FiberU (https://fiberu.org) has a lot of decent free training materials. Their emphasis is on physical installation, but they do cover DWDM, Bi-Di, and related physics in some of their videos. If you’re looking for DWDM design and provisioning, you’ll probably have to pay for vendor-specific courses. Here’s the FiberU syllabus that covers optical fiber testing along with DWDM and OTDR. https://fiberu.org/OSP/LP8.html -mel On Oct 1, 2019, at 1:24 PM, James Chang <traceroute316@gmail.com> wrote: Sorry... forgot to mention that I'm looking for recommendation of training courses in this particular area. Thanks, James On Tue, Oct 1, 2019 at 4:21 PM James Chang <traceroute316@gmail.com<mailto:traceroute316@gmail.com>> wrote: Hi All, Hopefully this is the right place to post this question. I'm a routing guy mainly working with ISIS/BGP for my company in our core space. I have an opportunity to get involve with our L2 DWDM network. We are a Cisco shop using NCS2K as DWDM nodes. But before jump into learning the NCS specific stuff, I would like to take a vendor neutral training course in Optical fiber testing with OSA/OTDR, OTN, DWDM signaling, OSNR/dispersion....etc. I think this will help me understand how to build out a DWDM network from ground up. I'm hoping someone I could get into designing network for my company. Thanks in advance, James