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Introduction to Networking Definitions and Terms

Jan 20, 2015




  • 1. Introduction to Networking Definitions and Terms

2. Chapter Objectives

  • After completing this chapter you will:
  • Be able to differentiate between peer-to-peer and server-based networks.
  • Be able to identify a network topology.
  • Understand the different types of network cabling.
  • Be able to explain the differences between various network access methods.
  • Understand Ethernet issues.
  • Identify OSI model layers.
  • Be able to explain when a specific network protocol is used.
  • Understand the difference between a MAC address and an IP address.

3. Chapter Objectives (cont.)

  • After completing this chapter you will:
  • Be able to correctly apply IP addressing concepts.
  • Understand the purpose of DHCP, WINS, and DNS.
  • Be able to properly configure a NIC for network connectivity.
  • Be able to use common network troubleshooting tools.
  • Be able to access a network printer.
  • Understand dial-up networking concepts and define commonly used network terms.

4. Chapter Objectives (cont.)

  • After completing this chapter you will:
  • Be able to define and label the basic parts of a wireless network.
  • Know that wireless networks operate at layers 1 and 2 of the OSI model.
  • Understand the difference between the two main types of wireless networks: ad hoc and infrastructure.
  • Know the three types of wireless NICs.
  • Understand the difference between a BSS and an ESS.
  • Be able to explain the purpose of an SSID and channel ID.
  • Know the three non-overlapping channel IDs used by the 802.11b standard.

5. Chapter Objectives (cont.)

  • After completing this chapter you will:
  • Understand the purpose of a wireless repeater.
  • Be able to explain the basic differences between the antennas and explain the concept of attenuation.
  • Know the difference between dBd and dBi.
  • Know the purpose and importance of a site survey.
  • Understand the difference between 802.11a, 802.11b, and 802.11g.
  • Understand the basics of wireless network security.

6. Networking Overview

  • Anetworkis two or more devices capable of communicating and sharing resources between them.
  • Two types of networks are LAN and WAN:
    • LAN (Local Area Network) A group of devices sharing resources in a single area such as a room or a building.
    • WAN (Wide Area Network) Two or more LANs communicating, often across large distances.The most famous WAN is the Internet.

7. Types of Local Area Networks

  • Two types of LANs are Server-Based and Peer-to-Peer Network:
    • Server-Based Network A basic type of LAN wherein users login to a controlling computer, called a server and is more secure. The server contains information about who can connect to the network and to what shared resources. It also provides some of these resources. These networks normally consist of 10 or more computers.
    • Peer-to-Peer Network One of two basic types of LANs wherein each computer user acts as a server. Each computer stores password and sharing information for its own resources. Usually has fewer than 10 computers.
  • NOS (Network Operating System) Special operating system on a server containing utilities for managing users, resources, and security.

8. Types of Local Area Networks Server-Based Network Network Figure # 1 9. Types of Local Area Networks Network Figure # 2 Peer-to Peer Network 10. Network Topologies

  • Network Topology Maps of how the physical or logical paths of network devices connect. The three major topologies arestar ,ring , andbus .
  • Star Topology Most common Ethernet network topology where each device connects to a central hub or switch.
  • Hub A device used with the Universal Serial Bus or in a star network topology that allows multiple device connections.
  • Switch In star networks, a Layer 2 central controlling device.A switch looks at each data frame as it comes through each port.
  • Ring Topology Network that is physically wired like a star network but, logically in a ring; passes control from one device to the next in a continuous fashion using a special data packet called a token. Used in Token Ring networks.
  • Bus Topology Network wherein all devices connect to a single cable.If the cable fails, the network is down.
  • Mesh Topology Network where all devices connect to each other by cabling to provide link redundancy for maximum fault tolerance. Most likely in WANs.

11. Network Topologies Network Figure # 3 Hub/Switch 12. Network Topologies Network Figure # 4 Star Topology 13. Network Topologies Logical Ring Topology Network Figure # 5 14. Network Topologies Network Figure # 6 Bus Topology 15. Network Topologies Network Table # 1Network Topologies 16. Network Cabling

  • Cable is normally used as a medium for transporting network data. The most common types aretwisted-pairandfiber-optic , althoughcoaxis still used in some old networks.
  • Twisted-Pair Cable Network cable of eight copper wires twisted into four pairs to preventcrosstalk .
    • UTP (Unshielded Twisted-Pair) Most common network cable that comes in different categories for different uses. Categories 3 (voice-grade), 4, and 5 (data). It is unshielded and more susceptible to interference.
    • STP (Shielded Twisted-Pair) Same as UTP cable, but with extra foil to prevent outside noise from interfering with data on the cable.
  • Crosstalk Where signals from one wire interfere with the signal on an adjacent wire.
  • Plenum cable is treated with Teflon or fire retardant materials to reduce the risk of fire.It produces less smoke and is less toxic when burning.

17. Network Cabling

  • Fiber-Optic Cable An expensive network cabling made of plastic or glass fibers that carry data in the form of light pulses. Most often used to connect network devices such as switches together into a network backbone or for connecting networks together in a WAN. More secure and not affected by crosstalk or other interference like copper cable.
    • Single-Mode A type of fiber-optic cabling that sends one light beam down the cable. Used for longer distance applications.
    • Multi-Mode A type of fiber-optic cabling that allows multiple light signals to be sent along the same cable. Used for shorter distances.
  • Coaxial Cable Type of copper network cabling used in older Ethernet networks as well as mainframe and minicomputer connections. Has a single, center wire conductor with an outer braided shield.

18. Network Cabling Network Figure # 7 UTP Cable 19. Network Cabling Network Figure # 11 Fiber-Optic Cable 20. Network Cabling Network Figure # 12 Coax Cable with Connector 21. Access Methods

  • There are standard rules by which computers on a network must adhere to in order to communicate. These rules are known as a common access method.
  • CSMA/CD (Carrier Sense Multiple Access/Collision Detect) A common access method used by Ethernet.
  • Token Passing The common access method used by fiber and Token Ring networks.
  • CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance) A common access method used in wireless and Apple networks.
  • Token Small data packet passed from onenetworked device to another in a ring topology.

22. Ethernet Issues and Concepts

  • Two types of transmissions used in Ethernet networks:
  • Half Duplex A serial device setting that allows either the sending or the receiving device to send data, one device at a time. Data can travel both ways on a cable, but not at the same time.
  • Full Duplex A serial device setting that allows the sending and receiving device to send data simultaneously.Data can travel both ways on a cable at the same time.

23. OSI Model

  • OSI Model (Open Systems Interconnect) A standard for information transfer across a network that was developed by the International Standards Organization.The model has 7 layers.
    • Physical Layer Layer 1 of the OSI model that defines how bits are sent and received across the network without regard to their structure.
    • Data Link Layer Layer 2 of the OSI model that accurately transfers bits across the network by encapsulating (grouping) them into frames.
    • Network Layer Layer 3 of the OSI model that coordinates data movement between two devices on separate networks.

24. OSI Model

    • Transport Layer Layer 4 of the OSI model that determines details on how the data is sent, supervises the validity of the transmission, and defines protocol for structuring messages.
    • Session Layer Layer 5 of the OSI model that manages communication and administrative functions b