[Iccrg] Meeting agenda (really! :-) )

[S. Keshav]

On Oct 12, 2006, at 5:00 AM, Bob Briscoe wrote:
Bob,

> Keshav,
>
> At 20:41 11/10/2006, S. Keshav wrote:
>> Bob,
>> This sounds like a good discussion to have. The need for fairness has
>> been grossly exaggerated, in my opinion, and is hard to justify. If
>> scheme A is fair to all users, and scheme B is unfair, but every user
>> with scheme B gets more than the same user with scheme A, would you
>> prefer B to A? I would.
>
> Of course. But such a situation would be extremely unusual. All the  
> practical scenarios involve conflicts of interests, with some users  
> getting more and some less.
>
I guess this assumes that you are already at the Pareto frontier. As  
I discussed in my earlier email, it is not clear to me that this is  
necessarily the case with today's transport protocols (especially  
when one of the hops is on a wireless link). A hypothetical unfair  
scheme that improves every flow's performance would certainly be  
better than wasting resources.

> I have to disagree that the need for fairness is hard to justify.  
> In particular, in a non-co-operative environment (like the  
> Internet, which is after all the object of debate), if the view of  
> fairness that prevails cannot be /enforced/, then some users can  
> take orders of magnitude more than their 'fair' share. Then, what  
> is the point of even having a congestion control protocol?
>
Let me restate my thesis:
Consider congestion control scheme A that guarantees fair allocations  
to all flows. Suppose I come up with scheme B that is not fair, but  
every flow that got an allocation r with A gets >= r with B. Some  
flows may indeed get *much* more than others, but every flow does  
better. I argue that scheme B is better than scheme A. Or, more  
obliquely, capitalism trumps socialism :-)

Now, your objection is that fairness needs to be enforced. But what I  
propose is to have the fair share be the lower bound on the  
allocation for all flows. That is the point of the congestion control  
scheme. (For that matter, if only a majority of flows improve,  
perhaps scheme B is still better.)

>>
>> --Paraphrased requirements (eliding application level  
>> requirements) --

BTW - this is not my wording - I just cut and paste if from the  
survey that Michael pointed to. I put it out as fodder for discussion

regards
keshav