I want to at the outset that I don't know what MCI does or why, and if I did know I would probably be under NDA and so I wouldn't be able to talk about what I knew. I used MCI as an example in my last note to this list because the person I was replying to had used MCI as an example. For all I know, MCI peers with space aliens, or doesn't, or not. But, getting to the provider independent portion of Jeff Young's recent message here:
the end of your post is interesting, however. it may come to the point where larger carriers are forced to tag local as's local and to peer on the 'local' basis. but what benefit for that added complexity? local networks would still need to buy transit from someone.
Right now we're sucking down a fair amount of backhaul, symmetric to the backhaul of a local Mom & Pop's transit provider, carrying traffic which is both to and from the same local area. If backhaul were free, or even cheap, or even available in the quantities we need, the engineering simplicity would win out -- it's easier to manage a network if there are fewer links and fewer powered boxes inside it. On the other hand we're having a lot of trouble getting enough backhaul on some paths -- at any price. So OK, let's assume that transit providers all come to every local area to pick up local customers. A Mom & Pop ISP buys transit from one of them, on the hopeful assumption that it will peer with the other locally present big providers, thus preventing traffic between endpoints 10 miles away from taking a 500 (or 2000) mile loop through some more distant private peerage or exchange point. This saves on the rarified wide area backhaul, and it is certainly better than what a lot of local markets have now. But if we're assuming the existence local links between big ISP's in each local market, what's wrong with the local exchange concept (since, as I said in an earlier message, sum(1 .. N-1) links are more expensive to build than N links and a GIGAswitch, for reasonable values of N)? And if you're doing a local exchange, why not let Mom & Pop's also connect there, so that their transit link can be a private 10Mb/s or FDDI wire between cages -- saving the end users money indirectly by cutting down the number of bypass carriages? And finally-- if each of the previous steps make sense and you get this far-- why not have big and little ISPs peer directly, sharing only routes which do not result in assymetric wide area expense? (Route segregation between local and wide area was already necessary for an earlier step.) This saves router backplane expense, which while easier (in 1997) to buy than wide area backhaul is still in shorter supply than some people would like. Some L2's are more reliable than some L3's -- and are almost always cheaper per bit carried. This changes "we'll only peer with you if you have a network topology similar to ours" into "we'll be happy to peer with you but be aware that we only send local routes when we peer at public exchanges, and if you want a full routing exchange it'll take 6 T3's worth of private peering -- can you afford it?" I think the network will work better and scale better when this kind of "peering" becomes the norm. If wide area telecom costs are the reason big guys don't like to peer with little guys, then by gum let's see peering and charging all take place exactly where the economics require it.