The Class B Profile Standard establishes a common method of interconnecting ITS field equipment such as traffic controllers and variable message signs (VMS)@ defines the protocol and procedures for establishing communications between those components@ and references common data sets to be used by all such equipment. Its application is intended for equipment sharing a single communications channel or subnetwork (subnet). The Class B Profile is just one part of NTCIP. NTCIP is a suite of protocols and standards that address all different aspects of transportation and traffic control communications. The Class B Profile addresses the need for a common field device communications standard. It establishes a method for interconnecting field devices@ defines the protocol and procedures to establish communications link between them@ and defines a common set of operation information variables.