Actually, MAE-WEST and much of the MCI net is now OC-3, and the remaining DS3 lines will be upgraded soon. And yes, it still doesn't take many T3's to fill that up, but don't forget that networks are designed with serious overbooking in mind, and IP's back-off algorithm seems to work real well in this situation. Ryan ---------- Previous Message ---------- To: rah cc: cypherpunks From: fair @ clock.org ("Erik E. Fair" (Time Keeper)) @ smtp Date: 05/06/96 07:58:46 PM Subject: Re: Is the network layer geodesic? The principle problem is that public exchange points do not scale beyond current LAN technology (i.e. half-duplex 100 Mb/s FDDI or Ethernet), and how many DS3 (T3; 45Mb/s full-duplex!) pipes does it take to fill that up? Two. Now, drop a DEC GIGAswitch in there (16 FDDI ports, 3.2Gb/s backplane), and now you can have sixteen peers on the exchange. Last count I saw, there are 1,800 ISPs operating in the USA alone, and *everyone* want to be at the exchange points. Oops. How many exchange points are there? Well: NSF Network Access Points (NAPs): New York (well, Pennsauken, NJ; Sprint), Chicago (Ameritech), San Francisco (Pac*Bell) MAE-EAST (D.C.), MAE-WEST (Mountain View-San Jose), MAE-LA, CIX (San Jose) FIX-EAST (D.C.), FIX-WEST (Mountain View; just for the Feds) SWAB (D.C., but almost no one left there). There are probably a few new ones that are forming that I am unaware of as yet, but the point is that they're small-fry. There are also probably exchange points outside the USA, but I bet they're being held up with PTT B.S. The Internet is amorphous. It ain't a star, exactly, but it still not too far from that. However, to get away from this situation into the rich and more fully amorphous connectivity we used to take for granted in the UUCP network, we're going to have to see a lot more cooperation on the part of the small ISPs in agreeing to talk *directly* to each other to exchange traffic, and more small exchange points, instead of the small number of large ones. Of course, this means that you, Mr. or Ms. Discriminating Internet Consumer, must educate yourself a little, and ask interesting questions like, "why do my packets have to go to California to get across town to the ISP my friend uses?" If the customers ask, the ISPs will serve. They just gotta know what you want (and you have to be willing, of course, to pay for it). Erik Fair