[e2e] a means to an end

Craig Partridge craig at aland.bbn.com
Mon Dec 1 10:27:57 PST 2008

Hi Dave:

Did you read my note?

* Your point about wireless was made in my note.

* Reliably translated didn't mean the address was right.  PUP works just
  fine in my definition.  What I meant was that the translation function
  was present and gave a useful result (rather than, say, "no address").  

I have the sense we're talking past each other (and to give other email
boxes a rest, I'll quit here).


In message <49342B8B.9000801 at reed.com>, "David P. Reed" writes:

>some points about the non-generality of your definition, which is tied 
>to a very specific systems architecture.  The need for such a "tie" has 
>always been my main point.
>I guess wireless communications systems are not part of your model.  
>Many such systems don't have a "communications graph".  (if you stand on 
>your head you can try to construct one if it is needed for some 
>discussion that cannot take place without one in hand, but Maxwell's 
>equations don't construct such a graph).
>I don't know what an object name is:  content addressable memories hold 
>information, but don't necessarily have "object names", nor is an 
>"object name" the primary retrieval means.
>Why "reliably translated"?   Xerox PUP used addresses that could be 
>mistranslated (48 bit UIDs), but the PUP protocol system worked 
>reliably, having been constructed in a manner that followed von 
>Neumann's constructive proof that you could build reliable systems out 
>of unreliable parts.
>Just as there is no need for "reliability" at the base of the network, 
>there is no need for "location" at the base.
>Craig Partridge wrote:
>> In message <49342367.7070503 at reed.com>, "David P. Reed" writes:
>>> So define "well defined place in the network" as YOU define it.
>> A stable object name that can reliably be translated to an address in a
>> communications graph.
>> Explaining a bit (since we seem to have an impedance mismatch):
>>     * stable object name -- it is a name that has longevity -- it isn't
>>       a temporary name created for 5 minutes on-line.
>>     * reliably translated to an address -- the address of the object
>>       can change but the object always exists -- you can address it (I'm bei
>>       careful here to permit intermittent connectivity ala DTN -- 
>>       what I'm saying is you can address the object and send it a request,
>>       that doesn't mean you can communicate with it in real-time).
>>     * communications graph -- I'd like a better term (as graphs
>>       model nodes and edges, which for wireless isn't the abstraction
>>       I want) but the point is that the combination of RF/wires/fiber/nodes
>>       that make up our communications networks are reasonably independent
>>       of geography. (I can have a subnet spanning continents.)
>> Note there's some clumsiness here -- I originally used "node" and then
>> chose "object".  Neither word is quite right.  I hope the broad point is
>> clear.
>> Thanks!
>> Craig

More information about the end2end-interest mailing list