scope:

NATO Intra-ship Tactical Control and Data Handling Systems have unique requirements for real-time, fault tolerant information exchange between peer systems. The NATO Naval Intraship Network Independent Interface (NIIF) defines standards for the interface between User Systems and a (common resource) Data Transfer System (see Figure 1). It provides the essential data transfer functions necessary for the User Systems to cooperate in an open systems environment. User Systems transfer information to other User Systems by invoking the data transfer services available from the Data Transfer System (DTS) at the Network Independent Interface. The Network Independent Interface is located at the boundary between the functionalities corresponding to layer 5 (Session) and layer 4 (Transport) of the Open System Interconnection Basic Reference Model (ISO 7498). ISO 7498 has been adopted by NATO, through STANAG 4250, as the NATO Reference Model for Open Systems Interconnection (OSI). The NATO OSI Reference Model describes the architecture for development of Technical Common Interface Standards (TCIS) for data processing and distribution systems in NATO.

At a time when commercial standards are gaining widespread consent also for military applications, transport protocols other than ISO are to be accepted, provided that the general principles of the NATO OSI Reference Model are maintained. This is even more important when these protocols provide new and operationally useful features and services (e.g. reliable multicast).

The NIIF enables User system implementations to be independent of the DTS implementation, once the protocols at Layers 4/3 have been established, thus relieving the individual users of the task of developing and incorporating the DTS functions in each open system component. Additionally, the placement of the NIIF at the Layers 4/5 functionality' boundary makes it possible to transparently introduce improved technology in the Data Transfer System. This relieves the Users from the requirement of developing facilities which implement the DTS functions.

The NIIF promotes interoperability of separately developed User and DTS equipments. It also is a major step toward the definition of interface standards which support multi-vendor sourcing of equipment and systems. It encourages evolution towards distributed processing architectures which are based on Local Area Networks and it promotes the use of peer-to-peer communications between cooperating systems based on the use of a shared-resource Data Transfer System.