Transcript Networks - ZSIS-ITGS

Networks
Network Hardware
For any network to function successfully, you
need specialized computer Hardware.
However, without the right knowledge, you
will not be able to choose the right equipment
and you can end up with a faulty network.
This PPT hopes to outline some of the
Hardware necessary for a fully functioning
and successful network.
Network Hardware
The five pieces of equipment to be covered in this
PPT are:
•Network Hub
•Network Switch
•Network Attached Storage (NAS)
•Server
•Cables
Network Hub
A network hub, also known as an ethernet
hub, is probably the most unsophisticated
piece of Hardware in computer
networking. This is because all it does is
receive data packets from every single
port and broadcast them out through
every single port without taking into
account the source or destination.
This results in many problems, in
particular, packet collisions.
However, many people still use
hubs because they are cheap.
Network Switch
A network switch is a Hardware device
that sends traffic from one part of a
network to different parts of the network.
While it may appear to be similar to a hub,
they are generally more intelligent and
more expensive. The reason why they are
more intelligent is because they have the
capacity to analyze the source and the
destination of the data packets that they
receive and this way they are able to
forward it to the correct destination.
Finally, a network router is a very
sophisticated piece of network Hardware
which can determine the next point to
forward any data packet it receives so that
it reaches its destination.
Network Attached Storage
NAS is simply a device such as a computer whose job is to
provide file-based storage services to other connected
devices within the network. A NAS device is used to aid or
replace the function of a file server which normally performs
other services such as carrying out database assistance. The
NAS device generally does not have other peripherals to be
attached to it. Even though it is a computer there is no need
for a mouse, keyboard or display system.
NAS
The use of Network Attached Storage increases the performance
of other devices such as file servers and a print server as it shares
resources to balance out these servers workload. However, the
performance impact of NAS devices will depend on the general
performance and traffic on the network it is located on.
Another great benefit by having a NAS device is that it enables the
centralization of data within the network which encourages
resource sharing in the network. This also means that storage
memory is saved as no files are duplicated. However, if accessed
by many users, just like other devices, its performance will be
reduced. Multiple NAS devices may be needed to handle the
amount of users that access it.
Servers
In simple English, Servers refer to combinations of
hardware and software with the objective of providing
services to clients. In the context of computer networking,
this refers to clients within networks. Nowadays, we are all
part of some computer network whether we realize it or not,
and it is Servers that make the network efficient and useful.
While there are many different types of Servers available
such as print, exchange and web servers, they all must
possess special characteristics which separate them from
other computer devices given that they are providing
services to users on a network.
Servers
One of the necessary characteristics of any server is a fast network
connection and high Input/Output throughput. If a network is to serve
its users with an outstanding service, it must do so in a fast manner
and be able to process a lot of data with ease. This is probably the
single most important feature that all Servers must have.
Another essential feature of a server is its availability and reliability.
Given that most networks work for 20+ hours per day and process
important (and sometimes confidential) data, Servers must be able to
stand long periods and not be very prone to failure. In order to achieve
a great level of reliability, Servers will use large computer fans or water
cooling as well as power supplies which cannot be interrupted. An
important industry where Servers are commonly used and relied upon
is the web hosting industry which is becoming bigger and more
important every year.
Cables
Twisted Pair
Twisted pair is the most used of all Network Cables. Its implementation
with the Ethernet cable has allowed physical connections between
network devices to be fast at an affordable price. The cable consists of
eight smaller cables which are paired up. Each pair is then twisted
around the other in order to cancel out electromagnetic interference.
Technologies has allowed for wireless networks to be made but having
a physical connection remains the most secure. Without Network
Cables networks would not have been possible in the beginning.
Cables
Optical Fiber (Fiber Optics)
Optical fiber cables are somewhat a new technology. It has been
around for several years but due to its expensive nature it’s not widely
used as much as other cables. The cable is made up of three distinct
components including a plastic jacket, cladding and the core. Data is
transmitted in the form of light that bounces whilst traveling in the core.
Optic fiber uses the principle of total internal reflection to create a
bouncing effect similar to shinning a LASER in a room full of mirrors.
Several advantages include faster data transmission, thinner than
other cables and no electromagnetic inference can occur.
Security
Security plays an important and necessary role in many parts of our lives.
In the computing world it is used to protect data. Whether you like it or
not, you are currently a stakeholder in various computer networks around
you. You may not know which ones or how, but the fact that you are,
means that you should be concerned about the Security of your personal
details as well as how it is being protected.
A good example would be banking. There are probably no banks in
existence that keep their customer’s data on paper anymore. This used to
happen in the past but it has all since then been transferred to an
electronic storage device. Such devices are all part of computer networks
in many banks which can only be accessed by authorized personnel.
However, network security become an issue as there are many who
attempt to break the codes and access such confidential data.
Security
Some common forms of Security on networks include password
protection or pin number access, firewalls and data encryption. While
the effectiveness of Security measures available has been increasing,
the number of hackers has also been increasing. This effectively means
that in order to remain secure in the computing world, you have to keep
up to date with new Security technologies and how it can benefit you.
Computer Security is certainly not something to take for granted,
especially when you analyze the potential cost of not actively protecting
your data from external attacks.
Quiz
1. Identify the 5 hardware devices covered in this
PPT
2. Define a NAS.
3. Identify the most efficient network cables.
4. Describe the most common network cables.
5. Compare the difference between these 2 cables.
6. Distinguish between a hub and a switch.
7. Explain two important features of a Server.
Research Network Security and answer the question for homework
1. Evaluate the various forms of network security
mentioned above.