10-Introducing Networking
- The Internet is broken into 4 Layers
- The TCP/IP Stack
    - note, these are written as they exist, from the bottom up
    - Layer 4
        - Application Layer
            - http
            - ftp
            - afp
            - POP3
            - DNS
            - IMAP
            - SMB
            - SMTP
            - Skype
            - etc
    - Layer 3
        - 2 Parts:
            - UDP
                - only reorders the packets, but ignores dropped packets
                - less process intensive
                - less delay
                    - skype uses UDP
            - TCP
                - reassembles and reorders the packets
                    - if a packet is dropped, it re-requests it
                    - more process intensive
    - Layer 2
        - Routing Layer
            - Routing tables
                - the Internet learns and shares its own routing tables
            - Internet Protocol
                - IP addresses
                - IPv4
                    - current version
                - IPv6
                    - future version, not yet in widespread use
            - Netmask
                - Subnet
            - default gateway
            - network address
        - Layer 2 breaks data up into small pieces called packets
    - Layer 1
        - basic, hardware layer
        - sends binary data from one computer (network card) to another
            - Ethernet
                - wifi, which is treated by the computer as a type of
                  Ethernet
            - Cable/DSL Modem
            - bluetooth
            - FireWire
        - MAC Addresses
            - media access control
            - hexadecimal number in pairs separated by :
- Bart Busschots
    - bartb.ie <http://bartb.ie/>
    - impodcast.tv <http://impodcast.tv/>
    - podfeet.com <http://podfeet.com/>