DMI - Diagnostic Monitoring Interface for Optical Transceivers

This document discusses common characteristics of DMI support across several Transition Networks Point System products. Different products have different sets of features, so some features you see here may not be supported by the product you are using.

Partial MIB variable name Description
RxPower Measured received optical power in microwatts. Returns 0 if the feature is not supported.
RxPowerAlarm Values: normal(1), notSupported(2), lowWarn(3), highWarn(4), lowAlarm(5), highAlarm(6), notApplicable(7)
Alarm status of measured receive optical power. A Warn value indicates that some component or media in the channel may be degrading and an inspection is warranted. An Alarm value indicates a more severe problem that may already be preventing traffic from flowing. Values with low indicate that the receive power is lower than expected, and values with high indicate that it is higher than expected. All values represent comparisons to a standard threshold known to the device, except for interfaces where a RxPowerThreshold variable is supported, in which case the default lowAlarm threshold may be overridden by setting a non-zero value into RxPowerThreshold. Additionally, when RxPowerThreshold is non-zero, the converter will stop passing traffic when a lowAlarm condition is detected.
The value notApplicable means that the interface you are examining is not one that can be ever expected to have DMI support. This arises when diverse interfaces are indexed by subdevice, and not all interfaces are candidates for DMI support. For example, this value will be returned if this variable is read for the subdevice corresponding to the serial port on a C4TEF100. Some devices never return notApplicable. The value notSupported means that the interface you are examining may be a candidate for DMI support in some configurations, but either due to the particular revision of the main board or due to the type of installed transceiver module, DMI support is not currently available.
RxPowerThreshold This variable allows the lowAlarm threshold for RxPowerAlarm to be adjusted. If a non-zero value (in microwatts) is set into this variable, it replaces the built-in threshold AND instructs the converter to stop passing traffic when the receive power drops below the new threshold. This feature is sometimes referred to as 'Intrusion Detection,' since tapping into a fiber to intercept traffic leads to a reduction in receive power. If this feature is not supported for the interface, this variable returns 0 and cannot be set.
Temp Internally measured temperature of transceiver in tenths of degrees C. Returns 0 if the feature is not supported.
TempAlarm Values: normal(1), notSupported(2), lowWarn(3), highWarn(4), lowAlarm(5), highAlarm(6), notApplicable(7)
Alarm status for internally measured temperature of transceiver. A Warn value may indicate either an environmental problem or that some component in the converter or chassis is degrading and an inspection is warranted. An Alarm value indicates an more severe problem that may already be preventing traffic from flowing. Values with low indicate that the temperature is lower than expected, and values with high indicate that it is higher than expected. All values represent comparisons to standard thresholds known to the device.
For information on notSupported vis-a-vis notApplicable, see discussion under
RxPowerAlarm.
TxBiasCurrent Measured transmit bias current in microamperes. Returns 0 if the feature is not supported.
TxBiasAlarm Values: normal(1), notSupported(2), lowWarn(3), highWarn(4), lowAlarm(5), highAlarm(6), notApplicable(7)
Alarm status for measured transmit bias current for the interface. A Warn value indicates that some component in the converter or chassis may be degrading and an inspection is warranted. An Alarm value indicates an more severe problem that may already be preventing traffic from flowing. Values with low indicate that the current is lower than expected, and values with high indicate that it is higher than expected. All values represent comparisons to standard thresholds known to the device.
For information on notSupported vis-a-vis notApplicable, see discussion under
RxPowerAlarm.
TxPower Measured transmit power, in microwatts. Returns 0 if the feature is not supported.
TxPowerAlarm Values: normal(1), notSupported(2), lowWarn(3), highWarn(4), lowAlarm(5), highAlarm(6), notApplicable(7)
Alarm status of measured transmit power. A Warn value indicates that some component in the channel may be degrading and an inspection is warranted. An Alarm value indicates a more severe problem that may already be preventing traffic from flowing. Values with low indicate that the transmit power is lower than expected, and values with high indicate that it is higher than expected. All values represent comparisons to standard thresholds known to the device.
For information on notSupported vis-a-vis notApplicable, see discussion under
RxPowerAlarm.
Ident Values: unknownUnspecified(0), gbic(1), solderedOn(2), sfp(3)
This variable shows the mounting style of the media connector. Values are from table 3.2 of Small Form Factor Committee document draft SFF-8472 Rev 9.5, 'Diagnostic Monitoring Interface for Optical Xcvrs.' In addition to the enumerated values, this MIB variable may return other values such as 0x04-0x7F which are currently reserved by SFF, and 0x80-0xFF which are vendor specific values.
ConnectorType Values: unknownUnspecified(0), sc(1), fibreChannelStyle1Copper(2), fibreChannelStyle2Copper(3), bncTnc(4), fibreChannelCoaxHeader(5), fiberJack(6), lc(7), mtrj(8), mu(9), sg(10), opticalPigtail(11), hssdcII(32), copperPigtail(33)
When the Ident variable indicates that the connector is socketed (rather than being soldered directly to the board), this variable shows the type of the connector detected in the socket. For soldered-on media connectors, Point-System standard variables such as ConnA and ConnB should be used to determine connector types.
Values above are from table 3.4 of Small Form Factor Committee document draft SFF-8472 Rev 9.5, 'Diagnostic Monitoring Interface for Optical Xcvrs.' In addition to the enumerated values, this MIB variable may return other values such as 0x0C-0x1F and 0x22-0x7F which are currently reserved by SFF, and 0x80-0xFF which are vendor specific values.
BitRate Bit rate of interface, in megabits per second. Returns 0 if the feature is not supported.
LenSupp9125 Maximum length in meters of media supported by the transceiver for 9 micron (125 micron jacket) singlemode fiber. Returns 0 if the length feature is not supported or this transceiver does not support this type of media.
LenSupp50125 Maximum length in meters of media supported by the transceiver for 50 micron (125 micron jacket) multimode fiber. Returns 0 if the length feature is not supported or this transceiver does not support this type of media.
LenSupp625125 Maximum length in meters of media supported by the transceiver for 62.5 micron (125 micron jacket) multimode fiber. Returns 0 if the length feature is not supported or this transceiver does not support this type of media.
LenSuppCopper Maximum length in meters of media supported by the transceiver for copper wire. Returns 0 if the length feature is not supported or this transceiver does not support this type of media.
Wavelength Wavelength of interface's optical transceiver, in nanometers. Returns 0 if the wavelength reporting feature is not supported or this interface is not an optical transceiver.