anthony morris


  • Two primary protocols
    • TCP (Transmission Control Protocol)
    • IP (Internet Protocol)
  • TCP/IP suite is used by OSes for communication on a network


  • Star topology
    • When all devices connect to one central switch
  • Bus topology
    • Multiple switches chained together in a single line


  • PAN (Personal Area Network)
    • A network of personal devices
    • Smallest network
    • Phone --> computer
  • LAN (Local Area Network)
    • Small network (Ex. office, home, or building)
  • MAN (Metropolitan Area Network)
    • Group of LANs in the same geographical area
    • Sometimes called a Campus Area Network (CAN)
  • WAN (Wide Area Network)
    • Group of LANs spread out over a wide geographical area
    • The Internet is the largest WAN


Address Translation

  • Gateway device substitutes private IP with its own public IP
    • When computers need access to other networks on the internet
  • Network Address Translation (NAT)
    • Designed to conserve public IP addresses needed by a network
    • Variations:
      • Static/Source Network Address Translation (SNAT)
        • Gateway assigns same public IP to host each time it makes a request to access the Internet
      • Dynamic Network Address Translation (DNAT)
        • Gateway has pool of public addresses it assigns to local host when it makes a request to access the Internet
  • Port Address Translation (PAT)
    • Process of assigning TCP port number to each ongoing session between local host and Internet host

Ports and Sockets

  • Port numbers
    • Ensure data is transmitted to correct process among multiple processes running on the computer
    • Divided into three types:
      • Well-known ports --> 0 to 1023
      • Registered ports --> 1024 to 49151
      • Dynamic and private ports --> 49152 to 65535
  • Socket
    • Consists of host's IP and port number of an application running on the host
    • Example:

Computer Science