DDM

DDM ( English Digital Diagnostics Monitoring ) is a function of digital monitoring of SFP transceiver performance parameters (as well as SFP + and XFP). It allows you to monitor in real time such parameters as: voltage , module temperature , bias current and laser power (TX), received signal level (RX). ^[one]

Changes in these parameters allow you to determine the state of the WDM system and the trails as a whole. To receive data, this functionality must be supported by both a transceiver and a switch .

The labeling of individual manufacturers uses the abbreviated form of DD (English Digital Diagnostics )
Cisco - DOM (English Digital Optical Monitoring ) - Digital optical monitoring.
Zyxel - DDMI (English Digital Diagnostic Monitoring Interface ) - Digital interface monitoring.

Note:
On D-Link managed switches, when this feature is enabled (available only for SFP ports), if the data on the port is not read correctly, the traffic on the port can be turned off, in which case the message “Err- Disabled ”, while the port will be physically able to Up, but in fact will not work. Copper ports may also appear “Err-Disabled” status, but this is not connected with the DDM function, but with physical problems with either the cable or the device connected to this port.

What transceiver optics support DDM / DOM? Since the DDM interface allows end users to display diagnostic data and alarms for fiber optic transceivers and can be used to diagnose why the optical transceiver system does not work, the optical system of the DDM transceiver is becoming increasingly popular. Typically, transceiver providers set thresholds that trigger a high level of alarm, a low level of alarm, a warning, or a low warning before sending. To be able to use the capabilities of DDM / DOM, optical transceivers are listed here that support DDM / DOM interfaces. ^[2]

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