Hi Brian, With your proposal:
http://www.cs.auckland.ac.nz/~brian/DFZng.pdf I get the impression that the result would be the Internet being much less meshed than it is at present. This would have negative impacts including: 1 - Less robustness in the event of link and router failure. 2 - Often longer path lengths (AKA "stretch") as a packet has to get out of one of the many Level 1 domains (or the one Level 0 domain) up to some Level 2 domain in order to get to another Level 1 (or the Level 0) before it could be delivered. This is true even if the ISP border routers connecting to the sites with the sending and receiving hosts are physically close, but happen to be of ISPs which are in separate domains. (I assume an ISP can only be in one domain, but perhaps I am wrong.) 3 - Therefore, further dimensions of "Balkanisation" of the Net, where actual packet delivery times and reliability levels depend not just on physical (partly geographic) topology, link capacities and traffic levels but also on which domain each host is in and how far the packet has to travel to go up and then down a level to the destination domain. 4 - Therefore, a lot of fuss as ISPs try to decide which domain to be in. 5 - Also, perhaps, more pressure on "sites" (as I think you nicely describe them) to multihome to various ISPs in different domains. However, that only helps with the path length if the "site" is smart enough to send outgoing packets to the optimal ISP's router. This wouldn't help with optimising which ISP and region an incoming packet arrives through when it is sent by a non-multihomed site or a multihomed site without the smarts to choose the best outgoing router. Also, I don't understand how your proposal would help with the central problem we are trying to solve - of a multihomed site's router requiring a separate route for every prefix advertised by any site anywhere at all. The fact that the destination site is in a different domain doesn't alter the fact that the multihomed site's router needs a separate route for that slice of address space, because the router still needs to decide which of the two or more upstream ISP routers to forward the packet to. - Robin -- to unsubscribe send a message to [EMAIL PROTECTED] with the word 'unsubscribe' in a single line as the message text body. archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg
