  In every form of digital store-and-forward communication, intermediate
forwarding nodes are computers, with attendant memory and processing resources.
This has inevitably stimulated efforts to create a wide-area infrastructure
that goes beyond simple store-and-forward to create a platform that makes more
general and varied use of the potential of this collection of increasingly
powerful nodes. Historically, these efforts predate the advent of globally
routed packet networking. The desire for a converged infrastructure of this
kind has only intensified over the last 30 years, as memory, storage, and
processing resources have increased in both density and speed while
simultaneously decreasing in cost. Although there is a general consensus that
it should be possible to define and deploy such a dramatically more capable
wide-area platform, a great deal of investment in research prototypes has yet
to produce a credible candidate architecture. Drawing on technical analysis,
historical examples, and case studies, we present an argument for the
hypothesis that in order to realize a distributed system with the kind of
convergent generality and deployment scalability that might qualify as
"future-defining," we must build it from a small set of simple, generic, and
limited abstractions of the low level resources (processing, storage and
network) of its intermediate nodes.
