Digital Diagnostics Monitoring

Some Nokia SFPs, XFPs, and the MSA DWDM transponder support the Digital Diagnostics Monitoring (DDM) capability, which allows the transceiver module to maintain information about its working status in device registers, including:

  • temperature

  • supply voltage

  • transmit (Tx) bias current

  • Tx output power

  • received (Rx) optical power

Note:

The optical transceiver DDM feature provides real-time values for guidance. For the specific values, the optical power data provides an accuracy of ±3 dB or better. The accuracy of this data is defined in the relevant standard for the transceiver type, such as SFF-8472 for SFP+. Use an optical power meter where precise optical power data is required. Contact your Nokia technical support representative for further assistance or clarification.

The transceiver is also programmed with warning and alarm thresholds for low and high conditions that can generate system events. These thresholds are programmed by the transceiver manufacturer.

No CLI command configuration is required to support DDM operations. However, the show>port port-id detail command displays DDM information in the Transceiver Digital Diagnostics Monitoring output section.

The Tx and Rx power displayed in the DDM output are average optical power in dBm.

DDM information is populated into the router MIBs, so the DDM data can be retrieved by Network Management using SNMP. Also, RMON threshold monitoring can be configured for the DDM MIB variables to set custom event thresholds if the factory-programmed thresholds are not at the desired levels.

The following are potential uses of the DDM data:

  • optics degradation monitoring

    With the information returned by the DDM-capable optics module, degradation in optical performance can be monitored and trigger events based on custom or the factory-programmed warning and alarm thresholds.

  • link/router fault isolation

    With the information returned by the DDM-capable optics module, any optical problem affecting a port can be quickly identified or eliminated as the potential problem source.

The following table describes supported real-time DDM features.

Table 1. Real-time DDM information

Parameter

User units

SFP/XFP units

SFP

XFP

Temperature

Celsius

C

Supported

Supported

Supply Voltage

Volts

µV

Supported

Supported

TX Bias Current

mA

µA

Supported

Supported

TX Output Power

dBm (converted from mW)

mW

Supported

Supported

RX Received Optical Power4

dBm (converted from dBm) (Avg Rx Power or OMA)

mW

Supported

Supported

AUX1

parameter dependent (embedded in transceiver)

-

Not supported

Supported

AUX2

parameter dependent (embedded in transceiver)

-

Not supported

Supported

The following table describes supported factory-programmed DDM alarms and warnings.

Table 2. DDM alarms and warnings

Parameter

SFP/XFP units

SFP

XFP

Required?

Temperature

- High Alarm

- Low Alarm

- High Warning

- Low Warning

C

Yes

Yes

Yes

Supply Voltage

- High Alarm

- Low Alarm

- High Warning

- Low Warning

µV

Yes

Yes

Yes

TX Bias Current

- High Alarm

- Low Alarm

- High Warning

- Low Warning

µA

Yes

Yes

Yes

TX Output Power

- High Alarm

- Low Alarm

- High Warning

- Low Warning

mW

Yes

Yes

Yes

RX Optical Power

- High Alarm

- Low Alarm

- High Warning

- Low Warning

mW

Yes

Yes

Yes

AUX1

- High Alarm

- Low Alarm

- High Warning

- Low Warning

parameter dependent (embedded in transceiver)

No

Yes

Yes

AUX2

- High Alarm

- Low Alarm

- High Warning

- Low Warning

parameter dependent (embedded in transceiver)

No

Yes

Yes

SFPs and XFPs

The availability of the DDM real-time information and the warning and alarm status is based on the transceiver. The transceiver may or may not indicate that DDM is supported. Although some Nokia SFPs support DDM, Nokia SFPs support DDM releases later than Release 2.0. Contact a Nokia technical support representative for more information about DDM support for specific 7210 SAS releases. Non-DDM and DDM-supported SFPs are distinguished by a specific value in their EEPROM.

Although DDM data may be available for SFPs that do not indicate DDM support in their EEPROM, Nokia has not validated or verified the accuracy of this information.

DDM information can be displayed for non-Nokia transceivers, but Nokia is not responsible for the formatting, accuracy, and other informational details.

Statistics collection

The DDM information and warnings/alarms are collected at one minute intervals, so the minimum resolution for any DDM events when correlating with other system events is one minute.

Note that in the Transceiver Digital Diagnostic Monitoring section of the show port port-id detail command output:

  • If the present measured value is higher than the either or both High Alarm, High Warn thresholds, an exclamation mark ‟!” displays along with the threshold value.

  • If the present measured value is lower than the either or both Low Alarm, Low Warn thresholds, an exclamation mark ‟!” displays along with the threshold value.

    A:Dut-A# show port 2/1/6 detail

.........

===============================================================================
Transceiver Digital Diagnostic Monitoring (DDM), Internally Calibrated
===============================================================================
                              Value High Alarm  High Warn   Low Warn  Low Alarm
-------------------------------------------------------------------------------
Temperature (C)               +39.3     +96.0      +94.0       -7.0      -8.0
Supply Voltage (V)             3.27      3.51       3.49       3.12      3.10
Tx Bias Current (mA)           18.8      77.0       70.0        5.5       4.5
Tx Output Power (dBm)          1.33      5.50       5.00       0.00     -0.50
Rx Optical Power (avg dBm)   -40.00     -8.50      -9.00     -33.98!   -35.23!
===============================================================================