From: Janet Davis (jlnd_at_cs.washington.edu)
Date: Wed Jan 14 2004 - 11:39:08 PST
It's looking like quiz section tomorrow is going to focus on the Fishnet
project (which is not unexpected). If you have unresolved questions about
the lectures, you might find it helpful to talk with someone one-on-one,
or feel free to ask your question again in quiz section.
Here are a few questions that have very short answers:
Q. The assignment mentions using echo packets for neighbor discovery. My
question is what are echo packets and how can they be used?
A. Oops -- this is a cut-and-paste error. The Ping protocol was called
the Echo protocol (because it echoes the message you send) in some
previous versions of Fishnet. Where you see "echo", read "ping" instead.
Q. In the original node.rb, there is an array that keeps track of the
nodes we have pinged that have not yet send acknowledgments back. If we
send out a ping to the broadcast address, we cannot know which nodes we
have pinged and therefore cannot ensure that we have received
acknowledgments from the necessary nodes. Do we need to worry about this?
A. No. The great thing about sending to the broadcast address is that you
can't be sure how many replies to expect. (Why?)
Q. Do I need to worry about retransmitting Ping packets if I don't get a
response?
A. No.
Q. Will we implement a sliding window protocol in a later assignment?
A. Yes.
Cheers,
Janet
-- Janet Davis jlnd_at_cs.washington.edu http://www.cs.washington.edu/homes/jlnd/ _______________________________________________ Cse461 mailing list Cse461_at_cs.washington.edu http://mailman.cs.washington.edu/mailman/listinfo/cse461
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