EXPERIMENT NO.

1
AIM: A. To Study RJ45 and CAT6 Cabling and connection using crimping tools.
B. To study various Network hardware & Network software

THEORY: 1. A).Crimping an RJ45 Connector Correctly

Proper Wiring for Ethernet Cat5/Cat5e/Cat6
Cables

Cables can transmit information along their length. To actually get that information where it needs to
go, you need to make the right connections to an RJ45 connector.

Your cable run needs to terminate into a connector, and that connector needs a jack to plug into.

Registered Jack 45 (RJ45) is a standard type of physical connector for network cables. RJ45 connectors
are commonly seen with Ethernet cables and networks.

Modern Ethernet cables feature a small plastic plug on each end of the cable. That plug is inserted into
RJ45 jacks of Ethernet devices. The term “plug” refers to the cable or “male” end of the connection
while the term “jack” refers to the port or “female” end.

T568A or T568B Wiring Standard:

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T568A and T568B are the two color codes used for wiring eight-position modular plugs. Both are
allowed under the ANSI/TIA/EIA wiring standards. The only difference between the two color codes is
that the orange and green pairs are interchanged.

There are no transmission differences between T568A and T568B cabling schemes. North
America’s preference is for T568B. Both ends must use the same standard. It makes no difference
to the transmission characteristics of data.

T568B wiring pattern is recognized as the preferred wiring pattern.

STEP 1:

Using a Crimping Tool, trim the end of the cable

you're terminating, to ensure that the ends of the
conducting wires are even.

STEP 2:

Being careful not to damage the inner conducting wires, strip off approximately 1 inch of
the cable's jacket, using a modular crimping tool or a UTP cable stripper.

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STEP 3:

Separate the 4 twisted wire pairs from each other, and

then unwind each pair, so that you end up with 8
individual wires. Flatten the wires out as much as
possible, since they'll need to be very straight for
proper insertion into the connector.

STEP 4:

Holding the cable with the wire ends facing away from you. Moving from left
to right, arrange the wires in a flat, side-by-side ribbon formation, placing them
in the following order: white/orange, solid orange, white/green, solid blue,
white/blue, solid green, white/brown, solid brown.

STEP 5:

Holding the RJ45 connector so that its pins are facing

away from you and the plug-clip side is facing down,
carefully insert the flattened, arranged wires into the
connector, pushing through until the wire ends emerge
from the pins. For strength of connection, also push as
much of the cable jacket as possible into the connector.

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STEP 6:

Check to make sure that the wire ends coming out of the
connector's pin side are in the correct order; if not, remove
them from the connector, rearrange into proper formation,
and re-insert. Remember, once the connector is crimped
onto the cable, it's permanent. If you realize that a mistake
has been made in wire order after termination, you'll have
to cut the connector off and start all over again!

STEP 7:

Insert the prepared connector/cable assembly into the

RJ45 slot in your crimping tool. Firmly squeeze the
crimper's handles together until you can't go any
further. Release the handles and repeat this step to
ensure a proper crimp.

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STEP 8:

If your crimper doesn't automatically trim the wire ends upon

termination, carefully cut wire ends to make them as flush with
the connector's surface as possible. The closer the wire ends are
trimmed, the better your final plug-in connection will be.

STEP 9:

After the first termination is complete, repeat process on the opposite

end of your cable

CONCLUSION: Thus, we have studied the use of a crimping tool for RJ-45.

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1. B) . To study various Network hardware & Network software.

· Switches

· Routers

· Hubs

· Gateways, Access Points, NICs, Bridges, Modems, Firewalls, and Cables (Classifications).

· Network Protocols (IP, TCP, UDP, HTTP, FTP, ARP, ICMP, IGMP)

Software/OS used: Ubuntu 12.04

Theory:

What is a Computer Network?

Computer network means an interconnected collection of autonomous computers. Two computers are said to
be connected if they are able to exchange information. The connection needs not to be via a copper wire,
fiber optics, microwaves and communication satellites can also be used. By requiring the computer to be
autonomous, we wish to include from our definition system in which there is a clear master/slave relation. If
one computer can forcibly start, stop or control another one, the computers are not autonomous. A system
with one control unit and many slaves is not a network, nor is a large computer with remote printers.

Advantages of Computer network:

●​ Resource Sharing
●​ High Reliability
●​ Saving Money

SERVER

Concept of a server is based on one or more personal computers to perform specific tasks for a number of
other PCs. The most common function is disk, file and print servers. A Disk Server provides low-level
support and performs basic read/write operation to disk sectors. A File Server is a higher-level support
mechanism, performing such functions as lockout and dynamic allocation of space on disk. In a star layout
the server is the principal connection point. All nodes, including the server, are connected to a hub. This
enables the server to house and administer software, file sharing, file saving and to allocate printers or other
peripherals. In a bus layout, the server acts like an arbitrator, each node talks to the server when requesting
information. The server then locates the information on one of the connected clients and sends it to the
requesting client. Servers in any network can be an ordinary node but having more capabilities of handling
the data and having more speed.

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WORKSTATION

A node or stand-alone PC that is connected to a network is called a Workstation. A workstation is generally a

Client. NIC (Network Interface Card): The network Interface Card (NIC) is the interface between the PC
and physical network connection. In Ethernet systems, the NIC connects to a segment of coaxial or UTP
cable (fiber NICs are available but not very common yet). As with any other type of adapter card NICs come
in ISA, PCMCIA, and PCI bus varieties. The NIC is responsible for the operation that takes place in the
physical layer of the OSI model. It is only concerned with sending and receiving) 0s and 1s, using the IEEE
802.3 Ethernet standard. In windows, the NIC card is identified in the network property; to use protocol with
NIC you must bind the protocol to the adapter card. This is typically done automatically when the protocol is
added. All the NICs are manufactured with a unique 4-bit Mac address using the WINIPCFG utility (from
the run menu). IT is also called a Network Adapter Card.

Function of NIC:

Ø Data Transfer

Ø Data Buffering

Ø Frame Construction

Ø Media Access Control

Ø Parallel/Serial Conversion

Ø Data Encoding/Decoding

Ø Data Transmission/Reception

CABLES

To transmit the data the medium must exist, usually in the form of cables or wireless media. Here are some
most commonly used cable types.

1. Thick Coaxial Cables (thick net) (RG-11)

Thick coaxial cables or thick wire is known as the Ethernet standard RG-11. This cable is mostly used as
backbone cable, distributing Ethernet signal throughout a building, an office complex or other large
installation. It is used in the 10base5 Ethernet standard. RG-11 is thicker and more studious than RG-58
coax. The length may be up to 500 meters with a max of five segments connected by repeaters. This gives a
total distance of 2500 meters. This is called a network diameter. RG-11 cable is typically orange; with black
rings around the cable every 2.5-meter to allow taps into the cable.

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2. Thin coaxial cables (thin net) (RG-58)

RG-58 is typically used for wiring laboratories and offices, or another small group of computers. The
maximum length of thin wire Ethernet segment is 185 meters, Which is due to the nature of the CSMA/CD
method of operation, the cable attenuation, and the speed at which signals propagate inside the coax. The
length is limited to guarantee that collision is detected when machines that are apart transmit at the same
time. BNC connectors are used to terminate each end of the cable. When many machines are connected to
the same Ethernet segment, a daisy chain approach is used. The BNC connectors allow the network interface
card to the next machine. The machine at each end of the cable must use a terminating resistor to eliminate
collision-causing reflection in the cable.

3. Twisted pair cables

Twisted pair is probably the most widely used cabling system in Ethernet in networks. Two copper wires
twist around each other to form the twisted pair cable. Depending on category several insulated wire strands
can reside in the cable. Twisted pair is available in two basic types Unshielded Twisted Pair (UTP)
Shielded Twisted Pair (STP)

Unshielded Twisted Pair Mostly the UTP is used. A twisted pair segment can’t exceed 100 meters. This
limitation is the only drawback to twisted pairs. Twisted pair is used for 10/100 based Ethernet networks.
UTP cables are wired as straight through or crossover cables. Straight through cables typically connect the
computer’s network interface can’t to a port on the hub. Crossover cables are used for NIC communication
and for hub-to-hub connections when no crossover port is available.

Category-5 cables can be purchased or crimped as either straight through or crossed. A category-5 cable has
8 thin. Colors coded wires inside that run from one end of the cable to the other. Ethernet networks for
communication use only wires 1, 2, 3 and to be connected in both jacks. Straight through cables are used for

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connecting to a hub. Crossed cables are used for connecting a hub to another hub (there is an exception:
some hubs are a built in uplink port that is crossed internally, which allows you to uplink hubs with a straight
cable instead.)

Shielded Twisted Pair

It is a 150Ω cable containing additional shielding that protects signals against electromagnetic Interference
(EMI) produced by electric motors, power lines etc. It is primarily used in Token Ring Network & where
UTP cable would provide insufficient protection against interface. Wires within cables are encased in a
metallic sheath that is conductive as copper in wires. This sheath when properly grounded converts its
ambient noise into current, like an antenna. This current is carried to wires within where it creates an equal
and opposite current flowing in twisted pairs thus getting canceled and no noise signal is produced.

4. Fiber Optic.

Fiber Optic relies on pulsed light to carry information. Two types of plastic or glass with different physical
properties are used (the inner core and the outer cladding) to allow a beam of light to reflect off the boundary
between the core and cladding. Some fiber optic cables allow many different paths, others allow one single
mode. They are called multimode and single mode fibers. A popular multimode fiber has core/cladding
dimensions of 62.5/125 nanometers.

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REPEATER

A Repeater is a purely electrical device that extends the maximum distance a LAN cable can span by
Amplifying signals passing through it. A Repeater connects two segments and broadcasts packets between
them. Since signal loss is a factor in the maximum length of a segment, a Repeater is used to amplify the
signal and extend the usable length. A common Ethernet rule is that no more than four repeaters may be used
to join segments together. This is a physical limitation designed to keep collision detection working properly.
Repeaters operate at layer 1 (Physical layer) of the OSI model.

BRIDGES

This network bridge provides an inexpensive and easy way to connect network segments. A bridge provides
Amplification function of a repeater plus, ability to select filter packets based on their addresses. When a
network grows in size, it is often necessary to partition it into smaller groups of nodes to help isolate traffic
and improve performance. One way to do this is to use a bridge, the operation of it is to keep one segment of
traffic to that side and another to the other side will cross the bridge, The bridge learns which packets should
cross it as it is used.

ROUTERS

A router is a device that connects two LANs together to form an inter-network. A router is the basic building
block of the Internet. Each router connects two or more networks together by providing an interface for an
Ethernet network and ring network to which it is connected. The router examines each packet of information
to detect whether the packet must be translated from one network to another network performing a function
similar to a bridge. Unlike a bridge, a router can connect networks that use different technologies, addressing
methods, media type, frame format and speeds. A router is a special purpose device designed to interconnect
networks. Such that three networks can be connected using two routers. Routers maintain routing tables in
their memories to store information about the physical connection on the network; the router examines each
packet of data, checks the routing table and then forwards the packet if necessary. Every other router in the

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path (between any state destinations) performs a similar procedure. Note that a router does not maintain any
state information about the packets; it simply moves them along the network. Routers are operated at layer
3(network) of the OSI model.

GATEWAYS

A node on a network that serves as an entrance to another network. In enterprises, the gateway node often
acts as a proxy server and a firewall. The gateway is also associated with both a switch, which provides the
actual path for the packet in and out of the gateway. It is also known as a computer system located on earth
that switches data signals and voice signals between satellites and terrestrial networks. A gateway can
operate at any layer of the OSI/RM. The hub of a gateway, also called a protocol converter, is much more
complex than that of a router or switch. Typically, a gateway must convert from one protocol stack to
another. E.g. a gateway may connect a TCP/IP network to an IPX. /SPX network. A Circuit Level Gateway
function provided by Application level gateway products enables trusted users on private networks to access
Internet services with all security of a proxy server. An Application Level Gateway provides a much stricter
form of security than packet filters, but they are designed to regulate access only for a particular application.

HUBS

Hubs are also called concentrators; expand one Ethernet connection into many. For example, a four-port hub
connects up to four machines via UTP cables. The hub provides a star connection for the four ports. Many
hubs contain a single BNC connector as well to connect the hub to existing 10base2 network wiring, the hub
can also be connected via one of its ports. One pot is desired to operate in either straight through or
crossover mode, selected by a switch on the hub. Hubs that can connect in this fashion are called stackable
hubs. A hub is similar to a repeater, except it broadcasts data received by any port to all other ports on the
hub. Most hubs contain a small amount of intelligence as well. Examining received packets and checking
them for integrity. If a bad packet arrives or the hub determines that a port is unreliable. It will shut down the
line under the error condition it appears. The hub also acts like a repeater. Because of its slight delay when
processing a packet, the numbers of hubs that may be connected in a series are limited.

There are three types of HUB passive hub, active hub and intelligent hub. The Passive hubs do not

process data signals with only the purpose to combine the signal from several network cables segments. All
devices attached to the passive hub receive another packets that pass through the hub .Hub does not clear up
or amplify the signals, on the contrary absorbs a small part of the signals that is why the distance between a
hub and a computer should not be more than half of the permissible distance between two computers.

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Passive hubs have limited functionality so are inexpensive and easy to configure. It has four ports with four
BNC (British Naval Connectors) female connectors to configure network stations or terminated with a 93 Ω
BNC Terminator. The active hubs incorporate electronic components that amplify and clean up the signals
that flaw between devices on the network. The process of cleaning up a signal is called “signal
regeneration”. The benefits of signals regeneration are:

●​ A network is more robust i.e. less sensitive errors.

●​ Distance between devices can be increased.

Active hubs cost is considerably more than passive hubs (active hub function impart as multiport repeaters).
Intelligent hubs are enhanced active hubs the following functions add intelligence to a hub. Intelligent Hubs
are units that have a form of integrated management capability. Hub Management A hub supports networks

network management protocols that enable the hub to send packets to the central network console. These
protocols enable the network console to manage or control hubs. Switching hubs Switching hubs include
circuitry that quickly routes signals between ports on the hub. Instead of repeating a packet to all ports on the
hub, it repeats a packet only to the port that connects to the destination computer for the packet.

SWITCHES It is similar to a bridge, with some important enhancements. First, as which may have multiple
ports, thus directing packets to several different segments further partitioning and isolating network traffic in
a way similar to routers. For ex., if an 8-port n way switch is there it can route packets from any input to any
output. Some or all of the incoming packet is called store and forward, which stores the received packet
before examining it for error before retransmitting. Bad packets are not forwarded. A switch typically has
auto-sensing 10/100 mbps ports and will just the speed of each port accordingly; furthermore, a managed
switch supports SNMP for further control over network traffic. Switches operate at layer 2 (Data Link) of
OSI model.

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SWITCHES

A network switch is a computer networking device that connects devices together on a computer network
by using packet switching to receive, process, and forward data to the destination device. Multiple data
cables are plugged into a switch to enable communication between different networked devices. Switches
manage the flow of data across a network by transmitting a received network packet only to the one or more
devices for which the packet is intended. Each networked device connected to a switch can be identified by
its network address, allowing the switch to regulate the flow of traffic. This maximizes the security and
efficiency of the network.

NETWORK SOFTWARE

IP(Internet Protocol)

The Internet Protocol (IP) is a network-layer (Layer 3) protocol that contains addressing information and
some control information that enables packets to be routed. IP is documented in RFC 791 and is the primary
network-layer protocol in the Internet protocol suite. Along with the Transmission Control Protocol (TCP),
IP represents the heart of the Internet protocols. IP has two primary responsibilities: providing
connectionless, best-effort delivery of datagrams through an internetwork; and providing fragmentation and
reassembly of datagrams to support data links with different maximum-transmission unit (MTU) sizes.

ARP (Address Resolution Protocol )

The Address Resolution Protocol (ARP) was developed to enable communications on an internetwork and is
defined by RFC 826. Layer 3 devices need ARP to map IP network addresses to MAC hardware addresses
so that IP packets can be sent across networks. Before a device sends a datagram to another device, it looks
in its ARP cache to see if there is a MAC address and corresponding IP address for the destination device. If
there is no entry, the source device sends a broadcast message to every device on the network. Each device
compares the IP address to its own. Only the device with the matching IP address replies to the sending
device with a packet containing the MAC address for the device (except in the case of “proxy ARP”). The
source device adds the destination device MAC address to its ARP table for future reference, creates a
data-link header and trailer that encapsulates the packet, and proceeds to transfer the data.

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RARP (Reverse Address Resolution Protocol)

Reverse ARP (RARP) as defined by RFC 903 works the same way as the Address Resolution Protocol
(ARP), except that the RARP request packet requests an IP address instead of a media access control (MAC)
address. RARP often is used by diskless workstations because this type of device has no way to store IP
addresses to use when they boot. The only address that is known is the MAC address because it is burned in
to the hardware.

ICMP

To make efficient use of the network resources, IP was designed to provide unreliable and connectionless
best-effort datagram delivery service. As a consequence, IP has no error-control mechanism and also lacks
mechanism for host and management queries. A companion protocol known as Internet Control Message
Protocol (ICMP), has been designed to compensate for these two deficiencies. ICMP messages can be
broadly divided into two broad categories: error reporting messages and query messages

●​ Error reporting Messages: Destination unreachable, Time exceeded, Source quench, Parameter
problems, Redirect
●​ Query: Echo request and reply, Timestamp request and reply, Address mask request and reply

RIP

The Routing Information Protocol (RIP) is one of the most commonly used Interior Gateway Protocol on
internal networks which helps a router dynamically adapt to changes of network connections by
communicating information about which networks each router can reach and how far away those networks
are. RIP is based on distance vector routing using the Bellman-Ford algorithm for calculating the distance
between nodes (routers). The routing tables at every node are updated every 30 seconds by transmitting
routing table updates. The distance vector metric can be number of hops or time delay. The router has a table
indicating the distance to each of its neighbor. The table at a router (node) has the first column to show the
distance vector metric. The third column in the table indicates the next node.

OSPF (Open Shortest Path First)

Open Shortest Path First (OSPF) is another Interior Gateway Protocol. It is a routing protocol developed for
Internet Protocol (IP) networks by the Interior Gateway Protocol (IGP) working group of the Internet
Engineering Task Force (IETF). The working group was formed in 1988 to design an IGP based on the
Shortest Path First (SPF) algorithm for use on the Internet. OSPF was created because in the mid-1980s, the
Routing Information Protocol (RIP) was increasingly incapable of serving large, heterogeneous
internetworks. OSPF being a SPF algorithm scales better than RIP.

Conclusion: Hence we have studied various network hardware & software.

Computer Engineering Computer Network Lab (CSL502) SEM V