What is Computer Network? Why?
If any computer is not connected to others it is called
"a stand-alone machine". Today
if anyone uses any stand-alone machine , he must be considered a stranger
because the world today is of computer networks. A network machine can
send/receive packets (bits of data per second) to/from any other machines e.g.
Internet. Our computers/tablet PCs/smart
phones can never be alone anymore. Yes, they have been connected to their
networks both local (e.g. the networks in our school) and global (e.g.
Internet). We can share our resources such as
files, printers etc. to each other through our local area network (LAN)
or we can exchange our data through the wide area network (WAN) like Internet.
Computer Network classified by Area Width
Types of Network Topology
Star/Extended Star Topology
The Server-Client Network What/How
What/How of the Network in Computer Classroom?
Because the operating software (OS) of all computers in
classroom is Windows7, so any who use them, those machines, should better
understand how they work, especially how to use the network of them.
Our computers in computer classroom are connected together
with the UTP (unshielded twisted pair) cables. Why? Because the unshielded
cables are lower cost than the shielded cables which have been used in the
signal noisy areas e.g. airports,
factories, etc. The style of their connection is "Star Topology"
which each machine has its own cable which connects directly to the
hub/switch. A hub/switch is the center
point of cables (both devices are similar to each other but a switch is more
clever than a hub) . Well our network is called Local Area Network (LAN). Any
LAN must has its workgroup name which required by the Operating System (OS) of
each computer, Windows7 .
If we consider only the "computer-workgroup LAN",
it is a peer-to-peer network that every machine is independent from each other
but shares its files/folders/printers to its peers. On the other hand, when
this workgroup connects to the server computer of "the School Media
Center", it must be a client-server network.
What is about the client-server network? It means that the
server computer of "the Media Center" is the manager/boss of other
computers which are only the clients. The server computer has been installed
with the operating-software-for-server such as Windows2003server/Windows2008server
, Linux or Unix, which can manage the
client computers of the network. The clients have to obey the server because
the latter has the power to control/ban the former. Yes, the clients can never
control/manage the server.
Every machine in the network is required to have its unique
"hostname" and "IP address". Only the server computer has the "static
IP-address" while the IP addresses of the client computers are
"dynamic" specified/controlled by the sever. If the user of any
client computer specify the static IP address himself, the server computer can
never share the Internet connection because the "IP address
conflict"problem could be occurred easily. Then the alien client will be
kicked off /faded away from the network simultaneously. Yes, the server computer
is the "Internet gateway" of the network.
OK., after selecting the "Local Area Network"
option, the "Local Area Network Connection Status" window appears.
You can see its speed of packets transmission (100 Mbps) , bytes of the
sent/received packets.
Then, when you click on the "Properties" button,
another window shows. To find and select the "Internet Protocol Version)
option, you can see its IPaddress has been obtained automatically by the
gateway/server computer (of the School Media Center).
By : Tanunya Sophon m.2/8 no.35
