WR stands for Wavelength Router.
It’s used to forward traffic on wavelength.
It’s called optical add drop multiplexer.
It can perform 3 functions:
- pass through
It contain what’s called WSS.
WSS is wavelength selective switch.
The WSS has the ability to add or drop any channel / wavelength from/ to any port in the WR.
Also it has the ability to attenuate any channel power to performance power adjustment and commissioning.