A computer network is formed by a few basic hardware elements. These devices link computers together in a format that enables them to exchange data with each other, sell refurbished cisco or with services like printers and fax machines.
Network Adapter
The most essential piece of hardware to link a computer to a network is a network adapter. This originally was manufactured on a separate board and slotted into an expansion slot on the motherboard of the computer. For this reason, the network adapter is often still called a network interface card, sell used cisco equipment even though it is usually integrated into the motherboard of modern computers. The network adapter translates data formats between the requirements of computers and the requirements of the network medium (either cable or radio waves).
Cable
Most networks in the world are connected by cable, despite the new popularity of wireless networks. The most common standard for network cable is called Ethernet. This was invented by Xerox, but the management of the standards is now the responsibility of the Institute of Electrical and Electronics Engineers (IEEE). sell cisco equipment Ethernet guidelines are published under the code 802.3. The most common configuration of network cable in the world today is called Unshielded Twisted Pair.
Hub
The hub is the simplest piece of equipment that can form a network. Every device in the network connects to a port on the hub via a dedicated cable (one cable per device). The hub has a series of sockets -- these are the ports. sell cisco used Any signal arriving on one port is automatically copied onto all other ports. The hub pays no attention to the destination address of any arriving data. It is also called a repeater because it repeats arriving data onto all other outlets.
Switch
A switch looks the same as a hub and it receives connections to networked devices in the same way. However, the switch examines arriving data packets and finds a destination address in the packet header. It associates an address with each of its ports. The arriving data is copied onto only that port bearing that address. Each port's address is, cisco sell in fact, the MAC address of the network adapter operating in the computer or device at the other end of the cable plugged into that port.
Bridge
Bridges are switches with only two ports. There is often confusion between switches and bridges. However, if it has more than two ports, it is a switch. Switches are also called multi-port bridges. The purpose of a bridge is to connect two segments of a network together. selling cisco equipment Network segmentation is a solution to a problem of network congestion where the network contains many computers. Bridges can also connect together dissimilar network media, such as cable and wireless segments.
Router
Hubs, switches and bridges operate within a network. Routers carry data beyond one network and across other to reach a destination that is not immediately connected. sell used equipment Routers operate with IP addresses and work together to form a chain passing data all over the world. A router must be connected to at least two networks in order to pass data beyond the boundaries of one network.
