Network+technologies


 * Network technologies **

media type="file" key="Part 1.MP3" width="240" height="20"A  router is a device that forwards  data packets between  computer networks, creating an overlay internetwork. A router is connected to two or more data lines from different networks. In a practical use, routers can be used to boost a signal to make it stronger for a person who might out the range of an Ethernet cable. Therefore you can go wireless by sending the signal over a distance, so the router does not need to be directly next to the device to work.
 * Routers **

media type="file" key="Part 2.MP3" width="240" height="20"A  network switch or  switching hub is a  computer networking device that connects <span style="font-family: Arial,sans-serif; font-size: 12pt;"> network segments. <span style="font-family: Arial,sans-serif; font-size: 120%;">Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Switches **

<span style="font-family: Arial,sans-serif; font-size: 12pt;">media type="file" key="Part 3.MP3" width="240" height="20"An Ethernet hub, active hub, network hub, repeater hub or hub is a device for connecting together several Ethernet devices jointly and making them act alone network segment. <span style="font-family: Arial,sans-serif; font-size: 12pt;">A network hub is an unsophisticated device in contrast with, for example, a switch. A hub does not scrutinize or manage any of the traffic that comes through it: any packet towards the inside any port is rebroadcast on all other ports. So in practical terms, if you have broadband and you want a connection to the internet and you can have more than one device connected via the Ethernet ports so you can have more than one laptop connected to the internet via the hub.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Hubs **

<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">media type="file" key="Part 4.MP3" width="240" height="20"Optical fiber can be used as a medium for telecommunication and <span style="font-family: Arial,sans-serif; font-size: 12pt;">computer networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">For short distance applications, such as a network in an office building, fiber-optic cabling can save space in cable ducts. This is because a single fiber can carry much more data than electrical cables such as standard <span style="font-family: Arial,sans-serif; font-size: 12pt;">category 5 Ethernet cabling, which typically runs at 1 Gbit/s. Fiber is also immune to electrical interference; there is no cross-talk between signals in different cables, and no pickup of environmental noise. Non-armored fiber cables do not conduct electricity, which makes fiber a good solution for protecting communications equipment in high voltage environments, such as power generation facilities, or metal communication structures prone to lightning strikes. They can also be used in environments where explosive fumes are present, without danger of ignition. Wiretapping (in this case, fiber tapping) is more difficult compared to electrical connections, and there are concentric dual core fibers that are said to be tap-proof.
 * <span style="font-family: Arial,sans-serif; font-size: 12pt;">Optical fiber **

<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">media type="file" key="Part 5.MP3"A cable is two or more <span style="font-family: Arial,sans-serif; font-size: 12pt;">wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry electric currents. An optical cable contains one or more optical fibers in a protective jacket that supports the fibers.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Cable **

**<span style="font-family: Arial,sans-serif;">Wireless technologies **

<span style="color: #4b4b4b; font-family: Arial,sans-serif; font-size: 12pt;">WiFi Technology is a standard of communication among wireless devices and computers all over the world.
 * <span style="color: #4b4b4b; font-family: Arial,sans-serif; font-size: 12pt;">WiFi Technology **<span style="color: #4b4b4b; font-family: Arial,sans-serif; font-size: 12pt;"> is a proficientused by mobiles, workplaces, home and computer systems all around the world. WiFi Technology is a spectrum radio technology and OFDM radio technology therefore it is an alternate of wireless LAN.

<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">WiMAX (Worldwide Interoperability for Microwave Access) is a communication technology for wirelessly delivering high-speed Internet service to large geographical areas. <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">WiMAX can provide at-home or mobile <span style="font-family: Arial,sans-serif; font-size: 12pt;">Internet access across whole cities or countries. In many cases this has resulted in competition in markets which typically only had access through an existing incumbent DSL (or similar) operator.
 * <span style="color: #4b4b4b; font-family: Arial,sans-serif; font-size: 12pt;">WiMax **

<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">A master Bluetooth device can communicate with a maximum of seven devices in a <span style="font-family: Arial,sans-serif; font-size: 12pt;">piconet (an ad-hoc computer network using Bluetooth technology), though not all devices support this limit. The devices can switch roles, by agreement, and the slave can become the master (for example, a headset initiating a connection to a phone will necessarily begin as master, as initiator of the connection; but may subsequently prefer to be slave). <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Bluetooth is a standard wire-replacement communications protocol primarily designed for low power consumption, with a short range (power-class-dependent, but effective ranges vary in practice; see table below) based on low-cost <span style="font-family: Arial,sans-serif; font-size: 12pt;">transceiver microchips in each device.
 * <span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Bluetooth **

<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">Before the advent of <span style="font-family: Arial,sans-serif; font-size: 12pt;">fiber-optic transmission, most long-distance telephone calls were carried via networks of microwave radio relay links run by carriers.
 * <span style="font-family: Arial,sans-serif; font-size: 12pt;">Microwave **

**Network** **administration**
<span style="background-color: white; font-family: Arial,sans-serif; font-size: 12pt;">A data center is a facility used to house computer systems and associated components, such as telecommunications and storage systems. It generally includes redundant or backup power supplies, redundant data communications connections, environmental controls (e.g., air conditioning, fire suppression) and security devices.
 * <span style="font-family: Arial,sans-serif; font-size: 12pt;">Data centres **