The origin of the switch |
| Author： Date：2016/10/19 13:23:55 |
"Switch" is a BoLaiCi, derived from English "Switch", original intention is "Switch", the tech world in the introduction of the word, translated as "exchange". In English, the verb "exchange" and a noun "switch" is the same word (note the "exchange" here refers to in telecommunications, signal exchange exchange is not the same concept with items).
In 1993, LAN switching equipment, in 1994, raised a hot wave of switching network technology in China. Actually, switching technology is a simple, low-cost, high performance and high density characteristics of exchange of products, reflects the complex switching bridge technique in the second layer of the OSI reference model. Like bridge, switch according to the MAC address of each packet forward relatively simply decision-making information. And this kind of packet forwarding decision is generally not considered hidden deeper other information. Unlike bridge switches forward delay is small, the operating performance close to a single LAN, far more than the ordinary bridge forwarding performance between interconnected networks. Switching technology allow bandwidth sharing type and special LAN segment adjustment, to relieve the bottleneck problems in the information flows between local area network (LAN). Now Ethernet, fast Ethernet, FDDI and ATM technology exchange products. Similar to the traditional bridge, switches provide many network interconnection function. Can switch the economy domain to divide network into small conflict, provide higher bandwidth for each workstation. Protocol transparency makes the switch in the case of software configuration simple installed directly in the multi-protocol network; Switches use the existing cable, Repeaters, hubs and workstation network card, don't have to be top hardware upgrade; Switches to the workstation is transparent, so management cost is low, simplifies the increase of network nodes, mobile and the operation of the network changes. Use of specially designed integrated circuit can make the switch to the line rate of all the parallel port forwarding information, provides a much higher than the traditional bridge operation performance. As a single Ethernet port theoretically to contain 64 octal number of packets, can provide 14880 BPS transmission rate. This means that one has 12 port, support 6 parallel data flow rate "wiring" Ethernet switches must provide overall throughput of 89280 BPS X14880bps/road traffic information flow (6). Application-specific integrated circuit technology makes the switch in the case of more port to realize the above performance, its port cost is lower than the traditional bridge. |