Understanding Computer Networks

Computer network is a collection of computers, printers and other equipment connected. Information and data moving through the wires to allow computer network users can exchange documents and data, the same print on a printer with the same and using hardware / software that is connected to the network. Each computer, printer or peripherals connected


with a network called a node. A computer network can have two, tens, thousands or even millions of nodes. A network usually consists of two or more computers interconnected among one another, and share resources such as CD-ROM, Printer, exchange files, or the ability to communicate with one another electronically. Connected computer, the possible contact with the media cables, telephone lines, radio waves, satellite, or infrared light.

B. Types of networks based on coverage:

There are three different types of Network / Network are:

a. Local Area Network (LAN) / Local Area Network.
A LAN is a network that is limited by the relatively small area, generally bounded by the area like an office environment in a building, or a school, and usually not far from about 1 km square.

Some models of LAN configuration, one computer is usually made in a file server. Which is used to store software (software) that govern network activity, or as software that can be used by computers that are connected to the network. The computers are connected to the network (network) is typically called workstations. Usually more below the workstation capabilities of the file server and has other applications in addition to applications for the network hard drive. Most LANs use the media cable to connect between one computer to another computer.


b. Metropolitan Area Network (MAN) / Metropolitan area network
A MAN, usually covering an area larger than the LAN, for example between regions within a province. In this case the network linking several small networks into a larger area of the environment, as an example that is: the network of the Bank where several branches of a bank in a big city is connected to one another. For example Bank BNI in the entire region or Surabaya Ujung Pandang.

c. Wide Area Network (WAN) / area of Large Scale Networks

Wide Area Networks (WAN) is a network that already use a scope usually means satellite or submarine cable as an example of the whole network BANK BNI in Indonesia or in other countries. Using the WAN facilities, a bank in Bandung can contact the existing branch office in Hong Kong, in just a few minutes. WAN usually rather complicated and very complex, using many means to connect between the LAN and WAN into Global Communications such as the Internet. But somehow between LAN, MAN and WAN is not much different in some ways, only just a different scope of its area

one among others.


C. Topology / Network Physical Form:
Topology of a network based on how to contact a number of nodes or central in forming a network system. Common network topology used is: Mess, Star (Star), Bus, Tree, and the Ring (Ring).


a. Mesh Network Topology
This network topology implementing fully the relationship between central. The number of channels should be provided to form a mesh network is a central number minus one (n-1, n = number of central). Level of network complexity is proportional to the increasing number of central installed. Thus, in addition to less economical also relatively expensive to operate.

b. Star Network Topology (Star)
In a star network topology, the central one is made as a central center. When compared with the mesh system, this system has a level of complexity of the simpler network so that the system becomes more economical, but the load carried by the center's central heavy enough. Thus the possibility of damage or disruption of this central larger.

c. Bus Network Topology
In this topology all connected directly to the central transmission medium with a configuration called a bus. Transmitting signals from a central not flown in two directions simultaneously. This is very different from what happens in the mesh or star network topology, which in both systems can be performed or the interconnection between the central communication simultaneously. bus network topology is not common for the interconnection between the central, but usually used in computer network systems.

d. Network Topology Tree (Tree)
This network topology is also known as multilevel network topology. This topology is usually used for interconnection between the central with a different hierarchy. To the lower hierarchy is described in the locations of low and increasingly higher up the hierarchy have. This type of network topology suitable for computer network systems.

e. Network Topology Ring (Ring)
To form a ring network, each must be connected to a central series with each other and this relationship will form a closed loop. In this system, each central should be designed in order to interact with the adjacent central and far apart. Thus, the ability to do a central switching to different directions. The advantage of this network topology, among others: the level of network complexity is low (simple), also when there is disruption or damage to a central traffic flow can then be passed into the other direction in the system. The most widely used in computer networks is jaringanbertipe bus and a tree (tree), it is for reasons of complexity, ease of installation and maintenance, and price to be paid. But only a tree-type network (tree) are recognized reliability as loss of one cable at a client, will not affect relations with other clients.