The data line interface has undergone great changes in the past ten years. There are too many types of USB interfaces. From Type A at the beginning to Micro B later to Type C now, USB interfaces have to "evolve" every few years.

You should have seen these interfaces more or less, some are on devices such as printers, and some are on early mobile phones or hard drives. In the beginning, the bandwidth of USB 1.0 was only 1.5 Mbps, but later this transmission speed became too much for various increasingly larger files, so it was necessary to find a way to increase its transmission speed. From the official release of USB 1.0 in 1996, the current Type C can reach a transmission bandwidth of 10 Gbps. In more than two decades, the USB interface has changed for several generations.

In the past few years, the data line interface has changed from generation to generation, but no matter how the network cable changes, the crystal head with the buckle will always look like that, but no one wants to change it? To talk about this issue, we must first figure out a concept, that is, the difference between consumer-grade products and engineering-grade products. The USB data interface is a consumer-grade product, while the RJ45 specification interface on the network cable is an engineering-grade product. Simply put, their application scenarios are different. The USB interface is mostly used on small mobile devices and appeared after 1996. The RJ45 interface standard was born in 1990, and it has been more than 30 years now. It was initially applied in various large servers and large equipment in the engineering field, and it was purchased by large companies and large enterprises.

These devices are not like mobile phones in your hand, which can be done with a few thousand dollars. Their cost is very high. They can be tens of millions at every turn. They are generally used until the life of the device expires. This makes the RJ45 interface must be very "functionally specific" and cannot be moved randomly. If the network cable interface changes from RJ45 to USB, it means that the ports on these large-scale devices should also be replaced with USB, and the original devices will be eliminated. Another example is all kinds of large servers all over the world. If you want to change the equipment, it will inevitably mean disconnecting from the network. For us living in modern times, can you imagine the scenario where the country or even the whole world is disconnected from the Internet? Even a few seconds can cause huge losses. So when the home network was first popularized, the network was connected to the phone line, which can also transmit data. The phone line connector specification is RJ11, which is a bit smaller than RJ45, but it can also be plugged into the RJ45 interface. There are many disadvantages, such as slow transmission speed and disconnection when a call comes in. So don't look at the network cable that is so worthless now, it can be regarded as a product of "technology decentralization". Compared with the consumer-grade USB interface, the RJ45 interface has many unique advantages. For example, from the perspective of operability, we should have seen the assembly process of the network cable when we installed the network for the new home. The installation master took a pair of pliers, a crystal head, and a cable, and when they were done with it, they slapped and pressed a network cable connector out. The whole process takes less than a minute. If you change to a USB interface, do you have to bring the raw materials to the site for welding one by one?

The second is reliability. There is a buckle on the back of the crystal head of the network cable, and each wire inside also has a corresponding small metal piece crimping wire. This makes the network cable very stable after it is inserted into the device, ensuring that it will not fall off due to vibration or shaking. After all, the network cable does not need to be plugged in or unplugged at all times, while the data cable is different.

To give another common example, our company’s server looks like this

If these wires are all replaced with USB, you can pull a lot of them off at random, and then you will have to go in and check them one by one when the time comes. Not to mention those larger servers with hundreds or thousands of network cables. If you switch to a USB interface, the maintenance personnel of the network equipment basically don't even think about getting off work. Then there is the difference in transmission distance. The effective transmission distance of the network cable is 100 meters. If the network speed is not demanding and can reach 200 meters, the packet loss will be more serious. What about USB? 5 meters. If you change the network cable to USB, then as long as your house is more than 5 meters away from the computer room, don't think about connecting to the network. There is another, that is the most important transmission speed of the network cable. The first household network cable was a CAT-3 cable, which appeared in 1990. At that time, its maximum transmission speed could reach 10 Mbps, while USB 1.0, which appeared only six years later, had a transmission speed of only 1.5 Mbps. The Gigabit network cables we commonly use now are Category 5 and Category 6 cables. Category 5 and Category 6 cables appeared in 2001, while the specification for Category 6 cables was in 2003.

Although the transmission speed of the USB 3.0 interface suddenly came to 5 Gbps, it was already in November 2008. Before that, the speed of the network cable was faster. Since it is faster, why bother to change the USB interface. Moreover, the transmission speed and stability of the network cable are affected by the material, whether it is a Category 5 or Category 6 cable, their crystal heads are the same in shape and size.

But if you really want to say, the RJ45 standard crystal head shape still has variants. For example, there is a mini RJ45 network cable interface, which is equivalent to a HUB. It is for professional use and can provide the MAC address of the computer. The actual application range is not large. But now that notebooks are getting thinner and thinner, most manufacturers have removed the network cable interface. Looking at it this way, everyone should know why the network cable interface is not replaced with a USB interface. To put it bluntly, each type of interface is designed according to requirements. They have their own application scenarios and factors that need to be considered when designing. a lot of.