Re: Can P2P applications learn to play fair on networks?

Iljitsch van Beijnum wrote:
>
> On 22-okt-2007, at 18:12, Sean Donelan wrote:
>
>> Network operators probably aren't operating from
altruistic 
>> principles, but for most network operators when the
pain isn't spread 
>> equally across the the customer base it represents
a "fairness" 
>> issue.  If 490 customers are complaining about bad
network 
>> performance and the cause is traced to what 10
customers are doing, 
>> the reaction is to hammer the nails sticking out.
>
> The problem here is that they seem to be using a sledge
hammer: 
> BitTorrent is essentially left dead in the water. And
they deny doing 
> anything, to boot.
>
> A reasonable approach would be to throttle the
offending applications 
> to make them fit inside the maximum reasonable traffic
envelope.
>
> What I would like is a system where there are two
diffserv traffic 
> classes: normal and scavenger-like. When a user trips
some predefined 
> traffic limit within a certain period, all their
traffic is put in the 
> scavenger bucket which takes a back seat to normal
traffic. P2P users 
> can then voluntarily choose to classify their traffic
in the lower 
> service class where it doesn't get in the way of
interactive 
> applications (both theirs and their neighbor's). I
believe Azureus can 
> already do this today. It would even be somewhat
reasonable to require 
> heavy users to buy a new modem that can implement
this.
Surely you would only want to set traffic that falls outside
the limit 
as scavenger, rather than all of it?

S

On 23-okt-2007, at 15:43, Sam Stickland wrote:

>> What I would like is a system where there are two
diffserv traffic  
>> classes: normal and scavenger-like. When a user
trips some  
>> predefined traffic limit within a certain period,
all their  
>> traffic is put in the scavenger bucket which takes
a back seat to  
>> normal traffic. P2P users can then voluntarily
choose to classify  
>> their traffic in the lower service class where it
doesn't get in  
>> the way of interactive applications (both theirs
and their  
>> neighbor's).

> Surely you would only want to set traffic that falls
outside the  
> limit as scavenger, rather than all of it?

If the ISP gives you (say) 1 GB a month upload capacity and
on the  
3rd you've used that up, then you'd be in the "worse
effort" traffic  
class for ALL your traffic the rest of the month. But if you
 
voluntarily give your P2P stuff the worse effort traffic
class, this  
means you get to upload all the time (although probably not
as fast)  
without having to worry about hurting your other traffic.
This is  
both good in the short term, because your VoIP stuff still
works when  
an upload is happening, and in the long term, because you
get to do  
video conferencing throughout the month, which didn't work
before  
after you went over 1 GB.