What are the different characteristics of switched Ethernet compared with * * * shared Ethernet?

Switched Ethernet does not need to change other network hardware, including cables and user's network card, but only needs to change the * * * exclusive hub with a switched switch, which saves the cost of user's network upgrade.

It can switch between high-speed and low-speed networks to realize the cooperative work of different networks. Most switched Ethernet networks have a port of 100MBPS. Connecting to the server through the corresponding network card of 100MBPS temporarily solved the bottleneck of 100 Mbps and became the first choice when upgrading the local area network.

It provides multiple channels at the same time, which provides more bandwidth than the traditional dedicated hub. Traditional * * exclusive 10 Mbps/ 100 Mbps Ethernet adopts broadcast communication mode, and only one pair of users can communicate at a time. If there is a conflict, it must be retried, and switched Ethernet allows transmission between different users, for example, 16.

Especially in terms of time response, lan switches is very popular. It provides wider bandwidth and higher speed at lower cost than routers. Unless there is a need to access a wide area network (WAN), switches will often replace routers.

Extended data

background

The initial development of Ethernet technology came from one of many pioneering technical projects of Xerox Palo Alto Research Center. People usually think that Ethernet was invented in 1973, when bob metcalfe wrote a memo to his PARC boss about the potential of Ethernet.

But Metcalfe himself thinks that Ethernet didn't appear until several years later. 1976, Metcalfe and his assistant David Boggs published an article entitled "Ethernet: Distributed Packet Switching Technology in Local Computer Networks".

1979, Metcalfe left Xerox to set up 3Com in order to develop personal computers and local area networks. 3Com lobbied DEC, Intel and Xerox, hoping to realize the standardization and normalization of Ethernet with them. This universal Ethernet standard was released on September 30th, 1980 in/kloc-0.

At that time, there were two popular non-public network standards, token ring network and ARCNET, which quickly shrank and were replaced under the impact of Ethernet tide. In the process, 3Com also became an international company.

Metcalfe once joked that Jerry Salz contributed to the success of 3Com. In an influential paper co-authored with others, Saltzer pointed out that token ring network is superior to Ethernet in theory. Influenced by this conclusion, many computer manufacturers either hesitate or decide not to use Ethernet interface as the standard configuration of their machines, so 3Com has the opportunity to make a fortune by selling Ethernet cards.

This situation has also led to another saying that "Ethernet is not suitable for theoretical research, but only suitable for practical application". Maybe this is just a joke, but it illustrates a technical point: usually, the actual data flow characteristics in the network are different from those estimated before the popularization of LAN, and it is precisely because of the simple structure of Ethernet that LAN is popularized.

Metcalfe and Saltzer used to work on the same floor of the Massachusetts Institute of Technology (MIT) MAC project, when he was doing his graduation thesis at Harvard University, during which he laid the theoretical foundation of Ethernet technology.

Baidu encyclopedia-switched Ethernet

Baidu Encyclopedia-Ethernet Technology