Perlman.

Since the database EBase became very popular in the market at the end of last year, especially after the sales of Xiaobawang game consoles exploded, the company under Tang Huan's name has become more attractive to high-end talents, basically there is no need for him, the boss, to spend his time digging people.

In the original time and space, David Boggs and Radia Pearlman both went to DEC this year, but they were recruited into the company by Zheru human resources department who was ordered to recruit network talents for the 386 plan. This kind of search ability made Tang Huan amazed.

It is generally believed that Ethernet was invented in 1973 because Robert Metcalfe wrote a memo to the boss of PARC about the potential of Ethernet.

However, Robert Metcalfe himself believes that Ethernet did not appear until a few years later, that is, in 1976, Robert Metcalfe and his assistant David Boggs jointly published an article called "Ethernet: Distributed Packet Switching for Regional Computer Networks" article.

Robert Metcalf left PARC to found 3COM, and David Boggs also left PARC, but after getting a master’s degree, he stayed on the West Coast, planning to study for a Ph. Confucianism.

As for Radia Perlman, after graduating from the Massachusetts Institute of Technology with a master's degree in mathematics, she worked on software development for network equipment.I don't know how Zheru's human resources department fooled her and brought her from the east coast to the west coast.

Don't underestimate this point. Universities in the United States are divided into circles. What kind of university a person chooses often means his future job level and even the scope of his spouse selection.

In the original time and space, Radia Perlman made a lot of achievements in technology. The most important point may be 1983. She invented the Spanning Tree Algorithms and developed STP for bridges and switches. The spanning tree protocol is of great significance for building large-scale networks.

Radia Perlman's work actually developed a basic data transmission method for the Internet.

Later, Radia Perlman was dubbed the "Mother of the Internet," but she reportedly didn't like the title.

It is no exaggeration to say that the technicians on site are all network experts.

However, Tang Huan did not want to enter the technical discussion immediately. He first asked about the possibility of investing in 3COM, because when Robert Metcalfe first founded the company, he attracted a lot of venture capital, leaving him without a say. Yes, there are some things that you just can’t decide on.

One of the manifestations is that the 3COM board of directors recently invited a new CEO. As for Robert Metcalfe, he was appointed as the chairman of the company's board of directors and concurrently serves as the company's vice president of marketing and sales. This can be regarded as a balance in the power structure. one time.

In Tang Huan's view, such operations by capitalists have their own reasons. Entrepreneurs with professional technical backgrounds may not be competent for the management of their own companies.

In the original time and space, Robert Metcalfe was finally kicked out in 1990, and ended up similar to the two founders of Cisco. The time was not far behind, and the two companies also entered a period of rapid growth after a brief adjustment .

Complaining too much is useless, the fact is so cruel, what entrepreneurs need is reflection, at least Tang Huan thinks so.

Moreover, Robert Metcalfe is very active and plays the role of prophet in the Internet world.

He once proposed the famous Metcalfe's Law, which is comparable to Moore's Law: "The value of a network is proportional to the square of the number of users connected to the network."

Various social software have verified the correctness of this statement. The value of a big V account with tens of thousands of fans on Weibo is obvious to all.

Of course, Robert Metcalfe's big mouth isn't always right, and it's a source of ridicule for himself.

For example, Robert Metcalf once predicted in 1995 that the Internet would usher in a devastating paralysis in 1996. In fact, of course, everyone is fine.

Robert Metcalfe also predicted that wireless networks would die in the mid-1990s, but the reality is that users are looking for WIFI signals everywhere.

Robert Metcalfe didn't stop there, and made another speech about the "social network bubble", and it seems that the related companies are still making a lot of money.

It can be seen that the mythological aura of the so-called pioneers was imposed by others. At least when Tang Huan dealt with Robert Metcalfe, he felt that the other party was normal.

For example, he could tell that Robert Metcalfe would be happy to see himself invest in 3COM, because Robert Metcalfe wanted to have another partner on the company's board of directors.

Even so, Robert Metcalf, who had no decision-making power, could only show embarrassment, "Don't look at me as the chairman of the board of directors, but I was played by those guys. Let it go."

"The situation is different now. We have officially launched the second-generation Fangyuan computer, which can be called the first 16-bit personal computer with practical value. This card's support for Ethernet technology is not enough for those people. Are you interested?" Tang Huan asked confidently.

"Even so, the board of directors will not agree to sell 20.00% of the shares, otherwise, the existing power structure will change." Robert Metcalfe spread his hands helplessly, "I suggest you lower your target, And use the more powerful sales performance of the second-generation Fangyuan computer as evidence of persuasion.”

Tang Huan rubbed his brows and had to accept the next best thing.

As a mechanical product, hard disk, no matter how big its capacity becomes or how fast its speed becomes, it cannot get rid of its position at the end of the industrial chain.

But the Internet is different. Those venture capitalists are all world-class in intelligence. Naturally, they have long been concerned, and they are unwilling to give up possible future benefits in the early stages of development.

Seeing that Tang Huan was doing good, Robert Metcalfe breathed a sigh of relief, and joked, "You'd better go to 3COM formally, and let the members of the board of directors see you, who has made hundreds of millions from the personal computer industry. A wealthy man, frighten these guys."

It seems that Robert Metcalf, who is a little frustrated, hopes that he can support the situation for him.

Tang Huan smiled and nodded, "Let's not talk about this, let's talk about the realization of Ethernet on the second-generation Fangyuan computer. Zheru mainly works on software. Your network card and driver, the sooner you get it Come out, the more the industry will know the advantages of Ethernet."

"To be honest, Zheru's enthusiasm for LAN is beyond my expectation. Can you tell me about any heavyweight applications you have?" Robert Metcalf asked tentatively.

Tang Huan glanced at Simeone appreciatively. Don't look at Simeone who has a lot of friendship with Robert Metcalf, but he is unambiguous in keeping business secrets.

"We are developing a major functional upgrade of the database EBase, which is to support the client-server structure." Tang Huanliang pointed out Zheru's technical dry goods.

"Can I have a look at the demonstration?" Robert Metcalfe, whose eyes lit up, suddenly became very interested.

Client/Server structure——C/S structure is also called Client–server model, that is, master-slave architecture. The characteristics of this technology can be seen only from the literal meaning.

The C/S structure is not a new thing. It has been studied by PARC as early as the 1970s, so Robert Metcalf is no stranger to it.

"Of course, we have already built a simulation platform." Tang Huan asked Simeone to prepare for the demonstration, while he continued to discuss the cooperation of Ethernet with Robert Metcalfe.

Glancing at David Boggs and Radia Perlman, Robert Metcalfe said with emotion, "Don, you have a long-term vision in terms of technology. The time when 3COM was established was just It is only a few months later than Zheru, but it is much worse in terms of structure."

"What you see is only the surface. I'm walking on thin ice." Tang Huan shook his head and loosened his tie. "After IBM's personal computer is launched, I don't know how many companies and brands will be eliminated."

"Don't worry, it is basically impossible for 3COM to enter the IBM camp. We are friends in the trenches." Robert Metcalfe laughed.

……

After the successful development of the Fangyuan second-generation computer, the work pressure it brought was not ordinary. Tang Huan wanted to go to Xiangjiang to relax, but he couldn't spare the time.

The executives under him were equally busy. For example, Hawkins, who had just inspected the game business in Japan, had just returned to the United States and brought a piece of news from United Artists to report to Tang Huan.

Michael Cimino, who won the Oscar for Best Picture and Best Director for a short time, directed the $4000 million epic Western "Heaven's Gate", which was released on November 11.

So far, the audience has complained about it, and the box office has been dismal, and it is expected to only recover about 150 million.

Lianmei, whose family fortune has been ruined, is panicked from top to bottom.

Even those who have made it clear that they will pledge their allegiance to EA in the future are starting to feel uneasy.Such a money-losing product won't scare EA away, right?

"The investment is 4400 million, and the income is less than 350 million. This gap is really frightening." Hawkins commented on the latest summary of "Heaven's Gate", with a look of worry on his face.

"Scared? Don't dare to buy?" Tang Huan smiled slightly. "In my opinion, the main responsibility for this crisis of United Artists lies with Andy Albert. The achievements made in the movie, and Michael Cimino also lived up to this trust, like a conceited hacker, adding new functions to the program he developed without restraint. "Heaven's Gate" The original edited version lasted 5 hours and 25 minutes, even if it was compressed to more than 3 hours in the end, impetuous audiences would not be interested in watching it at all.”

Speaking of this, Tang Huan extended the topic, "It can be said that the current video game development is still in the workshop stage. With the gradual strengthening of the hardware platform, the scale of work will increase accordingly, and then we will encounter Hollywood. The risk of such a big-budget movie is a question."

"In this case, I really should have considered it in advance." Hawkins nodded his head, "Since Andy Albert is so dereliction of duty, after we successfully acquire United Artists, should we keep him as CEO?"

"Let's keep our promise. At least we have to look at his follow-up performance. After all, the water in Hollywood is very deep. We laymen need consultants, and it's better to follow other people's rules of the game." Tang Huan nodded slightly. After the acquisition of Columbia and Panasonic’s acquisition of Universal, they were caught in the early stage, which can be described as lingering fear.

"What's more, Andy Albert's idea at the beginning also made some sense."

(End of this chapter)