lOMoAR cPSD| 47061011
LECTURE NOTES
ON
Data Communication and Networks
2025
IV B. Tech I Semester (JNTUA-R15)
Department of Electronics and Communication Engineering
SYLLABUS
15A04704 DATA COMMUNICATIONS & NETWORKING
UNIT-I
Introduction to Networks & Data Communications
The Internet, Protocols & Standards, Layered Tasks, OSI Model, TCP / IP, Addressing, Line
Coding Review, Transmission Media: Guided and unguided Media Review.
UNIT-II
Switching
Datagram Networks, Virtual Circuit Networks, Structure of a switch ,Ethernet Physical
Layer, Data Link Layer: Error detection and Correction Data Link Control: Framing,
Flow and Error Control Protocols, Noiseless Channel and Noisy Channel Protocol,
HDLC, Point-to-Point Protocol.
UNIT-III
Multiple Access
RANDOH, CDMA, CSMA/CD, CSMA/CA, Controlled Access, Channelization, Wired
LANs: IEEE Standards, Standard Ethernet, Fast Ethernet, Gigabit Ethernet, Wireless
LAN, IEEE 802.11, Bluetooth IEEE 802.16.
UNIT-IV
Network Layer
Design Issues, Routing Algorithms, Congestion control, Algorithms.IPV4 Addresses,
Connecting Devices, Virtual LAN IPV6 Addresses, Internet Protocol, Hardware Addressing
versus IP Addressing, IP Data Gram.
, lOMoAR cPSD| 47061011
UNIT-V
Transport Layer Protocol
UDP and TCP, ATM, Cryptography, Network Security
Text Books:
1. B. A. Forouzan, “Data Communications and Networking”, MGH, 4th ed. 2007. Reference
Books:
1. A. S. Tanenbaum, “Computer Networks”, PHI.
2. W. Stallings, “Data and Computer Communication”, PHI.
Unit-I Introduction to Networks &Data Communications
In Data Communications, data generally are defined as information that is stored in
digital form. Data communications is the process of transferring digital information between
two or more points. Information is defined as the knowledge or intelligence. Data
communications can be summarized as the transmission, reception, and processing of digital
information. For data communications to occur, the communicating devices must be part of
a communication system made up of a combination of hardware (physical equipment) and
software (programs). The effectiveness of a data communications system depends on four
fundamental characteristics: delivery, accuracy, timeliness, and jitter.
A data communications system has five components:
1. Message: The message is the information (data) to be communicated. Popular forms
of information include text, numbers, pictures, audio, and video.
2. Sender: The sender is the device that sends the data message. It can be a computer,
workstation, telephone handset, video camera, and so on.
3. Receiver: The receiver is the device that receives the message. It can be a computer,
workstation, telephone handset, television, and so on.
4. Transmission medium: The transmission medium is the physical path by which a
message travels from sender to receiver. Some examples of transmission media
include twisted-pair wire, coaxial cable, fiber-optic cable, and radio waves.
5. Protocol: A protocol is a set of rules that govern data communications. It represents
an agreement between the communicating devices.
The Internet:
, lOMoAR cPSD| 47061011
The Advanced Research Projects Agency Network (ARPANET) was an early packet switching
network and the first network to implement the protocol suite TCP/IP. Both technologies became
the technical foundation of the Internet. The ARPANET was initially funded by the Advanced
Research Projects Agency (ARPA) of the United States Department of Defense. The packet
switching methodology employed in the ARPANET was based on concepts and designs by
Americans Leonard Kleinrock and Paul Baran, British scientist Donald Davies, and Lawrence
Roberts. The TCP/IP communications protocols were developed for the ARPANET by computer
scientists Robert Kahn and Vint Cerf, and incorporated concepts from the French CYCLADES
project directed by Louis Pouzin.
As the project progressed, protocols for internetworking were developed by which multiple
separate networks could be joined into a network of networks. Access to the ARPANET was
expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science
Network (CSNET). In 1982, the Internet protocol suite(TCP/IP) was introduced as the standard
networking protocol on the ARPANET. In the early 1980s the NSF funded the establishment for
national supercomputing centers at several universities, and provided interconnectivity in 1986
with the NSFNET project, which also created network access to the supercomputer sites in the
United States from research and education organizations. The ARPANET was decommissioned in
1990.
PROTOCOLS & Standards
Protocol: A protocol is a set of rules that govern data communications. It represents an
agreement between the communicating devices.
• Syntax
• Semantics
• Timing
An association of organizations, governments, manufacturers and users form the
standards organizations and are responsible for developing, coordinating and maintaining
the standards. The intent is that all data communications equipment manufacturers and
users comply with these standards. The primary standards organizations for data
communication are:
1. International Standard Organization (ISO)
ISO is the international organization for standardization on a wide range of subjects. It is
comprised mainly of members from the standards committee of various governments throughout
, lOMoAR cPSD| 47061011
the world. It is even responsible for developing models which provides high level of system
compatibility, quality enhancement, improved productivity and reduced costs. The ISO is also
responsible for endorsing and coordinating the work of the other standards organizations.
2. International Telecommunications Union-Telecommunication Sector(ITU-T) ITU-T is
one of the four permanent parts of the International Telecommunications
Union based in Geneva, Switzerland. It has developed three sets of specifications: the V
series for modem interfacing and data transmission over telephone lines, the X series for
data transmission over public digital networks, email and directory services; the I and Q
series for Integrated Services Digital Network (ISDN) and its extension Broadband
ISDN. ITU-T membership consists of government authorities and representatives from
many countries and it is the present standards organization for the United Nations.
3. Institute of Electrical and Electronics Engineers (IEEE)
IEEE is an international professional organization founded in United States and is
compromised of electronics, computer and communications engineers. It is currently the
world’s largest professional society with over 200,000 members. It develops
communication and information processing standards with the underlying goal of
advancing theory, creativity, and product quality in any field related to electrical
engineering.
4. American National Standards Institute (ANSI)
ANSI is the official standards agency for the United States and is the U.S voting
representative for the ISO. ANSI is a completely private, non-profit organization
comprised of equipment manufacturers and users of data processing equipment and
services. ANSI membership is comprised of people form professional societies, industry
associations, governmental and regulatory bodies, and consumer goods.
5. Electronics Industry Association (EIA)
EIA is a non-profit U.S. trade association that establishes and recommends industrial
standards. EIA activities include standards development, increasing public awareness, and
LECTURE NOTES
ON
Data Communication and Networks
2025
IV B. Tech I Semester (JNTUA-R15)
Department of Electronics and Communication Engineering
SYLLABUS
15A04704 DATA COMMUNICATIONS & NETWORKING
UNIT-I
Introduction to Networks & Data Communications
The Internet, Protocols & Standards, Layered Tasks, OSI Model, TCP / IP, Addressing, Line
Coding Review, Transmission Media: Guided and unguided Media Review.
UNIT-II
Switching
Datagram Networks, Virtual Circuit Networks, Structure of a switch ,Ethernet Physical
Layer, Data Link Layer: Error detection and Correction Data Link Control: Framing,
Flow and Error Control Protocols, Noiseless Channel and Noisy Channel Protocol,
HDLC, Point-to-Point Protocol.
UNIT-III
Multiple Access
RANDOH, CDMA, CSMA/CD, CSMA/CA, Controlled Access, Channelization, Wired
LANs: IEEE Standards, Standard Ethernet, Fast Ethernet, Gigabit Ethernet, Wireless
LAN, IEEE 802.11, Bluetooth IEEE 802.16.
UNIT-IV
Network Layer
Design Issues, Routing Algorithms, Congestion control, Algorithms.IPV4 Addresses,
Connecting Devices, Virtual LAN IPV6 Addresses, Internet Protocol, Hardware Addressing
versus IP Addressing, IP Data Gram.
, lOMoAR cPSD| 47061011
UNIT-V
Transport Layer Protocol
UDP and TCP, ATM, Cryptography, Network Security
Text Books:
1. B. A. Forouzan, “Data Communications and Networking”, MGH, 4th ed. 2007. Reference
Books:
1. A. S. Tanenbaum, “Computer Networks”, PHI.
2. W. Stallings, “Data and Computer Communication”, PHI.
Unit-I Introduction to Networks &Data Communications
In Data Communications, data generally are defined as information that is stored in
digital form. Data communications is the process of transferring digital information between
two or more points. Information is defined as the knowledge or intelligence. Data
communications can be summarized as the transmission, reception, and processing of digital
information. For data communications to occur, the communicating devices must be part of
a communication system made up of a combination of hardware (physical equipment) and
software (programs). The effectiveness of a data communications system depends on four
fundamental characteristics: delivery, accuracy, timeliness, and jitter.
A data communications system has five components:
1. Message: The message is the information (data) to be communicated. Popular forms
of information include text, numbers, pictures, audio, and video.
2. Sender: The sender is the device that sends the data message. It can be a computer,
workstation, telephone handset, video camera, and so on.
3. Receiver: The receiver is the device that receives the message. It can be a computer,
workstation, telephone handset, television, and so on.
4. Transmission medium: The transmission medium is the physical path by which a
message travels from sender to receiver. Some examples of transmission media
include twisted-pair wire, coaxial cable, fiber-optic cable, and radio waves.
5. Protocol: A protocol is a set of rules that govern data communications. It represents
an agreement between the communicating devices.
The Internet:
, lOMoAR cPSD| 47061011
The Advanced Research Projects Agency Network (ARPANET) was an early packet switching
network and the first network to implement the protocol suite TCP/IP. Both technologies became
the technical foundation of the Internet. The ARPANET was initially funded by the Advanced
Research Projects Agency (ARPA) of the United States Department of Defense. The packet
switching methodology employed in the ARPANET was based on concepts and designs by
Americans Leonard Kleinrock and Paul Baran, British scientist Donald Davies, and Lawrence
Roberts. The TCP/IP communications protocols were developed for the ARPANET by computer
scientists Robert Kahn and Vint Cerf, and incorporated concepts from the French CYCLADES
project directed by Louis Pouzin.
As the project progressed, protocols for internetworking were developed by which multiple
separate networks could be joined into a network of networks. Access to the ARPANET was
expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science
Network (CSNET). In 1982, the Internet protocol suite(TCP/IP) was introduced as the standard
networking protocol on the ARPANET. In the early 1980s the NSF funded the establishment for
national supercomputing centers at several universities, and provided interconnectivity in 1986
with the NSFNET project, which also created network access to the supercomputer sites in the
United States from research and education organizations. The ARPANET was decommissioned in
1990.
PROTOCOLS & Standards
Protocol: A protocol is a set of rules that govern data communications. It represents an
agreement between the communicating devices.
• Syntax
• Semantics
• Timing
An association of organizations, governments, manufacturers and users form the
standards organizations and are responsible for developing, coordinating and maintaining
the standards. The intent is that all data communications equipment manufacturers and
users comply with these standards. The primary standards organizations for data
communication are:
1. International Standard Organization (ISO)
ISO is the international organization for standardization on a wide range of subjects. It is
comprised mainly of members from the standards committee of various governments throughout
, lOMoAR cPSD| 47061011
the world. It is even responsible for developing models which provides high level of system
compatibility, quality enhancement, improved productivity and reduced costs. The ISO is also
responsible for endorsing and coordinating the work of the other standards organizations.
2. International Telecommunications Union-Telecommunication Sector(ITU-T) ITU-T is
one of the four permanent parts of the International Telecommunications
Union based in Geneva, Switzerland. It has developed three sets of specifications: the V
series for modem interfacing and data transmission over telephone lines, the X series for
data transmission over public digital networks, email and directory services; the I and Q
series for Integrated Services Digital Network (ISDN) and its extension Broadband
ISDN. ITU-T membership consists of government authorities and representatives from
many countries and it is the present standards organization for the United Nations.
3. Institute of Electrical and Electronics Engineers (IEEE)
IEEE is an international professional organization founded in United States and is
compromised of electronics, computer and communications engineers. It is currently the
world’s largest professional society with over 200,000 members. It develops
communication and information processing standards with the underlying goal of
advancing theory, creativity, and product quality in any field related to electrical
engineering.
4. American National Standards Institute (ANSI)
ANSI is the official standards agency for the United States and is the U.S voting
representative for the ISO. ANSI is a completely private, non-profit organization
comprised of equipment manufacturers and users of data processing equipment and
services. ANSI membership is comprised of people form professional societies, industry
associations, governmental and regulatory bodies, and consumer goods.
5. Electronics Industry Association (EIA)
EIA is a non-profit U.S. trade association that establishes and recommends industrial
standards. EIA activities include standards development, increasing public awareness, and
