1. CASE STUDY
COMPUTER NETWORKS
Submitted to:
Prof. Vandana Kadam
Submitted by :
A040 SONAL . SHETH.
A041 SONAM . SINGH.
A042 BHUSHAN. TAMBE.
A043 DEVAYANI.
TELANGE.
THE K.E.T’s
V.G.VAZE COLLEGE OF ARTS , SCIENCE
AND COMMERCE.
MITHAGAR ROAD
MULUND ( E ) – 400 081.

2. CONTENTS :
1]. Introduction
2]. Connecting devices
3]. Communication channel
4]. Data Transmission
5]. Topology
6]. Line configuration
7]. Transmission mode
8]. Server
9]. Switching method
10]. Category of the network
11]. Security
12]. Network Layout

3. INTRODUCTION :
Given is the synopsis for the case
study of a networking system in one of the KOTAK
MAHINDRA’s branch
in dombivali.
Place : Kotak Mahindra Bank , Dombivali (w)
Date Of Visit : 20 august , 2009 .
Kotak Mahindra Bank is one of the best
organization where we can study about networking and
clear our concepts. We selected this particular network, so
that the impact of networking on a corporate world can be
studied closely. Mr .Prasad Mehta, a network engineer,
actually helped us to clear our all queries and concepts of
networking. In this case study, we have mainly focused on
the concepts of technological development in networking
field, along with the network design.
We were really interested to :
1]. To know how network operates?

4. 2]. What types of technology is available?
3]. How does information flow?
4]. Who is sharing the data and what kind of data is being
shared ? etc…
So finally, We have studied and tried
to put forward the concepts of networks, in a simplest form.
We have described the theory of every component in Kotak
Mahindra Bank, to make the concepts clear and easy.
BASIC CONCEPTS :
 Kotak Mahindra Bank has in all 34 centers in
Mumbai. Its main branch (head office) is in Wadala.
 The center has 20 computers, named from A to T
and have multiple laser printers which are shared by
all the computers. These are called as nodes, i.e.
linking devices. It also has a TMS (Token Machine
System).
CONNECTING DEVICES :

5.  Connecting devices used are switches and routers.
Switches are used because a hub has only 8 ports and
if a system wants to connect more than 8 devices to a
hub, a hub becomes inefficient .So a switch is used to
connect a number of devices, which is then
connected to one of the port of a hub, so that the rest
of the ports of the hub remain free.
THEORY :
 Switches : They are hardware and/or software
devices capable of creating temporary connections
between two or more devices linked to a switch , but
not to each other.
 Routers : It is an interconnecting device. Routers
are more complicated. They have access to network
layer addresses and contain software that enables
them to determine which of several possible paths
between those addresses is the best for a particular
transmission. Thus, routers relay packets among
multiple interconnected networks. Routers operate in
physical data link and network layers of the OSI
model.
COMMUNICATION CHANNEL :

6.  The devices are connected to a switch using cat-5
UTP (unshielded twisted pair) straight Cu-cable. The
end connectors used for the cat-5 cables are called
RJ-45 (regulated Jacks 45) connector.
THEORY :
 The medium defines the speed at which data can
travel through a connection.
 Cat-5 Unshielded twisted pair cable : It is a
cable belonging to category 5. It supports upto 10
megabit/sec. These cat-5 cables are capable of
carrying data effectively at about 80-90 m . Main
advantages of UTP are its cost and ease of use . UTP
is cheap , flexible and easy to install.
 RJ-45 : It is a snap-in plug like connector with 8
conductors. The connector is attached to the cable
and the jack is the device that the connector plugs
into. Thus, one end of cat-5 cable is inserted in RJ-45
slot of computer and other end is terminated on
Ethernet port of a switch.

7. DATA TRANSMISSION :
 The transmission of binary data across a link is
accomplished in serial mode.
THEORY :
 Serial Data Transmission : In serial data
transmission one bit follows another , so we need
only one communication channel rather than ‘n’ to
transmit data between two communicating
devices.
 The advantage of serial data transmission is that
with only one communication channel, serial
transmission reduces the cost of transmission over
parallel by roughly a factor of ‘n’.
 In serial mode, one bit is sent with each clock
pulse.

8. TOPOLOGY :
 In this centre, a star topology is used. Because, it
is less expensive, requires less cabeling and easy
to install and reconfigure.
THEORY :
 The term topology refers to the way a network is
laid out, either physically or logically.
 Two or more devices connect to a link; two or
more links form a topology.
 Topology of an network is the geometric
representation of the relationship of all the links
and linking devices to each other.
 There are four basic topologies possible.
1]. Mesh
2]. Star
3]. Bus
4]. Ring

9.  These four topologies describe how the devices
in a network are interconnected rather than their
physical arrangement.
 STAR TOPOLOGY : In a star topology,
each device has a dedicated point to point link
only to a central controller , usually called a
‘hub’.
 The devices are not directly linked to each
other.
 A star topology does not allow direct traffic
between devices.
 The controller acts as an exchange. If one
device wants to send data to another, it sends the
data to the controller, which then relays the data
to the other connected device.

10. DEVICE DEVICE
A B
HUB
DEVICE DEVICE
C D
 A star topology is less expensive. In a star
topology, each device needs only one link and
one I/O port to connect it to any number of
other devices. This factor makes it easy to
install and reconfigure.
 Other advantage is robustness. If one link fails,
only that link is affected. All other links remain
active. So, as long as, a hub is working , it can
be used to monitor link problems and detect

11. defective links. So, it leads to easy fault
identification and fault isolation.
LINE CONFIGURATION :
 For communication, point to point line
configurations is used.
THEORY :
 Line configuration : It refers to the way two
or more communication devices attach to a link.
A link is the physical communication pathway
that transfers data from one device to another.
 Point To Point Configuration : It provides
a dedicated link between two devices. The
entire capacity of the channel is reserved for
transmission between those two devices.
 Most point to point line configuration use an
actual length of wire or cable to connect the two
ends, but other options, such as microwave or
satellite links are also possible.

12. TRANSMISSION MODE :
 The transmission mode used is full-duplex.
THEORY :
 Transmission mode : The term is used to define
the direction of signal flow between two linked
devices.
 Full-duplex mode : In duplex mode, both stations
can transmit and receive simultaneously.
 In full duplex mode, signals going in either
direction share the capacity of the link. This
sharing can occur in two ways : either the link
must contain two physically separate transmission
paths, one for sending and another for receiving ,
or the capacity of the channel is divided between
signals traveling in opposite directions.

13. SERVER :
 The main server is in Wadala. It stores the
database of all connecting devices. When we make
and changes in a file stored in a particular device,
connected to a server , same changes are made to
the file which is stored on the server. The
application installed in every connecting device,
can be accessed directly from the server as well.
THEORY :
 Server is a computer or a device with high storage
capacity, that stores all data, entered on the various
devices, connected to the server.
 A server is really important data storage system
and also it is very sensitive. Thus, it is kept in a
separate room called ‘server room’.
SWITCHING METHOD :
 It uses packet switching method.
THEORY :

14.  In a packet – switched network, data are transmitted
in discrete units of potentially variable length blocks
called ‘packets’.
 The maximum length of the packet is established by
the network. Longer transmissions are broken up into
multiple packets. Each packet contains not only data
but also a header with control information.
 The packets are sent over the network node to node.
At each node, the packet is stored briefly then routed
according to the information.
CATEGORY OF THE NETWORK :
 Local area network (LAN) used , allows to share
different resources like laser printer between
computers.
THEORY :
 A local area network is usually privately owned and
links the devices in a single office, building or
campus. LAN size is limited to a few kilometers.
 LAN are designed to allow resources to be shared
between personal computers or workstations. The

15. resources to be shared can include a hardware or a
software.
 LAN’s are distinguished from other types of
networks by their transmission media, size and
topology. A given LAN may use only one type of
transmission medium.
 Traditionally, LAN’s have data in the 4 to 16 Mbps
range.
IP ADDRESS :
 All the branches of Kotak Mahindra use ‘0’ ( zero )
series IP address , specified by Kotak Mahindra’s
head branch. It comes under class A.
SECURITY :
 Network security issues include protecting data from
unauthorized access and viruses.
 Unauthorized access : For a network to be useful
, sensitive data must be protected from unauthorized
access. Protection can be accomplished at a number
of levels. At the lowest level are user identification
codes and passwords. Every device has its own
network address, by which anyone can connect to the

16. device and access the data. But if a user
identification code and password are not known then
we can connect to that device but cannot access the
data.
 At a higher level, are encryption techniques. In these
mechanisms, data are systematically altered in such a
way that if they are intercepted by an unauthorized
user, it will not be accessible.
 VIRUSES : Because a network is accessible from
many points it can be prone to computer viruses. A
virus is an illicitly introduced code that damages the
system. A good network is protected from viruses by
hardware and software designed specially for that
purpose.
NETWORK LAYOUT :
 Every centre of Kotak Mahindra sends its data to the
main branch for updating.
 All computers, from A to T, are attached to a switch
with the help pf a cat-5 cable and RJ-45 connector.
One end of the cat-5 cable is inserted in RJ-45 slot of
computer and other end is terminated on Ethernet
port of a switch.

17.  The switch is then connected to a hub. One port of
hub has a connection with a laser printer, which is
shared by all the computers, Also, a hub has a
connection with a TMs ( Token Machine System ), so
that TMS can register the token of a customer on the
computer, directly. Other ports of a hub remain free.
 HUB is then connected to a router, which route the
packets from one network to the other, so that it gets
to the final destination.
 Since, the data cannot be sent directly through a
network, it has to convert into digital form, in short,
it has to be modulated, so that it can travel through a
network easily and safely. For this, a modem is
connected to a router, which modulates and transfers
the data through lease lines.
 To setup the internet connection, various service
providers such as Siffy broadband, Reliance , etc are
used.
 When a connection is established, data flows through
the lease lines and is received by the modem at the
receiver’s side i.e. at the main centre. Modem then
demodulates the data and sends it to the router
connected to it.
 Routers then route this data to the main server and
data gets stored on the server.

18.  If the device at the receiver’s side wants to reply to
the data to one of the device, the entire process is
reversed.
 In this way data can be received and accessed by any
Kotak Mahindra branch.
CONCLUSION : This is how networking takes place in
Kotak Mahindra’s branch.