[j-nsp] How to shut down laser on any optics

[Olivier Benghozi]

This would prove once again that vendor_endorsed_and_overcharged optics are just a useless scam.

This being said, we didn't experience this neither with Skylane nor Cubeoptics transceivers (currently on MPC7-MRATE / 18.4R[2-3]-[S*]). It «just works» as we expect (laser is switched off when the channel is disabled in the config). I would only expect to see another behaviour from some buggy/cheap/crappy network gears, whatever how lite the official specifications are, and therefore see this issue as a bug in a Juniper case.

Example of 2 different channels of a QSFP+ PLR4 (MTP):

Physical interface: xe-3/1/1:0 (disabled)
  Lane 0
    Laser bias current                        :  0.000 mA
    Laser output power                        :  0.000 mW / -40.04 dBm
    Tx laser disabled alarm                   :  On
Physical interface: xe-3/1/1:1 (in use)
  Lane 1
    Laser bias current                        :  32.453 mA
    Laser output power                        :  0.501 mW / -3.00 dBm
    Tx laser disabled alarm                   :  Off
[...]




> Le 24 juin 2020 à 18:59, Jared Mauch <jared at puck.nether.net> a écrit :
> 
> They would either need to have the GPIO wired for this pin on the PCBs and/or implement disable sets this bit AND the optic would need to honor it.