In bus topologies, all computers are connected to a single cable or backbone, by a transceiver either directly or by using a short drop cable. All ends of the cable must be terminated, that is plugged into a device such as a computer or terminator. Most bus topologies use coax cables.
Star topology
A star topology is connected by cables to a hub. In this topology management of the network is made much easier such as adding and removing devices, because of the central point. However because it is centralized more cable is required.
Ring topology
In a ring topology network computers are connected by a single loop of cable, the data signals travel around the loop in one direction, passing through each computer. Ring topology is an active topology because each computer repeats (boosts) the signal before passing it on to the next computer.
Mesh topology
A Mesh topology provides each device with a point-to-point connection to every other device in the network. These are most commonly used in WAN's, which connect networks over telecommunication links. Mesh topologies use routers to determine the best path.
Tree topology
A tree topology is a combination of bus and star topologies. Nodes are connected in groups of star-configured workstations that branch out from a single root. The root node usually controls the network and sometimes network traffic flow. This topology is easy to extend. When new users need to be added, it is simply a matter of adding a new hub. It also is easy to control because the root provides centralized management and monitoring.
Network Management
Network management is a software system used to control all of the functions of network devices. In the OSI management model the five management functions are:
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Accounting management: is a process of identifying individual and group access to various network resources to ensure proper access capabilities (bandwidth and security) or to properly charge the various individuals and departments.
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Configuration management: is the process of identifying, tracking and modifying the setup of devices on the network. This category is extremely important for devices that come with numerous custom settings (e.g. routers and file servers).
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Fault management: is the process of identifying and locating
faults in the network. This could include discovering the
existence of the problem, identifying the source, and possibly
repairing (or at least isolating the rest of the network from)
the problem.
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Performance management: is the process of measuring the
performance of various network components. This also includes
taking measures to optimise the network for maximum system
performance (periodically measuring of the use of network
resources).
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Security management: is the process of controlling (limiting, restricting) access to the network and resources on it. This could include setting up and managing access lists in routers (creating "firewalls" to keep intruders out), creating and maintaining password access to critical network resources, identifying the points of entry used by intruders and closing them.
Network Hardware
File server
File sever is a processor that controls a central repository of data that can be downloaded or manipulated in some manner by a client. The most common choice for file server software is Network file system. A protocol which allows a computer to access files over a network as if they were on its local disks.
Email server
An email sever is a device that distributes files or information in response to requests sent via electronic mail. Examples on the Internet include Almanac. Mail servers are also used on Bitnet which is an academic and research computer network connecting approximately 2500 computers and provides interactive, electronic mail and file transfer services, using a store and forward protocol. A mail server could be used to provide remote services which might now be provided via FTP or WWW.
WWW server
A World Wide Web server is simply a device that answers requests for documents from World Wide Web clients over the Internet. All World Wide Web servers use a language, or protocol to communicate with web clients called the Hypertext Transfer Protocol. This is where the http in a web URL comes from. All types of data can be exchanged using this protocol including HTML, graphics, sound and video.
Modem
Modulator-demodulator - a device or program that enables a computer to transmit data over analogue telephone lines. Computer information is stored digitally, whereas information transmitted over telephone lines is transmitted in the form of analogue waves. A modem converts between these two forms.
Network card
A computer circuit board or card that is installed in a computer so that it can be connected to a network
Router
A device that determines the next network point to which a data packet should be forwarded enrooted toward its destination. The router is connected to at least two networks and determines which way to send each data packet based on its current understanding of the state of the networks it is connected to. Routers create or maintain a table of the available routes and use this information to determine the best route for a given data packet.
Hub
A hub is a network device that connects multiple computers on a LAN so they can communicate with one another, the rest of the network, and the Internet. All users connected to a hub share the available network bandwidth (unlike a switch, which provides full bandwidth to each computer).
Switch
A switch is a device that channels incoming data from any of multiple input ports to the specific output port that will take the data toward its intended destination
Cross over cable
Twisted pair patch cable wired in such a way as to route the transmit signals from one piece of equipment to the receive signals of another piece of equipment, and vice versa.
Network Software
Outlook express
This program allows peoples to exchange electronic mail with peoples around the world. Peoples can exchange messages with friends, colleagues, family members and clients.
Internet Explorer
Microsoft's free World-Wide Web browser for Microsoft Windows. Internet Explorer is the main rival to Netscape Navigator. Both support the same core features and offer incompatible extensions.
Antivirus
A software program designed to identify and remove a known or potential computer virus.
Firewall
A combination of hardware and software that provides a security system, usually to prevent unauthorized access from outside to an internal network or intranet. A firewall prevents direct communication between network and external computers by routing communication through a proxy server outside of the network. The proxy server determines whether it is safe to let a file pass through to the network. A firewall is also called a security-edge gateway.
Window
The operating system for Personal Computers and Networked Computers. Constantly upgraded. Commonly used version are Windows 95, Windows 98, Windows Me, Windows 2000, Windows NT4, Windows XP (Home and Professional).
Window NT
The most advanced version of the Windows operating system, Windows NT is a 32-bit operating system that supports pre-emptive multitasking. There are actually two versions of Windows NT: Windows NT Server, designed to act as a server in networks, and Windows NT Workstation for stand-alone or client workstations.
Class C Network Address (194.10.1.0) for diagrams.