Re: [conex] ConEx credit & audit: status update

[David Wagner <[e-mail]>]

Hi Bob, 

I agree, the abstract document should remain abstract. :-)
Anyway, right now, section 5.5.1 introduces credit as a signal used to avoid RTT-estimations at the audit (amongst other thoughts in this section). 
And I think we reached a state, at which we can exclude that this is possible to full extend.
I think you'll reflect that in your update and just intended to clarify on which basis I start with the audit doc and that I'll continue to use the term credit. 

Cheers,
David 


On Friday 18 October 2013 16:56:31 Bob Briscoe wrote:
> David,
> 
> Dealing with credit wording in abstract-mech is 2nd on my todo list now.
> 
> I'm pretty sure the position is that abstract-mech is abstract. It 
> doesn't define any details, only a thought framework. ConEx consists 
> of a number of variables that can each be re-defined a little to 
> allow others to be re-defined a little.
> 
> This new definition of credit is not cast in stone. It's an 
> experimental approach the w-g is running with to see where it takes 
> us. So the correct place to define the current precise meaning of 
> ConEx concepts is in the experimental docs (destopt), not the 
> informational overview (abstract-mech).
> 
> However, I won't completely agree or disagree with you until I've 
> re-loaded state - I need to check what Matt was willing to agree to 
> and consider how I could reword abstract-mech to include and hint at 
> the new meaning of credit without over-constraining.
> 
> I'll be in touch with a final decision on abstract-meach wording 
> before the end of Saturday (hopefully).
> 
> 
> Bob
> 
> At 14:28 18/10/2013, David Wagner wrote:
> >Hi *,
> >
> >we now are sure to understand that credit will not allow to 
> >completely avoid handling time estimations in the audit, but rather 
> >represents a risk for future congestion. Therefore, I think we 
> >should change the respective section in abstract-mech and we even 
> >could change the term to something more distinct like "congestion risk".
> >
> >I'd propose to keep the word credit to not cause (more) confusion 
> >but to make clear the meaning of that signal in the abstract-mech 
> >draft. I would then refer to that text in the audit draft.
> >
> >Agree?
> >
> >David
> >
> >On Wednesday 16 October 2013 19:52:29 Bob Briscoe wrote:
> > > ConEx chairs,
> > >
> > > David Wagner, Mirja Kuehlewind & I have been meeting over the past 2
> > > days to sort out whether the approach to credit the w-g agreed is
> > > correct and feasible.
> > >
> > > You may recall that last July we agreed at the working group meeting
> > > in Berlin to go with David Wagner's idea of requiring audit to check
> > > for a non-negative balance of (credit - (loss or ECN)) as well as
> > > (re-echo - (loss or ECN)), so the source has to effectively 'pay'
> > > twice for congestion, with credit and with re-echo.
> > > (See draft-wagner-conex-credit-00 Section.3.3. "Credit As Congestion
> > > Surcharge")
> > >
> > > The more I think about the idea, the more I like it - I'm grateful to
> > > David for thinking up this idea - it's solved an otherwise major
> > > problem. We all agree that there are still some niggles with it,
> > > which we will write up by updating David's draft (above).
> > >
> > > But more importantly (if the relevant co-authors agree) we will
> > > reflect this change in thinking with the relevant normative text in:
> > >          draft-ietf-conex-destopt and
> > >          draft-ietf-conex-tcp-modifications.
> > >
> > > For these expt track docs, we aim to issue new revisions before
> > > Monday's deadline, even there is no ConEx meeting planned for Vancouver.
> > >
> > > We intend to write up a full (Informational) spec of audit and credit
> > > by revising
> > >          draft-wagner-conex-credit-00 (we may use a new filename to
> > > include the word audit).
> > >
> > > This will document all the potential attacks against ConEx and the
> > > way the audit function handles them. We'll need to build a new
> > > implementation to test it, then we can include reference pseudocode
> > > in the draft (all the ideas from the auditor in my PhD that Toby
> > > Moncaster implemented are just as applicable to these attacks, even
> > > with the change in the definition of credit).
> > >
> > > Matt Mathis & I will also be making the few promised updates to
> > >          conex-abstract-mech (Informational)
> > > before Monday.
> > >
> > >
> > >
> > > Bob
> > >
> > >
> > > ________________________________________________________________
> > > Bob Briscoe,                                                  BT
> > >
> > > _______________________________________________
> > > conex mailing list
> > > [e-mail]
> > > https://www.ietf.org/mailman/listinfo/conex
> > >
> >
> >
> >--
> >Dipl.-Inf. David Wagner
> >Institute of Communication Networks and Computer Engineering (IKR)
> >University of Stuttgart
> >Pfaffenwaldring 47, D-70569 Stuttgart, Germany
> >
> >web: www.ikr.uni-stuttgart.de   email: [e-mail]
> >phone: [phone]        fax: [phone]
> >-------------------------------------------------------------------
> 
> ________________________________________________________________
> Bob Briscoe,                                                  BT 
> 
> 


-- 
Dipl.-Inf. David Wagner
Institute of Communication Networks and Computer Engineering (IKR)
University of Stuttgart
Pfaffenwaldring 47, D-70569 Stuttgart, Germany

web: www.ikr.uni-stuttgart.de   email: [e-mail]
phone: [phone]        fax: [phone]
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