This document provides the methodology to be used by vendors and third party independent laboratories in the formation of a Telecommunications Energy Efficiency Ratio (TEER). The requirements and definitions in this document are for DC/DC converters that are deployed in the telecommunications industry. This standard represents one part of the larger ATIS suite of standards concerning Telecommunications Energy Efficiency (ATIS-0600015.11.2016). This standard (ATIS-0600015.11.2016) specifically addresses DC/DC converters and is to be used in conjunction with ATIS-0600015. Purpose This document provides a set of definitions@ requirements@ and guidelines for calculating the Telecommunications Energy Efficiency Ratio (TEER) of DC/DC converter products. The test methodology employed to verify the power consumption@ used as part the TEER calculation@ is specific to power equipment and therefore differs from ATIS- 0600015.