Can P2P applications learn to play fair on networks?

Sat Oct 27 03:30:44 UTC 2007

On 10/22/07 2:01 AM, "Mikael Abrahamsson" <swmike at swm.pp.se> wrote:
> Could someone who knows DOCSIS 3.0 (perhaps these are general
> DOCSIS questions) enlighten me (and others?) by responding to a few things
> I have been thinking about.
> 
> Let's say cable provider is worried about aggregate upstream capacity for
> each HFC node that might have a few hundred users. Do the modems support
> schemes such as "everybody is guaranteed 128 kilobit/s, if there is
> anything to spare, people can use it but it's marked differently in IP
> PRECEDENCE and treated accordingly to the HFC node", and then carry it
> into the IP aggregation layer, where packets could also be treated
> differently depending on IP PREC.
>
> This is in my mind a much better scheme (guarantee subscribers a certain
> percentage of their total upstream capacity, mark their packets
> differently if they burst above this), as this is general and not protocol
> specific. It could of course also differentiate on packet sizes and a lot
> of other factors. Bad part is that it gives the user an incentive to
> "hack" their CPE to allow them to send higher speed with high priority
> traffic, thus hurting their neighbors.

Yes, as a part of the DOCSIS specification (waiting for D3.0 not required);
however, implementations vary on the CMTS end of the equation though.
Having this capability ubiquitously on the CMTS equipment simplifies the
problem space greatly (plus removes that hacked CPE risk).

-ron