DEFINITIONS
Before describing the approach that the FIArch Group has followed, it is important to explain
some definitions that we have used in our work.
We define as “architecture” a set of functions, states, and objects/information together with
their behavior, structure, composition, relationships and spatio-temporal distribution34. The
specification of the associated functional, object/informational and state models leads to an
architectural model comprising a set of components (i.e. procedures, data structures, state
machines) and the characterization of their interactions (i.e. messages, calls, events, etc.).
We define as "fundamental limitation” (of the Internet architecture) a functional, structural,
or performance restriction or constraint that cannot be resolved with current or clearly
foreseen paradigms as far as our understanding/knowledge goes. On the other hand, we define
as "challenging limitation” a functional, structural, or performance restriction or constraint
that could be resolved (as far as our understanding/knowledge goes) by replacing and/or
adding/removing a component of the architecture that would in turn change the global
properties of the Internet architecture. We also define the term “Re-engineering” as a method
for overcoming a challenging limitation, by the replacement of an instance of an existing
component of an architecture that would not change the global properties of the Internet
architecture.
In the following, we use t