Subject: Re: [ppsp] 转发: New Version Notification for draft-deng-ppsp-bfbitmap-03.txt

From: Arno Bakker <[email-masked]>
Date: Wed, 20 Nov 2013 13:39:35 +0100

On 21/10/2013 04:44, 邓灵莉/Lingli Deng wrote:
> Hi all,
> 
> With Rachel's help and input, we have updated the BF draft, with more
> specific description about PPSP protocol integration added. After a
> preliminary analysis, it seems that both the current extended tracker
> protocol and peer protocol can incorporate this new algorithm pretty
> easily.
> 
> Your comments are more than welcome.
> 

Hi all

after the meeting I kept on thinking about the use of bloom filters to
convey chunk availability. One additional problem with their use is that
the peer protocol does not tolerate structural omissions ("miss-hits")
in the chunk availability.

Take the example of a single peer with no content (leecher) talking to a
peer with the complete content (seeder). If the bloomfilter that is sent
by seeder is lossy, and does not convey that the seeder has all,
the leecher will be stuck forever waiting to download the unreported
chunks.

More general, in scenarios with multiple peers the bloomfilter creation
algorithm will have to ensure that for each chunk there is least one
peer that reports it as available for download.

Regards,
    Arno