packets and Protocols

packets and Protocols

1. Protocol Stacks

   • An implementation of a computer networking protocol suite
   • The suite is the definition of the protocols
   • The stack is the software implementation of them
   • The set of protocols used in a communications network
   • Example
     • TCIP Stack
       • Application
         • Transport
           • Network/internet
             • Data link layer

2. IP

   • 32 bits
   • Internet Protocol

3. MAC

   • 48 bits
   • 6 pairs of hexidecimals
   • permentaly hard wired into your device

4. TCP

   • used with IP

5. HTTP

   • Hypertext Transfer Protocol
   • Used to transfer multimedia data over the internet. Uses port 80 for transfer of web traffic

6. FTP

   • Used to copy a file between locations over the internet
   • allows connection to resume so often used for downloading large files
   • File Transfer Protocol

7. Packet Switching

   • Data is broken down into packets
   • Each packet contains:
     • Source + destination addresses
     • error handling - checksum etc.
     • tracking information
   • Packets may take different routes to reach their destination
   • Packets are reassembled on delivery
   • Advantages
     • Makes hacking harder as they may only intercept a packet
     • Data transmission will continue even if part of the path fails
     • Helps packets to avoid bottlenecks and slowing of data transfer

8. Routing

   • Routers are hard ware devices which connect networks together
     • Can connect networks to the internet
   • Router choses best path for packets to travel down
     • Use headers and forwarding tables to determine best path for packets
       • Use protocols to communicate with each other and configure the best route between any two hosts