Some questions from a discussion in my office this morning.
1. Can you give an example of redundant retransmissions caused by coarse feedback?
During class I explained what coarse feedback means but never gave a real example on how this could lead to redundant retransmissions. Vern Paxson gave a real example in his thesis (Page 317-318, ftp://ftp.ee.lbl.gov/papers/vp-thesis/dis.pdf). I could not explain any better than Vern Paxson so let me just refer you to the thesis for the example.
2. To pessimistically estimate the loss rate on an alternative path consists of default paths with loss rate of p1, p2, .. pk, can we really sum up the loss rate (Slide 64, Lecture 10)??
I stand corrected. We assume that loss rate on the paths are independent. Thus, the loss rate on the alternative path, i.e., probability that a packet is lost on one of these default paths, should be 1 – (1-p1)(1-p2)..(1-pk).
Thanks to Luochen for pointing out the error.