Computer Networking Experiments MU

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Experiment No.1
Aim : Study of RJ45 and Cat 6 cabling using crimping tool
Apparatus : RJ45 Socket, Cat 6 Cable, Crimping Tool.
Theory : CAT 6 Cable:
#Category 6 cable (Cat 6), is a standardized twisted pair cable for Ethernet and other
network physical layers that is backward compatible with the Category 5/5e and Category 3
cable standards.
$Cat 6 must meet more stringent specifications for crosstalk and system noise than Cat 5 and
Cat 5e. The cable standard specifies performance of up to 250 MHz, compared to 100 MHz for
Cat 5 and Cat 5e.
#Whereas Category 6 cable has a reduced maximum length of 55 metres (180 ft) when used
for 10GBASE-T, Category 6A cable is characterized to 500 MHz and has improved alien
crosstalk characteristics, allowing 10GBASE-T to be run for the same 100-metre (330 ft)
maximum distance as previous Ethernet variants.
#Cat 6 cable can be identified by the printing on the side of the cable sheath.[3]
Cable types,
connector types and cabling topologies are defined by ANSI/TIA-568.
#Cat 6 patch cables are normally terminated in 8P8C modular connectors, using either T568A or
T568B pin assignments; performance is comparable provided both ends of a cable are
terminated identically.
$If Cat 6-rated patch cables, jacks and connectors are not used with Cat 6 wiring, overall
performance is degraded and may not meet Cat 6 performance specifications.[4]
CAT 6 Cables can be either Straight-Through Cables or Crossed Cables. The following
diagram shows the Normal use of Crossed and Straight cables.
Straight Cable: Straight wiring method is used to connect PCs or other equipment to a HUB or
Switch. The following shows the colour-coded placement of wires in Straight Wiring.
Crossed Cable: Crossed cables are used to connect PCs to one other PC or to connect a HUB
to a HUB. Crossed cables are sometimes called Crossover, Patch or Jumper cables. Colour
coding in crossed wiring is show below.

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RJ-45 Connectors:
RJ45 is a standard type of connector for network cables. RJ45
connectors are most commonly seen with Ethernet cables and
networks. RJ45 connectors feature eight pins to which the wire
strands of a cable interface electrically. Standard RJ-45 pinouts
define the arrangement of the individual wires needed when
attaching connectors to a cable. Although used for a variety of
purposes, the RJ-45 connector is probably most commonly used
for 10Base-T and 100Base-TX Ethernet connections. Note that it is very important that a single
pair be used for pins 3 and 6. If one conductor from one pair is used for pin 3 and a conductor
from another pair is used for pin 6, performance will degrade.

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Crimping:
Crimping is a method of ensuring that the wires stay secure in the RJ 45 socket after making a
working ethernet cable. The cables can be made by referring to the straight wired or cross wired
charts, as needed.
Procedure:
i. Strip off about 2 inches of the ethernet cable sheath.
ii. Untwist the pairs - don't untwist them beyond what you have
exposed, the more untwisted cable you have the worse the
problems you can run into.
iii. Align the colored wires according to the wiring diagrams above.
iv. Trim all the wires to the same length, about 1/2" to 3/4" left exposed
from the sheath.
v. Insert the wires into the RJ45 plug - make sure each wire is fully
inserted to the front of the RJ45 plug and in the correct order. The
sheath of the ethernet cable should extend into the plug by about 1/2"
and will be held in place by the crimp.
vi. Crimp the RJ45 plug with the crimper tool. vii. Verify the wires ended
up the right order and that the wires extend to the front of the RJ45 plug
and make good contact with the metal contacts in the RJ45 plug
viii. Cut the ethernet cable to length - make sure it is more than long enough
for your needs.
ix. Repeat the above steps for the second RJ45 plug.
Conclusion : Thus we have studied Networking Tools and Crimping of network cable in
Straight-through & Crossover modes.

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Experiment No.2
Aim: Study and Insrtallation of Cisco Packet Tracer
Theory:
1)Study of cisco packet tracer :
Packet Tracer is a cross-platform visual simulation tool designed
by Cisco Systems that allows users to create network topologies and
imitate modern computer networks. The software allows users to
simulate the configuration of Cisco routers and switches using a
simulated command line interface. Packet Tracer makes use of a drag
and drop user interface, allowing users to add and remove simulated
network devices as they see fit. The software is mainly focused towards
Certified Cisco Network Associate Academy students as an educational
tool for helping them learn fundamental CCNA concepts. Previously
students enrolled in a CCNA Academy program could freely download
and use the tool free of charge for educational use.
Packet Tracer allows students to design complex and large networks,
which is often not feasible with physical hardware, due to costs. Packet
Tracer is commonly used by CCNA Academy students, since it is
available to them for free. However, due to functional limitations, it is
intended by CISCO to be used only as a learning aid, not a replacement
for Cisco routers and switches. The application itself only has a small
number of features found within the actual hardware running a
current Cisco IOS version. Thus, Packet Tracer is unsuitable for
modelling production networks. It has a limited command set, meaning
it is not possible to practice all of the IOS commands that might be
required. Packet Tracer can be useful for
understanding abstract networking concepts, such as the Enhanced
Interior Gateway Routing Protocol by animating these elements in
a visual form. Packet Tracer is also useful in education by providing
additional components, including an authoring system, network protocol
simulation and improving knowledge an assessment system.
It is a drag and drop system where we need to select or device and
place wherever on the screen. For wire connections, select ports from
the devices accordingly and connect the wires by pulling it towards
the other device.
The devices range from networks devices like routers, hubs and
switches to end devices like pc, television and laptops. The
connections are done by wires like copper straight through and
copper cross over wires etc. Components like mcu boards can also
be used.

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2) Instalation of Cisco Packet Tracer
STEP 1 –
After Cisco Packet Tracer download, click on the downloaded exe file. Once below
Window will appear, click the “Next” option –

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STEP 2 –
On the next screen, select “I accept the agreement” and click on “Next”.
STEP 3 –
Setup will show the folder in which the program’s shortcuts
will be created. If you want to change the folder, you can
change it. Click on “Next”.

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STEP 4 –
Then the program will ask whether to create a Desktop icon and create a Quick
Launch icon. Make your choice and click on “Next”.
STEP 5 –
The summary of the settings we selected is displayed. Click on “Install”.

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STEP 6 –
The cisco packet tracer installation starts as shown below.
STEP 7 –
Cisco packet tracer Installation gets completed and the below screen is shown. Click
on “Finish”.
Click “OK” on next pop up asking you to close or restart your computer.
STEP 8 –
Packet Tracer is installed and ready to be used.

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Note – new updates, features and bug resolved versions of packet tracer is
introduced on regular time intervals.
Conclusion: From this experiment, we learn about the network simulator cisco packet
tracer, how it is used and Installed in our devices.

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Assignment No.1
Explain Network Devices?
There are many network devices explaining a few below:
1)Repeaters: Repeaters are network devices operating at physical layer of the OSI
model that amplify or regenerate an incoming signal before retransmitting it. They
are incorporated in networks to expand its coverage area. They are also known as
signal boosters.
When an electrical signal is transmitted via a channel, it gets attenuated depending
upon the nature of the channel or the technology. This poses a limitation upon the
length of the LAN or coverage area of cellular networks. This problem is alleviated by
installing repeaters at certain intervals.
Repeaters amplifies the attenuated signal and then retransmits it. Digital repeaters
can even reconstruct signals distorted by transmission loss.So, repeaters are
popularly incorporated to connect between two LANs thus forming a large single LAN.
Types of Repeaters
According to the types of signals that they regenerate, repeaters can be classified into
two categories −
• Analog Repeaters − They can only amplify the analog signal.
• Digital Repeaters − They can reconstruct a distorted signal.
According to the types of networks that they connect, repeaters can be categorized
into two types −
• Wired Repeaters − They are used in wired LANs.
• Wireless Repeaters − They are used in wireless LANs and cellular networks.
According to the domain of LANs they connect, repeaters can be divided into two
categories −
• Local Repeaters − They connect LAN segments separated by small
distance.
• Remote Repeaters − They connect LANs that are far from each other.

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Repeater
2)Hub: A hub is a physical layer networking device which is used to connect multiple
devices in a network. They are generally used to connect computers in a LAN.
Hub

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A hub has many ports in it. A computer which intends to be connected to the network
is plugged in to one of these ports. When a data frame arrives at a port, it is broadcast
to every other port, without considering whether it is destined for a particular
destination or not.
Simulation of hub in cisco packet tracer
3)Routers: Routers are networking devices operating at layer 3 or a network layer of
the OSI model. They are responsible for receiving, analysing, and forwarding data
packets among the connected computer networks. When a data packet arrives, the
router inspects the destination address, consults its routing tables to decide the
optimal route and then transfers the packet along this route.
Features of Routers
• A router is a layer 3 or network layer device.
• It connects different networks together and sends data packets from one
network to another.
• A router can be used both in LANs (Local Area Networks) and WANs (Wide
Area Networks).
• It transfers data in the form of IP packets. In order to transmit data, it uses IP
address mentioned in the destination field of the IP packet.
• Routers have a routing table in it that is refreshed periodically according to the
changes in the network. In order to transmit data packets, it consults the table
and uses a routing protocol.

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• In order to prepare or refresh the routing table, routers share information among
each other.
• Routers provide protection against broadcast storms.
• Routers are more expensive than other networking devices like hubs,bridges
and switches.
• Routers are manufactured by some popular companies like −
o Cisco
o D-Link
o HP
o 3Com
o Juniper
o Nortel
Types of Routers
A variety of routers are available depending upon their usages. The main types of
routers are −
• Wireless Router − They provide WiFi connection WiFi devices like laptops,
smartphones etc. They can also provide standard Ethernet routing. For indoor
connections, the range is 150 feet while its 300 feet for outdoor connections.
• Broadband Routers − They are used to connect to the Internet through
telephone and to use voice over Internet Protocol (VoIP) technology for
providing high-speed Internet access. They are configured and provided by the
Internet Service Provider (ISP).
• Core Routers − They can route data packets within a given network, but cannot
route the packets between the networks. They helps to link all devices within a
network thus forming the backbone of network. It is used by ISP and
communication interfaces.
• Edge Routers − They are low-capacity routers placed at the periphery of the
networks. They connect the internal network to the external networks, and are
suitable for transferring data packets across networks. They use Border
Gateway Protocol (BGP) for connectivity. There are two types of edge routers,
subscriber edge routers and label edge routers.
• Brouters − Brouters are specialised routers that can provide the functionalities
of bridges as well. Like a bridge, brouters help to transfer data between
networks. And like a router, they route the data within the devices of a network.

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Router
4)Switches: Switches are networking devices operating at layer 2 or a data link layer
of the OSI model. They connect devices in a network and use packet switching to
send, receive or forward data packets or data frames over the network.
A switch has many ports, to which computers are plugged in. When a data frame
arrives at any port of a network switch, it examines the destination address, performs
necessary checks and sends the frame to the corresponding device(s).It supports
unicast, multicast as well as broadcast communications.
Features of Switches
• A switch operates in the layer 2, i.e. data link layer of the OSI model.
• It is an intelligent network device that can be conceived as a multiport network
bridge.
• It uses MAC addresses (addresses of medium access control sublayer) to send
data packets to selected destination ports.
• It uses packet switching technique to receive and forward data packets from
the source to the destination device.
• It is supports unicast (one-to-one), multicast (one-to-many) and broadcast (one-
to-all) communications.
• The number of ports is higher – 24/48.
Types of Switches
There are variety of switches that can be broadly categorised into 4 types −

15. 1)Unmanaged Switch − These are inexpensive switches commonly used in home
networks and small businesses. They can be set up by simply plugging in to the
network, after which they instantly start operating.
2) Managed Switch − These are costly switches that are used in organisations with
large and complex networks, since they can be customized to augment the
functionalities of a standard switch.
3) LAN Switch − Local Area Network (LAN) switches connects devices in the internal
LAN of an organization. They are also referred as Ethernet switches or data switches.
These switches are particularly helpful in reducing network congestion or bottlenecks.
4) PoE Switch − Power over Ethernet (PoE) switches are used in PoE Gogabit
Ethernets. PoE technology combine data and power transmission over the same cable
so that devices connected to it can receive both electricity as well as data over the
same line.
Switch
Simulation of switch and router