Network Node
A device connected to a network. Examples are workstations, file servers, and print server interface devices to connect printers to the network. Each network node is a physical device connected to other nodes in the network by a cable (or by radio waves or infrared beams in wireless network).
File Server
The file server is the computer the network software runs on. It's where the files that are stored on the network physically live. The file server computer is used only as a file server and runs no user application unless the user is using a nondedicated network operating system (which is not recommended). The file server may contain just one network interface card (NIC) or multiple cards, and its connected to the either by direct wire bus (Ethernet), through a hub (ARCNET), or through a connector. Peer-to-peer networks don't use file servers. There is less network overhead on a peer-to-peer network, so there is less network software to store. Peer-to-peer network store shared data files on the local hard disks of the individual network workstations.
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Workstations:
This is the user PC runs everyday applications. This machine can be a Macintosh, a Unix workstation, or an XT, AT, 386, 486 or Pentium PC. Some networks have more powerful workstations than file servers if the user application would benefit-for example, mathematical" analysis and computer-assisted design applications.
Network Card ( NIC):
The physical component installed in the computer to make the physical connection to whatever network wiring. Many network cards use idiot lights on the back of the cards to show if it is working properly.
Print Server:
Network software running on a PC dedicated to printing, or in a specialized network interface device( a small box which connects one or more printers to the network cable) makes a print server. The print server handles the printer. feeding it prints jobs from print queues stored on a file server. A separate print server computer is optional in the network, since the fileserver can do double duty, running print server software along with the NetWare operating software..
The Wire:
Type of cables used in routing the data across the network. Each type of cable has advantages and limitations.
1. Coaxial Cable:
The most common type of cable used with LANs is coaxial cable (coax). It is composed of a single wire conductor surrounded by a conductive wire shield, usually standard and braided wire. The shield protects the inner conductor form outside electrical interface and attached to an earth ground. This shield is also known as a drain because it directs electrical interference to the earth ground. The shield is covered with a polyvinyl coating that insulates the cable from the outside environment. Because of the built-in shielding, Coax can carry a data signal over long distances without loosing signal quality..
2. Twisted Pair Cable:
The second most common type of cable used on LANs is twisted pair. It consists of two or more wires covered by a thin rubber jacket and intertwined together or "twisted" to form a pair. The twisted prevents the wire from running side-by-side in the housing. When wires run side-by-side the signals from one wire may be inducted into neighboring wire creating interference known as crosswalk. Twisted pair can be shielded or unshielded.
3. Fiber Optic Cable:
Fiber optic cabling for LANs is the least common cabling method used primarily due to its high cost. It consists of a glass or special plastic filament, which runs the length of the cable. A light beam is directed through the filament. The beam is modulated various ways provide a signal. Fiber optic cable supports higher speed than coax or twisted pair and carries a signal over a greater distance without attenuating (signal weakening). Data transmitted over fiber optic cable is relatively secure from being "trapped", which makes this technology attractive to user with security concerns.
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