 |
Hub Port | |||
|
Hubs are central connectivity devices for resources on a network. Many systems such as computers, printers, network storage, and more connect to hubs to communicate with each other. Switches and Routers. Two Types of Hubs.Hubs are used mainly for local area networks and use Ethernet technology to communicate between devices but in reality a Hub is a multiport Ethernet Repeater. Switches are more efficient in the communication while routers are used when a network is deployed in a wide area. Ethernet Technology was invented by Robert Metcalfe while working at Xerox PARC in 1,973 to communicate computers over short distances. Later was founder of 3Com. Ethernet repeaters where somewhat inneficient because they forward all the traffic to all Ethernet devices, while switches are Bridges that communicate at the data link layer that forward only well formed packets thus eliminating the transmission of collisions and packet errors. Jerry Saltzer was one of the people that made 3Com a success as Metcalfe sometimes jokingly says. Saltzer cowrote a very influential paper suggesting that token-ring was superior to Ethernet. As a result, computer manufacturers decided not include Ethernet as an standard feature, which allowed 3Com to build a business around selling add-in Ethernet cards. While in Paper Token Ring looked better, Ethernet worked best in practice than in theory. That is: Typical networks differ from what had been expected before LANs became common in ways that favor the simple design of Ethernet. Combine that with the cost advantage of Ethernet and you have the reason of the great success of Ethernet technology. The early bridges where slower than repeaters because they examined packets one by one but in 1,989 Kalpana introduced the Etherswitch which does the bridging in hardware. Switches over Hubs.Because switches deliver packets only to the port they where intended for, traffic is less public than in Shared Ethernet. The slightly better isolation of devices from each other, the bandwidth advantages and the elimination of the chaining limits in hubbed Ethernet have made switched Ethernet the technology of choice. Switched Ethernet still suffer from a number of issues:
Some vendors offer options to combat these problems as: spanning-tree protocol to maintain the active links of the network as a tree while allowing physical loops for redundancy. Port protection features (hackers almost never are not on a switch-switch link). VLANs that keep different classes of users separate in the same physical infrastructure and fast routing to route between those VLANs. żDo you enjoyed this article? Comment this resource at your Website or Blog linking to this page. | |||