[c-nsp] forced up/up on a fiber link

[Dale W. Carder]

On Oct 23, 2012, at 5:59 AM, Phil Mayers wrote:

> On 23/10/12 10:20, Damian Holdcroft wrote:
>> I remember reading something, somewhere, about the lasers sending pulses
>> for link detection. I don't seem to be able to find anything on fibre link
>> detection at the moment though. Does anybody know anything about it?
> 
> I don't think this happens on normal links. As has been said, SX and LX optics do indeed "fire into the air". "Link up" is a different matter; this usually is based on light detection and autoneg.
> 
> Some high-power equipment has "eye protection". I've never entirely figured out how this works, but it cuts off the laser when the fibre goes down.

See ITU G.664.

Dale