In the video I don't think that they mentioned it, but In the show notes it says that DWDM is used as a SONET alternative, but I got the impression from the video that DWDM was the technology that transferred data over the SONET connection.
Network + Wavelength Division Multiplexing
SONET is at its heart a TDM (Time Division Multiplexing) based technology.
DWDM is not; it is a WDM (Wavelength Division Multiplexing) technology.
Though SONET transmissions can be transmitted over the DWDM network; DWDM signal cannot be tranmitted over the SONET connection.
If we (I assume it was me) implied that (what you said) then I was mistaken and I need to add an errata to that video. Can you please tell me what particular episode so that I can post the errata soon. Thank you!
OK, thank you for your response. I think I get it now. I rewatched the video, and was just confused. All of this is new and very bewildering to me.