Computer Networking

Homework 6, 18 April 2013

This homework assignment has five questions; answer all of them. This assignment is due no later than 1:00 p.m. on Thursday, 2 May.

If you mail in your assignment, please submit a printable document — a PostScript .ps or PDF .pdf document, for example — and not a source document — a Word .docx or Latex .tex document, for example.

1. A system with DNS-like structure needs more resources to handle growing demand. Two possible resource choices are to add more cache to existing nodes or to add more nodes (with the same cache amount) to the system. Describe 1) the system features you would use to help decide between the two possibilities, and 2) an example using the features to make a decision.
2. A peer-to-peer node could base its routing decisions on load information from possible next-hops. This sounds like a good idea; is it? Explain your answer.
3. Is it always the case that a hybrid peer-to-peer architecture can be said to have a small-world topology? Justify your answer.
4. You work for a content-distribution company based on a peer-to-peer network. Your boss discovers that data access follows Zipf’s law, and wants you to optimize the data distribution in the network to improve performance. What kind of peer-to-peer architecture would you like the system to have to make your job as easy as possible? Explain your answer.
5. Is a Chord ring directional? That is, if a node n in a Chord ring is searching for item i without using the finger table, does it know if it should go to the left or right (to its predecessor or successor)? Explain your answer.