How are switches classified? What are the main types of switches?

Time : Sep. 08, 2022    View : 11

Switch (Switch) means “switch” and is a network device used for electrical (optical) signal forwarding. It can provide an exclusive electrical signal path for any two network nodes of the access switch. The most common switches are Ethernet switches. Other common ones are telephone voice switches, fiber switches and so on.

How are switches classified?

       Broadly speaking, there are two types of network switches: WAN switches and LAN switches. WAN switches are mainly used in the field of telecommunications, providing a basic platform for communication. The local area network switch is used in the local area network to connect terminal devices, such as PCs and network printers. From the transmission medium and transmission speed, it can be divided into Ethernet switches, Fast Ethernet switches, Gigabit Ethernet switches, FDDI switches, ATM switches and Token Ring switches. From the scale of application, it can be divided into enterprise-level switches, department-level switches and workgroup switches. The scales divided by various manufacturers are not completely consistent. Generally speaking, enterprise-level switches are rack-type switches, and department-level switches can be rack-type (with fewer slots) or fixed-configuration types. The stage switch is a fixed configuration type (the function is relatively simple). On the other hand, from the perspective of the scale of the application, when used as a backbone switch, a switch that supports large-scale enterprise applications with more than 500 information points is an enterprise-level switch, a switch that supports a medium-sized enterprise with less than 300 information points is a department-level switch, and a switch that supports 100 Switches within one information point are workgroup switches.

 

       Ethernet switch

       With the rapid development of computers and their interconnection technology (also commonly referred to as “network technology”), Ethernet has become the most popular short-distance Layer 2 computer network to date. The core component of Ethernet is the Ethernet switch.

 

      Whether it is manual switching or program-controlled switching, it is for the transmission of voice signals, and it is a “circuit switching” that requires an exclusive line. The Ethernet is a computer network that needs to transmit data, so it uses “packet switching”. But no matter which switching method is adopted, the characteristic that the switch provides “exclusive path” between two points will not change. As far as Ethernet devices are concerned, the essential difference between switches and hubs is that when A sends information to B, if it passes through the hub, all network nodes connected to the hub will receive this information (that is, send it in the form of broadcast). , but the network card will filter out the information not sent to the machine at the hardware level; and if it passes through the switch, unless A notifies the switch to broadcast, the information C sent to B will never be received (the situation where the control authority of the switch is obtained to monitor except).

 

       Ethernet switch manufacturers have launched Layer 3 or even Layer 4 switches according to market demand. But in any case, its core function is still Layer 2 Ethernet data packet exchange, but with a certain ability to process IP layer or even higher layer data packets. A network switch is a device that expands the network and can provide more connection ports in the subnet to connect more computers. With the development of the communication industry and the advancement of the informatization of the national economy, the network switch market has shown a steady upward trend. It has the characteristics of high cost performance, high flexibility, relative simplicity, and easy implementation.

       Optical switch

       Optical switching is a next-generation switching technology that is being developed. All switching technologies are based on electrical signals. Even optical fiber switches first convert optical signals into electrical signals, and after exchange processing, convert the optical signals back to another optical fiber. Due to the low photoelectric conversion rate and the physical bottleneck in the processing speed of the circuit, people hope to design an “optical switch” that does not need to undergo photoelectric conversion. is the switch light path. This will greatly improve the processing speed of the switch.