There are two main solutions for building CWDM and DWDM backbone networks:
Active - built from transponders and muxponders providing full optical demarcation point. This solution is agnostic to the routers, switches, and ADMs within the network.
Passive - built from passive filters and coloured optics plugged into different equipment such as routers, switches and ADMs (add drop multipelxer).
Which is the preferred solution, and which one is considered the inferior one, and why?
Read all about it in this white paper.