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Digital Diagnostics Monitoring (DDM)
About Digital Diagnostics Monitoring (DDM)
Digital Diagnostics Monitoring (DDM) is a feature used in optical transceiver modules that enables you to view real-time information about transceivers, such as optical output and input power.
For information about which F5® transceiver modules support DDM, see F5® Platforms: Accessories.
Supported platforms
Digital Diagnostics Monitoring (DDM) is available on these platforms, when running BIG-IP® software version 12.1.0 or later, for transceiver modules that support DDM.
- BIG-IP 5000 Series
- BIG-IP 6900 Series
- BIG-IP 7000 Series
- BIG-IP 8900 Series
- BIG-IP 10000 Series
- BIG-IP 11000 Series
- BIG-IP 12000 Series
- VIPRION® B2100
- VIPRION B2150
- VIPRION B2250
- VIPRION B4300
- VIPRION B4450
Enabling DDM on a system
Viewing DDM state on a system
Viewing DDM information for optical tranceiver modules
About the units uWatts and dBm
The transceiver modules supply optical power in units of .1 uWatts. Per SFF-8472, the measured Tx and Rx power is in mW. The power is provided as a 16 bit unsigned integer with the power defined as the full 16 bit value (0-65535) with LSB equal to 0.1uW, yielding a total range of 0 to 6.5535 mW (~ -40 to +8.2 dBm).
Most displays of optical power are in dBm (deciBels/milliwatts). Decibels is a ratio of two power levels, one of which is considered the reference value. The db is a logarithmic scale. The m in dBm refers to the reference power which is 1 milliwatt.
To convert between the raw hardware readings of .1 uWatts and dBm, use this formula:
10 * log10f(raw_power/10000.0)
Viewing DDM log messages
About DDM monitoring with SNMP
For the Digital Diagnostic Monitoring (DDM) capability available on F5® platforms, you can use the industry-standard System Management Network Protocol (SNMP) protocol to read information collected from optical transceiver modules, when available. This information is in BIG-IP® Core Statistics. You can then use SNMP and the F5-BIG-IP-SYSTEM-MIB file to access this information.
When you use SNMP to access the information that DDM collects, note this F5 DDM behavior:
- F5 interface rows are indexed by interface name.
- Information in the F5-BIG-IP-SYSTEM-MIB file is read-only. SNMP objects cannot modify or configure DDM information.
- SNMP can monitor all transceivers that support DDM.
- The thresholds that SNMP monitors are the vendor-specified thresholds read from the transceivers.
- The F5 MIB file monitors optical receive and transmit level power.
- If a threshold is exceeded, the F5 DDM notification message contains the value that exceeded the threshold.
- SNMP sends traps when a DDM-monitored transmit or receive power reading crosses a warning or alarm threshold.
For more information about setting up SNMP monitoring, see External Monitoring of BIG-IP® Systems: Implementations.