Re: [p2pi] After-BoF charter

[Laird Popkin <[e-mail]>]

I'm in violent agreement. :-)

- Laird Popkin, CTO, Pando Networks
  mobile: [phone]

----- Original Message -----
From: "Bob Briscoe" <[e-mail]>
To: "Richard Woundy" <[e-mail]>
Cc: [e-mail], [e-mail]
Sent: Tuesday, August 12, 2008 5:01:58 AM (GMT-0500) America/New_York
Subject: Re: [p2pi] After-BoF charter

Richard, Bruce, Laird & all,

Yes, of course, I agree with you all. I shouldn't have said the w-g 
should define what optimality means. I didn't mean that, sorry. 
Indeed, I originally gave counter-examples of NZ & Oz where 
localisation would be more important than reducing cross-domain.

But I /did/ mean that the w-g should document what different parties 
might reasonably want optimality to mean.

I want the charter to acknowledge the same old point I started with 
at the mic and on the list:
- that unconditional localisation will not be sufficient for /any/ 
ISP, so the parameters that the ALTO service will have to gather are 
more than just the static ones: topology and policies
- To avoid this being inconsistent with the other rule about not 
using fast changing metrics like congestion, we have to say 
congestion will have to be taken into account, but only long term 
averages in time, and probably across broad groups of paths.

The first thing you teach a learner driver is how to stop. Then you 
teach them how to start. Similarly, before you start moving traffic 
in one direction, you also have to know /when/ to stop and /how/ to 
move it back in the other direction.



Bob

At 17:17 11/08/2008, Woundy, Richard wrote:
> >I believe you have just stated what is optimal for two providers, 
> but I'm not convinced that the entire universe of providers agrees with you.
>
>I have to agree with Bruce. I still maintain that for Comcast, 
>access costs are much more of interest than transit / cross-ISP 
>traffic costs. But I have heard that the relative magnitude of costs 
>could be different for other ISPs.
>
>Some examples I am aware of:
>- ISPs in geographies outside of North America / Europe / East Asia, 
>due to relative scarcity of intercontinental/international fiber trunks.
>- Smaller ISPs, due to their smaller geographic footprint and lower 
>traffic commitments, leading to higher transit costs.
>- Universities and other 'special case' ISPs, as Henning pointed out 
>in an earlier email on costs.
>
>-- Rich
>
>
>----- Original Message -----
>From: [e-mail] <[e-mail]>
>To: Bob Briscoe <[e-mail]>
>Cc: [e-mail] <[e-mail]>; Lisa Dusseault <[e-mail]>
>Sent: Mon Aug 11 09:51:48 2008
>Subject: Re: [p2pi] After-BoF charter
>
>Good points Bob, most of which I agree with. A little clarification
>below:
>
>On Aug 8, 2008, at 8:40 PM, Bob Briscoe wrote:
>
> > Enrico,
> >
> > Charter generally looks good.
> > Generally agree with Lars, Dave's & Laird's responses so far.
> > My additional 3 penny's worth:
> >
>[snip]
>
> >
> > 3/ What does optimal mean, and what does better mean?
> >
> > The charter has hidden assumptions about what optimal is, and what
> > better is. From whose perspective? It needs to either say what
> > these assumptions are, or say that the w-g will define what optimal
> > means in a w-g document.
>
>I would suggest that there will be different views of optimal for
>different providers, and the WG should work on capturing that fact
>and developing solutions that can deal with it.
>
> >
> > As I have to keep saying, and as Richard Woundy from ComCast has
> > agreed, excessive cross domain traffic is much less bad than
> > excessive local traffic.
>
>I believe you have just stated what is optimal for two providers, but
>I'm not convinced that the entire universe of providers agrees with
>you. I think the WG needs to deal with the fact that some providers
>will care about reducing backhaul traffic and others will care about
>reducing inter-domain traffic.
>
>Rather than trying to get this all nailed down in the charter, I
>think it would be good if the charter mentioned the problem of
>defining optimality from a variety of perspectives as one of its work
>items.
>
>I also note that the charter is ultimately intended only to specify
>the interface between clients and "peer selection services"  - so we
>need to make sure that the information carried across that interface
>is sufficiently rich to allow for a range of different definitions of
>optimality. We don't need to get everyone to buy into a single
>definition of optimality.
>
>The rest of your email below finds me in complete agreement.
>
>Bruce
>
> >
> > I agree that the /current/ traffic arrangement resulting from p2p
> > has excessive cross-domain traffic. But this is the not-seeing-
> > beyond-the-first-step problem I tried to explain at the mic in the
> > ALTO BoF.
> >
> > Once traffic is sitting in an optimum arrangement (possibly
> > bootstrapped by ALTO then optimised by e2e congestion control), the
> > best place to add the /next/ connection will likely be cross-domain
> > not local. Because the optimium is a /balance/ of light congestion
> > across both. This is why the goal MUST NOT be unconditional
> > localisation. That could eventually drive the network /beyond/ the
> > balance, persistently trying to drive up congestion in the access
> > and backhaul. That will be much worse than excessive cross-domain
> > traffic.
> >
> > You might say it would be nice to have that problem.
> >
> > But if this service only does localisation, it will only be safe /
> > if/ it is used by a minority. If the popularity of an ALTO service
> > goes beyond a certain point, it will start to kill the ISP's local
> > network. Of course, then less people will use it and an equilibrium
> > might be reached. But that's what I said. Optimisation is a
> > process, not just a first step. ALTO has to be able to move traffic
> > out, not just in.
> >
> > \
> >  \
> >   \      /\
> >    \    /  \ ^----- <<<---goal
> >     \  /    V
> >      \/
> >
> > NOT
> > \
> >  \
> >   \
> >    \          <<<---goal
> >     \
> >      \
> >       \
> >        \
> >         \
> >          \
> >
> >
> > Bob
> >
> > At 20:06 07/08/2008, Enrico Marocco wrote:
> >> We have tried to collect all comments received during the meeting, in
> >> mailing list and hallway discussions. The new version of the charter,
> >> available as always at http://alto.tilab.com/docs/charter.txt, should
> >> reflect at least some of them. Please take a look and comment.
> >> Feel free
> >> to say if you don't like it -- entirely or partially -- and why;
> >> or if
> >> you like it. And why.
> >>
> >> Major changes include:
> >> + terminology: dropped terms like "the oracle" and "best peer";
> >> + scope: removed cache/TURN/whatever service discovery;
> >> + path selection: stressed the importance of routing preferences and
> >>   peering policies;
> >> + forbidden third-party queries;
> >> + mentioned IRTF for analysis on more sophisticated metrics.
> >>
> >> The current version of the charter is also more explicit about what
> >> pieces of information will be provided by an ALTO service; I'll
> >> start a
> >> separate thread specifically for this discussion.
> >>
> >> --
> >> Ciao,
> >> Enrico
> >>
> >>
> >> _______________________________________________
> >> p2pi mailing list
> >> [e-mail]
> >> https://www.ietf.org/mailman/listinfo/p2pi
> >
> > ______________________________________________________________________
> > ______
> > Bob Briscoe, <[e-mail]>      Networks Research Centre, BT
> > Research
> > B54/77 Adastral Park,Martlesham Heath,Ipswich,IP5 3RE,UK.    +44
> > 1473 645196
> > _______________________________________________
> > p2pi mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/p2pi
>
>_______________________________________________
>p2pi mailing list
>[e-mail]
>https://www.ietf.org/mailman/listinfo/p2pi

____________________________________________________________________________
Bob Briscoe, <[e-mail]>      Networks Research Centre, BT Research
B54/77 Adastral Park,Martlesham Heath,Ipswich,IP5 3RE,UK.    [phone] 

_______________________________________________
p2pi mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/p2pi
_______________________________________________
p2pi mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/p2pi