Michael Dillon michael at
Sat Aug 22 22:48:42 UTC 1998

On Sat, 22 Aug 1998, Owen DeLong wrote:

> Since flow studies are confidential information, I will not quote from them.
> However, I will say that I would think it intuitively obvious to almost anyone
> on this list that Web Hosters don't OFFER very many packets that aren't a
> response to a REQUEST.

I know nothing of packets being OFFERED or REQUESTED. I only know of two
networks which are peering and exchanging traffic. Neither network OFFERS
or REQUESTS data. They both perform an identical function of routing
packets through an exchange point. I can measure those streams of bits and
determine that one peer has more bits going out than coming in. This is
clearly an asymmetry. The question is that if such asymmetries become more
common and if the spreads between bits in and bits out increases, can we
continue to consider these two networks to be peers in the same way we
considered two networks to be peers in 1994.

Or do we need to update our definition of what peering means and provide
interconnect choices between pure peering and pure transit? The users and
the web servers are largely irrelevant background noise in this discussion
of peering relationships. Yes, we know that they exist and how they use
the network. Yes, we know that if networks specialize in certain types of
customers it will result in asymmetries at exchange points. That is the
context, but I believe that we can factor out that context from the
peering relationship itself and the reason that I believe we can and
should factor out that context is that BOTH TYPES OF CUSTOMER PAY FOR
SERVICE. Web browsing customers pay for service and web hosting customers
pay for service. Their relationship to their network provider is a done
deal. Once their packets enter the network they are merely packets full of
bits that cross exchange points between peers. Forget the end points of
the packet flows. Look at what is happening between the two network peers.

> The shifting of the traffic flows is
> changing at roughly the same rate on BOTH sides, not because of one sides
> business model.

Yes. And I don't pretend to have all the answers here and I don't intend
to imply that only one type of provider should pay the other type. Let's
remember that any two peers are exchanging traffic at several points in
the network. But the only situation in which a dialup provider and a
webhosting provider will not have problematic asymmetry is when both
providers have POPs in the same set of cities and both providers
have private exchange points in every one of those cities. Then, although
there would be asymmetry of traffic flows, if you go by my model where
only inter-city transit has a value, there would be no value asymmetry in
this situation.

> Generally, the purchaser pays shipping in almost all
> commerce.  This has been true for a very long time.

I hesitate to draw parallels between the movement of atoms and that of

Michael Dillon                 -               Internet & ISP Consulting
Memra Communications Inc.      -               E-mail: michael at
Check the website for my Internet World articles -        

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