Re: [alto] Review of draft-livingood-woundy-p4p-experiences-04

["Livingood, Jason" <[e-mail]>]

Thank you, Enrico.  We have incorporated your comments into -06, available
now at 
http://www.ietf.org/internet-drafts/draft-livingood-woundy-p4p-experiences-0
6.txt

Regards
Jason


On 5/6/09 12:11 PM, "Enrico Marocco" <[e-mail]>
wrote:

> I think the draft is in a good shape and, even if not a product of the
> WG, would make for an informational document useful for ALTO too.
> However, there are still a few things that should be taken care of.
> 
> 
> GENERAL COMMENTS
> 
> Terminology: text in Abstract and Introduction sections (S. 2.) seems to
> use the term "P4P" to refer to the DCIA initiative and the term
> "iTracker" for the technology. However, in the reminder of the document
> both terms are used to refer to the technology; this could generate
> confusion, especially now that "P4P" is also the name of a solution
> proposed in this working group, a solution derived by the one evaluated
> in the trial the document describes, but not the same one. I would
> suggest to revise the terminology in the draft and replace the term
> "P4P" with "iTracker" whenever it is used to indicate the technology. I
> would also suggest (see comments about S. 2.) to add an informative
> reference to the SIGCOMM paper describing the solution tested in the trial.
> 
> Different iTrackers: in S. 3. the four types of iTracker evaluated in
> the trial are introduced, but not described. Accurate descriptions are
> quite strangely proposed later in the text (S. 5.), after their actual
> evaluation; I think that moving such descriptions before the results (S.
> 4.) would improve the readability. Also, I recall from Minneapolis (and
> the minutes from the meeting seem to reflect that) that the "random"
> approach does not really consist of a random selection, rather it is the
> native approach Pando clients would follow without P4P support. If that
> is the case, it may make sense using a different name ("native"?) for
> that approach.
> 
> 
> Section 2. Introduction
> 
>    P4P's so-called "iTracker" technology was conceptually discussed with
>    the IETF at the Peer to Peer Infrastructure (P2Pi) Workshop held on
>    May 22, 2008, at the Massachusetts Institute of Technology (MIT).
> 
> I would add two informative references here, to some document describing
> the technology actually evaluated in the trial (10.1145/1402946.1402999,
> e.g.) and to the workshop report (draft-p2pi-cooper-workshop-report-01,
> in IESG evaluation).
> 
>    video file as in order to measure the effectiveness of P4P iTrackers.
> 
> s/as in order to/in order to/
> 
> 
> Section 4.2. Impact on Downloads, or Downstream Traffic
> 
>    However, we did notice that download activity in our access network
>    increased somewhat, from 56,030 MB for Random, to 59,765 MB for P4P
>    Generic Weight, and 60,781 MB for P4P Coarse Grained.  Note that for
>    each swarm, the number of downloaded bytes our logs report is very
>    close to the number of downloaders multiplied by file size.  But they
>    do not exactly match due to log report errors and duplicated chunks.
>    One factor contributing to the differences in access network download
>    activity is that different swarms have different numbers of
>    downloaders due to random variations during uniform random assignment
>    of downloaders to swarms (see Table 1).  One interesting observation
>    is that Random has higher cancellation rate (3.17%) than that of the
>    guided swarms (1.77% to 2.22%).  Whether guided swarms achieve lower
>    cancellation rate is an interesting issue for future investigation.
> 
> This text is repeated word-by-word in the following section (S. 4.3.);
> I'd suggest to remove it. If you agree to do this change, I'd also
> suggest to change the title of the section to "Impacts on Downloads" and
> to add a paragraph to describe the data show in Table 2, just as the
> remove paragraph did for Table 1.
> 
> 
> Section 4.3. Other Impacts and Interesting Data
> 
> The section is actually about the impacts on the traffic (i.e. what the
> ISP cares about), as opposed to the previous section that was about the
> impacts on the downloads (i.e. what users care about); I'd suggest to
> make the dichotomy explicit changing the title to something like
> "Impacts on upstream and downstream traffic."