[c-nsp] Optic Shutdown TX State?

[Tim Durack]

On Fri, Aug 12, 2016 at 10:24 AM, Nick Hilliard <nick at foobar.org> wrote:

> Tim Durack wrote:
> > OSA measurement confirms this unexpected behavior. I have a case open
> with
> > Cisco to investigate optics turning on/off when router port is in a
> > shutdown state. (C6880, SUP2T, 15.2(1)SY1a)
>
> this is device-dependent.  On a juniper or extreme box, disabling the
> interface does not affect the laser TX.  On a Juniper, you can log into
> the line card and manually power down the laser. On a Brocade (foundry),
> it will put the laser into ALS mode, i.e. will turn up the laser every
> couple of seconds to see what happens, but will otherwise stay down.
>
> In general, all inserted transceivers should be assumed to be
> transmitting all the time, and that inspecting TX with your remaining
> good eye would be a poor idea.
>
> Nick
>
>
Thanks, this is very helpful.

Definitely platform dependent, and possibly platform inconsistent. From a
Cisco perspective, it seems that shutdown is normally TX off.

For me this is less of a safety issue and more of a system matter. TX
on/off is unexpected on an OSA measurement. TX on/off cycle also has an
effect on EDFA AGC.

-- 
Tim:>