[e2e] Overly Overlay; Peer to peer is commonplace

[David P. Reed]

At 06:00 PM 1/7/2002 -0800, Jim Gettys wrote:
>I do question the claim that there will be many more nodes of the
>wireless/nomadic kind than fixed, unless I'm missing something.
>Even if wireless becomes ubiquitous to replace alot of short cables, there
>is no reason I can see that this needs to contribute to the global routing
>problem...  Am I missing something?

This depends on your view about how many nomadic devices there will be, how 
far they will move as they travel around, and where the cost of re-routing 
will be borne as they travel.

I think potentially nomadic devices will outnumber static ones - so every 
endpoint should be assumed movable.

They may or may not move often, and they may or may not move far when they 
are moved.

Now the end-to-end argument would argue that a global backbone cannot 
provide the nomadic routing function, and should provide something useful 
and simple instead, upon which a variety of nomadic routing functions can 
be based.  (I note that the same argument, however, argues that the global 
backbone should move as much routing function to the endpoints as possible 
- but ideas like source routing are disparaged despite their better fit).

So the essential question is: what is a sensible base routing function in 
the global backbones that does not preclude a range of potentially 
effective and efficient choices in nomadic devices, and in particular what 
kind of addresses should it provide for specifying routes.

It seems to me that this requires untangling some issues lumped together in 
the current IP (v4 or v6) hierarchical addresses.

Certainly the current practice of IP address assignment does not 
standardize effectively how to solve the following typical problem:

Imagine I have a two part device, consisting of an interface Int and a 
based unit Bas.   I introduce them to each other through some means so that 
they know each other and can communicate locally using (say) 802.11.

I then transport Int with me in my suitcase to a hotel.  I take it out and 
start using it, perhaps on a local 802.11 net.   How does it find Bas, and 
how does Bas find it?

Then my friend picks up Bas (which may have a camera in it, perhaps) and 
transports it to a third location.  How do Bas and Int maintain their linkage?

While I'm gone, I ask my landlord to sublet my apartment and put all my 
gear in storage.  I hope that unrelated set of activities doesn't interfere 
with Bas & Int.

DNS is really inapplicable for hordes of 2 part devices like this (DNS 
servers have poor time constants and cost money).

It also seems inappropriate for nomadic relationships to depend on fixed 
rendezvous points that introduce unnecessary points of failure.




- David
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