[e2e] architecturally speaking

[Kevin Fall]

I would agree w/Lloyd's comments, and I would suggest that if people want to read the
paper version of the DTN architecture (which has considerably more rationale included
than the ietf-draft version) they look at:

	http://www.dtnrg.org/papers/IRB-TR-03-003.pdf

And, as Lloyd suggested below, the software should be forthcoming very shortly.

I will look over this Plutarch architecture more carefuly.  So far it does
seem to have several similar concepts, but I was left with the question as
to what sort of environments it is targeted for and the justification for
some of the decision(s).  In particular:

	.. this paper concentrates on naming and addressing issues for
	establishing connectivity between radically heterogeneous networks,
	a problem that the Internet Protocol only partially solved.  In this paper,
	we are literally concerned only with 'inter-networking,' and not with any
	of the many other networking issues such as the units, timeliness or
	guarantee of resource allocation, security or auditing.  A concrete
	realization of our framework must address these issues, but within the contexts
	of the particular networks being connected:  we do not believe it is
	sensible to address them through a single unifying overlay network protocol.

Given that DTNRG is somehow focused precisely on an overlay network protocol
approach (but with a particular service definition of non-interactive delivery in the
worst cases), I'm particularly interested in why this is apparently rejected by the
authors.  Further, in environments where long periods of disconnection and/or high
delays may be encountered, my hunch is that some of the mechanisms suggested
for supporting dynamic mappings within contexts (using soft-state, using some form of
request/response name binding) might be difficult.

- K
www.dtnrg.org

>
> From:  Lloyd Wood <l.wood at eim.surrey.ac.uk>
> To:    Jon Crowcroft <Jon.Crowcroft at cl.cam.ac.uk>
> cc:    end2end-interest at postel.org
> Subject: Re: [e2e] architecturally speaking
> Date:  Thu, 27 Mar 2003 19:18:32 GMT
>
> On Wed, 2003-03-26 at 15:09, Jon Crowcroft wrote:
> > fyi, we just sent this you know where -
> 
> where? Are we supposed to read minds, or what?
> lamentably out-of-date/incomplete list on:
> http://www.cl.cam.ac.uk/%7Ejac22/out/
> no help. Still, at least the paper's online. Asking for accurate
> metadata/context as well possibly too much, really; fortunately,
> academics have journals simply to organise their output meaningfully.
> 
> > http://www.cl.cam.ac.uk/~jac22/out/plutarch.pdf
> 
> Plutarch: An Argument for Network Pluralism
> Jon Crowcroft, Steven Hand, Richard Mortier, Timothy Roscoe, Andrew
> Warfield, 24 March 2003.
> 
> Hmmm, heterogenity, late-binding of names and contexts; a very similar
> approach to the Interplanetary Internet 'bundle' idea...
> 
> ..which is currently being expressed in some recently-submitted
> delay-tolerant networking drafts:
> http://www.ietf.org/internet-drafts/draft-irtf-dtnrg-arch-00.txt
> http://www.ietf.org/internet-drafts/draft-irtf-dtnrg-ipn-bundle-xfer-00.txt
> http://www.ietf.org/internet-drafts/draft-irtf-dtnrg-bundle-spec-00.txt

> 
> Bundling protocol software shortly available from:
> http://www.dtnrg.org/
> and very possibly by this weekend.
> 
> L.
> 
> <http://www.ee.surrey.ac.uk/Personal/L.Wood/><L.Wood at ee.surrey.ac.uk>
>