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, voltage . 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, voltage . DDMI stands for Digital Diagnostic Monitoring Interface. It is a standardized interface—under the SFF-8472 agreement—that allows devices to read real-time health information directly from optical transceivers like SFP, SFP+, and QSFP modules. The information provided by this command is known as digital optical monitoring (DOM) information. Most of the transceivers in use today feature the DDM function.