jnc at ginger.lcs.mit.edu
Mon Sep 25 16:34:36 UTC 1995
From: Tony Li <tli at cisco.com>
> The only charging scheme that I can see working is to charge people for
> advertising routes, with the charge related to the scope over which the
> advertisement is seen. That way, there's a direct relationship between
> the amount of resources consumed, and the amount charged
A global charging scheme implies that there is a centralized, global
charging authority. ... What MAY fly, however, is if individual backbones
charge for advertisements as well as bandwidth.
Ah, I wasn't clear; I was not proposing that this charging be done through any
centralized authority. My mental model was much more like your latter thought;
individual ISP's would charge for carrying routes, so it would be distributed
and decentralized. There are lots of problems you have to work, through,
though (see below).
Mind, I'm not saying that I'm positive that charging for routes is a
*practical* or *desireable* business strategy (there are clearly all sorts of
problems). Some sort of cooperative effort to keep routing table sizes down
might be more effective overall (i.e. higher cost/benefit ratio) than charging
(which is going to have a lot of administrative overhead).
However, we might not be able to make that work, in which case charging is the
ultimate fallback; having a feedback loop from consumption of resources
(routing table entries) to consumers of them is an industrial-strength approach
to solving the problem.
This would be charged back through regional ISPs, who would decide which
backbones to connect to and charge back to their respective customers.
Right, your charge would effecitively be related to the scope over which the
advertisment was seen, since more the ISP's that carried it -> a bigger total
However, there are lots of niggling little problems you have to work out. Here
are a few.
ISP's cannot charge a flat price per route, since it's not clear that more $$$
will instantly translate into more route-carrying capacity. Set the $$$/route
too low, and people will just pay, and the ISP won't have the capaccity. The
fact is they have a limited capacity for routes, so there has to be a price
curve to discourage further routes as an ISP nears capacity. This will ensure
that route resources get allocated to the people who need them the most -> can
make best use of them. Even if ISP's do charge a flat price, on a first-come
first-served basis, all that will do is create a seceondary market in routes
for that ISP; i.e. windfall profits for some, etc. Better would be a "treasury
auction" type system. All this is a lot of work, I know; maybe the ISP will
just go the flat price route and stay out of the secondary market. (Of course,
that leads to the ability to manipulate; hold back a few routes, wait till the
price peaks, and then leak them out onto the market; etc, etc..)
Another concerns the cross-charging; i.e. with two large providers it easy,
they both carry lots of routes for each other, so probably it's a wash (i.e.
no money changes hands when the dust settles). But what about small providers?
Ideally, you'd like small providers who are being "good guys" (i.e. generating
only a few routes) to also have a wash, and the ones who are "bad guys" (ie..
generating lots of routes) to have to pay for it. In other words, small
providers have to charge the large providers something for carrying their
routes through a small scope (the small ISP) which balances what the large
ISP's will charge for carrying the small ISP's route(s). However, this model
breaks down when you get to the level of customers; nobody is going to pay
customers for carrying routes! So, there remain some holes to be closed up
What I'm leading to with all this is that yes, we could create a very
efficient (in the sense of allocating costs accurately) market for carrying
routes, but it would be very inefficient (in terms of the amount of overhead
B/S). Which goes back to my comment above, that maybe charging for routes does
not make sense in a larger business context. However, not charging for routes
implies we have to come up with another way of controlling routing table
I'd be delighted to have a serious conversation about the pros and cons of
various charging schemes. Maybe charging's a loser, maybe it's not, but if
we're going to consider it, let's look at it seriously, not discard it offhand
as "politically incorrect" for the 'net, or whatever.
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