Re: [p2pi] One more proposed definition of fairness...

[Joe Touch <[e-mail]>]

Nicholas Weaver wrote:
> 
> On Jun 8, 2008, at 10:41 PM, Joe Touch wrote:
>> ...
>>> EG, the ISP can at a single bidirectional point in the network 
>>> (admittedly keeping lots of state, but...) for a large group of users 
>>> infer the congestion on each TCP flow,...
>>
>> That's the point, however, where things stop when someone uses 
>> encrypted transport layers.
> 
> As long as the end point address is NOT encrypted, it doesn't matter.

How might I infer the congestion on each TCP flow when I can't see TCP 
connections, e.g.?

>> ...
>>> Yes, this is a LOT of engineering work to get right [1], but I 
>>> believe it is doable, and could accomplish the stated definition of 
>>> fairness (or something very close to it).
>>
>> A key question is whether it's worth the state it will take to get 
>> right. An endpoint might open a few thousand flows just to help 
>> overload your system ;-)
...

...
> c)  If a single host or small group of hosts starts doing behavior 
> designed to disrupt the flow cache deliberately (eg, >10k ACTIVE TCP 
> flows), I think the ISPs device can start doing some rate limiting on 
> flow creation as well, as there is a strong case that such is suspicious 
> behavior.

How can you infer that >10K flows from a host is deliberate disruption? 
If I buy an Internet connection from an ISP, I get as many flows as I 
can connect to.

Or have you decided that "the Internet" is now only as many flows as you 
can track efficiently? (see below)

>>> Furthermore, you can resist the attacks you mentioned.  Because the 
>>> ISP can prevent the user from minting new IP addresses (as they 
>>> control the point of attachment), this prevents address forging.
>>
>> Sure - the local ISP can prevent that. You can't prevent someone 
>> accessing multiple ISPs (cable, DSL, etc.), but presumably you don't 
>> care about that?
> 
> Yeah, why should the ISP care?  Its because common congestion pretty 
> much only occurs within the ISP, so it is the ISP's problem to mitigate, 
> and in the ISP's interest to mitigate.
> 
> Someone who's using multiple ISPs to transfer more bits is paying for 
> those extra bits, and it doesn't really matter.

Maybe I'm missing something, but if I have one ISP, I paid for THOSE 
bits too. How I use them is up to me, not the ISP.

Joe

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