The current Internet architecture is built around layers of different functions, where the Network Layer provides a technology-independent abstraction on top of a large set of autonomous, heterogeneous networks. The Internet Protocol (IP) is one mechanism for achieving such an abstraction. By making the choice for a rudimentary ``best-effort" service, the Internet has not been able to effectively respond to new requirements (security, manageability, wireless, mobility, etc.) Today, Internet Service Providers (ISP's) may be willing to provide better than best-effort service to their customers or their peers for a price or to meet a Service Level Agreement (SLA). The lack of a structured view of how this could be accomplished, given the current IP model, has led to numerous ad hoc solutions that are either inefficient or incomplete.

RINA is a clean-slate internet architecture that builds on a very basic premise, yet fresh perspective that networking is not a layered set of different functions but rather a single layer of distributed Inter-Process Communication (IPC) that repeats over different scopes---i.e., same functions / mechanisms but policies are tuned to operate over different ranges of the performance space (e.g., capacity, delay, loss). Specifically, a scope defines a Distributed IPC Facility (DIF) comprised of the set of IPC processes, running on different machines, that collaboratively provide a set of well-defined flow services to upper application processes. Application (user) processes can themselves be IPC processes of an upper DIF that is providing services over a wider scope.