100G over 100 km of dark fiber

[Jared Brown <nanog-isp () mail com>]

Hello NANOG!

I need to push 100G over 100 km of dark fiber. Since there are no 100G pluggable optics with this reach (~25 dB), I 
have been offered coherent transport systems to solve my problem. This is all good and well, except total system costs 
start from high five figures.

So, my question is, do I have any other options?

I can't help noticing that you can break out a 100G QSFP into four 25G QSFPs. 25G DWDM systems are relatively 
inexpensive (low five figures), but can you make 25G DWDM go 100 km?

I only need the one 100G, so I don't really need a highly scalable DWDM system. I can't put anything midspan, or if I 
could it would cost more than just going with a coherent system.


Jared