Switch 'is an imported term derived from the English word' Switch ', originally meaning' switch '. When the Chinese technical community introduced this term, it was translated as' exchange '. In English, the verb 'exchange' and the noun 'switch' are the same word (note that 'exchange' specifically refers to signal exchange in telecommunications technology, which is not the same concept as item exchange).
In 1993, LAN switching devices emerged, and in 1994, a wave of switching network technology emerged in China. In fact, switching technology is a switching product with the characteristics of simplification, low price, high performance, and high port density, reflecting the complex switching technology of bridging technology in the second layer operation of the OSI reference model. Like a bridge, a switch simply forwards decision information based on the MAC address in each packet. And this forwarding decision generally does not consider other deeper information hidden in the package. Unlike the bridge, the switch has a very small forwarding delay and operates close to the performance of a single LAN, far exceeding the forwarding performance between ordinary bridging internet networks.
Switching technology allows bandwidth adjustment between shared and dedicated LAN segments to alleviate bottlenecks in information flow between LANs. Existing switching products with Ethernet, Fast Ethernet, FDDI, and ATM technologies.
Similar to traditional bridges, switches provide many network interconnection functions. Switches can economically divide the network into small conflicting domains, providing higher bandwidth for each workstation. The transparency of the protocol allows the switch to be directly installed in a multi-protocol network with simple software configuration; The switch uses existing cables, relays, hubs, and workstation network cards, without the need for high-level hardware upgrades; The switch is transparent to the workstation, which reduces management overhead and simplifies the operation of adding, moving, and changing network nodes.
The use of specially designed integrated circuits enables switches to forward information in parallel across all ports at line rate, providing much higher operational performance than traditional bridges. The specialized integrated circuit technology enables the switch to achieve the above performance with more ports, and its port cost is lower than that of traditional bridge connectors.