North American Network Operators Group

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

  • From: Joe Greco
  • Date: Fri Oct 26 07:55:06 2007

> Rep. Boucher's solution: more capacity, even though it has been 
> demonstrated many times more capacity doesn't actually solve this 
> particular problem.

That would seem to be an inaccurate statement.

> Is there something in humans that makes it difficult to understand
> the difference between circuit-switch networks, which allocated a fixed 
> amount of bandwidth during a session, and packet-switched networks, which 
> vary the available bandwidth depending on overall demand throughout a 
> session?
> Packet switch networks are darn cheap because you share capacity with lots 
> of other uses; Circuit switch networks are more expensive because you get
> dedicated capacity for your sole use.

So, what happens when you add sufficient capacity to the packet switch
network that it is able to deliver committed bandwidth to all users?

Answer: by adding capacity, you've created a packet switched network where
you actually get dedicated capacity for your sole use.

If you're on a packet network with a finite amount of shared capacity,
there *IS* an ultimate amount of capacity that you can add to eliminate 
any bottlenecks.  Period!  At that point, it behaves (more or less) like
a circuit switched network.

The reasons not to build your packet switched network with that much
capacity are more financial and technical than they are "impossible."  We
"know" that the average user will not use all their bandwidth.  It's also
more expensive to install more equipment; it is nice when you can fit
more subscribers on the same amount of equipment.

However, at the point where capacity becomes a problem, you actually do
have several choices:

1) Block certain types of traffic,

2) Limit {certain types of, all} traffic,

3) Change user behaviours, or

4) Add some more capacity

Come to mind as being the major available options.  ALL of these can be
effective.  EACH of them has specific downsides.

... JG
Joe Greco - Network Services - Milwaukee, WI -
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.