[e2e] a means to an end

Scott Brim swb at employees.org
Fri Nov 7 09:50:18 PST 2008


On 11/5/08 4:48 AM, Jon Crowcroft allegedly wrote:
> the "level of indirection" is exactly what I am talking about but
> noone appears to be designing a service that implements this with a
> view to the workload (including secure update rate) it should
> sustain.

I'm saying it doesn't have to be "a service".  Or technically I suppose
I'm saying that it can be many independent "services", but there doesn't
have to be a widely coordinated infrastructure mechanism by which IDs
can be mapped directly to locators.  Relatively slow-moving, public
nodes can update their location directly in a mapping service (including
DNS), but fast-moving or more security-conscious nodes can use a level
of indirection, for example a "home agent" or a rendezvous point, in
which case the central mechanism does not know where the node actually
is.  So I'm questioning the requirements for updating a central service,
and pointing out that a level of indirection via the rendezvous points
has advantages.

> the two way mapping is needed  because of audit/accountability
> trails

Generally that's privileged information, and should _not_ be publicly
available in a general service.  If you need to know who was involved
in a communication, for example to arrest him, you do need a mapping
from locator to originating site, and you need to request coordination
with the node's home site, etc.  I don't believe that has anything to
do with a general mechanism for mapping from locator-of-the-moment to
ID-of-the-moment.


On 11/5/08 7:26 AM, Ali Ghodsi allegedly wrote:
> Can DHTs be part of the solution, and if not, what are the essential
> features which they are lacking? (trying to fish for research
> problems)

Yes but again IMHO you can either keep locators up-to-date in the DHT
-- Jon's approach -- or you can keep the information relatively
stable, pointing to a set of nodes which need to be accessed to get
the current answer (and which might be DHT nodes or not).


On 11/7/08 4:31 AM, Jon Crowcroft allegedly wrote:
> my and my big mouth -
>
> i knew this would get hijacked into a philosohpy discussion.

I'm going to split all that out into a different reply.  This one is
just about your idea.

Scott



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