lesson 3

• ISP (internet service provider)

  Provides you with your internet connection
• Router


  Device that passes traffic back and forth
• Gateway


  Device that routes traffic between networks
• NAT (Network Address Translation)


  Used by routers to share a single IP address among many devices
• DHCP (Dynamic Host Configuration Protocol)


  Automatically request and be assigned IP Addresses and other network settings
• Hostnames


  Human-readable label
• Domain Name


  Base part of website names
• DNS (Domain Name System)


  How computers convert human-readable domain names and hostnames to numerical IP addresses
• Ethernet


  Standard wired network technology
• Network interface/network adapter


  Computer's wired Ethernet connection and Wifi connection are basically both network interfaces
• Network interfaces can also be implemented entirely in software, so they don't always directly correspond to hardware devices
• Localhost


  The hostname "localhost" always corresponds to the device you're using, uses loopback network interface
• MAC Address


  Unique identifier designed to identify different computers on a network
• Port


  When application wants to send and receive data traffic, it has to use 1 to 65 535
• Protocol


  Different ways of communicating over the internet, TCP and UDP most common
• Packet


  A unit of data sent between devices
• Firewall


  Piece of hardware or software that blocks certain types of traffic
• HTTP (Hypertext Transfer Protocol)


  Standard protocol modern web browsers and the web itself uses
• URL (Uniform Resource Locator)

  Aka web address
• Data Network


  System that transfers data between network access points through data switching
• Data Rate


  Transmission speed
• Baud Rate


  Rate at which information is transferred in a communication channel, in the serial port context 9600 baud = 9600 bits per second
• Peak Data Rate


  Fastest data transfer rate
• Bursty Data Rate


  Data is transmitted intermittently
• Peer to peer networks


  Involve two or more computers pooling individual resources, each computer acts as both client and server
• Client server networks


  Involve multiple clients or workstations connecting to at least one central server
• Disadvantages and limitations of peer to peer networks

  • Less secure
  • Resources can become overburdened
  • Difficult to provide system wide services
• Disadvantages and limitations of client server networks

  • Higher initial setup cost
  • Requires a greater level of expertise in hardware and software
• Usage


  • Peer to peer - for homes or small businesses
  • Client server - used in environment where growth is expected