Re: [p2pi] After-BoF charter

["Woundy, Richard" <[e-mail]>]

>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
>>
>>
>> _______________________________________________
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>
> ______________________________________________________________________ 
> ______
> Bob Briscoe, <[e-mail]>      Networks Research Centre, BT  
> Research
> B54/77 Adastral Park,Martlesham Heath,Ipswich,IP5 3RE,UK.    +44  
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