(NOTE: Didn't realize I would be taking notes until after the break, so the first part is a bit light)

-- Complete Network: every node connected to every other node with zero degree separation;

-- If there more than two people in the network need an addressing scheme;

-- Bi-directionality is zero degrees;

-- Dyad - two connections; triad - three connections;

-- One way link = broadcast (speaker cannot hear) = one to many;

-- Conversation is most complex mode;

-- Token system is unicast (one person at a time broadcasting message);

-- Multicast has several nodes, each repeats the message as they go along. some might be listeners (end points). However, each node must receive the message before it can send it out;

-- EXAMPLE: Time Warner: built for broadcast, not bi-directionality. So what do you do? Limit bandwidth. Phone companies were already prepared for bi-directional communication, and thus better suited for Internet.

Types of Networks:

  • Public transit
  • Bank (ATM)
  • Foursquare
  • Power
  • Telephone
  • Radio
  • Traffic Light
  • Plumbing

-- Discussion of power grid network

CLASS BREAK

-- Origins of The Internet:

  • Military wanted network resistant to bomb damage (DARPA)
  • University labs collaborating on physics data
  • Another network that starts with fear of nuclear war: interstate highway network

-- Similarities between Internet and Highway network:

  • Highway is a grid system (roads going north/south, ring roads around major cities) strategically designed
  • Route 66 not part of system, put together as a "beta"
  • Benefits: redundant, roads and bridges designed for massive vehicles, ring roads give you bypass routes (faster)layered.

--Discussion of distributed, centralized and decentralized networks:

  • Centralized: hub and spoke. everything passes through hub
  • Decentralized: small complete networks joined with a few redundant links. points at edges of hubs most important. there is no central point of control; every unit is entirely independent and has minimal contact with other points. Any node can reproduce by just starting another cell. Same for internet.
  • Distributed: more regular structure across whole thing with distributed control. No hub. In a distributed network, you can distribute control back out. There's a chain of command. Each person has stuff they are responsible for, but still have a chain of command.

-- How do we get to Google from NYU? NYU -->ATT-->Verizon-->Google

-- When you describe the Internet, it's "turtles all the way down." There's no central point, but there is a core. Tier 1 providers: large, many companies linked. (ATT, Orange, Verizon, Level 3). Cable companies have legal advantage (see "net neutrality"). Ma Bell was a common carrier (could not control what was said), cable companies have no restriction. Time Warner could turn off Gilligan's Island if it wanted to. Same structure being applied to net neutrality. Google/Verizon deal.

-- Remember that government policies and historical factors play a role in the business of the Internet.

email Tom by end of week if you can't access wiki