Subject: [Iccrg] review of open-research draft
From: [email-masked] (Lachlan Andrew)
Date: Fri Sep 19 18:46:38 2008

Greetings Wes,

2008/9/19 Eddy, Wesley M. (GRC-RCN0)[VZ] <[email-masked]>:
> I've reviewed the open-research draft:
> http://tools.ietf.org/html/draft-irtf-iccrg-welzl-congestion-control-ope
> n-research-02
>
> - Section 2.3, final paragraph: It seems to me that if an architecture
> is
>  built to support cost-fairness that equal-costs result in flow-rate
>  fairness as a degenerate case; that is, flow-rate fairness is a
> special
>  case of cost-fairness.  One can be used to build the other, but not
>  vice-versa.

I think that over-simplifies the problem.  In a general network, cost
accumulates along a path (a two-hop flow will have the sum of the
costs of the two links) while flow rate doesn't.

I'm not exactly sure what you mean by "equal cost", but I'm guessing
that you mean that all flows have equal utility functions.  If that is
the case, then we certainly don't get equal rate in multi-bottleneck
networks.

My own comment on that paragraph would be that deciding between
rate-fairness and cost-fairness *does* need more research.  I'm not
convinced that either is understood well enough for "assessing how bad
fairness problems could become if they are not addressed rigorously".
However, I agree that more research won't necessarily convince either
side to change their opinions, and that debate is needed for that.

Cheers,
Lachlan

-- 
Lachlan Andrew Dept of Computer Science, Caltech
1200 E California Blvd, Mail Code 256-80, Pasadena CA 91125, USA
Ph: +1 (626) 395-8820 Fax: +1 (626) 568-3603
http://netlab.caltech.edu/lachlan

From: [email-masked] (Eddy, Wesley M. (GRC-RCN0)[VZ])
Date: Fri Sep 19 18:28:03 2008
Subject: [Iccrg] review of open-research draft
Message-ID: <[email-masked]>

I've reviewed the open-research draft:
http://tools.ietf.org/html/draft-irtf-iccrg-welzl-congestion-control-ope
n-research-02

I found it to be much-improved over previous versions, and generally
in good shape.  I think the authors and editors have done a nice job
with it.  I know they still have a list of a few things they want to
do with it, but it seems near to publishable to me.  They've made some
very complex and thorny topics easy for a reader to quickly grasp and
understand the basics of.

Here are my comments:

- Section 1, 2nd paragraph: change "prima-dual" -> "primal-dual"
- Section 1, 3rd paragraph: at end of second sentence, a reference to
the
  ICCRG survey of congestion control RFCs may be sensible
  (draft-irtf-iccrg-cc-rfcs)
- Section 1, 4th paragraph: first sentence should have "in order to
avoid
  congestion collapse" appended to it.

- Section 2.1, first paragraph: change "interstellar" -> "space" ...
This
  one made me smile a bit because the Internet doesn't extend to other
  stars (yet) :). Getting it to other planets is proving to be
challenging
  enough that IP has been rejected by some parties (though not me :))!!!

- Section 2.1, 5th paragraph: This should also more clearly say that
multiple
  congestion control techniques interacting with one another is not yet
well-
  understood.

- Section 2.3, final paragraph: It seems to me that if an architecture
is
  built to support cost-fairness that equal-costs result in flow-rate
  fairness as a degenerate case; that is, flow-rate fairness is a
special
  case of cost-fairness.  One can be used to build the other, but not
  vice-versa.

- Section 3.7, it may be worth mentioning that its possible this issue
  would be different in a cost-based fairness regime, and it's worth
  thinking about how.  This section is interesting to me; I think the
  conclusion "By design, new congestion control protocols need to
  enable one end to check the other for protocol compliance." is pretty
  terrifying, and think that would be a cool topic to talk more about
  in the RG, personally.

From: [email-masked] (Eddy, Wesley M. (GRC-RCN0)[VZ])
Date: Fri Sep  5 15:52:48 2008
Subject: [Iccrg] meeting at IETF 73
Message-ID: <[email-masked]>

We've put in a request for an ICCRG meeting slot at the upcoming
IETF 73 meeting in Minneapolis (November 16-21):
http://www.ietf.org/meetings/73/

The agenda is being drafted.  If there are presentations that
people would like to give, please let me and/or Michael know,
and we'll set aside a time slot.  If people have test results or
analyses of CUBIC that could serve as inputs to the ICCRG
evaluation of CUBIC for experimental deployment on the Internet,
this will be a very good time to present them to the group.