ISDS Final: Networks

  1. Networks
    Links multiple computer systems and enables them to share data and resources
  2. Types of computer networks:
    • Local area network (LAN)
    • Wide area network (WAN)
    • Metropolitan area network (MAN)
    • Campus area network (CAN)
    • Personal area network (PAN
  3. LAN
    • Uses cables, radio waves, or infrared signals
    • Links computers in a limited geographic area
  4. WAN
    • Uses long-distance transmission media
    • Links computer systems a few miles or thousands of miles
    • Internet is the largest WAN
  5. MAN
    • Designed for a city
    • Larger than a LAN, smaller than a WAN
  6. CAN
    • Several LANs located in various locations on a college or business campus
    • Smaller than a WAN
    • Use devices such as switches, hubs, and routers
  7. PAN
    • Network of an individual’s own personal devices
    • Usually within a range of 32 feet
    • Usually use wireless technology
  8. USB wireless network adapter
    • Plugs into a USB port
    • Usually provides an intuitive graphical user interface (GUI) for easy configuration
  9. USB dongle
    • Device inserted into a USB port that adds additional features to the base system
    • Examples: enabling network connectivity and increasing RAM
  10. Wireless PC card adapter
    • About the size of a credit card
    • Inserted into a slot on the side of most notebooks and netbooks
    • Has built-in WiFi antenna that provides wireless capability
    • LED lights that indicate whether the computer is connected
  11. Hub
    • Joins multiple computers together in a single network
    • Does not manage traffic between the connections
  12. Switches
    • Filter and forward data between nodes
    • Are similar to routers but work within a single network
  13. Routers
    • Connect two or more networks
    • Inspect the source and target of a data package
    • Determine the best route to transmit data
  14. Wireless access point (WAP)
    • Receives and transmits radio signals
    • Joins wireless nodes to a wired network
  15. Server
    Computer or device with software that manages network resources, such as files, e-mails, printers, databases
  16. File server
    • Most common type of server
    • High-speed computer that provides program and data files to network users
  17. Network administrator
    • Also called network engineer
    • Installs, maintains, supports computer networks
    • Interact with users
    • Handle security
    • Troubleshoot problems
  18. Peer-to-peer (P2P) networks
    • Share files without a file server
    • Easy to set up
    • Best used for home or small offices with no more than 10 computers
    • Do not require a network operating system
    • Can be slow if there are too many users
    • Security not strong
  19. Wireless LAN
    Connects users through radio waves instead of wires
  20. Client/server networks
    • Made up of one or more file servers and clients (any type of computer)
    • Client software enables requests to be sent to the server
    • Wired or wireless connections
    • Do not slow down with heavy use
  21. Intranet
    • Password-protected network controlled by the company
    • Accessed only by employees
  22. Virtual private network
    • Operates over the Internet
    • Accessible by authorized users for quick access to corporate information
    • Uses secure, encrypted connections and special software
  23. Bus topology
    • Practical for home or small office
    • One node transmits at a time
    • Terminators signify the end of the circuit
    • Uses contention management—technique that specifies what happens when a collision occurs
  24. Star topology
    • For office buildings, computer labs, and WANs
    • Easy to add users
  25. Ring topology
    • For a division of a company or one floor
    • Not in common use today
    • Node can transmit only when it has the token—special unit of data that travels around the ring
  26. Protocols
    standards used by networks to permit communication between network-connected devices
  27. Modulation protocols
    ensure that the modem can communicate with another modem, even if by a different manufacturer
  28. Protocol suite
    contains the protocols of the network and specifies its network architecture, or how the network works
  29. Network layers
    • divide network architecture for separate treatment
    • Each network layer can operate and be governed by its own protocols
  30. Protocol stack
    vertical arrangement of network layers
  31. Ethernet
    • most-used LAN protocol
    • Ethernet star networks
    • Most popular versions—use twisted-pair wiring and switches
    • Sends data in a fixed-size unit called a packet
  32. WiFi
    • Uses radio waves to provide a wireless LAN standard at Ethernet speeds
    • Needs a central access point—could be a wireless router
  33. Point of presence (POP)
    • WAN connection point used to obtain access to the WAN
    • Wired or wireless
  34. Backbones
    • High-capacity WAN transmission lines
    • gigaPoP (gigabits per second point of presence)—transfers data exceeding 1 Gbps (1 billion bits per second)
  35. Transmission Control Protocol/Internet Protocol (TCP/IP)
    Protocols that define how the Internet works
  36. Transmission Control Protocol (TCP)
    Defines how Internet-connected computers can exchange, control, and confirm messages
  37. Internet Protocol (IP)
    Provides a distinct identification to any computer connected to the Internet: the IP address or Internet address
  38. Circuit switching
    • Used by the public switched telephone network to send data over a physical end-to-end circuit
    • Provides a direct connection between devices
  39. Packet switching
    • Used for computer communication
    • Divides and sends outgoing messages as packets, which are reassembled on receipt
    • More efficient and less expensive than circuit switching
  40. Latency
    delay introduced when a given packet is examined by many routers
  41. Congestion
    occurs when the network is overloaded, causing some packets to be further delayed
Card Set
ISDS Final: Networks
Slides for chapter on Networks