Comprehensive Explanation of switched Ethernet Technology

Many people may not quite understand the switched Ethernet technology. First of all, let everyone know from bridges, multi-port bridges to switches, then we will introduce the working principle of the switched Ethernet technology and the advantages of the switched Ethernet technology. Ethernet machine, which is a SWITCH in English, is also translated as a SWITCH or a SWITCH-type hub. Let's first review the development process of LAN.

The combination of computer technology and communication technology has promoted the rapid development of computer LAN. From the emergence of ALOHA at the end of 1960s to the debut of the 1990s-Mbps switched Ethernet technology, in just over thirty years, it has taken a leap from work order to duplex, from sharing to exchange, from low speed to high speed, from simple to complex, from expensive to popular. In the middle and late 1980s s, due to the sharp increase in traffic, the development of technology led to the increasing performance of the LAN. The earliest 1 Mbps speed was widely replaced by today's 100BASE-T and 100CG-ANYLAN, traditional media access methods are limited to making a large number of sites share access to a public transmission media, both CSMA and CD.

In the early 1990s s, with the improvement of computer performance and the increasing traffic, traditional local area networks have already surpassed their own load. Switched Ethernet technology emerged, greatly improving the performance of local area networks. Compared with the network topology of the shared media based on bridges and devices, the network switch can significantly increase the bandwidth. With the addition of the switched Ethernet technology, you can establish a geographically dispersed network, so that each port of the LAN switch can transmit information in parallel and at the same time, and the LAN can be highly expanded.

From Bridge, multi-port bridge to switch

The development of LAN switched Ethernet technology goes back to two port bridges. A bridge is a forwarding device used to connect to a similar LAN. From the perspective of the network structure, the bridge is an end-to-end connection at the DCE level; from the perspective of the layer, the bridge forwards data frames at the logical link layer; similar to the functions of a repeater on the first layer and the device on the third layer. Two-port bridges are developed almost simultaneously with Ethernet.

The switched Ethernet technology (SWITCH) was developed on the basis of multi-port bridges in the early 1990s S. It implements the lower two layers of the OSI model and is closely related to the bridge, even known as "many associated bridges" by industry insiders, the current switched Ethernet technology is not a new standard, but a new application of existing technologies, it is an improved LAN bridge. Compared with traditional bridges, it can provide more ports (4 ~ 88), better performance, stronger management functions, and cheaper prices. Some LAN switches now implement Layer 3 of the OSI reference model to implement simple routing selection. Currently, Layer 3 switching is very popular. Similar to a telephone switch, an Ethernet switch provides other bridging technologies, such as CUTTHROUGH, in addition to STOREANGFORWORD ).

Working principle of switched Ethernet Technology

The principle of the Ethernet switch is very simple. It detects the MAC (media access layer) addresses of the Source and Destination addresses of packets from the Ethernet port, and then compares them with the dynamic search table in the system, if the MAC address of the data packet is not in the query table, add the address to the query table and send the data packet to the target port.

Advantages of switched Ethernet Technology

The switched Ethernet technology does not need to change other network hardware, including cables and user network cards. Instead, you only need to change the shared HUB with a switched switch to save your network upgrade costs. You can switch between high-speed and low-speed networks to achieve collaboration between different networks. Currently, most switched Ethernet networks have Mbps ports. The corresponding Mbps Nic is used to connect to the network. This solves the bottleneck of 10 Mbps and becomes the preferred solution for upgrading the network lan.

It provides multiple channels at the same time, providing more bandwidth than the traditional shared hub. The traditional shared 10 MBPS/100MPS Ethernet adopts the broadcast communication mode, and can only communicate with one user at a time, in case of a collision, you have to try again, while the switched Ethernet technology allows different users to transmit data. For example, a 16-port ethernet switch allows 16 sites to communicate between eight links. Particularly in terms of time response, LAN switches are favored. It provides a higher bandwidth and a higher speed than the router at a lower cost than the router. unless there is a requirement for a wide area network (WAN), the switch has a tendency to replace the router.