AOL & Cogent

David Schwartz davids at
Sun Dec 29 01:03:27 UTC 2002

On Sat, 28 Dec 2002 18:34:01 -0500, Leo Bicknell wrote:

>All in all, I find ratios an extremely poor way of validating a
>peer.  I can think of many cases where it is in both parties interest
>to peer, but where the traffic might be extremely unbalanced.  Yes,
>the fact that it is unbalanced can shift costs from one provider
>to another, and that's a very real problem to solve.  The correct
>way to solve it is not to force a transit model though, but to use
>careful circuit provisioning and various technical tools to move
>the cost back to something more equal.  Heck, even a settlement,
>much as I hate them, would be better than just turning the thing

	When Cogent cut off their peering with AOL, AOL customers now find that they
experience lags reaching content providers that use Cogent. Also, of course, 
Cogent customers find that AOL's customers have trouble reaching their 

	I submit, however, that the pain is suffered more nearly equally. Assume for 
the moment  that AOL is very large and all eyeballs and Cogent is very small 
and all content. The argument would likely be made that poor connectivity 
between Cogent and AOL hurts Cogent more as a significant number of people 
can't reach their customer's sites well.

	But I submit that while the harm is lesser to each AOL customer (since only 
a small fraction of the sites they might wish to reach are congested), there 
are more AOL customers. The aggregate harm or benefit would be expected to be
nearly the same. After all, each delayed or dropped packet harms one customer 
of each company.

	In general, however, eyeballs are more sensitive to delays. If I get a slow 
page load of a Microsoft site, Microsoft isn't harmed as much by that one 
delay as I am. So the aggregate benefit to AOL's customers would be expected 
to be greater than that to Cogent's.

>What's even funnier is that most people apply them equally in both
>directions.  They want to make the claim that being out of ratio
>(such as in this case) shifts costs onto their network.  Well, many
>people do the same thing in reverse.  If they saw a 1:3 they would
>not peer with someone /even though they are shifting cost to the
>other party/.  I've never understood how someone can argue that a
>ratio is about protecting their company from bearing a disproportionate
>amount of the cost, and then also prevent their company from shifting
>that cost to someone else (assuming the other party would agree).

	Well the pipes and routers go both ways at the same speed. So the aggregate 
cost to set up, say, an OC12 peering connection is best utilized if the OC12 
is nearly maxed both ways. It's not wholly unreasonable to say that if you're 
going to go through the cost of setting up a peering connection at a 
particular speed, you want to move as much total traffic over it as possible.

	But, as I'm sure we all know, this whole charade is just about dreaming up a 
way to charge someone money.

	Currently, traffic between Cogent and AOL seems to be experiencing delays of 
under one second each way. There is no packet loss. The situation is quite 
tolerable though, of course, it could be better.

	Also, one philosophical point that I think is especially important for 
network operators to keep in mind. The usual definition of the 'Internet' has 
IP in it somewhere. While this may be what currently defines the Internet, 
the protocol could change entirely and it would still be the Internet.

	The Internet is a philosophy and what that philosophy has brought into 
being. The philosophy is about making a genuine best effort to 
intercommunicate with anyone else who makes a similar effort. An Internet 
product is one that reflects this philosophy, not one that happens to work 
over today's Internet. An Internet company is one that operates under this 
philosophy, not one that happens to own routers, pipes, or pass IP traffic.


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