The NTCIP Framework, shown in the figure below, uses a layered or modular approach to communications standards, similar to the layering approach adopted by the Internet and the International Organization of Standards (ISO). In general, data communications between two computers or other electronic devices can be considered to involve the following primary layers, called "levels" in NTCIP, to distinguish them from those defined by the International Organization for Standardization (ISO) and the Internet. The five levels are: information level, application level, transport level, subnetwork level, and plant level.

The levels in the NTCIP framework are somewhat different from communication stack layers defined by ISO’s Open Systems Interconnect (OSI) seven-layer reference model and other standards developing organizations.

Also, the NTCIP stack extends beyond the just the "communications stack" to include levels for the informational data and interfaces to the physical communications infrastructure. The levels and terminology used in NTCIP were chosen for simplicity and ease of understanding by most readers, and relevance to our typical applications in the transportation industry. [excerpted from 9001 v04.06, Section 2.4; 2009]

To ensure a working system, deployers should select and specify at least one NTCIP protocol or profile at each level. The NTCIP standards publication numbers are shown in the boxes. The lines connecting standards at different levels show the choices for the optional standards that will typically work together.