User:Amy Suo Wu/Physical Media

Physical Media

Properties and methods of protocols:

1. TCP (Transmission Control Protocol) > Transport layer (only responsible for making sure everything arrives; data travels to correct destination) > Uses the three way handshake > Creates an imaginary circuit between sender and receiver > Robust quality > Conservative and liberal. Accepts everything, but if it's corrupt will immediately delete.

+ Telephone call ("opening and closing sentences to establish conversation") + Offline meetings (would be nice if entire conversation would end with one miscommunication) + Make the circuit visible by throwing wool or rope of some sort.

2. IP (Internet Protocol) > Partner of TCP (together they make a protocol suite) > As the engine in the car, but doesn't know how to steer. > Responsible for routing and fragmentation

  ROUTING

> Flexible routing system called hopping, doesn't know final destination, but knows next nearest > Makes datagram containing "expiring date"

  FRAGMENTATION

> Gets disintegrated into small packages (called datagrams) which can be send over the network. > Packages are then reassembled to make a whole file again > Get's refragmentated to fit the network size (smaller "roads" will only allow smaller packages)

+ Chinese whisper (program a hub to change data slightly) + fragmentation reminds of of IKEA + Datagram looking where to go

3. TCP/IP > Fascilitates peer to peer communication > Distributed technology i.e. Rhizome model > Universal language > Robust flexible, strong > Open to broad variety of computers > Result of the action of autonomous agents

4. DNS (domain name system) > Translator from names to numeral (because computers read numbers more easily and humans read words better) > Predecessor was called hosts.txt, and was called namespace (centralized system) > DNS is decentralized database. > Inverted tree like structure (hieracy) > Decentralized because one layer can only talk to the next layer and not deeper layers.

+ current political system (politicians trying to communicate to lower levels) + institution + cross reference (for one document you need another document)

Question: where does DNS live?