Is it really the case that people with routers at exchange points actually consider a packet addressed to one of their own customers to be theft of service? So far, I note, we haven't heard any position expressed by any of the big folks, just by others outraged on their behalf.

No, this is an attack. If a packet goes where it is not supposed to (i.e. no route was explicitly advertised) then the party who's sending that packet made an illegitimate route. That qualifies as a deliberate routing attack. That is enough to get kicked off any IXP. Pointing default to somebody over IXP is simply theft. In effect you get somebody's router to sort your packets out. That is covered by applicable criminal statutes. Needless to say, this is also a ground for being kicked off IXPs. Finally, most IXP operators do not seem to be diligent in explaining to new IXP members to be that being at IXP is by no means a guarantee that anybody would want to peer.

And of course, to be in a position to "dump data" on a router at an exchange, one must have one's own router there peering with *somebody*, right? So the problem, if there is one, is that not all pairs of routers at an exchange are necessarily allowed to communicate. ATM, anyone? (Gasp cough choke)

It is not a problem. The problem is that people seem to have a hard time understanding that Internet is not a free for all. If two parties cannot agree on terms of bilaterial exchange, that's their problem, ok? There are two reasons for restrictions on who peers with whom -- first is technical, as peering at exchange point is essentially excercise in trust; and if somebody doesn't look like (doesn't have track record, have a person with apparent drug problems as technical spokesman, etc) that they can give you sane routes, and won't mangle routes you give them then big ISPs are not willing to bet their business on that somebody staying sane. The second reason is economical. When players in one weight category are talking to each other at many exchange points they don't subsidise each other. When a large provider talks to a regional provider at one IXP it effectively spends much larger share of backbone resources delivering traffic (for example, A is a member of Big 6, say B.F.C.; B is an ISP in Mukhosransk, where one IXP is located. When B's customer sends a packet to A's customer in Lost Wages B pays for delivery from one corner of Mukhosransk to another; A pays for getting it from Mukhosransk to Lost Wages; it is exactly the same when packet is sent back. Thus A pays for disproportionate share of the communication cost.) Obviously A does not have any interest in subsidising a competitor. On the other hand, if B has particularly interesting content providers which are in high demand by A's customers (say, Mukhosranskie Novosti) A may decide that it is still worth to peer with B. When there's C, of about the same size as A peering is obviously a matter of mutual benefit; so B.F.C. and, say, A.F.T. won't have any problem reaching a peering agreement. So, this is very simple -- don't mess with the market. It is healthy as is. Obviously big players want to keep their market share, but they are not in collusion to keep others shut off. A small provider can choose whose customer he wants to be, and when he's grown up enough to have population of his customer and content providers to be sufficient leverage he will be automatically accepted into the "Big something". A question with Europe is more interesting. It is generally recognized that Europeans pay more than their share when they drag bits to Boone Blvd; so there should be no problem with peering save for bureaucratic boneheadedness so cherished by some well-known companies. --vadim