Data Communication Lecture Slides containing a timeline on the history of data communication and the definition ob basic data communication terms and concepts based largely on the book Electronic Communication by Wayne Tomasi.

1. ECE 521F
Data Communications
ECE 521F (Data Communications)
ECE @Saint Louis University, Baguio City 1
Prepared by: Engr. Jeffrey Des B. Binwag

2. Course Outline
• PRELIMINARY PERIOD
– Introduction to Data Communications
– Data Communications Circuits
– Serial and Parallel Data Transmissions
– Overview of Networking Issues, Network Architectures, and
Protocol Architectures
– The Open Systems Interconnection
– QUIZ 1
– Data Communications Codes
– Error Control Codes
– Data Terminal Equipment, Framing, and Synchronization
– Serial Interfaces
– Data Communications Equipment
– QUIZ 2 ECE @Saint Louis University, Baguio City 2

3. Course Outline
• MIDTERM PERIOD
– Introduction to Data Link Protocols
– Data Link Protocols
• Character-Oriented Protocols
• Bit-Oriented Protocols
• Asynchronous Data Link Protocols
• Synchronous Data Link Protocols
• SDLC and HDLC
– QUIZ 3
– Introduction to Switched Circuits
– Circuit Switching and Packet Switching
– Local Area Networks, Applications, and Architectures
• Ethernet
• Ring
• Token Ring
• FDDI
– QUIZ 4
ECE @Saint Louis University, Baguio City 3

4. Course Outline
• FINAL PERIOD
– Local Area Networks and Interconnections
• Repeaters
• Bridges and Switches
• Routers and Gateways
– QUIZ 5
– The Internet
• Overview of the Internet
• The Internet Protocol
• Domain Name Systems
• Internet Protocol Over Internet
– QUIZ 6
ECE @Saint Louis University, Baguio City 4

5. Course Requirements
• Quizzes
• Groupworks
• Homeworks
• Exams
• 60% Class Standing Scores
– Quizzes, Groupworks, Homeworks
• 40% Exam Score
• Term Grade= 50 + 30(CS)/TCS+20(Exam)/Exam Total
• FG=(PG+MG+TFG)/3
ECE @Saint Louis University, Baguio City 5
Grading System

6. ECE @Saint Louis University, Baguio City 6
21 3
4 cm
3 cm
2 cm
2 cm
3 cm
2 cm
Page Format
(for homeworks/ seatworks)
• Computer printout
• Margins in red ink
• Text in black ink
• Section 1 contains the
• Subject
• Schedule
• Room
• Section 2 contains the names of
group members in two columns
• Section 3 remains blank for
scores/remarks
• Font is Arial, 12 pt.
• CONTENTS
• Homework Title/ Coverage
• Answers to Questions/
Solutions to Problems
• Essential Learning Insights

7. Module 1
Introduction to Data
Communications
Chapter 21
Electronic Communications Sytems , Fifth Editon
By: Wayne Tomasi
ECE @Saint Louis University, Baguio City 7
Prepared by: Engr. Jeffrey Des B. Binwag

8. Introduction
• Data Communications. The transmission, reception, and processing of
digital information.
• Data. Information that is stored in digital form. Information that has
been, processed, organized and stored.
• Data Communications Network. Systems of interrelated computers
and computer equipment connected through the public telephone
network or similar network infrastructure.
Any system of computers, computer
terminals, or computer peripheral equipment to transmit and/or
receive information between two or more locations.
• Network. A set of devices, nodes, or stations interconnected by media
links.
• Internet. A public data communications network used by millions of
people worldwide to exhange business and personal information.
• Intranet. Private data communications networks used by many
companies to exchange information among employees and resources.
• Worl Wide Web (WWW). A server-based application that allows
subscribers to access the services offered by the Web.
ECE @Saint Louis University, Baguio City 8

9. Data Communication Network Example:
Public Switched Data Networks (PSDN)
ECE @Saint Louis University, Baguio City 9

10. History of Datacom
• 1753. One of the earliest means of communicating
electrically coded information through a 26 wire
system.
• 1833. Carl Friedrich Gauss developed a system based
on a 5x5 matrix representing 25 letters.
• 1832. The telegraph (the first data communication
system) was invented by Samuel F.B. Morse.
• 1840. The American patent for the telegraph was
granted.
• 1844. The first telegraph line was established
between Baltimore and Washington D.C. conveying
the first telegraph message “What hath God
wrought!”
ECE @Saint Louis University, Baguio City 10

11. History of Datacom
• 1849. The first slow-speed telegraph printer was
invented.
• 1850. Western Union Telegraph Company was formed
in Rochester, New York, for the purpose of carrying
coded messages from person to another.
• 1860. “High-speed” printers (15 bps) became
available.
• 1874. Emile Baudot invented the a telegraph
multiplexer that allowed signals from up to six
different telegraph machines to be transmitted
simultaneously over a single wire.
• 1875. The telephone was invented by Alexander
Graham Bell.
ECE @Saint Louis University, Baguio City 11

12. History of Datacom
• 1899. Guglielmo Marconi succeeded in sending
radio (wireless) telegraph messages.
• 1920. The first commercial radio stations
carrying voice information were installed.
• 1930s. Konrad Zuis, a German engineer,
demonstated a computing machine.
• 1940. Bell Laboratories developed the first
special purpose computer using
electromechanical relays for performing logical
operations.
• 1946. The first modern-day computer (ENIAC)
was developed by J. Presper Eckert and John
Mauchley at the University of Pennsylvania.
ECE @Saint Louis University, Baguio City 12

13. History of Datacom
• 1949. The U.S. National Bureau of Standards
developed the first all-electronic diode based
computed capable of executing stored-programs.
• 1950s. “Batch processing” computers used punched
cards as an input interface, printers as an output
interface, and magnetic tape reels for data storage.
The first general purpose computer in the
form of an automatic sequence-controlled calculator
was developed jointly by Harvard University and IBM
Corporation.
• 1951. Remington Rand Corporation built the first
mass-produced electronic computer (UNIVAC).
ECE @Saint Louis University, Baguio City 13

14. History of Datacom
• 1960s. Batch-processing systems were replaced
by on-line processing systems with terminals
connected directly to the computer through
serial or parallel communication lines.
• 1968. The landmark US Supreme Court
Carterfone decision allowed non-Bell (non AT&T)
equipment to be connected to the vast AT&T
network.
• 1969. The internet began to evolve at the
Advanced Research Projects Agency (ARPA)
through the ARPANET.
• 1970s. Microprocessor-controlled
microcomputers were developed.
ECE @Saint Louis University, Baguio City 14

15. History of Datacom
• 1980s. Personal computers became an essential
item in the home and the workplace. Since
then, the need to exchange digital information,
and consequently, the need for data
communication circuits, networks, and systems
increased exponentially.
• 1983. AT&T agreed in a court settlement to
divest itself of operating companies that provide
basic local telephone service to various
geographic regions of the US as a result of an
anti-trust suit filed by the federal government.
• Mid 1980s to 1995. The United Stated National
Science Foundation (NSF) funded a high-speed
backbone calles the NSFNET.ECE @Saint Louis University, Baguio City 15

16. History of Datacom
• 1989. Tim Berners-Lee and Robert Cailliau build
the prototype system which became the World
Wide Web at CERN.
• 1991. Anders Olsson transmits solitary waves
through an optical fiber with a data rate of 32
billion bits per second.
• 1992. Neil Papworth sends the first SMS (or text
message).
Internet2 organization is created.
• 1994. Internet radio broadcasting is born.
• 1999. 45% of Australians have a mobile phone.
Sirius satellite radio is introduced.
ECE @Saint Louis University, Baguio City 16

17. History of Datacom
• 2001. First digital cinema transmission by
satellite in Europe of a feature film by Bernard
Pauchon and Philippe Binant is undertaken.
• 2003. Apple launches the iTunes Music Store and
sells one million songs in its first week.
MySpace is launched.
• 2004. What would become the largest social
networking site in the world, Facebook is
launched.
• 2005. YouTube, the video sharing site is
launched.
• 2006. Twitter, microblogging is introduced.ECE @Saint Louis University, Baguio City 17

18. History of Datacom
ECE @Saint Louis University, Baguio City 18
Source: http://www.internetsociety.org/internet/what-internet/history-internet/brief-history-internet
• Internet Timeline

19. Module 2
Datacom Network, Architecture,
Protocols, and Standards
Chapter 21
Electronic Communications Sytems , Fifth Editon
By: Wayne Tomasi
ECE @Saint Louis University, Baguio City 19
Prepared by: Engr. Jeffrey Des B. Binwag

20. Datacom Network, Architecture,
Protocols, and Standards
• Network Architecture. A system that outlines
the products and services necessary for the
individual components within a data
communications network to operate together.
It is a set of equipment, transmission media,
and procedures that ensures that a specific
sequence of events occurs in a network in the
proper order to produce the intended results.
ECE @Saint Louis University, Baguio City 20

21. Datacom Network, Architecture,
Protocols, and Standards
• Data Communications Protocol. Sets of rules
governing the orderly exchange of data within
the network or a portion of the network.
• Protocol Stack. The list of protocols used by a
system which normally includes one protocol
per layer.
ECE @Saint Louis University, Baguio City 21

22. Datacom Network, Architecture,
Protocols, and Standards
• Network Protocol Clasification.
– Current. Most modern and sophisticated
– Legacy. Old but still useful
– Legendary. Old and no longer in use
• Computer Network General Classification.
– Broadcast. Involves all stations in the network
sharing the communications channel.
– Point to point. Involves only two stations at a time.
ECE @Saint Louis University, Baguio City 22

23. Datacom Network, Architecture,
Protocols, and Standards
• Connection-Oriented Protocol.
– Requires a handshake prior to transmission
– Generally requires acknowledgement procedures
– Often provides an error control mechanism
– Connection is dropped by a specific handshake
when it is no longer needed
*Handshake. A connection procedure that ensures the
integrity of the connection between stations in a
network prior to the exchange of data between them.
ECE @Saint Louis University, Baguio City 23

24. Datacom Network, Architecture,
Protocols, and Standards
• Connectionless Protocol.
–Does not require a handshake prior to
transmission
–Does not support error control or
acknowledgment procedures
–Is more efficient because the data being
transmitted do not justify the extra overhead
required by connection-oriented protocols
ECE @Saint Louis University, Baguio City 24

25. Datacom Network, Architecture,
Protocols, and Standards
• Standard. An object or procedure considered by
an authority or by general consent as a basis of
comparison.
• Data Communications Standards. Guidelines
that have been generally accepted by the data
communications industry. They outline procedures
and equipment configurations that help ensure an
orderly transfer of information between two or
more data communication equipment of networks.
ECE @Saint Louis University, Baguio City 25

26. Datacom Network, Architecture,
Protocols, and Standards
• Classification of Standards.
–Proprietary Standards. Closed system
standards generally manufactured or controlled
by one company.
–Open System Standards. Guidelines that can be
used by any company to produce compatible
equipment or software after a royalty has been
paid to the original company.
ECE @Saint Louis University, Baguio City 26

27. Standards Organizations for Data
Communications
• ISO. International Standards Organization
• ITU-T. International Telecommunications Union-
Telecommunications Sector
• CCITT. Comité Consultatif Internationale de Télégraphie
et Téléphonie
• IEEE. Institute of Electrical and Electronics Engineers
• ANSI. American National Standards Institute
• EIA. Electronics Industry Association
• TIA. Telecommunications Industry Association
ECE @Saint Louis University, Baguio City 27

28. Standards Organizations for Data
Communications
ECE @Saint Louis University, Baguio City 28
ISO
ITU-T IEEE ANSI
EIA TIA

29. Standards Organizations for Data
Communications
• ITU-T Study Groups:
– Network and Service Operation
– Tariff and Accounting Principles
– Telecommunications Management Network and Network Interface
– Protection Against Electromagnetic Environment Effects
– Outside Plant
– Data Networks and Open Systems Communications
– Characteristics of Telematic Systems
– Television and Sound Transmission
– Language and General Software Aspects of Telecommunication Systems
– Signaling Requirements and Protocols
– End-to-end Transmission Performance of Networks and Terminals
– General Network Aspects
– Transport Networks, Systems, and Equipment
– Multimedia Services and Systems
ECE @Saint Louis University, Baguio City 29

30. Standards Organizations for Data
Communications
• IAB. Internet Architecture Board
– Oversees Internet architecture protocols and procedures.
– Manages processes used to create Internet standards and serves as an
appeal board for complaints on the proper of execution of such
processes.
– Administers various Internet assigned numbers.
– Represents Internet Society interests in liaison relationships with other
organizations.
– Source of advice for guidance to the Internet Society concerning
technical, architectural, procedural, and policy matters concerning the
Internet and its enabling technologies.
• IETF. Internet Engineering Task Force
• IRTF. Internet Research Task Force
ECE @Saint Louis University, Baguio City 30

31. Standards Organizations for Data
Communications
ECE @Saint Louis University, Baguio City 31
IAB
IETF IRTF

32. Layered Network Architecture
• The layering of network responsibilities allows each layer to
add value to services provided by sets of lower layers.
• Layered architecture facililitates peer-to-peer network
protocols.
• Layered architecture allows different computers to
communicate at different levels.
• When technological advances occur, it is easier to modify
one layer’s protocol without having to modify all the other
layers.
• The disadvantage of layered architecture is the tremendous
amount of overhead required.
ECE @Saint Louis University, Baguio City 32

33. Layered Network Architecture
• Protocol Data Unit (PDU). A unit of data used to facilitate
seamless exchange of information between layers of the
protocol stack. Consists of a header and/or trailer
appended to the data as it passes through a layer.
• Encapsulation. The process of adding a protocol data unit
as the data frame passes from an upper layer to the layer
immediately below it. (Downward direction)
• Decapsulation. The process of removing a protocol data
unit as the data frame passes from a lower to the layer
immediately above it. (Upward direction)
ECE @Saint Louis University, Baguio City 33

34. Popular Layered Protocols
• OSI (Open Systems Interconnection). A seven layer
protocol developed and adopted by the ISO and the ITU-T
in 1983.
• TCP-IP (Transmission Control Protocol/Internet Protocol).
A three or four layer protocol developed by the
Department of Defense of the United States before the
inception of the OSI model.
• CISCO THREE-LAYER MODEL. A Three-layer logical hierarchy
developed by CISCO that specifies where things belong,
how they fit together, and what functions go where.
ECE @Saint Louis University, Baguio City 34

35. Open Systems Interconnection
 User networking applications and interfacing to
the network
 Encoding language used in transmission
 Job management tracking
 Data tracking as it moves through a network
 Network addressing and packet transmission on
the network
 Frame formatting for transmitting data across a
physical communications link
 Transmission method used to propagate bits
through a network
ECE @Saint Louis University, Baguio City 35
LAYERS FUNCTIONS

36. Open Systems Interconnection
ECE @Saint Louis University, Baguio City 36
TCP/IP

37. Open Systems Interconnection
ECE @Saint Louis University, Baguio City 37

38. OSI and its Protocol Data Units
ECE @Saint Louis University, Baguio City 38

39. TCP-IP Protocol Layers
• Network Access Layer. Provides a means of
physically delivering data packets using frames or
cells.
• Host-to-host Layer. Services the process and
Internet layers to handle the reliability and session
aspects of data transmission.
• Internet Layer. Contains information that pertains
to how data can be routed through the network.
• Process Layer. Provides applications support.
ECE @Saint Louis University, Baguio City 39

40. CISCO Protocol Layers
• Core Layer. Top layer responsible for transporting large
amounts of data traffic reliably and quickly. Primarily tasked
to switch traffic as quickly as possible.
• Distribution Layer/Workgroup Layer. The communication
point between the access and the core layers that provides
routing, filtering, WAN access, and control on the number
of data packets allowed to access the core layer.
• Access Layer/Desktop Layer. Responsible for access
control, segmentation (creation of collision domains), and
workgroup connectivity to the distribution layer.
ECE @Saint Louis University, Baguio City 40