Wide Area Network

Computer Network is a system consisting of the computer and its devices that work together to achieve a goal. The purpose of the network is the computer:

Sharing of resources, for example the use of shared CPU, Hard Drive, Memory
Communication, for example Electronic mail, instant messaging, chat
Access to Information, for example Browsing
In order to achieve the same purpose, every piece of computer network request and provide the service (service). The party requesting the service are called clients (client) that provides services and called the waiter (server). This architecture is called client-server systems, and is used in almost all computer network applications.

Types of Computer Networks

1. Local Area Network (LAN)

Commonly abbreviated Local Area Network LAN is a computer network that covers only a small area networks, such as campus computer networks, buildings, offices, in homes, schools or smaller. Currently, most LANs based on the IEEE 802.3 Ethernet technology using a switch, which has a data transfer rate of 10, 100, or 1000 Mbit / s. In addition to Ethernet technology, the current 802.11b technology (or so-called Wi-Fi) is also often used to form a LAN. Places that provide LAN connectivity with Wi-Fi technology called hotspots.

On a LAN, each node or computer has the computing power of its own, different from the concept of a terminal dump. Each computer can access resources on the LAN in accordance with the permissions that have been set. These resources can be either data or a device such as a printer. On a LAN, a user can also communicate with other users using the application.

In contrast to Wide Area Networks or Wide Area Network (WAN), the LAN has the following characteristics:

1. Having rapidly to higher data
2. Covering a narrower geographical area
3. Does not require leased telecommunication lines from telecom operators

Usually one of the computers in the computer network server that will be used to manage all the systems in the network

2. Metropolitant Area Network (MAN)

Metropolitan area network or abbreviated as MAN is a network in a city with high speed data transfer, linking various locations such as campuses, offices, government and so on. MAN network is a combination of multiple LANs. The range of this MAN among 10 to 50 km, MAN is the right network to establish a network between offices in the city between factories / establishments and headquarters are within its range.

3. Wide Area Network

WAN stands for information technology term in English: Wide Area Network is a computer network covering a large area as an example of the computer networks between regions, cities or even countries, or can be defined as well as computer networks require routers and public communications channels.

WANs are used to connect a local network to another local network, so that the user or computer in one location can communicate with users and computers in other locations.

By function: Basically any existing computer network that serves as a client and server. But there is a network that has a dedicated computer as a server and the other as a client. There is also a computer that does not have a specific function as a server only. Because it is based on function then there are two types of computer networks:

a. Client-server

That is a computer network with a dedicated computer as a server. A service / service can be provided by a computer or more. An example is a domain such www.detik.com served by many of the web server computer. Or it could be a lot of service / services provided by a single computer. Examples are jtk.polban.ac.id server which is a computer with a multi service that mail server, web server, file server, database server and others.

b. Peer-to-peer

That is a computer network in which each host 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 and also gives access to the file soal_uas.doc 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.

Based on the topology of the network: Based on [the network topology], computer networks can be distinguished:

1. Bus topology
2. Star Topology
3. Ring Topology
4. Topology Tree (Hierarchical)
5. Mesh Topology (Random)

Basic Components of Computer Network

To be able to build a network, there are some basic components that must be met, namely:

Physical Component

a. Computer Unit

Provide a minimum of 2 units of computer or multiple computers as needed, These computers later its acting as a server, and there is also a role as a workstation

b. Network Card or LAN Card (Network Interface Card)

In the visible LAN Card can easily be identified from its shape, which generally have port (jack) as terdapt on the phone, but a little bigger. This component is used onboard is already installed on some computers sold in the market today, if not mean you should add a way to plant the slot PCI / ISA section your computer mainboard ..

c. Cable Networks

wires in a network is used as a link. Although there is now a wireless network technologies (LAN) cable but still often used because it is easy to operate. There are several different types of cables are commonly used to build a network, among others:

c.1 Twisted Pair Cables

This cable consists of multiple wires wrapped around each other. The two types of cables that are included in this type of cable is Shielded Twisted Pair (STP) with a layer of aluminum foil and Unshielded Twisted Pair (UTP)

c.2 Coaxial Cable

Physical display cable consists of a copper wire core coated by an insulator and surrounded by the outer konduktur then covered with such materials as PVC outer insulator layer.

c.3 Fiber

Fiber optic cable consists of a glass fiber core and outer layers are wrapped like the cables are generally

d. Connectors

Connectors are used as a means of connecting the cable to plug LAN card that is in your computer CPU. Connector type is adjusted to the type of cable used as rj-45 paired with UTP / STP, BNC / T pairs with coaxial cable while type fiber optic ST connector is used.

e. Tang Kriping

Tang kriping Serves to clamp the cable with connectors already attached so it does not come off easily during installation. Using the pliers is adjusted by jebis cable you will use to build the network.

f. Hub

Hubs are network components that have plugs (ports). Generally hub has a port number ranging from 4, 8, 16, 24 to 32 plus 1 port (uplink) to connect to the server or to another hub. Hubs are used to unify network cables from each workstation, server or other device.

g. Bridge and Switch

Bridge used to connect separate networks and media liaison despite using models or different topologies. So similar to the bridge in our daily lives. While Switch looks like a hub, switch more clever difference being able to analyze the data that is passed to it before sending destination. In addition, he has the speed of data transfer from the server to the workstation or vice versa.

h. Router

Routers have the ability to filter or filter data passing across the network based on specific rules or protocol. Such as bridges, routers can also be used to connect multiple LAN and even WAN network model.

Non-Physical Component

In addition to the physical components that have been described previously, there are also non-physical component if we are going to learn to build a network, such as:

a. Operating Systems for Computers

There are many operating systems that you can use to build a computer network. For computer servers usually Microsoft Windows NT 4 Server, Microsoft Windows 2000 Server, Microsoft Windows 2003 Server, Novell Netware and Linux. As for the client / workstation you can use the Microsoft Windows 98, ME, 2000 Professional, XP and linux distro.

b. Network Protocols

Network protocols are the rules that are used in the network so that the computer-member computers and computer networks of different platforms can communicate with each other. TCP / IP (tranmission Control Protocol / Internet Protocol) is a protocol.

Wiring Techniques

As described in the previous chapter 3.3, there are several types of cables that can be used to build a computer network or in this case the LAN. But according to the authors by reason relatife easier procurement of cables, cheap and simple in the installation process as well as general use at this time, the choice fell on the type of cable types Unshielded Twisted Pair Twisted Pair (UTP).

UTP cable consists of 8 pieces of fine wires wrapped around each other into 4 pairs. The four pairs of cables are:

* Couples green cable with White Green lease
* Couple wiring color Orange with White lease Orange
* Blue color cable Couple lease with White Blue
* Cable Couple lease brown color with White Chocolate

Category UTP Cable

Cat 1: Used for communication devices, such as cable telephon.

Cat 2: Data transfer speeds up to 4 Megabits per second.

Cat 3: Usually used for token ring topology with data transfer speeds up to 10 Mbps.

Cat 4: Data transfer speeds reaching 16 Mbps

Cat 5: Data transfer speeds up to 100 Mbps

Cat 5e: Data transfer speeds up to 100 Mbps - 1 Gigabits.

Cat 6: The data transfer rate of up to 2.5 Gigabit Ethernet within 100 meters or 10 Gigabits within 25 Meters.

Standardization of UTP Cable

UTP Cabling Installation sequence generally follows the rules of the international standard EIA / TIA 568A and EIA / TIA 568B. To order EIA / TIA 568A wiring sequence is as follows:

Sequence to 1: White Green

Sequence 2: Green

Sequence 3: White Orange

Sequence 4: Blue

Sequence to 5: White Blue

Sequence 6: Orange

Rank 7: White Chocolate

Sequence to 8: Brown

While the order of EIA / TIA 568B cord sequence is as follows:

Sequence to 1: White Orange

Sequence 2: Orange

Sequence 3: White Green

Sequence 4: Blue

Sequence to 5: White Blue

Sequence 6: Green

Rank 7: White Chocolate

Sequence to 8: Brown

Cabling Type UTP

There are 2 types of UTP cabling connectors are RJ-45 type straight and cross type.

a. Type Straight

Straight type means that one end of the cable to the other end of the cable has the same wiring order in accordance with the standard EIA / TIA 568B. This type is used to connect the PC to the Switch, the Switch Router, Router to a PC to Hub and Hub.

b. Type of Cross

In this type of end of the cable using a standard sequence of EIA / TIA 568A and the other end of the cable it again using a sequence of TIS / EIA 568B and use to connect the PC to PC, Switch / Hub to Switch / Hub, and the PC to the router.