Digital Diagnostics Monitoring (DDM), also known as Digital Optical Monitoring (DOM) or Diagnostic Monitoring Interface (DMI), is a standardized feature defined by SFF-8472 that allows network devices to monitor real-time optical transceiver parameters such as temperature . Digital Diagnostics Monitoring (DDM), also known as Digital Optical Monitoring (DOM) or Diagnostic Monitoring Interface (DMI), is a standardized feature defined by SFF-8472 that allows network devices to monitor real-time optical transceiver parameters such as temperature . SFP DOM (Digital Optical Monitoring), also referred to as DDM, is a standardized mechanism that allows optical transceivers to report real-time operating parameters such as optical power, temperature, voltage, and laser bias current. Built into modern SFP/SFP+/ SFP28 /QSFP family modules and standardized by SFF-8472, DDM/DOM exposes real-time values for the module's temperature, supply. DDM, short for Digital Diagnostic Monitoring, literally refers to the function of diagnosing the working status of optical modules, functioning like a diagnostic tool. It can provide the host with real-time data about the module's internal operating conditions, including parameters such as voltage.