Switch#show int tran
Transceiver monitoring is disabled for all interfaces.

If device is externally calibrated, only calibrated values are printed.
++ : high alarm，+:high warning,-:low warning,--:low alarm.
NA or N/A:not applicable，Tx:transmit,Rx:receive.
mA: milliamperes, dBm: decibels (milliwatts).

                                            Optical   Optical
          Temperature   Voltage   Current   TxPower   RxPower
Port      (Celsius)     (Volts)  （mA）    （dBm）   （dBm）
--------  -----------   -------   -------   -------  --------
Twe1/0/1  35.5          3.29      34.2      -0.8      -1.9
Twe1/0/2  36.9          3.32      37.1      -2.1      -1.2