Multicast Traffic on Backbones

Fri Jun 15 09:27:35 UTC 2001

John Olp wrote:

> > 	In any event, it has always been my position that where
> > possible and within
> > reason, ISPs will be most competitive (and the Internet will
> > remain the most
> > stable) if they can develop and implement pricing models that
> > charge their
> > customers based upon the actual cost to provide the customer with the
> > service.

> Precisely the thoughts I intended to provoke.

> Assuming the group members are other customers of foo and/or bar, then foo
> and/or bar are charging both you and those customers (essentially charging
> you for something already paid for).  Even if foo/bar is just routing to
> some other network and just passing on their overcharge to you,
> the argument
> stands that someone is charging twice for the same traffic.

	No, they are not being charged for the same thing. The originator is being
charged for the originating network's costs of getting his traffic off the
originating network towards the recipient. The recipient is charged for the
recipient network's costs of getting his traffic from the originating
network and to the recipient.

	In the simplest case, where your ISP and my ISP meet directly at a peering
point and you send me a packets, the costs go like this:

	You pay for your line and your ISP's costs of keeping that line
operational. You pay the cost of getting traffic from your line to wherever
the router is that peers with my ISP. You pay part of your ISP's costs in
maintaining that peering link.

	I pay for my line and my ISP's costs of keeping that line operational. I
pay for some of my ISP's costs in keeping that link to you operational.

> While it might be true that you have a cost based on your transit/peering
> agreements (i.e. the pricing model), the argument stands that multicast
> doesn't cost more.  The truth is, it costs less.  You're just
> being charged
> more because you accept it.  And to recoup your cost, you consider passing
> it on to your customer (who with this model concludes multicast isn't cost
> effective).

	But it does cost you more. You are ignoring the example of mine wherein it
clearly costs you more.

> I haven't begun to conceive a model that works to everyone's satisfaction,
> but it's plainly obvious the existing model doesn't work in favor of
> multicasting.  You can bet that whoever is pocketing the
> overcharges is not
> going to stop on their own accord.  But until we come up with the right
> model, the profit potential of unicast is going to remain an
> obstacle to the
> general acceptance of multicast.

	You now have two self-contradictory arguments. One argument is that people
are profiteering from multicast. The other is that they make more money with
unicast. You can't have it both ways. If ISPs can get rich off of multicast,
then they will promote it. Eventually, competition for multicast will bring
the prices more in line with the actual cost to provide the service.

	While I agree that multicast is caught in a catch-22, it's not the one you
think, it has nothing to do with cost. It just has to do with the fact that
nobody wants multicast until enough other people have it. There are a few
ways out of this (killer app, gradually increasing penetration,
early-adopter incentives, and so on) but none of them have much to do with
pricing.

	DS