The document discusses various aspects of computer networking including definitions of modem, connectors, cables, adapters, circuits, switches, and leased lines. It then discusses hardware/software requirements, protocols, transmission media, and email in networking. It provides descriptions of common protocols like TCP/IP, X.25, frame relay, ATM, and sonet. It also discusses functions of protocols, how protocols work at sending and receiving computers, and differences between TCP and IP.

1. Prepared by Mr.Manish Jha
Section Officer and faculty, University
of Petroleum & Energy
Studies,Dehradun

2.  Modem- A device that enables a computer to transmit
data over telephone lines.
 Connector- A device that mating and demating
electrical power connection.
 Cables- It consists of bundle of wires with connector
on the ends.
 Adaptor- It is a physical device that allow to interface
between one hardware to another interface hardware.
 Circuits- is a specific path between to points by which
signals can be carried out.
 Switches- It is a network device that select a path or
circuit to send unit of data to its next destination.
 Leased Lines- It is a telephone line connection that has
been used for private purpose

3.  1. Hardware and Software Requirement
 2. Protocol
 Transmission Media
 E-Mail

4.  Protocol is a set of rules and procedure for
communicating.
 There are many protocols
 Some Protocol works only at particular OSI.
 Protocol can also work together is a suit.
 How Protocol Works – Data is transmitted over
the network and to be break down in a
systematic steps. Each steps its own rules and
procedure.

5.  TCP/IP
 X.25
 Frame Relay
 ATM 2
 Sonet
 Function of Protocol

6.  The protocol steps must be carried out in a consistent order
that is the same on every computer in the network. In the
sending computer, these steps must be executed from the
top down. In the receiving computer, these steps must be
carried out from the bottom up.
 The Sending Computer
 Protocols at the sending computer:
 Break the data into smaller sections, called packets, that the
protocol can handle.
 Add addressing information to the packets so that the
destination computer on the network can determine that the
data belongs to it.
 Prepare the data for transmission through the NIC and out
onto the network cable.

7.  The Receiving Computer- Protocols at the receiving
computer carry out the same series of steps in reverse order.
They:
 Take the data packets off the cable.
 Bring the data packets into the computer through the NIC.
 Strip the data packets of all the transmitting information
that was added by the sending computer.
 Copy the data from the packets to a buffer for reassembly.
 Pass the reassembled data to the application in a usable
form.
 Both sending and receiving computers need to perform each
step in the same way so that the data will have the same
structure when it is received as it did when it was sent.

8.  TCP/IP – It consists of multiple protocols, each of
which transfer data across the network in a different
form at with different option such as error checking.
 X.25- It uses packet switching. Difference :-
 TCP/IP has only end-to-end error checking and flow
control; X.25 has error checking from node to node.
 To compensate for the fact that a TCP/IP network is
completely passive, TCP/IP has a more complicated
flow control and window mechanism than X.25 has.
 X.25 has tightly specified the electrical and link levels;
TCP/IP is designed to travel over many different kinds
of media, with many different types of link service.

9.  Other protocols written specifically for the
TCP/IP suite include:
 SMTP (Simple Mail Transfer Protocol) E-
mail.
 FTP (File Transfer Protocol) For exchanging
files among computers running TCP/IP.
 SNMP (Simple Network Management
Protocol) For network management.

10. Types of Internet Protocol ?-
A. Electronic Mail- SMTP,IMAP (Internet Message Access
Protocol), POP3 (POST OFFICE PROTOCOL3)
B. FTP
C. HTTP- It allows to shown the web page in web
broswer.
D. Telnet
E. Gopher
F. Usenet
What is Domain ?
Role on Domain Name System .
Role of DHCP- ( Dynamic Host Configuration Protocol)

11.  Difference between TCP and IP.
IP Addressing
Domain Name Server

12.  Domain Name Server
 It’s a network service that translate “names”
into IP Address.
 Domain Name & Host Name
 .com Yahoo -
 .com google
 ac.in upes
 Host Name

13.  IP uses 32 bits
 1 byte= 8 bits
 4 bytes= 32 bits
 IP consists of 4 numbers and number always
between 0 to 255.
 It consists of two components –One
component is network portion of the address.
 Second component is Host portion of the
address.

14. Types of OSI Layers :
1. Application Layer
2. Presentation Layer
3. Session Layer
4. Transport Layer
5. Network Layer
6. Data Link Layer
7. Physical Layer

15. OSI- Open System Interconnection was
developed in 1984 by ISO (International
Standard Organization) . OSI model is a set of
seven layers that ensure that must travel from
one device to another device over the
network. In earlier it was called
internetworking.
Application Layer – This layer actually interact
with the operating system or application
whenever user transfer file,read message and
perform other network activities

16. Presentation Layer takes the data provided by the Application layer and
converts it into a standard format that the other layers can understand.
SESSION LAYER : The session layer tracks connections, also called sessions.
The session layer should keep track of multiple file downloads requested
by a particular FTP application, or multiple telnet connections from a
single terminal client, or web page retrievals from a web server.
TRANSPORT LAYER :-
 DATA LINK LAYER
 The data link layer provides error-free transfer of data frames from one
node to another over the physical layer, allowing layers above it to
assume virtually error-free transmission over the link. To do this, the data
link layer provides:

17.  The upper layers of the OSI model represent
software that implements network services like
encryption and connection management.
 The lower layers of the OSI model implement
more primitive, hardware-oriented functions
like routing, addressing, and flow control.

18.  PHYSICAL LAYER
 The physical layer, the lowest layer of the OSI
model, is concerned with the transmission and
reception of the unstructured raw bit stream over a
physical medium. It describes the
electrical/optical, mechanical, and functional
interfaces to the physical medium, and carries the
signals for all of the higher layers.
Network Layer of the OSI model known as OSI
Network Layer has a role to carry data from the
source address to destination address . Like,
TCP/IP address.

19.  Cloud computing is basically an Internet-based
network made up of large numbers of
 servers - mostly based on open standards, modular
and inexpensive. Clouds contain
 vast amounts of information and provide a variety
of services to large numbers of
 people. The benefits of cloud computing are
Reduced Data Leakage, Decrease evidence
 acquisition time, they eliminate or reduce service
downtime, they Forensic readiness, they
 Decrease evidence transfer time

21.  History
 The Cloud is a metaphor for the Internet, derived from its
common depiction in network diagrams
 (or more generally components which are managed by
others) as a cloud outline.
 The underlying concept dates back to 1960 when John
McCarthy opined that "computation may
 someday be organized as a public utility" (indeed it shares
characteristics with service bureaus
 which date back to the 1960s) and the term The Cloud was
already in commercial use around
 the turn of the 21st century. Cloud computing solutions had
started to appear on the market,
 though most of the focus at this time was on Software as a
service.

22.  Types of services:
 These services are broadly divided into three
categories:
 Infrastructure-as-a-Service (IaaS)
 Platform-as-a-Service (PaaS)
 Software-as-a-Service (SaaS).

23.  Types by visibility:
 Public Cloud
 Hybrid Cloud
 Private Cloud

24.  Public Clouds
 A public cloud is one in which the services and infrastructure are
provided off-site over the Internet. These clouds offer the greatest level of
efficiency in shared resources; however, they are also more vulnerable
than private clouds. A public cloud is the obvious choice
 when :-
 Our standardized workload for applications is used by lots of people,
such as e-mail.
 we need to test and develop application code.
 we have SaaS (Software as a Service) applications from a vendor who has
a well-implemented security strategy.
 We need incremental capacity (the ability to add computer capacity for
peak times).
 We are doing collaboration projects.
 We are doing an ad-hoc software development project using a Platform as
a Service (PaaS) offering cloud.