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NTCIP Transport and Subnetwork Level Profiles

This Fact Sheet was written on September 25, 2009. The statuses of the standards at the time were as follows: NTCIP 2101 V1.19 (Published November 2001), NTCIP 2102 V1.09 (Published September 2005), NTCIP 2103 V2.07 (Published December 2008), NTCIP 2104 V1.11 (Published September 2005), NTCIP 2201 V1.15 (Published September 2005), NTCIP 2202 V1.05 (Published December 2001), NTCIP 8003 1.08 (Published December 2001).

This Fact Sheet was written on September 25, 2009.

This Fact Sheet was last verified on September 28, 2009

 Check the ITS Standards Search to see if there has been subsequent development activity.


The National Transportation Communications for Intelligent Transportation System (ITS) Protocol (NTCIP) is a family of standards that provides both the rules for communicating (called protocols) and the vocabulary (called objects) necessary to allow electronic roadside equipment from different manufacturers to operate with each other as a system. The NTCIP is the first set of standards for the transportation industry that allows transportation systems to be built using a "mix and match" approach with equipment from different manufacturers. Therefore, NTCIP standards reduce the need for reliance on specific equipment vendors and customized one-of-a-kind software. To assure both manufacturer and user community support, NTCIP is a joint product of the National Electronics Manufacturers Association (NEMA), the American Association of State Highway and Transportation Officials (AASHTO), and the Institute of Transportation Engineers (ITE). More information concerning the NTCIP family of standards and their related documents is available in the NTCIP 9001 - NTCIP Guide, available on-line at (

Prior to the establishment of NTCIP, traffic management centers used a number of proprietary protocols to exchange information with field devices such as traffic signal controllers and dynamic message signs. The goal of all NTCIP standards including these transport and subnetwork level standards, is to identify a common set of non-proprietary communications protocols that address requirements for center-to-center and center-to-field communications and promote interoperability.

This fact sheet addresses the six NTCIP standards that fall within the Transport and Subnetwork levels of the NTCIP Framework as well as the NTCIP 8003 - Profile Framework standard which explains the overall framework profiles and their relationship to each other. The six transport and subnetwork NTCIP standards that are the focus of this fact sheet are:

  • NTCIP 2101 - Point to Multi-Point Protocol Using RS-232 Subnetwork Profile
  • NTCIP 2102 - Point to Multi-Point Protocol Using FSK Modem Subnetwork Profile
  • NTCIP 2103 - Point-to-Point Protocol Over RS-232 Subnetwork Profile
  • NTCIP 2104 - Ethernet Subnetwork Profile
  • NTCIP 2201 - Transportation Transport Profile
  • NTCIP 2202 - Internet (TCP/IP and UDP/IP) Transport Profile

These standards are profile standards that define subsets or combinations of established base standards, in many cases Internet community standards referenced at the bottom of this fact sheet, used to provide specific functions or services. The profiles provide a basis for the development of uniform, nationally recognized conformance to ITS standards.

What are these standards for?

The standards referenced above define a set of rules and services for exchanging transportation management information between transportation management applications and equipment in an interoperable manner. The standards numbered 22XX are in the transport level which is on top of the standards numbered 21XX in the subnetwork level of the NTCIP communications framework. The subnetwork level standards define rules and procedures for exchanging data between two entities over particular communications media and interface with the plant level or physical communications infrastructure. These subnetwork standards define the point-to-multi-point and point-to-point protocols using RS-232, FSK Modems, and Ethernet communications media. The transport level standards define the routing, message encoding/decoding specifics, and basic network management functions. The transport standards include the TCP/IP (connection-oriented) and UDP/IP (connectionless-oriented) Internet protocols as well as the transportation transport profile allowing for non-networked connection to the subnetwork level. NTCIP 8003 explains the overall NTCIP profile framework including the transport and subnetwork levels.

Who uses them?

These standards should be used by transportation and traffic engineers involved with the design, specification, selection, procurement and installation, operation, and maintenance of networks of NTCIP devices and center-to-center communication. NTCIP device hardware and software designers, center-to-center system architects, and application (computer program) developers should find this standard especially relevant to their efforts.

How are they used?

These standards define a set of protocol features used to assure that the transportation management center computer-based devices and field devices "speak" a common language. These lower level protocols ensure that a message at the higher protocol level is understood by the device it was intended for, and equally important, it must not be misunderstood or misinterpreted by another device on the same network. Protocol features meet specific requirements for data transfers to and from devices and centers. The standards contain mandatory requirement statements that are applicable for all device and center communications claiming conformance to these standards. The standards also contain options and conditional requirements which may be applicable for certain environments where the device and center are communicating.

These standards are intended to be used in conjunction with one of the NTCIP device profiles at the information level which provide the content for that particular device or NTCIP center-to-center communications. In addition, these standards need an application level standard to bridge between the transport levels and the information level. It must be used with the NTCIP Global Object Definitions (NTCIP 1201), which provides the glossary of common object definitions used by multiple NTCIP traffic control devices.


Communications between a transportation management center’s central computer and NTCIP devices as well as between centers necessitates at least one transport level and subnetwork profile. This is accomplished by using the NTCIP transport and subnetwork profiles listed above.

These standards provide protocol features that allow the transport, routing, message encoding/decoding and basic network management functions needed for networked and non-networked systems. In addition, the NTCIP 8003 - Profile Framework document describes the overall NTCIP approach to multi-level protocol communications.

Related documents

The following ITS standards should be considered when using this standard:

The following set of standards and documents, while not part of the ITS standards, should also be considered when using this standard:

How to obtain Standards
American Association of State Highway and Transportation Officials
Institute of Transportation Engineers
Association of Electrical and Medical Imaging Equipment Manufacturers (NEMA), formerly known as National Electrical Manufacturers Association