PLAN forms an integral part of our approach towards Active Networking, as described in [2]. PLAN is a simple, functional programming language based on a subset of ML with some added primitives to express remote evaluation. Please see the PLAN grammar [6] for syntactic details.
PLAN is resource limited, in two ways. All PLAN programs are guaranteed to terminate, limiting the resources consumed on any particular active node. Further, PLAN applications (that is, series of PLAN packets spawned from an initial packet) are limited by a global resource bound, thus limiting the resources consumed from the network at large.
PLAN relies on the existence of services, which make up a library of functions available to a PLAN program. These are described in more detail in Section 6.