BBN Peering issues

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1

The question above is rather interesting, and what I'd like to know is
what are the various types of "peering" that various ISPs have arranged
between each other?

PEERING == Equal relation ship wher provider A announces routes to themselves
and their customers to provider B and Provider B does likewise. There is
no announcement by either party of non-customer 3rd party routes to the other.

TRANSIT == Provider A is a customer of provider B. Provider A announces
routes to itself and it's customers. Provider B announces a complete routing
table and/or a default route to provider A.

These are separate and distinct entities from Exchange points... Exchanges
(places where traffic gets handed off) come in the following varieties:

PUBLIC == An exchange point where multiple providers connect with each other
across a shared media, such as ATM, FR, Ethernet, FDDI, etc. Generally most
public exchanges are run by a third party to whom all of the ISPs connecting
have a customer relationship.

PRIVATE == A circuit or virtual circuit between two providers which does not
provide a shared media type of environment with multiple providers. Generally,
there is no third party customer relationship, other than possibly one or both
ISPs paying a telco for a circuit.

There are many different financial arrangements that can be made around private
peering. One of the most common ones I've seen is to bring up multiple circuits
and agree that provider A pays for one circuit while provider B pays for the
other. No other money changes hands.

Sometimes, provider A is willing to pay for all circuits just to get better
connectivity for their customers.

I hope this clarifies the terms.

Owen

2

TRANSIT == Provider A is a customer of provider B. Provider A announces
routes to itself and it's customers. Provider B announces a complete routing
table and/or a default route to provider A.

Pardon me if this seems pedantic, but it's late, I've had a hard week, and,
well, I *am* pedantic. :slight_smile:

I would like to modify this definition such that if Provider B announces
*any* route to Provider A which does not belong to Provider B or a customer
of Provider B, then Provider B is giving Provider A transit. Please note
that "default route" is a special case which is still covered under this
definition because "default" includes netblocks not owned by the provider
or the provider's customers.

Furthermore, if Provider B propagates *any* of Provider A's routes to
Provider C, and Provider C is not a customer of Provider B, then again,
Provider B is giving Provider A transit.

Full tables/default route are not the point, IMHO. The point is, did the
packet originate or terminate outside both networks (counting "customers"
as part of the networks)? If either end point is not inside one of those
networks (or customers thereof), the someone has given someone else transit.

Another pedantic point (which most people on this list understand):
"customer" == "someone to whom you provide transit" by my definition. This
follows because a provider will announce "customer" routes to a "peer".

From here on out, it starts getting circular and my head begins to hurt. :slight_smile:

I'm sorry if this bored most of you, but people have answered this twice
and still didn't get it exactly correct IMHO. Feel free to point out my
errors if I've committed any.

TTFN,
patrick

P.S. I really wanted to say "Provider B is providing Provider A ...", but
it's already too confusing. :slight_smile: