LESSON OBJECTIVE

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LESSON OBJECTIVE

• The history of networking.
• Networking devices.
• Network topology.
• Lans and Wans.
• VPNs
• Bandwidth

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SNEAKERNET TECHNOLOGY
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Why were networks created

• To avoid duplication of equipment and resources
  like printers.
• Reduce files being duplicated all over the place.
• Communicate efficiently.
• To increase productivity by staff not having to
  wait to print something or share a file.
• Save money

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DIAL-UP POINT TO POINT CONNECTIONSIN 1980S
Companies used own standards
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BULLETIN BOARDS
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NETWORK DEVICES
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REPEATER
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HUB AND BRIDGES
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SWITCH
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ROUTER
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NETWORK TOPOLOGY
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LAN (Local Area Network)

• Ethernet
• Token ring/FDDI
• (Fiber Distributed Data Interface)

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WAN (Wide Area Network)
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Some common WAN technologies are

• Modems
• Integrated Services Digital Network (ISDN)
• Digital Subscriber Line (DSL)
• Frame Relay
• US (T) and Europe (E) Carrier Series T1, E1,
  T3, E3
• Synchronous Optical Network (SONET)

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Common wan line terms

• Term Bandwidth
• Modem 56kbps
• DLS 12kbps to 6.1Mbps
• ISDN 128kbps
• Frame Relay 56kbps to 44.736
• T1 1.544 Mpbs
• T3 44.7 Mbps

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MAN (Metropolitan-area networks)
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(SAN) Storage-area networks

• A SAN is a dedicated, high-performance
  network used to move data between servers and
  storage resources.

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VPN (Virtual Private Networks)
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• ACCESS VPN provide remote access for mobile and
  small office, home office (SOHO) users to an
  Intranet or Extranet over a shared
  infrastructure. Access VPNs use analog, dialup,
  ISDN, DSL, mobile IP, and cable technologies to
  securely connect mobile users, telecommuters, and
  branch offices.
• INTRANET VPN use dedicated connections to link
  regional and remote offices to an internal
  network over a shared infrastructure. Intranet
  VPNs differ from Extranet VPNs in that they allow
  access only to the employees of the enterprise.
• EXTRANET VPN use dedicated connections to link
  business partners to an internal network over a
  shared infrastructure. Extranet VPNs differ from
  Intranet VPNs in that they allow access to users
  outside the enterprise.

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Bandwidth
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MEASUREMENT OF BANDWIDTH

• Bits per second
• Kbps
• Mbps
• Gbps
• Tbps

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THROUGHPUT

• A true measure of network performance is how many
  bits per second can be carried at any one time.

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MEASUREMENT FORMULA
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END OF FIRST PART OF CHAPTER 2

• Now its your turn, please action the following
• Do the quiz on the module.
• Read the module.

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• OSI Layer model
• TCP/IP Layer model

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International Organization for Standardization
(ISO)
OSI model Open System Interconnection
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Layer 7 - Application

• Closest to the user.
• Email, Telnet, HTTP

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Layer 6 - Presentation

• Ensures information sent out from the application
  layer can be read by another application.
• Encryption and decryption processing.
• Uses standard formats such as
• TIFF, JPEG, GIF, MIDI, MPEG
• DOC, XLS, MDB
• Services Application layer.

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Layer 5 Session

• Services Presentation layer.
• Establishes, manages, and terminates sessions
  between two hosts.
• Provides efficient data transfer for the
  presentation and application layer.
• Uses protocols
• Network File systems (NFS), X-Windows system and
  Appletalk.

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Layer 4 - Transport

• Services Session layer.
• Segments data from sending host and reassembles
  it into a data stream at receiving host.
• Ensures reliable transmission.
• Establishes maintains and terminates virtual
  circuits.
• Error correction and recovery.

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Layer 3 - Network

• Services Transport layer.
• Selects the correct path on a Wan.
• Uses logical (IP) addressing systems.
• A router is considered a layer 3 networking
  device.
• Creates a packet or datagram with a header which
  contains information about source and destination
  logical (IP) address.

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Layer 2 Data Link layer

• Services Network layer.
• Provides reliable transit of data across a
  physical link. Uses FCS (Frame check sequence)
  error detection.
• Concerned with physical (MAC) addressing system.
• Uses Frames, and flow control, inserts physical
  (mac) addresses.
• A NIC, Bridge and a switch are considered layer 2
  networking devices.

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Layer 1 - Physical

• Services the Data Link layer.
• Defines the electrical functions of
  transmissions.
• Encodes the frames into bits for transmission.
• Concerned with cabling media, and networking
  devices Repeaters, Hubs.

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TCP/IP model

• The U.S. Department of Defense (DoD) created the
  TCP/IP reference model, because it wanted to
  design a network that could survive any
  conditions, including a nuclear war.

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File Transfer Protocol (FTP) Hypertext Transfer
Protocol (HTTP) Simple Mail Transfer Protocol
(SMTP) Domain Name System (DNS) Trivial File
Transfer Protocol (TFTP)
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TCP/IP MODEL
Transport Control Protocol (TCP) User Datagram
Protocol (UDP)
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TCP/IP MODEL

• Internet Protocol (IP)

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TCP/IP MODEL
The network access layer refers to any particular
technology used on a specific network.
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PEER TO PEER COMMUNICATIONS
PDU Protocol Data Units
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ENCAPSULATION
EMAIL
Segments for reliable transmission
Data packets/ datagrams with logical IP addresses
Frames with physical mac addresses
Converts data to bit and bytes for transmission
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LAYER DETAILS
Name Brief Desc. Network Device PDU Type Protocols used
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