NETWORK computer is a collection of computers; printers and other equipment
are connected in one unit. Information and data moves through the wires
or wireless computer network allowing users to each other
exchanging documents and data, print on the same printer and together
using hardware / software that connects to the network. Every computer,
printers or peripherals that are connected by a network called a node. A network
computers can have two, tens, thousands or even millions of nodes.
Types of Computer Networks
In general, a computer network is divided into five types, namely;
1. Local Area Network (LAN)
Local Area Network (LAN), a privately owned network within a building
or campus-sized to several kilometers. LANs are often used
for connecting personal computers and workstations in the office
a company or factories to use shared resources (resource,
such as printers) and exchange information.
2. Metropolitan Area Network (MAN)
Metropolitan Area Network (MAN), basically a LAN version
larger and usually use the same technology with a LAN.
MAN could include corporate offices are located close together or too
a city and can be used for private purposes (private) or public.
MAN is able to support data and voice, even to relate to the network
cable television.
3. Wide Area Network (WAN)
Wide Area Network (WAN), its scope covers a wide geographical area,
often includes a country or even continent. WAN consists of a collection of machines
which aims to implement programs (applications) user.
4. Internet
Actually there are many in this world networks, often using a device
hardware and software that is different. People who connect to the network
often wish to communicate with others who connect to the
other network. This desire requires the relationship between network
often not compatible and different. Usually to do this required
a machine called a gateway in order to engage and implement
the necessary translation, both hardware and software.
A collection of interconnected networks is called the Internet.
5. Wireless Networking
Wireless network is a solution to communication that cannot
perform by using a cable network. For example, people who want to
get information or to communicate despite being located above
car or plane, it is absolutely necessary because the network without wires
cable connection is not possible to be made in the car or plane. Currently the network
without wires is rapidly adopted by utilizing satellite services and is able to
provide faster access speeds than the network
cables.
Computer Network Topology
Topology is a way of connecting computers to one computer
other and thus forms a network. How that is currently widely used is the bus,
token-ring, star and peer-to-peer network. Each of these topologies have characteristics,
with advantages and disadvantages.
1. BUS Topology
Profit
• Cable Saver
• Layout simple cable
• Easy to develop
Loss
• Detection and isolation of very small error
• Density of traffic
• If one client is damaged, then the network cannot function.
• Required repeater for long distance
2. Topology Token RING
Token-ring method (often called a ring anyway) is how to connect a computer
so that the ring-shaped (circles). Each node has the same level.
The network will be called as a loop, data is sent to node and each
information received by the node address is checked whether the data were for him or
not
Profit
• Cable Saver
Loss
• Sensitive error
• Development of more rigid network
3. STAR Topology
Centralized control, all links must pass through the center of the channel data
all the nodes or the client chooses. Central node is called the primary station
or server and the other is called the secondary stations or client server. After
network connection initiated by the server, each client server at any time
using a network connection without waiting for commands from the server.
Profit
• Most flexible
• Installation / changing station is very easy and does not interfere with other network
• Control centrally
• Ease of detection and isolation of errors / defects
• Easy network management
Loss
• Profuse cable
• Need special handling
• Control center (HUB), so the critical element
4. Topology Peer-to-peer Network
Peer meaning co-workers. Peer-to-peer network is a computer network
consists of installments computers (usually no more Than 10 computers with 1-2
printers). In this network to the preferred system is the use of the program,
data and printers together. Computer users cans be named Dona
using a computer program installed on Dino That Is, and They both cans
same print to the printer at the same time.
This network system cans also be used at home. Computer users have WHO
computer 'old', for example, AT, and Want to buy new computers, say a Pentium
II, no need to dispose of old computers. He simply put the cards in network
the second computer is then connected by special cables Used
for network systems. Compared with the three Ways above, this network system
Simpler making it Easier to learn and Used.
Benefits Network
* Resource Sharing, to use resources in together. Suppose that there is a user is located 100 km away from the data, do not get the difficulty in using these data, as if the data is located Nearby. Often this means the computer network that distance problem.
* High Reliability, with the computer network We Will gets a high reliability by having alternative sources of supply. For example, all files cans be saved or copied to two; three more computers or networks connected that acre. So if one machine breaks, then copy on another machine, That Can Be Used.
* Saves money. Have small-sized computer price / performance ratio is better than a big computer. Large such computers as mainframes have speeds approximately ten times the speed of a small computer / personal. Will Remain, the price of mainframes a thousand times more expensive than personal computers. The imbalance of the ratio of price / performance and speed of this is to make the system designers to build systems that consist of personal computers.
