Checking 100GE Transmit (TX) and Receive (RX) Optical Power in Juniper Routers

For checking transmission links on Cisco Routers, it is good to know how to find out the optical power of 100GE modules or interfaces for troubleshooting and making sure the desired or optimal range is meet.

Here are the sample commands for checking the Transmit/Output (TX)  and Receive/Input (RX) optical power.

show interfaces diagnostics optics <interface-name>

Sample Output:

fnt@JUNIPER-ROUTER1-re0> show interfaces diagnostics optics et-0/0/0
Physical interface: et-0/0/0
Module temperature : 28 degrees C / 82 degrees F
Module voltage : 3.2960 V
Module temperature high alarm : Off
Module temperature low alarm : Off
Module temperature high warning : Off
Module temperature low warning : Off
Module voltage high alarm : Off
Module voltage low alarm : Off
Module voltage high warning : Off
Module voltage low warning : Off
Module temperature high alarm threshold : 75 degrees C / 167 degrees F
Module temperature low alarm threshold : -5 degrees C / 23 degrees F
Module temperature high warning threshold : 73 degrees C / 163 degrees F
Module temperature low warning threshold : -3 degrees C / 27 degrees F
Module voltage high alarm threshold : 3.6030 V
Module voltage low alarm threshold : 3.0090 V
Module voltage high warning threshold : 3.5340 V
Module voltage low warning threshold : 3.0720 V
Laser bias current high alarm threshold : 72.000 mA
Laser bias current low alarm threshold : 2.500 mA
Laser bias current high warning threshold : 66.000 mA
Laser bias current low warning threshold : 5.000 mA
Laser output power high alarm threshold : 6.3095 mW / 8.00 dBm
Laser output power low alarm threshold : 0.1479 mW / -8.30 dBm
Laser output power high warning threshold : 4.4668 mW / 6.50 dBm
Laser output power low warning threshold : 0.2344 mW / -6.30 dBm
Laser rx power high alarm threshold : 5.6234 mW / 7.50 dBm
Laser rx power low alarm threshold : 0.0347 mW / -14.60 dBm
Laser rx power high warning threshold : 4.4668 mW / 6.50 dBm
Laser rx power low warning threshold : 0.0550 mW / -12.60 dBm
Lane 0
Laser bias current : 25.011 mA
Laser output power : 0.941 mW / -0.27 dBm
Laser receiver power : 1.126 mW / 0.52 dBm
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser receiver power high alarm : Off
Laser receiver power low alarm : Off
Laser receiver power high warning : Off
Laser receiver power low warning : Off
Tx loss of signal functionality alarm : Off
Rx loss of signal alarm : Off
Tx laser disabled alarm : Off
Lane 1
Laser bias current : 25.011 mA
Laser output power : 1.309 mW / 1.17 dBm
Laser receiver power : 1.498 mW / 1.75 dBm
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser receiver power high alarm : Off
Laser receiver power low alarm : Off
Laser receiver power high warning : Off
Laser receiver power low warning : Off
Tx loss of signal functionality alarm : Off
Rx loss of signal alarm : Off
Tx laser disabled alarm : Off
Lane 2
Laser bias current : 25.011 mA
Laser output power : 0.975 mW / -0.11 dBm
Laser receiver power : 1.116 mW / 0.48 dBm
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser receiver power high alarm : Off
Laser receiver power low alarm : Off
Laser receiver power high warning : Off
Laser receiver power low warning : Off
Tx loss of signal functionality alarm : Off
Rx loss of signal alarm : Off
Tx laser disabled alarm : Off
Lane 3
Laser bias current : 25.011 mA
Laser output power : 1.150 mW / 0.61 dBm
Laser receiver power : 1.345 mW / 1.29 dBm
Laser bias current high alarm : Off
Laser bias current low alarm : Off
Laser bias current high warning : Off
Laser bias current low warning : Off
Laser receiver power high alarm : Off
Laser receiver power low alarm : Off
Laser receiver power high warning : Off
Laser receiver power low warning : Off
Tx loss of signal functionality alarm : Off
Rx loss of signal alarm : Off
Tx laser disabled alarm : Off

{master}

For filtered output matching to TX and RX:

show interfaces diagnostics optics <interface-name>  | match dB

Sample Output:

fnt@JUNIPER-ROUTER1-re0> show interfaces diagnostics optics et-0/0/0 | match dB
Laser output power high alarm threshold : 6.3095 mW / 8.00 dBm
Laser output power low alarm threshold : 0.1479 mW / -8.30 dBm
Laser output power high warning threshold : 4.4668 mW / 6.50 dBm
Laser output power low warning threshold : 0.2344 mW / -6.30 dBm
Laser rx power high alarm threshold : 5.6234 mW / 7.50 dBm
Laser rx power low alarm threshold : 0.0347 mW / -14.60 dBm
Laser rx power high warning threshold : 4.4668 mW / 6.50 dBm
Laser rx power low warning threshold : 0.0550 mW / -12.60 dBm
Laser output power : 0.940 mW / -0.27 dBm
Laser receiver power : 1.128 mW / 0.52 dBm
Laser output power : 1.309 mW / 1.17 dBm
Laser receiver power : 1.494 mW / 1.74 dBm
Laser output power : 0.975 mW / -0.11 dBm
Laser receiver power : 1.117 mW / 0.48 dBm
Laser output power : 1.149 mW / 0.60 dBm
Laser receiver power : 1.345 mW / 1.29 dBm

From the details above last output, it can be interpreted as:

Threshold for Transmit (TX) power:(Ideal range is from 8dBm to -8dBm)
Alarm High: 8.00 dBm
Warning High:6.50 dBm
Warning Low:-6.30 dBm
Alarm Low:-8.30 dBm

Threshold for Receive (RX) power: (Ideal range is from 7.5dbM to -14dBm)
Alarm High:7.50 dBm
Warning High:6.50 dBm
Warning Low:-12.60 dBm
Alarm Low: -14.60 dBm

Current Reading (TX) (Still in optimal light level)
Lane 0:-0.27 dBm
Lane 1: 1.17 dBm
Lane 2: -0.11 dBm
Lane 3: 0.60 dBm

Current Reading (RX) (Still in optimal light level)
Lane 0: 0.52 dBm
Lane 1: 1.74 dBm
Lane 2: 0.48 dBm
Lane 3: 1.29 dBm