Lecture 1. TCP/IP Overview and History

1. Lecture 1. TCP/IP Overview and History

Semester – 7-th
Lectures
Laboratory classes
Modules
Course Project
Exam
– 2 academic hours per a week
– 2 academic hours per a week
–2
–1
Computer networks let you make more mistakes faster than any invention in
human history – with the possible exceptions of handguns and tequila.
Lecture 1. TCP/IP Overview and
History
Topics of the lecture 1:
1. APPAnet is the predecessor of the Internet.
2. Packet-switching mode and redundant topology.
3. Concepts: communication, internetwork, internet, intranet, Internet,
and other concepts.
4. Protocol, stack of protocols, protocol suite.
5. TCP/IP architectural model.

2. An Interconnection of Different LANs

When networks with different technologies, such as Ethernet and Token Ring need to be
connected together, this requires reconstruction of the data frames. To do this, a special
intermediary device called a gateway is used.
A gateway is a device that can connect a LAN to a LAN, a LAN to a WAN, a LAN to a
mainframe, translate protocols, or convert transmission media.
In the general case a gateway can require information from above the application layer of the
OSI model. In TCP/IP networks gateways require information from three bottom layers.
The Ethernet network was first deployed in 1976.
The Token Ring LAN was introduced by IBM in 1984 and was then standardized with
protocol IEEE 802.5.
The ARCNet (Attached Resource Computer Network) was invented in 1976 and was
first put into service at Chase Manhattan Bank in 1977.
Interconnection is the physical linking of different networks with each other by means of a
special equipment and physical media of the data transmission.
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Gateway – шлюз.

3. Advanced Research Projects Agency - ARPA

ARPA researches played a central role in launching the
Information Revolution. The agency developed and
furthered much of the conceptual basis for the ARPANET
— prototypical communications network launched nearly
half a century ago — and invented the digital network
protocols that gave birth to the Internet.
Agency overview
(by 2009)
Formed
- 1958
Since 1972
- DARPA
Headquarters
- Arlington,
Virginia
Employees
- 240
Annual budget
- $3.2 billion
Agency executive - Regina E.
Dugan , Director
Website - www.darpa.mil
At first DARPA was created as the Advanced Research
Projects Agency (ARPA), by Public Law 85-325 and
Department of Defense Directive 5105.41, in February
1958 in response to the surprise Sputnik launch by the
Soviet Union in 1957.
The Defense Advanced Research Projects Agency
(DARPA) is an agency of the United States Department
of Defense responsible for the development of new
technology for use by the military.
DARPA has been responsible for funding the
development of many technologies which have had a
major effect on the world, including computer
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networking.

4. Information Processing Techniques Office (IPTO)

was born in 1962 under the direction of Joseph
Licklider to support research dealing with the field of
computer related technologies. For 25 years IPTO was
responsible for DARPA’s information technology
programs.
IPTO did not perform research individually, but rather
invested in breakthrough technologies and seminal
(продуктивних) research projects that led to significant
developments in computer hardware and software.
Some of the most fundamental advances came in the areas of networking,
communications, computer graphics, advanced microprocessor design, parallel
processing and artificial intelligence. IPTO was conducting an investment
strategy in line with the vision of the office’s first director, J. C. R. Licklider.
Licklider believed that humans one day would interact closely with computers,
which, in his words, can be gateways to a vast world of online information.
Licklider was a brilliant visionary (блискучим провидцем) and pioneer in the field of
human-computer interaction and specifically in the field of interactive computing.
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http://www.livinginternet.com/i/ii_ipto.htm
Information Processing Techniques Office (IPTO)

5. Structures of the communication systems

а) the topology of the telephone system
(Toll office – міська і міжміська телефонна
станції)
б) the distributed switching system,
proposed by Paul Baran from RAND
corporation
The redundant topology and the packet switching mode of data
transmission were the first progressive features of the new network design.
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6. The Scheme of the ARPA Network

Wesley Clark suggested
to employ small
computers at each site
to perform networking
functions and leave the
mainframes alone.
All of the small computers could speak the same language which would facilitate
communication between them. Each host computer (mainframe) would only have
to adapt its language once in communicating with its small computer. Each
mainframe would be connected to the network via its small computer which would
act as a sort of gateway into networks.
Larry Roberts adopted Clark's idea. He called the small computers the Interface
Message Processors (IMPs). Roberts decided that the network should start
out with four sites: UCLA, the Stanford Research Institute (SRI), the University
of Utah, and UC Santa Barbara. This would be the core and the network could
grow from there.
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7. IMP - Interface Message Processor

The front panel of the IMP
IMP - Interface Message Processor is the core component of the network.
The IMP was built on the modified Honeywell DDP-316 minicomputer with 12K
16-bit words of core memory. It provided data transmission between dissimilar
computers (mainframes) that resided on the different universities.
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The IMPs were interconnected by 56-kbps lines leased from telephone companies.

8. The ARPAnet in December 1969

ARPANET was the internetwork that became the basis for the Internet.
In August 1969, the first IMP had been delivered to UCLA. A month later, the
second IMP had been delivered to SRI. The two IMP were connected by means
of 56-kbps lines leased from telephone companies and the ARAPNET was born.
http://som.csudh.edu/fac/lpress/history/arpamaps/
In 1969, The University of Utah Computer Science Department became the fourth node on the ARPANET
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9. Initial ARPAnet Configuration (December 1969)

1. At the UCLA Leonard Kleinrock
established a Network
Measurement Center, with an SDS
Sigma 7. It was the first computer
attached to the IMP;
2. At the Stanford Research Institute
the SDS 940 computer was used.
3. The University of California, Santa
Barbara (UCSB) possessed IBM
360/75, running OS/MVT;
4. The University of Utah's Computer Science Department used a DEC PDP-10
operating on TENEX.
The Interface Message Processor (IMP) was the packet switching node used to
interconnect different computers to the ARPANET from the late 1960s to 1989. It was
the first generation of gateways, which are known today as routers.
An IMP was a ruggedized Honeywell DDP-516 minicomputer with special-purpose
interfaces and software.
ARPAnet was closed in early 1990s.
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10. Logical Map of the ARPANet, February, 1982

http://www.vox.com/a/internet-maps
Logical Map of the ARPANet, February, 1982
By 1982, the network only had about 100 nodes. But that was enough to
support an online community
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11. Pioneers of Computer Networking

Larry Roberts
( was born in 1937)
Paul Baran
(was born in 1926)
Wesley Clark
(was born in
1927)
Leonard Kleinrock
(was born in 1934)
J.C.R. Licklider - American computer scientist who created the idea of a universal network
which his successors developed into the internet, the first Director of the IPTO. He was a
brilliant visionary and pioneer in the field of human-computer interaction and specifically the
field of interactive computing.
Larry Roberts is sometimes called the "father of the ARPANET.“ He was also the principal
architect of the ARAPNET.
Paul Baran had proposed two ideas that became very important in the development of the
ARPANET: the first - to build a distributed network; the second - to use a packet switching
for data transmitting.
Leonard Kleinrock is an American engineer and computer scientist, a professor at
UCLA's Henry Samueli School of Engineering and Applied Science. He made several
important contributions to the field of networking, in particular to the theoretical foundations
of computer networking. He played an influential role in the development of the ARPANet. 11
https://www.ibiblio.org/pioneers/roberts.html
J.C.R. Licklider
(11 Mar 1915 - 26
Jun 1990)

12. Packet-Switching in the Networking

Packet switching method is used by some network technologies to deliver data
across network connections of any complexity.
The packet switching method of data delivery is used by Ethernet networks and
TCP/IP networks.
Router is a basic component of the packet switching networks.
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13. Components of a Modern Complex Network

A computer network consists of devices: end devices and intermediary devices;
medium and services.
End devices are servers and workstations that communicate with people.
Intermediary devices are routers, switches and other communication devices
Devices and medium are the physical elements or hardware of the network.
Services and processes are the communication programs, called software, that
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run on the network devices.

14. End Devices

End devices are network devices that allow people to communicate
with each other. Also these devices serve requests generated by
people.
Some examples of end devices are:
• Computers (work stations, laptops, file servers, web servers);
• Network printers;
• VoIP phones;
• Security cameras;
• Mobile handheld devices (such as wireless barcode (штрих-код)
scanners, PDAs).
In the context of IP and TCP protocols, end devices are referred to as hosts.
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15. Intermediate Network Devices

Examples of intermediate network devices are:
Network Access Devices (hubs, switches, and wireless access points);
Internetworking Devices (routers);
Communication Servers and Modems;
Security Devices (firewalls).
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16. List of Functions of Intermediate Network Devices

Processes running on the intermediary network devices perform
such functions:
• the regeneration and retransmission of data signals;
• the maintaining information about what routes exist through
the network and internetwork;
• the notification of other devices about errors and
communication failures;
• sending data along alternate routes when there is a link
failure;
• classifying and sending messages according to QoS priorities;
• the permission or denying the data flow based on security
settings.
Intermediate – проміжний, перехідний, проміжний ланцюг, посередник
Intermediary – посередник, посередництво, проміжний
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17. Network Media

On computer networks such media are used:
• metallic wires within cables (twisted pair and coaxial cables);
• glass or plastic fibres (fibre optic cable);
• radio waves for wireless transmission.
Criteria for choosing a network media are:
• The distance the media can successfully carry a signal.
• The environment in which the media is to be installed.
• The amount of data and the speed at which data must be transmitted.
• The cost of the media and their installation.
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18. Common Data Network Symbols (Pictograms)

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19. Definition of some Network Concepts

A communication is a process of exchanging information between two or more
network entities, for example, end devices.
A communications is a system for transmitting information, for example,
computer network, telephone, TV and so on.
In the world of computer networks, networking is the practice of interfacing two
or more network computing devices (end devices) with each other for the
purpose of data exchanging.
Internetworking is the interconnection of two or more networks via special
means and technologies.
An internetwork (or internet) is a group of networks connected by routers for
communication purposes. Hence, an internetwork might be a heterogeneous
network. Inherently, the words internetwork and internet are simply a
contraction of the phrase interconnected networks.
The Internet is a publicly accessible system of networks that connects computers
around the world via the TCP/IP protocols.
The intranet is a connection of private LANs and WANs that belongs to an
organization or enterprises.
"to interconnect" is equal to "to connect with one other".
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20. An internetwork and the Internet

LANs and WANs may be interconnected into an internetwork - a
global mesh of interconnected computer networks.
The Internet is the most well-known and widely used publicly-accessible
internetwork that was created by means of TCP/IP protocols.
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21. Definition of the term “Protocol”

1)
In computer networking a protocol is a standard procedure for
regulating data transmission between network computers
(network devices).
2)
A protocol is a set of rules governing the transmission process of
messages and their format which computers can exchange on the
network.
IP (Internet Protocol) is the sample of computer network protocols.
A standard is a protocol (official document) that has been endorsed
(схвалений) by the networking industry and ratified by a standards
organization, such as:
•the Institute of Electrical and Electronics Engineers (IEEE) or
•the Internet Engineering Task Force (IETF).
Many of the networking protocols refer to other widely utilized protocols
or industry standards.
The use of standards in developing and implementing computer networks
ensures that products from different manufacturers can work together for
efficient communication.
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22. Protocol Stack or Protocol Suite

A protocol stack is a set of network protocols.
All these protocols work together and perform a complex of interrelated
networking tasks.
All protocols of a stack are divided into layers.
A protocol suite (комплект) is a group of interrelated
network protocols that are necessary to perform
communication functions on a network.
A protocol stack is a complete set of interrelated
network protocols that are divided into layers and
work together to provide networking capabilities.
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23. Network Protocols Describe:

• the format or structure of the message
(protocol data unit);
• the method by which networking devices
share information about pathways with
other networks;
• how and when error and system
messages are passed between devices;
• the setup and termination of data transfer
sessions.
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24. OSI Reference Model

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25. TCP/IP Architectural Model

TCP/IP architectural model describes components
and functions of the TCP/IP protocol stack.
TCP and IP are two main protocols of the TCP/IP
protocol stack.
This model is known by different names:
• the TCP/IP architectural model;
• the DARPA model (after the Defense Advanced
Research Projects Agency - agency that was
largely responsible for developing TCP/IP);
• the DoD model (after the United States
Department of Defence).
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26. TCP/IP Architectural Model (or DoD Model)

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27. The Comparison of the TCP/IP and OSI Models

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28. The Communication Process

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29. The communication process

The communication process in accordance with the TCP/IP
model consists of these steps:
1. Creation of data at the application layer of the originating
source device (end device);
2. Segmentation and encapsulation of data as it passes down
the protocol stack in the source device (end device);
3. Generation of the signal onto the medium at the network
access layer of the stack (in fact, by means of a equipment
of the OSI Physical layer);
4. Transportation blocks of the data through the internetwork,
which consists of medium and an intermediate devices;
5. Reception of the data at the network access layer of the
destination (end device);
6. Decapsulation and reassembly of the data as it passes up
the stack in the destination device;
7. Transfer this data to the destination application at the
Application layer of the destination end device.
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30. Types of data blocks of the TCP/IP model

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31. Protocol Data Units and Encapsulation

The protocol data unit refers to blocks of information that are
created at each level of the reference model.
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32. Questions for self check

1.
2.
3.
4.
5.
6.
What does the abbreviation ARPA mean?
Tell about a role and purposes of ARPA.
Tell about a role and purposes of IPTO.
Describe the scheme of the ARPA Network.
What does the IMP stand for? What are the functions of IMP?
What topology is called redundant? Why is redundant topology
used for large regional networks?
7. Explain the packet-switching mode?
8. Tell about an initial configuration of the ARPANet?
9. Name the main end network devices and explain briefly their role
and designation.
10. Name the main intermediary network devices and explain briefly
their role and designation.
11. What does the term ‘protocol’ mean in computer networking?
12. Describe the TCP/IP architectural model.
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