[Iccrg] RE: updated CTCP draft

[Murari Sridharan]

Good points I'll add appropriate bounds for the constants and also clarify how dwnd stays positive.

-----Original Message-----
From: Lachlan Andrew [mailto:lachlan.andrew at gmail.com]
Sent: Tuesday, November 20, 2007 7:57 PM
To: Murari Sridharan; iccrg IRTF list
Subject: Re: updated CTCP draft

Greetings Murari,

I've finally started reading your draft -- sorry for the delay.

I'll get back to you once I've read it properly, but here are a couple
of preliminary points:

- I don't think it can be declared "safe" yet, since the "Control Law"
section doesn't specify  alpha.  A later section says "we use
alpha=1/8", but the draft doesn't say that that is part of the
*requirements* of the algorithm.  I could implement this with
alpha=10000 and claim that it satisfies the protocol description.  If
you want to say these parameters are tunable, you might want to
specify a range in which they can be varied, and specify a "default"
value in the algorithm description.

- Someone recommended using MUST, SHOULD, RECOMMENDED, MAY etc
according to the normal practice for normative RFCs.  I'd say you
"SHOULD" do that (you don't have to if there is a good reason not to,
but otherwise please do it).

- It seems that  dwnd  can become negative if diff<gamma.  In
particular,  if  dwnd(t)=0, then  dwnd(t+1) = -1.  Is that what you
mean?  In an RFC, I believe it is important to be very precise about
things like clipping.

- I'd much rather see a separation of  algorithm/implementation  from
justification/motivation.  As one of many examples, discussion of
fairness doesn't (to me) belong in the section defining the algorithm.
 This will also make clearer whether "automatic setting of gamma" is
part of the algorithm or not.  Unlike the other points, this doesn't
affect whether or not it is "safe", so it is up to you, but I think it
will make the document much easier to use.

Cheers,
Lachlan

On 30/10/2007, Murari Sridharan <muraris at microsoft.com> wrote:
>
> Lachlan you must have seen my mail to iccrg on the updated draft, this had a
> few more cosmetic changes, some more cleanups than the doc I sent out, but
> from a technical stand point it's the same.
>
> http://www.ietf.org/internet-drafts/draft-sridharan-tcpm-ctcp-01.txt
>
> Thanks


--
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