The computer network is a system that consists of computers and other network devices are connected to each other, working together to achieve a goal. Network devices is critical to the ongoing relationship or communication between computers.
Information moved from computer to computer using a network rather than through human intermediaries. So make information exchange easier and faster.
Most basic network has two computers that communicate with each other by cable medium or any other medium. When your computer is connected to another computer, you can move information quickly and efficiently.
In the book "Networking Complete" explained that a bunch of computers and other equipment are connected together is called network, while the concept of the connected computer and share resources (resources) is called networking.
Network Building Blocks
All of the network, be it large or small, require specialized hardware network. For small networks, the hardware may consist of nothing more than a network interface card (NIC) on each computer, cable for each computer and network switch where all the computers are connected. Large networks may be artifacts of additional components such as a router or repeater.
Small or large, all networks are built from the following basic building blocks:
Client computer
Computers are used by end users to access existing resources dijaringan. Client computer is sometimes designated as a workstation.
Computer server
The computer that provides resources used to be together, such as disk storage and printers, as well as network services, such as e-mail and Internet access. Server computers running the operating system in particular specialized tissues such as Windows Server 2003, NetWare, or Linux, as well as special software to provide network services. For example, the server may be running Microsoft Exchange to provide e-mail to the network, or run the Apache Web Server so that computers can serve Web pages.
Network interface card (NIC)
Network interface card installed in the computer allows computers to communicate over a network. Almost every NIC implements networking standard called Ethernet. Each client computer and the server must
has a network interface card (or built-in network port) if you want to be part of the network.
Cable
Computers in a network are usually physically connected to each other by using a cable. Although there are some popular types of cables, wires commonly used today is a twisted pair or also called 10BaseT. Other cable types are also commonly used is coaxial or also called 10Base2. For high-speed network connection, sometimes used fiber-optic cables. In most cases, cable laid through the wall and collected diruangan called central wiring closet. But for smaller networks, cable is usually just laid on the floor.
Switch
Cable networks are usually not connected directly to the computer. Instead, each computer is connected by cable to a device called a switch. Switch, instead, connect to the network. Each switch contains multiple ports, typically 8 or 16. Thus we can use
8 port switch to connect eight computers.
Switches can be connected to each other to build a larger network. Old network might still exist that use a tool called a hub than a switch. Hub provides the same function as a switch but not seefesien switch.
Wireless networks
On the wireless computer network to communicate with other computers via radio signals. In wireless networks, radio transmitter and a radio receiver replacing the cable. The main advantage is the flexibility of the wireless network. With a wireless network, we do not need to pull the wires through the walls or the ceiling, and a client computer can be located anywhere as long as the broadcast network distance. The main disadvantage of the wireless network is less secure than wired network.
Software Network
Despite the critical network hardware, in fact actually running the network is the software. Many software must be set up according to the order for the network to work. Computer servers in particular uses a special operating system network (network operating system or NOS) to function efficiently, and the client computer requires a properly configured network settings in order to access the network.
The purpose and benefits of building a computer network
In building a computer network must have a purpose and benefits that are very helpful to us as follows:
Sharing resources
We can divide the existing resources in the sense that it can be used together as the program, equipment, or other peripherals that enable every person who is on a computer network without having to be affected by the location.
Media communication
May allow for communication between network users, both for teleconferencing, instant messaging, chat, send electronic mail (e-mail) or send other important information.
Data Integration
Can prevent reliance on a central computer, each process data should not be done on one computer but can be distributed to other places or in other words can be done by the other computers in the
tissue.
Security of data
Computer network system can provide protection against data through setting user permissions and passwords, as well as other protection techniques.
Web Browsing
To access information on the network, such as web browsing. Almost everyone who reads this article may never use a web browser (such as Internet Explorer, Mozilla Firefox, Netscape, Opera and others). The web browser enables us to see the information in a web server somewhere on the Internet.
Development and maintenance easy and cost-saving.
For example, a company can save on equipment that must be used.
Network-Based Application
Network is used to provide network services for network users. Applications available networks in general, ie file services, print services, web services, e-mail, file transfer service.
File Service
The computer where the file is stored is called a file server. The other computer (the access) is called the client, and that can be done is to read and write to these files, without the need to create a local copy of the file on the disk drive client. The service is usually transparent to the end user.
Print Service
Printers are connected to a computer called a print server. Client computer can send a file to the print server, which then prints the file to the printer. This server is usually transparent to the user.
Web Service
The server stores a variety of information, including text, graphics, animations, images, video, and audio. End user uses a web browser to request information from a server. The server returns information displayed by the web browser.
E-mail
End users create e-mail using the e-mail client and send e-mails to a particular person. E-mail server to help the process of sending e-mail.
File Transfer Service
Files are also stored on the server. This server allows a computer (client) to copy the files from the server to their local disk drive and replace the contents of the file on the file server with the files on the local disk drive client.
Classification of computer networks based on area
Computer networks can be classified based on the size of the network area LAN, MAN, WAN.
LAN (Local Area Networking)
Local Area Network is a network of personal property in a single location, usually on one floor of a building, campus, or all the computers in an enterprise. The magnitude of the coverage area of a LAN network can be several kilometers.
MAN (Metropolitant Area Networking)
Metropolitan Area Network is basically a larger version of LAN and generally using the same technology. And coverage may be a group of adjacent branches.
WAN (Wide Area Networking)
Wide Area Network to reach a large geographical area, usually a country or continent.
Computer Networks Based on Role (function)
Based on the role then there are three types of computer networks, the client-server (sometimes also called server-based), peer-to-peer, hybrid network:
Client-Server
That computer networks where the network is there a dedicated computer as a server. The server has a responsibility to provide a service / services provided to other computers.
Common services provided by servers typically provide services such as file services, print services, web services, e-mail, file transfer service. Where will the computer (client) can access the services provided by the server.
Peer-to-peer
Is a network of computers where each computer can be a server and a client simultaneously. For example, the file sharing between computers on the network Windows Network Neighbourhood there are 5 computers (we named A, B, C, D and E) are granted access to the files they have. At one point A to access the file share of B named data_nilai.xls filesoal_uas.doc and also gives access to C. When accessing a file from B then A serves as a client and as a give file access to C then A is acting as a server. Both functions were performed by the same A network like this so called peer to peer.
Hybrid Network
Most of the network is actually in fact a hybrid network. In this network generally have active domains and workgroups. Hybrid network is a network-based client-server which in addition to the network servers provide resources most needed by the user, but the user is still
can access the resources provided by other users (peer-to-peer) in a workgroup.
Network topology
Based on the network topology, computer networks can be distinguished:
Bus Topology
Star Topology
Topology Ring
Mesh Topology (Random)
Topology Tree (Hirarkies)
Linear Topology
