[c-nsp] Optic Shutdown TX State?

[Nick Hilliard]

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