"Switch" is an imported word, derived from the English "Switch", the original meaning is "switch", when the Chinese technology community introduced this term, it was translated as "switch". In English, the verb "exchange" and the noun "switch" are the same word (note that "exchange" here refers specifically to the exchange of signals in telecommunications technology, and is not the same concept as the exchange of goods).
In 1993, local area network switching equipment appeared, and in 1994, a domestic upsurge of switching network technology started. In fact, the switching technology is a switching product with simplification, low price, high performance and high port density. It embodies the complex switching technology of bridging technology in the second layer of the OSI reference model. Like the bridge, the switch makes a relatively simple decision to forward the information according to the MAC address in each packet. And this forwarding decision generally does not consider other deeper information hidden in the packet. The difference with bridges is that the switch forwarding delay is very small, and the operation is close to the performance of a single LAN, which far exceeds the forwarding performance between ordinary bridged Internet networks.
Switching technology allows bandwidth adjustments for shared and dedicated LAN segments to alleviate bottlenecks in the flow of information between LANs. Existing Ethernet, Fast Ethernet, FDDI and ATM technology switching products.
Similar to the traditional bridge, the switch provides many network interconnection functions. The switch can economically divide the network into small conflicting domains and provide 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, repeaters, hubs, and workstation network cards, without the need for high-level hardware upgrades; the switch is transparent to workstations Yes, such management overhead is low, which simplifies the operations of adding, moving, and changing network nodes.
The use of specially designed integrated circuits enables the switch to forward information in parallel at all ports at the line rate, providing much higher operating performance than traditional bridges. Application-specific integrated circuit technology enables the switch to achieve the above performance with more ports, and its port cost is lower than that of traditional bridges.