Tuesday, July 7, 2009

introduction of LAN network


Pengertian dan Prinsip Kerja LAN
================================


LAN network can be defined as a number of system or network
limited computer located in one building, one kompleksgedung
or a campus and not using the public media of communication facilities
such as a phone, but media owners and managers komunikasinya
LAN is the owner itself.
From above definition we can know that a LAN is limited by
physical location. The use of LAN itself mengakibatkansemua
computer that is connected in a network can exchange data or with
other related words. Cooperation is growing from only
exchange of data to use the equipment together.
Generally use the LAN hub, will follow the principles of the hub
alone. In this case is that the hub does not have the knowledge
destination address so that the broadcast data delivery, and also because
hub has only one collision domain, so when one of the port
the busy port-port the other must wait.



Components LAN Dasar
===========================

Some of the basic components that are usually formed as a LAN is
following:




• Workstation
------------
Workstation is a node or host in the form of a computer system.
This computer system can be either a PC or can also be a computer
such as a large minicomputer systems, and even a Mainframe.
Can work alone workstation (stand-alone) can also use
network to exchange data with the user workstation or the other.

• Server
-------
Hardware (hardware) which works to serve the network and
workstation that is connected to the network generally tersebut.pada source
resources (resources) such as a printer, disk, and so the aim
used together by the user at the workstation and is
work on the server. Based on the type of services the server disk is known,
file server, print server, and a server can also have some
service functions at once.

• Link (link)
----------------
Workstations and servers may not work if the equipment
not physically connected. Relationships in the LAN is known as
transmission media that included cable. The few examples of
link is:
1.Kabel Twisted Pair
• Cable is two, namely Shielded and Unshielded Twisted Pair Twisted
Pair (UTP)
• More is known because it is a telephone cable
• Relatively inexpensive
• a short distance
• Easy to be affected by interference
• The speed of data that can be supported is limited, 10-16 Mbps

2.Kabel coaxial
• Generally used on television
• The distance that is relatively more
• The speed of data in the higher appeal Twisted Pair, 30 Mbps
• The price is relatively inexpensive
• larger size of Twisted Pair

3.Kabel Fiber Optic
• a far distance
• a high-speed data, 100 Mbps
• the relatively small size
• Difficult to influence interference
• Price is still relatively expensive
• Installation is relatively difficult


• Network Interface Card (NIC)
-----------------------------
A workstation is not connected directly with the cable network
tranceiver or cable, but through a series of electronics that
is specifically designed to handle network protocol known as
Network Interface Card (NIC).

• Network Software
-----------------
Without a network the network software will not work
as desired. This software also allows the system
one computer to communicate with another computer system.

Supporting LAN equipment
=======================

a.Repeater
------------
• On the OSI, to work on the Physical layer
• Forwarding and strengthen the signal
• Many used the topology Bus
• easy to use and relatively cheap price
• Does not have knowledge of the destination address so that delivery
data broadcast
• Only have one collision domain, so when one of the busy port
port-port then the other must wait.

b.Hub
-----
• Working on the Physical layer
• Forward signal
• Does not have knowledge of the destination address
• relatively easy to use and affordable price
• Only have one collision domain

c.Bridge
--------
• Working in the Data Link layer
• Past use addresses to forward the data to the destination
• Automatically create a table for the interpreter received masing2 port

d.Switch
--------
• Working in the Data Link layer
• Each port swith inside the collision domain has its own
• Have a table that has a center of an interpreter for the list
all port
• Allows transmission duflex the full (two-way)

e.Router
--------
• Router or filtering function to filter data traffic
• Define and select the alternative routes that will be passed by data
• Connecting the network between LAN, WAN and even the

LAN topology
=============

The Network topology is the order of the track the flow of data within the
physical network that connects one with a noose knot
another. Here are some of the existing network topology and
used to this, namely:
• Star topology
Some of the knot / node connected with a central / host, which forms
physical network, such as stars, all in direct communication and
managed by the host in the form of Mainframe computers.


[Pc1]
|
[PC2 ]-------[ Server ]---------[ PC3]
/ \
/ \
[PC4] [PC5]




• topology Hierarkis
Shaped like a tree branch off the parent consists of a computer (host)
associated with the knot / node in another step. Levels of more
function as the high-level working underneath.

[Server]
/ \
[server / PC] [server / PC]
/ \ / \
/ \ / \
[Pc1] [PC2] [PC3] [PC4]



• Bus topology
Some of the knot / node associated with the data path (bus). Masing2 node
can perform the tasks and operations yangberbeda but all have
the same hierarchy.



[Pc1] [PC2] [PC3] [PC4]
| | | |
================================ = backbone
| | | |
[Pc1] [PC2] [PC3] [PC4]


• Loop topology
Is the relationship between knot / node is in the form of a serial
the circle is closed. In this form there is no central node / host, all
have the same hierarchy.


[Pc1]
[PC2] | [PC3]
\ | /
(_) <== Loop
/ \
[PC4] [PC5]



• Ring topology
This form is a combination of topology and loop bus, if any
one knot / node is broken, it will not affect the communication node
the other as separate from the data path.



[PC1a]
[PC1b ]__|__[ PC1c] < |
[PC2] | [PC3] <\ | /
(_) <== Loop
/ \
[PC4] [PC5]



• Web topology
Is a form of topology that each knot / node in the network
can be interconnected with other nodes through multiple links.
The form of a web network with n nodes, akan use of link
n (n-1) / 2.


[Pc1]
/ / \ \
[PC2 ]=-+---+=[ PC3]
| / \ |
[PC4 ]=-------=[ PC5]




By using all the advantages and disadvantages masing2 configuration,
allows the development of a new configuration that combines
topology, along with some new technology so that an ideal condition
network system can be met.