Homework 6

INSTRUCTIONS

Out: Nov 28, 2005.
Due: At the start of lecture, December 7 (Wednesday), 2005. We will accept only solutions that are typed-up and printed out (figures and tables may be drawn by hand). No written solutions or online handins.
Resources you are allowed to use: Unless otherwise mentioned, the only resources you can use are the lectures slides, your notes, the Tanenbaum textbook, and any other textbook on OS's, architecture, data structures or previous CS material. You cannot refer to any online resources (unless otherwise mentioned). You cannot use ready-made solutions under any circumstances..
 Relevant Lectures: 31-40.
 Points: Unless otherwise mentioned, a problem is worth 5 points. The HW is worth a total of 30 points. If a question has multiple parts, the 5 points are split equally among the parts.
 Warning: Homeworks are individual efforts. Although you are allowed to discuss HWs with your fellow students, you are expected to solve them yourself and type up the solution yourself. For detailed information on penalties, cheating and playing it safe, see this page.

PROBLEMS

  1. Define the term "RPC"? A Sun machine makes an RPC to a Windows machine - since the former uses big-endian format and the latter uses little-endian format, is it true that the RPC will not work? Why or why not?
  2. Is the original wired telephone network circuit-switched or packet-switched? What about IP telephony services? Name one advantage of each (circuit- and packet-swtiched) for telephone communications.
  3. Mention THREE major differences between NFS and AFS.
  4. The Gnutella P2P system floods a query message out, with a TTL -- all this results in extra messages sent out on the network. Propose TWO ways in which the basic Gnutella system can be augmented so that these extra messages can be cut down, without compromising on the number of results that the querying node gets back. For backwards-compatibility, make sure you do not change any of the basic existing Gnutella Query mechanisms (e..g, don't replace flooding with a routing algorithm).
  5. Go on the Internet and find out about the technical details and the current status of the SETI@Home project, then write a short (< 200 words) paragraph on it.
  6. Problem 9.17 from text.

Updated: Nov 28, 2005. (c) Indranil Gupta.