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C2C Standards Framework

The full list of C2C communications profile standards and their current statuses at the time of advisory publication are listed in the C2C Profiles Standards section of this advisory. These standards are described in more detail in this section according to their level in the NTCIP communications stack.

Information Level C2C Communications Standards

Information Level standards define the messages and data, informational level dialogs, as well as the type of message encoding and naming rules. Although message set and data dictionary standards are outside the scope of this advisory, encoding schemes are part of the NTCIP Family of C2C standards. This includes Center-to-Center Naming Conventions which define a standardized way to create names for centers, devices, etc. The information level standards follow the NTCIP numbering convention of "11XX" and "12XX."

Application Level C2C Communications Standards

Application Level standards define the rules and procedures for exchanging information data. In the OSI model, these standards roughly equate to the Session, Presentation, and Application Layers. In the NTCIP C2C standards family, Application Level standards include Web Service Description Language with options for either the Simple Object Access Protocol (SOAP) or XMLDirect using eXtensible Markup Language (XML) encoding, Data Exchange ASN (DATEX-ASN) using either XML or Abstract Syntax Notation One (ASN.1) with Basic Encoding Rules (BER) or Octet Encoding Rules (OER), and FTP (File Transfer Protocol). Committee working draft standards were explored for a fourth communication protocol, Common Object Request Broker Architecture (CORBA); however, based on feedback from the transportation community, the FHWA and Standard Development Organizations (SDO) have decided not to further pursue CORBA standards development. These application level standards follow the NTCIP numbering convention of "23XX."

Transport Level C2C Communications Standards

Transport Level standards define the rules and procedures for exchanging the Application data between two or more points on a network, including routing and switching. In the OSI model, these standards roughly equate to the Transport and Network Layers. In the NTCIP C2C standards family, Transport Level standards include the User Datagram Protocol (UDP) over Internet Protocol (UDP/IP) for connectionless transport services and the Transmission Control Protocol over Internet Protocol (TCP/IP) for connection-oriented transport services. All of the Application Level standards can utilize TCP/IP. Only the DATEX-ASN standard can support both TCP/IP and UDP/IP applications. These standards follow the NTCIP numbering convention of "22XX."

Subnetwork Level C2C Communications Standards

Subnetwork Level standards define the rules and procedures for encoding and decoding the information at the bit level to be transmitted and received between two points in a network. In the OSI model, these standards roughly equate to the Data Link and Physical Layers. In the NTCIP C2C standards family, Subnetwork Level standards include the high-bandwidth Ethernet and Point-to-Point over RS-232 Protocol standards, although other industry standards such as ATM and SONET could also be used. These subnetwork level standards follow the NTCIP numbering convention of "21XX."

C2C Standards Framework Summary

For each C2C interface, deployers must select a protocol or profile (combination of protocols and base standards) from each level of the NTCIP framework. For more detailed information, please see the NTCIP 9001 — NTCIP Guide.

C2C Introduction

C2C Profiles Standards