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 a 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. Workstation capabilities more usually under 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 Surabaya.
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 respects, the scope of its area is only just a different one from another.
2.Protocol
Protocol is the main rules governing the communication between multiple computers on a network, the rules include guidelines that apply to the ways or methods of accessing a network, physical topology, the types of cables and the speed of data transfer.
Known protocols are as follows:
a. Ethernet
Ethernet protocol is by far the most widely used, the Ethernet access method called CSMA / CD (Carrier Sense Multiple Access / Collision Detection). This is a system where each computer listens to the cable network before sending anything into it. If there is no activity in a tissue or clean the computer will transmit the data, if any other transmissions on the cable, the computer will wait and try to re-transmission if the network is clean. Sometimes, two computers can transmit at the same time, when this happens, each computer will be back and will wait for random chance to transmit data back. This method is known to the coalition, and will not effect the speed of transmission on the network. The Ethernet protocol allows for linear bus, star, or tree. Data can be transmitted over twisted pair cable, coaxial, or fiber optic cable at speeds of 10 Mbps.
b. LocalTalk
LocalTalk is sebuh network protocols being developed by Apple Computer, Inc.. for Macintosh machines. The method used by LocalTalk is CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance). Similar to the CSMA / CD .. LocalTalk adapters and special twisted pair cable can be used to connect multiple computers through a serial port. Macintosh Operating System is a network connection enables peer-to-peer without the need for additional specific applications. LocalTalk protocol allows for linear bus, star, or tree model using twisted pair cables. The most glaring deficiency is the speed of transmission. Transmission speed of only 230 Kbps.
c. Token Ring
Token protocol developed by IBM in mid-1980. The access methods through the passage of a token in a circle like a ring. In token ring, the computers are connected to each other like a ring.A token moves signal rotates in a circle (ring) in a network and moving from one computer to the next computer, if at a stopover in one of the computer there was data to be transmitted, the token will transport it to where it wanted addressed data, token moves on to connect to each other between each computer.
Token Ring protocol requires a network model Stars using twisted pair cable or fiber optic cable.And can perform the transmission speed of 4 Mbps or 16 Mbps. Along with the development of Ethernet, Token Ring usage dwindled until now.
d. FDDI
Fiber Distributed Data Interface (FDDI) is a network protocol that connects between two or more networks even at great distances. Aksesnyayang method used by FDDI is a token model. FDDI uses two physical ring topology. Baiasanya transmission process using a single ring, but if there is a problem is found it will automatically use the second ring. An advantage of FDDI is speed using fiber optic cable at speeds of 100 Mbps.
e. ATM
ATM stands for Asynchronous Transfer Mode (ATM) is a network protocol that transmits at speeds of 155 Mbps or more. Mentarnsmisikan ATM data into a single package where another transfer protocol on the big-small package. ATM supports various media such as videos, CD-audio, and pictures. ATM working on Star topology model, using fiber optic cable or twisted pair cables. ATMs are generally used to connect two or more LANs. He is also widely used by Internet Service Providers (ISPs) to increase speed Internet access for their clients.
Conclusion to the Protocol:
3. Required hardware
Hardware needed to build a computer network are: Computer, Network Card, Hub, and everything associated with network connections such as printers, CD-ROMs, scanners, Bridges, Routers and other data required for the transformation process in the network.
a. File Servers
A file server is the Network very stout heart, a very fast computer, has a huge memory, hard drives of large capacity, with fast network cards. Network operating system is stored here, also includes several applications and data needed for networking.
A file server is in charge of controlling the communication and information between the nodes / components in a network. As an example of managing the delivery of a database or word processing files from one workstation or node, to another node, or receive emails at the same time with other tasks .... seen that the task is very complex file server, he must also save the information and dividing rapidly. So that at least a file server has beberpa characters like those below:
- Processor at least 166 megahertz or faster processor (Pentium Pro, Pentium II, PowerPC).
- A fast hard drive and large capacity or approximately 10 GB
- A RAID (Redundant Array of Inexpensive Disks)
- A tape for backing up data (for example. DAT, Jaz, Zip, or CD-RW)
- Having a lot of network ports
- The network card is quick and Reliability
- Approximately 32 MB of memory
b. Workstations
Entire computer connected to the file server in the network referred to as a workstation. A workstation has a minimum; network card, network applications (network software), a cable for connecting to a network, typically a workstation that does not require a Floppy for data to be stored and can be placed on a file server. Almost all types of computers can be used as a computer workstation.
c. Network Interface Cards (NICs) or Network Card
Network Card (NIC) is a device that provides media to connect between computers, most inernal network card is a card, ie a network card installed in expansion slot inside the computer. Some computers like a MAC computer, using a special box which is plugged into the serial port or SCSI port of the computer. In the notebook computer is no slot for the network card commonly called PCMCIA slot. Many unused network cards today are: Ethernet cards, LocalTalk connectors, and Token Ring network card. It is currently popular is Ethernet, then followed by Token Ring, and LocalTalk
d. Ethernet Card / Ethernet Network Card
Ethernet network cards are usually purchased separately by the computer, except as a Macintosh computer that already include an Ethernet network card inside it. Ethernet network cards generally have to provide connections to port coaxial cable or twisted pair cable, if designed to BNC coaxial cable konenektorya is, and if designed for twisted pair cable will have a RJ-45 connectors. Some ethernet network card is sometimes also have the AUI connector. All were in connect with coaxial, twisted pair, or with a fiber optic cable.
Ethernet Network Card
From Top to Bottom:
RJ-45 connectors, connectors AUI, and BNC connectors
e. LocalTalk Connectors / LocalTalk connector
LocalTalk is a network card for macintosh computer, it uses a special adapter box and cables attached to the port for the printer. The disadvantage of LocalTalk is speed compared to Ethernet data transfer rate, bi Ethernet computer networks are nothing new today. Almost in every company there is a computer network for facilitating information flow within these perudahaan. Internet is gaining in popularity today is a giant computer network is a network of connected computer networks and can interact with each other. This can happen because of the development of network technology very rapidly, so that within a few years the number of computer network users who are members of the Internet doubled. can melt away up to 10 Mbps, while the LocalTalk can only operate at a speed of 230 Kbps or equal to 0:23 MPS.
f. Token Ring Cards
Token Ring network card looks similar to an Ethernet network card. One difference is the type of connectors on the back of the card network, Token Ring type generally has a 9 pin DIN connector that connects to the cable network card Network.
g. Hub / Concentrator
A Concentrator / Hub is a device that unites the network cables from each workstation, server or other device. In a Star topology, twisted pair cable coming from a workstation into the hub. Hub has a lot of slots concentrator which can be installed by the port number of the destination card.
Traits possessed Concentrator are:
- Usually consists of 8, 12, or 24 port RJ-45
- Used in topology Star / Star
- Usually sold with special applications ie applications that set the Management port.
- Commonly called hub
- Usually in pairs on a special shelf, which also contains no Bridges, routers
h. Repeaters
The easiest example is on a LAN using star topology using unshielded twisted pair cable.Where known maximum length for a twisted pair cable unshileded is 100 meters, then to strengthen the signal from the cable dipasanglah a repeater on the network.
i. Bridges / Bridge
Is a device which divides one network into two networks, is used to obtain an efficient network, which is sometimes very rapid network growth hence the need to bridge it. Most Bridges can know the address of each segment of each computer on the network side and also on other networks beside it as well.
Likened to that Bridges was like a traffic cop at the crossroads of governing during rush hour. He arranged for information between the two sides of the road network remains well and regularly.Bridges also can be used to connect between the cable network that uses a different type or different topologies.
j. Routers
A Router interpret informaari from one network to another network, he is almost the same as Bridge but rather clever bit, the router will find the best path to send a message Based on the destination address and source address.
While Bridges can know the address of each computer on each side of the network, routers know the addresses komputerr, bridges and other routers. router can know the whole network to see which side of the most busy and he can pull data from a busy side until that side of net.
If a company has a LAN and want to connect to the Internet, they must purchase a router. This means that a router can translate the information between your LAN and the Internet. This also means finding the best alternative route for sending data through the Internet.
This means that Router:
- Set the signal path efficiently
- Set the message protocol between the two
- Set the Message of the linear network topology Bus and Star (star)
- Set the message passing between Fiber optic cables, cable or twisted pair koaksialm
REFERENCES
- http://www.ai3.itb.ac.id/Tutorial/LAN.html
- http://www.w3.org/TR/REC-html40
- http://sunsite.ui.ac.id/student/ristek/sig/infosys/artikel/artikel3/protokol1.htm
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