NETWORK COMPUTER SCIENCE

Computer science network - a network computer is very necessary to be studied below are some things that might be useful for you money want to know what a computer network and how to work, if you want to see the history of computers please look in on the historical development of computers.

Communication was initially dependent on transportation: roads between cities, between provinces / states and between countries / continents. Then communication can occur remotely via telegraph (1844), telephone (1867), electromagnetic radio waves (1889), commercial radio (1906), television broadcast (1931), then through television, the world became smaller because people can learn and get information about happening in other parts of the world. In telecommunications, information conveyed through signals. Signals are of two kinds:

Kinds of kinds of signal

1. Digital: specifically refers to information that is represented by two
state 0 or 1. Digital data transmitted by the two conditions represented only 0 and 1 .....

2. Analog: continuous signal with a variation of the strength and quality. Eg sound, light and temperature can change its strength and quality. Analog data is sent in an ongoing, continuous electrical signal in the waveform television, telephone and radio is a telecommunications technology that uses an analog signal, while the computer using a digital signal to transfer information. But this time the digital signal is also used for voice, picture and combination of both.

On the other hand, the computer that was originally used as calculating machines and data processing, is used as a means of communication since the computer network. Computer network computer network is a set of computers in large numbers of separate but interconnected in carrying out their duties. Say for example, two computers connected to each other when both

exchange information. Form of connection can be via: copper wire, fiber optics, microwave, satellite communications.

In a computer network: The user must explicitly:

- Entering or log in to a machine

- Convey the task of remote

- Move the files

- Handle yourself in general throughout the network management

Computer networks become important for humans and their organizations because of a computer network having a favorable destination for them. The purpose computer network is to:

1. resource sharing / share sesumber: all programs, equipment and data that can be used by any person without any dijaringan

influenced sesumber location and user. For example: BUREAU Academic Staff sent a list of new students to the library in print form by directly printing them on a computer printer in the library of academic BUREAU. Or conversely the library staff to get immediate file a list of new students that are stored on your computer BUREAU academic staff.

2. high reliability / high reliability: availability of alternative sources whenever necessary. For example in the banking or military applications, if one machine is not working, organizational performance is not compromised because of other machines have the same source.

3. save money: build a network with small computers are cheaper than using mainframes. Data

stored in a computer that acts as a server and other computers that use the data to act as a client. This form is called Client-server.

4. scalability / scalability: improving performance by adding

server or client computer easily without disturbing the performance of

computer server or an existing client computer first.

5. medium of communication: it allows collaboration between people who are far from each other through either a computer network to exchange data and communicate.

6. broad information access: can access and obtain information from a remote

7. communication person-to-person: used to communicate from one

person to another

8. interactive entertainment

In the introduction of computer networks, discussion viewed from two aspects:

hardware and software. In recognition hardware includes the type of transmission, and other forms of computer network or topology. While the discussion will include the composition of its software protocols and data travel from one computer to another computer in a network

Hardware: Classification of Computer Network There are two classifications of computer networks that is differentiated by technology and distance transmission.

1. Transmission Technology

Broadly speaking there are two types of transmission technology:

a. broadcast network

have a single communication channel shared by

all existing machines on the network. The messages are small,

called packets and delivered by a machine then received by

other machines. Portion of the address on the package containing the information

about to whom the package is intended. When receiving sebuat package, the machine will check the address, if the package is for the engine, the engine will process the packet. If not then ignore the machine.

b. network point-to-point

consists of multiple connections of individual pairs of machines. To

go from one source to a destination, a packet on the network of this type may be through one or more intermediary machines.

Often have to go through many routes (route) which may be different

the distance. Therefore the routing algorithm plays an important role in

network point-to-point. As a general grip (although many exceptions), smaller networks and geographically localized broadcasting tends to wear, whereas larger networks usually use point-to-point.

2. Distance

The distance is important as a measure of classification because it required different techniques for different distances. The following table illustrates the relationship between distance and the processor is placed in the same place

Here are limited and are briefly described simple LAN, MAN, WAN and the Internet.

a. LAN: connecting personal computers in the office

perpusahaan, factory or campus LAN can be distinguished from type

other network based on three characteristics: size, transmission technology

and network topology

b. MAN

LAN version is a larger size and usually use the technology

The same with the LAN. MAN capable of supporting data and voice, and can even be associated with cable television networks. MAN has only

c. WAN

Covering a wide geographical area, often covering the state or

the continent. WAN consists of a collection of machines that aim to run the programs (applications) users. This machine is called HOST. HOST is connected by a communication subnet or simply called SUBNET. Subnet task was to bring a message from one host to another host. In most WAN subnet consists of two components: cable transmission and switching elements

d. Internet

There are many networks in the world, often with hardware and software that is different. People who are connected to the network often expect to be able to communicate with others connected to other networks. Desires such as these require the relationship between networks that are often incompatible and different. Sometimes using a machine called GATEWAY as a translator between incompatible networks. Collection of connected networks or internetworks called INTERNET. INTERNET A common form is a collection of LANs connected by WAN