TUe Computer Science, System Architecture and Networking

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2IC15 Computer Networks
Introduction
Igor Radovanovic
Thanks to A. Leon-Garcia I. Widjaja
TU/e Computer Science, System Architecture and
Networking
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The aims of the course

• To stress the importance of networks (WHY)
• To inform you HOW networks work and WHAT the main
  issues are that need to be taken into account
  when designing those
• To give you a flavor WHY the things are as they
  are
• To help you in designing networked applications
  (HOW)
• To give you a solid basis for the future research
  in this area (IMPROVE)
• To have fun!

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What a network actually is?

• Does a connection mean a network?
• An interconnected or intersecting configuration
  of system of components
• An intricately connected system of things or
  people
• A network of spies
• A web of intrigue
• Networking
• Communicate either with or within a group
• You have to network if you want to have a good
  job!

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Telecommunication network

• A network of transmission systems arranged so
  that messages may be passed from one part of the
  network to another.
• Transmission system
• transmits a signal from one place to another.
• Signal electrical, optical or radio

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What about computer network?

• Physically physical infrastructure connecting
  access points
• infrastructure cables, repeaters, hubs,
  switches, routers
• access point physical location where a terminal
  (a user of the network) attaches
• Network Interface Cards and OS are included
• Logically a facility for the exchange of
  information between disparate applications
• disparate unrelated, not sharing memory

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Why networks?

• Why on Earth should anyone be interested in
  networks?
• What is your motivation to follow this course?
• Why does one want to do the work in networking?
• Why is that area so important?
• Benefits social, economical, cultural
• MATRIX

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Need for networks

• To improve our lives
• To serve various applications
• Actually, we (or applications) require SERVICES
  from the network
• Sometimes SERVICES are provided without a request
  (maybe even a need)
• What is a SERVICE?

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Motivation for network development

• Information technology revolution
• Technology development
• Industrial development
• Economics
• Social aspects
• Peoples needs

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Technology development

• Communication development
• Telephone
• Radio
• Television
• Satellite
• All of these required connection to the user

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Communication networks

• Telephone network
• 1960s Undersea cable carried 138 calls
• 1996 Fiber-optic cable carried 1.5M calls
• 10 000 times/35 years
• 2005 Mobile networks more than 2 billion users
• Data network
• 1969 4 hosts on the Internet
• 1983 500 hosts
• 1995 4.5 million hosts, 30 million users
• 2007 434 million hosts
• Almost 1 000 000 times/24 years

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Networking trends

• Telephony networks
• Voice carried on the Internet
• BT is planning to transform its UK
  telecommunications infrastructure into a pure
  IP-based network by 2009.
• June 2004

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Internet Phone networks

• Latest mobile phones equipped with WiFi cards
• PDAs equipped with GSM GPRS
• Is voice going to be carried on the Internet
  network?
• What will happen to existing phone networks?
• Companies, operators?

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Communication networks

• Data rate growth over years

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Computer processor development

• The number of transistors integrated into a
  processor

Taken from www.intel.com
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Predictions in computer development
I think there is a world market for maybe 5
computers (Thomas Watson, top man of IBM,
1943) There is no reason for any individual to
have a computer in their home ( Ken Olsen, top
man of DEC, 1977)
TU/e Computer Science, System Architecture and
Networking
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A number of Internet Domains

• A group of computers whose hostnames share a
  common suffix, the "domain name".

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Top-level domain names
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Importance of networks

• Metcalfes Law
• The usefulness, or utility, of a network equals
  the square of the number of users.
• Join the fun!

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Motivation for network development

• Information technology revolution
• Technology development
• Industrial development
• Economics
• Social aspects
• Peoples needs

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Industrial development

• Implementation of IT in enterprises, governments,
  institutions
• Companies started to spread around the world
• Communication among departments from different
  locations became essential in company development
  

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Getting mature

• Time to learn how to use technology
• Time before this technology impacts the social
  and economical aspects of the society
• Social aspects Printing machine
• 1500-1550 time of glory
• New religions (bibles printed in large
  quantities)
• New discoveries (maps)
• Economical aspects roads and networks
• 1925 different city planning
• 1960s large shopping malls along highways
• 50 years of learning

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Motivation for network development

• Information technology revolution
• Technology development
• Industrial development
• Economics
• Social aspects

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Economical impact

• E-commerce
• Electronic banking
• Electronic ticket reservation
• Electronic shopping (Amazon.com)
• E-business
• Internet
• Intranet
• Extranet
• 28 of Dutch companies had it operational in 2002

www.ebusiness-watch.org
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Motivation for network development

• Information technology revolution
• Technology development
• Industrial development
• Economics
• Social aspects

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Social aspects

• Can networks fulfill peoples needs?
• Can people benefit from networks?
• E-learning
• Better communication
• Working from home
• Second life
• How do networks change our lives?
• Difficult to predict what will happen

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Key factors in communication network evolution
user
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Role of technology

• Technology should not only be available but also
  be cost-effective
• Technology limitation
• Old technologies replaced by new ones - recycling

fiber
coax
copper
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Key factors in communication network evolution
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Role of the market

• Trends and hypes
• There must be a critical mass for the new service
• 1970 picture-phone service - hype
• late 1970s cellular radio telephony - trend
• Any recent trends or hypes?

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Key factors in communication network evolution
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Role of standards

• Interoperability of equipment of different
  vendors
• The value of the network depends on the size of
  community it can reach
• More suppliers -gt more competition -gt lower price
• Standardization bodies
• International Telecommunication Union (ITU)
• Internet Engineering Task Force (IETF)
• Institute of Electrical and Electronic Engineers
  (IEEE)

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Key factors in communication network evolution
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Role of regulations

• Governmental regulation for industry protection
• or open market competition
• 1984 split of ATT
• Examples from Today in Telecom (Nov 2005)
• Philippines telecom regulator National
  Telecommunications Commission (NTC) has banned
  the use of foreign Internet protocol (IP) codes.
  
• Tom Online, a Chinese Internet service provider,
  is in talks with China CNC and China Telecom to
  provide PC-Telephone services through Skype in
  the country. These two operators are licensed to
  provide Internet telephony in China. Earlier,
  Chinese government proposed a plan to ban
  Internet telephony to protect the revenues of
  state run telecom companies.

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Key factors in communication network evolution
Do not forget a user!
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Avoiding user consequences

• Telecom pushed technology-pushed strategy
• Wireless Application Protocol (WAP)
• Advertised as internet made mobile
• In fact was just a protocol
• Multimedia Messaging Service (MMS)?
• a successful replacement of SMS a hype

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An example of an IP network
Taken from www.ntt.net
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IP network in The Netherlands
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Research areas in networking

• Routing
• Security
• Ad-hoc networks
• Wireless networks
• Optical networks
• Protocols
• Quality of Service
• Peer-to-peer networks
• Cross-layer design
• for improving the non-functional properties