Understanding Networks Class Notes 9.6.11

Reviewed Syllabus and discussed scope of class, logistics and assignments

  • Tom recommends Tuesday afternoon office hours because first years will be in Red’s class
  • Advice: don’t get in trouble with ITS – you’re on your own if you do something unethical
  • Final assignment will be a networking project carried out by the entire class. The Class will design and implement a networked system that addresses some existing need on the floor.

Question: What questions about the internet keep us awake at night? 

 -Security of nodes
 -Net neutrality
 -How physical networks shape social networks
 -Parental supervision
 -Dave discusses shadow communication systems and encryption

Story about phone networks in 19th Century: up until 1888 there was no cross network communication. Multiple phones were required have full coverage. Following a snowstorm in 1888 that damaged phone lines, govt. mandated consolidation and Bell crated a single network that was governed by common carrier laws (Bell had to make lines accessible to all parties and couldn’t control the content of communications).

Question: What’s the difference between a TV and an iPad? 

	-One way vs. two way flow of info
	-Paternalistic vs. peer
        -Do generic limits on screen time make sense is there difference between passive and active consumption of screen-based content?

Data networks tend to presume openness to allow for interoperability 

	-Makes them vulnerable to misuse
	-How best to keep openness while limiting misuse?

Rule #1 of networking and love: “Listen, listen, listen, speak”

Network Types

  • Dyad: two things talking to each other. Point to point communication.
  • Triad: introduces the need for addressing, order of speaking and distinction between point to point communication or broadcast
  • number of potential dyads in a network, as a count of nodes: (N2-N)/2
  • number of potential sub-nets in a network, as a count of nodes: 2N-N-1

Decentralized (token ring network)

  • Requires all points for data transmission
  • Set order
  • Limited number of links

Centralized(Star Network)

  • All communications must pass through single node

Complete Network

  • Direct communication between all nodes
  • All nodes equal access

Hybrid Network

  • Combo of centralized and decentralized
  • A series of complete networks linked by single nodes
  • Allows for slower growth of complexity
  • Internet is a hybrid network

“Completeness” of as network refers to the proportion of 1 to 1 links between nodes “Diameter” describes the farthest distance between two nodes within the network

Do networks really describe everything? Technical metaphors and their limits: tendency to use prevailing technology to describe everything in the world (e.g. past metaphorical use of “engines” or “steam power”).

Thought Experiment: Imagine Google shut down. What would be different? 

 -Use Bing? Nope, it depends on Google’s data.
 -Discussion of web rings as and the need for a curator to organize the information
 -Greater diversity of information without Search Engine Optimization and content aggregation?

Usenet as a precursor to Wikipedia: 

 - Usenet: shared info in an open and discursive manner.  Sustained relationships more important
 - Wikipedia: users do not see how info has changed unless they seek it out.

Politics of Network infrastructure and resources

Why does AT&T’s network suck? 

 -Infrastructure limitations?
 -Profit motive?  Only good enough to retain customers

Tom tells story about Swiss govt. losing money on the auction of 3g licenses because telecom companies had undergone mergers/buyouts to eliminate competitive bidding.

How would Democratic vs. Republican administrations handle FCC distribution of bandwidth differently? Perhaps place emphasis on it being a public resource vs. an exploitable commodity.

European system might be better because there are more parties involved and thus more need for compromise.