Mitchell Technical Institute Telecommunications

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Mitchell Technical InstituteTelecommunications

• EC 234 Introduction to Data Communications
• Networking Basics Overview
• Mike Benjamin, Instructor
• Never Stop Learning

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Standards

• It has long been accepted in the
  telecommunications industry that standards are
  required to govern 3 characteristics of
  communications equipment.
• Physical
• Electrical
• Procedural

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• In the past this view has not been embraced by
  the computer industry.
• Communication equipment vendors recognize that
  their equipment needs to interface to and
  communicate with other vendors equipment.
• ATT, Verizon, Motorola, Altel, Qwest etc.
• Computer vendors have traditionally attempted to
  monopolize their customers.
• Example MAC and Microsoft
• There are Advantages and Disadvantages of the
  standards making process.

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Principle Advantages of Standards

• 1. Assures there will be a large market for a
  particular piece of equipment or software.
• This encourages mass production and competition
  resulting in lower costs.
• 2. Allows products from multiple vendors to
  communicate giving customers more flexibility and
  choices.

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Principle Disadvantages of Standards

• 1. Tend to freeze technology.
• By the time a standard is developed, reviewed,
  and tested more efficient techniques may
  already be possible.
• 2. May result in multiple standards for the same
  thing.
• Various Standards making organizations have begun
  to cooperate more closely.

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Multiple Organizations

• Develop and incorporate standards.
• 5 Organizations well discuss throughout the
  semester.

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ISOC

• 1. Internet Society a professional membership
  society with more than 150 organizational and
  6000 individual members in over 100 countries.
• Addresses issues that confront the future of the
  internet.
• An organizational home for groups responsible for
  the internet infrastructure.

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• Such as the IETF Internet Engineering Task
  Force.
• IAB Internet Architecture Board.

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IEEE 802

• Institute of Electrical and Electronics Engineers
  802.
• A standards committee that develops LAN/MAN
  standards.
• LAN Local Area Network
• MAN Metropolitan Area Network

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ITU-T

• International Telecommunications Union field of
  telecommunications.
• An international organization within the United
  Nations Systems where governments and the private
  sector work to develop standards.

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ATM Forum

• An international non-profit organization formed
  with the objectives of accelerating the use of
  ATM products and services.
• ATM Asynchronous Transfer Mode.
• Promotes industry cooperation and awareness.

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ISO

• International Organization for Standardization
  a worldwide federation of national standards
  bodies from more than 140 countries, one from
  each country.
• A non-government organization that promotes the
  development of standardization.

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• ISOs work results in international agreements
  that are published as international standards.

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Fundamental parts of a Network

• Network
• A group of computers connected together in a way
  that allows information to be exchanged between
  computers.
• Node
• Anything that is connect to the network.
• While a node is typically a computer, it can also
  be a printer, copy machine, etc.

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• Segment
• Any portion of a network that is separated, by a
  switch, bridge, or router, from other parts of
  the network.
• Backbone
• The main cabling of a network that all of the
  segments connect to.
• Typically, the backbone is capable of carrying
  more information than the individual segments.

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• Topology
• The way that each node is physically connected to
  the network.
• Local Area Network (LAN)
• A network of computers that are in the same
  general physical location, usually within a
  building or campus.
• If the computers are far apart, then a WAN is
  used
• Wide Area Network (WAN)

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• Network Interface Card (NIC)
• Every computer and device on a network connect to
  the network through a NIC.
• In most desktop computers, this is an Ethernet
  card that is plugged into a slot on the
  computers motherboard.
• Media Access Control (MAC) address
• This is the physical address of any device, such
  as the NIC in a computer.
• The MAC address, which is made up of two equal
  parts, is 6 bytes long.

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• The first 3 bytes identify the company that made
  the NIC.
• The second 3 bytes are the serial number of the
  NIC itself.
• Unicast
• A transmission from one node addressed
  specifically to another node.
• Multicast
• A node sends a packet address to a special group
  address.

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• Devices that are interested in this group
  register to receive packets addressed to the
  group.
• An example a Cisco router sending out an update
  to all of the other Cisco routers.
• Broadcast
• A node sends out a packet that is intended for
  transmission to all other nodes on the network.

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What is an IP Address?

• Every machine on the Internet has a unique
  identifying number, called an IP address.
• A typical IP address looks like this
• 216.27.61.137
• There are 4.3 billion possible combinations of IP
  addresses in IPv4.

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• IP addresses are normally expressed in decimal
  format.
• But computers communicate in binary form.
• 216.27.61.137 in binary form
• 11011000.00011011.00111101.10001001
• The four sets of numbers in an IP address are
  called
• Octets.

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• If you add all the number positions together you
  get 32.
• Which is why IP addresses are considered 32-bit
  numbers.
• Each number position has 2 possible states
• Either a 1 or a 0.
• Each octet can contain any value between 0-255
  (256 possible combinations)
• Certain ranges (values) are restricted from use.

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• IE- 0.0.0.0 is a default network IP address.
• 255.255.255.255 is reserved for broadcasts.
• Octets are also used to create classes of IP
  addresses used for business, government, other
  entity.
• Octets split into two sections
• Net
• Host (sometimes referred to as node)
• Net section always contains the first octet.

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• It is used to identify the network that the
  computer belongs to.
• Host identifies the actual computer on the
  network.
• Host section always contains the last octet.
• There are 5 IP classes
• Default Network 0.0.0.0.

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Class A

• Very large networks, such as international
  company.
• First octet is from 1 126

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Class B

• Used for medium size networks, large college
  campus
• First octet is from 129 - 191

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Class C

• Used for small to mid-size businesses
• First octet is from 192 - 223

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Class D

• Used for multicasts
• First octet is from 224 239

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Class E

• Used for experimental purposes only.
• First octet is from 240 - 254

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Broadcast

• Messages that are intended for all computers on a
  network as sent as broadcasts.
• 255.255.255.255

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Hub, Switch, Router

• What is the difference between a Hub, Switch, and
  a Router?
• In a word
• INTELLIGENCE
• They are all devices which let you connect one or
  more computers to other computers, networked
  devices, or other networks.

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• Each has 2 or more connectors called ports into
  which you plug in the cables to make the
  connection.
• Varying degrees of magic happen inside the
  devices.

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HUB

• Typically the least expensive, least intelligent,
  and least complicated of the three.
• Its job is very simple anything that comes in
  one port is sent out to the others.
• Every computer connected to a hub sees
  everything that every other computer on the hub
  sees.

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SWITCH

• Does essentially what a hub does but more
  efficiently.
• By monitoring the traffic that comes across it,
  it can learn where particular addresses are.
• IE if it sees traffic coming from machine A on
  port 2, it now knows machine A is on port 2, and
  can route traffic for machine A to port 2.

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• The difference between a switch and a hub is that
  a switch will only route traffic where it needs
  to go instead of sending it to every port.

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ROUTER

• Smartest and most complicated of the 3.
• Come in all shapes and sizes, from small 4 port
  routers to large routers that run the internet.
• A computer that can be programmed to make traffic
  routing decisions.
• All routers include an interface for configuring
  how it treats traffic.

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Levels of Operation

• Hubs operate at OSI layer 1, the physical layer.
• Switches operate at OSI layer 2, the data link
  layer.
• Routers operate at OSI layer 3, the network layer.

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Summary

• Standards and Organizations
• Network Fundamentals
• IP Address
• Hub
• Switch
• Router

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