Foundations

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Foundations

• How we got to where we are

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Information Communications Technology

• Telephone and messaging service to all parts of
  the world
• Worldwide digital communications
• Entertainment services
• Personal computers
• Worldwide connectivity via the Internet and the
  World Wide Web
• Access to information of all kinds

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How Did We Get to Where We Are

• We started with simple hand-keyed Morse code
  telegraphy
• Introduced voice telephone networks
• Moved to digital technology within them
• Then to the provision of data communication
  networks of two types
• the TDM synchronous, circuit-oriented networks of
  the telephone industries and
• the best-effort, packet-switched internetworking
  strategies of the US DoD, which grew into the
  Internet and gave us the IP Networks of today.

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Where Will We Be Tomorrow?

• A ubiquitous broadband, multimedia, IP-based
  network
• with a large set of communication services
• serving an immense array of applications
  dependent on information and communications
  technology (ICT)
• which are available to enable and support all
  aspects of modern society.

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Applications Enabled by ICT

• Banking and Financial Transactions
• Transportation and Travel
• Business
• Commerce
• Property Management
• Education
• Medicine
• Entertainment
• Security
• Military Affairs
• Justice
• Industry

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ICT Services

• Information Storage, Retrieval, Distribution,
  and Processing
• Messaging IM, email
• Conferencing
• Telemetry, Telematics
• Reservations and Scheduling
• Inventory and Catalog Management
• Command and Control
• Billing, Accounting, Paying
• Audio, Video and Data

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ICT Applications

• E-Commerce
• Publishing
• Supply Chain Management
• Social Networking
• Multimedia Broadcasting

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Are these new ideas?

• No, they are not!
• A man named Casson said it all back in 1910, when
  the telephone revolution had come and gone.

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It has all been said before!

• In 1910, H.D. Casson wrote a book, entitled The
  History of the Telephone, in which he made it
  obvious that the future had arrived!
• The History of the Telephone is a fascinating
  book. It provides a detailed, on-the-spot
  recounting of the early days with Bell and the
  ATT Co,
• In addition it describes existing and potential
  telephone applications that we are still
  implementing and re-inventing!
• The coverage of social implications is amazing.
  The insights in THOTH have been repeatedly
  rediscovered in every review that has taken place
  since.
• http//sailor.gutenberg.org/by-title/xx710.html

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The History Of The Telephone

• Thirty-five short years, and presto! The newborn
  art of telephony is fullgrown. Three million
  telephones are now scattered abroad in foreign
  countries, and seven millions are massed here, in
  the land of its birth.
• So entirely has the telephone outgrown the
  ridicule with which, as many people can well
  remember, it was first received, that it is now
  in most places taken for granted, as though it
  were a part of the natural phenomena of this
  planet. It has so marvellously extended the
  facilities of conversation--that "art in which a
  man has all mankind for competitors"--that it is
  now an indispensable help to whoever would live
  the convenient life.

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From THOTT

• The disadvantage of being deaf and dumb to all
  absent persons, which was universal in
  pre-telephonic days, has now happily been
  overcome and I hope that this story of how and
  by whom it was done will be a welcome addition to
  american libraries.
• What we might call the telephonization sic of
  city life, for lack of a simpler word, has
  remarkably altered our manner of living from what
  it was in the days of Abraham Lincoln. It has
  enabled us to be more social and cooperative. It
  has literally abolished the isolation of separate
  families, and has made us members of one great
  family.

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• It has become so truly an organ of the social
  body that by telephone we now enter into
  contracts, give evidence, try lawsuits, make
  speeches, propose marriage, confer degrees,
  appeal to voters, and do almost everything else
  that is a matter of speech.
• Casson described uses of the telephone that we
  still hear pundits predicting today. For
  example, he noted that "There seems to be no sort
  of activity which is not being made more
  convenient by the telephone."

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• The hundred largest hotels in New York City have
  twenty-one thousand telephones--nearly as many as
  the continent of Africa and more than the kingdom
  of Spain.
• The Christmas Eve orders that flash into Marshall
  Field's store, or John Wanamaker's, have risen as
  high as the three thousand mark.
• Whether the telephone does most to concentrate
  population, or to scatter it, is a question that
  has not yet been examined.

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• It is certainly true that it has made the
  skyscraper possible, and thus helped to create an
  absolutely new type of city, such as was never
  imagined even in the fairy tales of ancient
  nations. its efficiency is largely, if not
  mainly, due to the fact that its inhabitants may
  run errands by telephone as well as by elevator.
• It is used to call the duck-shooters in Western
  Canada when a flock of birds has arrived and to
  direct the movements of the Dragon in Wagner's
  grand opera "Siegfried.

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• At the last Yale-Harvard football game, it
  conveyed almost instantaneous news to fifty
  thousand people in various parts of New England.
• At such expensive pageants as that of the Quebec
  Tercentenary in 1908, where four thousand actors
  came and went upon a ten-acre stage, every order
  was given by telephone. . In the last ten years
  there has been a sweeping revolution in this
  respect. Government by telephone!

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• Next to public officials, bankers were perhaps
  the last to accept the facilities of the
  telephone. As for stockbrokers of the Wall Street
  species, they transact practically all their
  business by telephone
• The telephone arrived in time to prevent big
  corporations from being unwieldy and
  aristocratic. The foreman of a Pittsburg coal
  company may now stand in his subterranean office
  and talk to the president of the Steel Trust, who
  sits on the twenty-first floor of a New York
  skyscraper.

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• The long-distance talks, especially, have grown
  to be indispensable to the corporations whose
  plants are scattered and geographically misplaced.

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Predicted Applications from Casson

• In-room hotel service
• Shopping by phone
• Run errands by phone, enabling skyscrapers,
  disbursed cities
• News gathering, sports results
• Stock transactions
• Mobile - boats, trains
• Management of disbursed activities, businesses
• Democracy in business
• 911 Emergency services

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and many more.

• To-day the telephone goes to sea in the passenger
  steamer and the warship. Its wires are waiting at
  the dock and the depot, so that a tourist may sit
  in his stateroom and talk with a friend in some
  distant office.
• In the operation of trains, several dozen roads
  have now put it in use, some employing it as an
  associate of the Morse method and others as a
  complete substitute. It has already been found to
  be the quickest way of despatching trains. It
  will do in five minutes what the telegraph did in
  ten. And it has enabled railroads to hire more
  suitable men for the smaller offices.

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• In news-gathering, too, much more than in
  railroading, the day of the telephone has
  arrived.
• But it is in a dangerous crisis, when safety
  seems to hang upon a second, that the telephone
  is at its best.
• In the supreme emergency of war, the telephone is
  as indispensable, very nearly, as the cannon.
  This, at least, is the belief of the Japanese,
  who handled their armies by telephone when they
  drove back the Russians

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• It is the instrument of emergencies, a sort of
  ubiquitous watchman.
• When the girl operator in the exchange hears a
  cry for help--"Quick! The hospital!" "The fire
  department!" "The police!" she seldom waits to
  hear the number. She knows it. She is trained to
  save half-seconds. And it is at such moments, if
  ever, that the users of a telephone can
  appreciate its insurance value.
• When instant action is needed in the city of New
  York, a General Alarm can in five minutes be sent
  by the police wires over its whole vast area of
  three hundred square miles.

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• If a disaster cannot be prevented, it is the
  telephone, usually, that brings first aid to the
  injured.
• After the destruction of San Francisco, Governor
  Guild, of Massachusetts, sent an appeal for the
  stricken city to the three hundred and fifty-four
  mayors of his State and by the courtesy of the
  Bell Company, which carried the messages free,
  they were delivered to the last and furthermost
  mayors in less than five hours.

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• Every fourth American farmer is in telephone
  touch with his neighbors and the market.
• The first farmer who discovered the value of the
  telephone was the market gardener.
• As yet, few farmers have learned to appreciate
  the value of quality in telephone service, as
  they have in other lines. The same man who will
  pay six prices for the best seed-corn, and who
  will allow nothing but high-grade cattle in his
  barn, will at the same time be content with the
  shabbiest and flimsiest telephone service,
  without offering any other excuse than that it is
  cheap.

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• But this is a transient phase of farm telephony.
  The cost of an efficient farm system is now so
  little-- not more than two dollars a month, that
  the present trashy lines are certain sooner or
  later to go to the junk-heap with the sickle and
  the flail and all the other cheap and
  unprofitable things.

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Prescient, or what?

• If you consider that the invention of wireless
  communications occurred about the same time
  1900 - maybe we should recognize that we have
  been in the post-modern era of telecommunications
  ever since?

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The Beginning - Telegraphy
1845
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Where Are We Now?

• Let me start by telling you something about
  how the
• telephone system works and
• how the Internet works.

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Early 21st Century Telephony

• The voice signal generated by the microphone in
  your telephone set is transmitted along a twisted
  pair of copper wires to the nearest Local Office.
  
• There it is sampled 8000 times per second
• and the sample values are quantized into one of
  255 amplitude levels and
• represented by an 8-bit binary number
• an octet, or byte, of 1s and 0s.

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Calling

• When you pick up the phone, the network is
  notified and sends you a dial-tone to let you
  know that it is ready willing and able to accept
  your input.
• In the telephone world you respond by dialing
  dialing a telephone number.
• The telephone number is a command to the network
  to make a connection from your phone line to that
  of the called party, and to check the status of
  that partys phone.
• If it is available the network rings the called
  party and sends you a copy of the ringing sounds.
  If not, it sends you a busy signal.

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• When the called party answers you have a direct
  connection to them
• Then it is up to you to decide what to do
• talk to the machine,
• hang up, or
• talk to the person/machine who/that answered.
• The connection will be maintained until one of
  you hangs up.

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Number Please

• That gives you a connection, but how did it get
  established.
• It used to be done by young women the voice
  with a smile plugging wires together in a
  switchboard.

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Todays Answer is the Advanced Intelligent
Network

• In the AIN, the establishment of the connection
  is done through a signaling system that runs on a
  packet-switched data network which is separate
  from the transport network.
• This signaling system, called SS7, has three
  types of nodes
• service switches,
• service controls, and
• signal switches.

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AIN in action

• When you dial, the number is received by a
  service switch where it is sent to the service
  control a database where the connection
  details are stored.
• After the availability of the called party is
  assured, this connection information is sent to
  the signal transfer points the voice switches -
  to make the connection.

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Basic Signaling Architecture
Service Control
Signal Transfer
Service Switch
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Basic Call Setup
Signal Transfer
STP
STP
Service Switch
SSP
SSP
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Benefits of SS7

• Having a signaling system that is separate from
  the talking system means that expensive
  communications bandwidth is not tied up while
  dialing takes place (even touch-tone dialing
  takes a lot of time) freeing up a lot of
  communications capacity.
• More than, since the actual telephone number is
  stored in memory, it allows such services as 911,
  411, 1-800 numbers, group dialing, and so on
• This also allows such neat things as directing
  calls to an appropriate 24-hour-service-centre
  depending on the time-of-day.

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Shared Circuits - Multiplexing

• Telephone wires and cables are expensive
• Your telephone call is multiplexed (combined)
  with thousands of others on a time-sharing basis
  on very high capacity digital transmission links
  as it moves along the established circuit from
  one signal switch to another on its way to the
  destination.
• This is called time division multiplexing

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Time Division Multiplexing
In telephony each source is sampled 8,000 time
per second
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TDM Applications

• Digital Telephony
• Data Communications
• Satellite Access
• Optical Fibre
• Cellular Radio

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Data Communications

• The digital time division multiplexed telephone
  (TDM) networks, based on 64 kbps digital voice
  channels, are the major carriers of data
  communications as well.
• Data transmission rates on the worlds
  telecommunication networks vary from 56 kbps from
  a voiceband modem on your phone line to 1.5 Mbps,
  or so, on DSL, to 10s of Terabits per second on
  optical fiber trunks.

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Digital TDM Hierarchy
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SONET Rates
Optical systems now carry 160 OC-192 signals
using lDM on a single fibre
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Computer Communications

• A parallel genesis of modern networks started
  with what some call
• computer communications,
• more properly referred to as
• packet-switched communications, that
• grew out of a solution to requirements of the
  US DoD for command and control messaging networks
  that could survive nuclear war.

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DoD requirements

• The DoD requirements originated with ARPANET and
  DDN to meet DOD requirements
• survivability
• no central points of failure
• availability
• security

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• network interoperability
• accommodate heterogeneous networks and terminal
  equipment
• handle surge traffic
• lots of excess capacity
• parallel routes
• support priority traffic

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The Origins of the Internet

• As one of those confluences that occur in
  technological evolution, there were groups of
  researchers with common backgrounds (MIT,
  Berkley, Stanford) who had used computers with
  serial character communications USART ports and
  teletype machines as terminals.
• They had extended the access to their own
  computers locally over twisted-pair wiring and
  remotely over telephone lines with rudimentary
  modems, as a convenience that led to experiments
  with time-shared computing.

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• So, they took to connecting across the continent
  to keep in contact, and being lazy souls
  -developed the software that enabled their
  activities for exchanging messages and files.
• They knew that computer output only came in
  bursts when the Enter key was depressed - and
  so they invented ways to transmit data in short,
  intermittent packages called packets.
• the idea grew
• and turned into the solution to the DoD problem.

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Line Sharing

• The idea of using packets short blocks of data
  for communications between computers,
• in a day when telephone or data line charges were
  high,
• allowed the line to be shared in a simple way
  first you, then me the Aphonse-Gaston protocol
  for getting through the narrow doorway.

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Bursty Data

• This idea is based on the observation that
  computer data is bursty. This made perfectly
  good sense at the time.
• After all, the only time when data had to be
  communicated was when you hit the ENTER key and
  the contents of the keyboard memory buffer had to
  be sent to the mainframe, or when a screen full
  of characters had to be sent, or an email sent.
• So, knowing that data is bursty one can package
  it with the address of the sender and the address
  of the recipient written on the face of the
  envelop and give it to the network to deliver.

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As the Post Office Does

• The first station knows which truck to put your
  letter on to get it on its way.
• The distribution center in Ottawa knows which
  trucks go to Montreal and points East and North,
  and which go to Toronto, and points West and
  South.
• A similar situation is true of every sorting
  station the letter goes through. When it gets to
  its final destination, the local mail room gets
  it to you.

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• Great! A connectionless network. A fire and
  forget system launch and leave! Makes very
  efficient use of the trucks on each intermediate
  link.
• The smarts are in the network, not in some
  centralized switching center.
• Every switch (router) is equal to every other.
• This is called a peer-to-peer network.

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Routing

• OK, so how do routers know the routes to support
  this internetworking idea?
• Each router in the network has software that asks
  every adjacent router to provide routing
  information about all the routers that it is
  connected to continuously - throughout the
  entire internetwork!

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• The packet-switching concept grew into a suite of
  protocols, called the Department of Defense
  Protocol Standards, developed as part of the
  ARPANET.
• From this beginning, the internetworking
  protocols have grown into what is now known as
  the TCP/IP or Internet Protocol Suite.
• The governing body for this suite of protocols is
  the IETF the Internet Engineering Taskforce.

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Recent Status

• The telecommunication industry and its clients
  the worlds telephone companies using
  circuit-emulating, TDM digital networks, and
• Computer operators using best effort, TCP/IP
  packet switched routers to interconnect networks,
  mostly consisting of Ethernet-based local area
  networks.

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Recent Status

• Recently (which means really recently) we have
  the computer communications community, i.e., the
  Internet providers, moving very quickly to
  introduce new technology (equipment and
  methodologies) that improves the quality of
  service in best effort TCP/IP networks so that
  they can carry the output of continuous sources
  such as voice and video.

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• The improvement in quality has been so rapid in
  fact that the worlds telecommunications
  companies (carriers) and cable TV companies have
  started to deploy packet switches in their core
  networks and to employ IP LAN technologies in
  their wired and wireless local loops.
• The introduction of IP technology into the
  carrier networks has also been driven by the
  flexibility and power it affords.
• Local Area Networks

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Convergence

• The worlds networks are beginning to converge
  towards a reliance on the use of an
  ever-expanding TCP/IP suite of protocols with new
  mechanisms to provide circuit-like connections to
  subscribers that are capable of carrying
  streaming information such as voice and
  television.

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Convergence

• Convergence used to be a future for
  communications.
• Today it is the present.
• The goal is a single portal
• For all services radio, TV, telephone, email,
  file transfer, www access, space management,
  personal command and control, etc.
• Offered by a single network.

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Common basis

• The exciting accelerant to this progress is that
  the same programming technologies are used in the
  applications running in the computers, on the
  terminal equipment, and in the network.
• An application designed for a communications
  switch is written in the same language, using the
  same software components, that the business data
  processing entities it connects are.

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Result

• One example of the power of this that comes to
  mind is that a customer of can have access to
  their profile as recorded in a merchants back
  office to, say review an account, or to more
  powerfully - change an address.
• The implications of client access to back-office
  data bases are profound.

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Fall Rush

• An example of the service opportunities created
  by an all-IP network is a certain telephone
  company that services an area with many
  universities.
• Every Fall they had to connect thousands of new
  subscribers in a short period.
• They stopped physically disabling the phone
  service into student quarters, relying on
  software disabling in their data bases. The
  phone number/location data was preserved.
• This allowed them to put up a web page where a
  student could provide name and address along
  with a credit card number, which when verified
  caused the phone line to be activated
  immediately, without human intervention.
• The implication is that outsiders were able to
  change crucial entries who to charge for
  service - in the companys data base the holy of
  holies!

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Hibernia Atlantic TransAtlantic Cables
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