I have well hi-lighted the advantages of my NIRA model before (no scalability problem, no churn,...) In response to the current discussions, I should add: No changes in the hosts, no requirement that IPv4 addresses have to be worldwide unique forever (i.e.IPv4 address depletion is no issue with this model).
By looking at Brian's concept: It is, by all its new details, just another form of hierarchy like Nimrod or PNNI, with a node aggregation which is a) cumbersome in doing and b) underperforming wrt its result. In some older email I expressed my suspicion that the term "stretch" has been invented just to discriminate hierarchy. Well, if you only accept hierarchical models like Nimrod, PNNI, ISLAY, or Brian's new proposal than this criticism is appropriate.
If I can route towards the destination (while ignoring any prefixes, but guided by geo.coordinates) as close as I want by design, than I can afford (!!) to treat sites (as defined by Brian) being nodes in my topology of lowest level s, whose adjacent links have such high weights that the site wouldn't be used for transit. (with the current BGP design no one can afford to extend the routing tables by let's say a factor 100 or 1000). But if that site is the destination node, IP forwarding may be done via any of the site's adjacent links (to different ISPs) - i.e. multihoming is just multipath routing.
Postal mail versus email:
By looking at not so normal situation one may recognize whether a concept is sane or insane:
If I send a letter, let's say from Germany to Sausolito, but the receiver has moved to a different place, it is perfectly ok that the last postal office would realize the receiver's relocation and would send the letter back.
It would be insane to disseminate that someone has changed his address to all postal offices in the world, just for the effect that an incorrect destination address could be detected by the ingress postal office.
I think the existing postal concept is sane, and of course, with the NIRA concept the email would also be sent to (at least California) and then returned. I think it would be ok if the email is returned with not deliverable. It would also be great if the first node who returns the email could also return the new address, if known, respectively any other node on the way back - just as an assist of the DNS.
Imho, it could be so simple. Sometimes I compare my situation with Platon's cove story. Because I am not so good in BGP I am bad in interpreting the shadows on the wall, hence my model is ignored.
In einer eMail vom 20.11.2007 06:11:51 Westeuropäische Normalzeit schreibt firstname.lastname@example.org:
With your proposal: