When to use CWDM and DWDM?

Hi all,
My understanding is that you would use "generally" DWDM to get more channels than CWDM, because CWDM is slightly less accurate than DWDM so the optics are cheaper.
I only need two channels to start with, but 10Gbps, for this reason do I need to deploy a DWDM mux rather than CWDM mux with an eDWM mux attached?
Extra info;
Single dark fibre between two sites. I want Fibre Channel at 1Gbps and Ethernet at 10Gbps between the two sites. This is not FCoE. Is it best to use DWDM here, and also could anyone recomment the products I would need to do this?
Many thanks,
J.

Tom, the info you'll do is incorrect, the 10Gig Link is limited always at 80Kms, even amplified, that's limited by chromatic dispersion, so if you want to archive longer distances you must attach a second OAD plus an optical amplifier.
http://www.cisco.com/en/US/prod/collateral/modules/ps5455/product_data_sheet0900aecd806a1c36.html
Below Image 7
"In unamplified point-to-point links, 1-Gigabit DWDM traffic can typically achieve distances around 80km, and 10-Gigabit DWDM traffic can typically reach 60km. In amplified point-to-point links, 1-Gigabit DWDM traffic can typically achieve distances between 100 and 120km, and 10-Gigabit DWDM traffic can typically reach 80km (limited by chromatic dispersion)."
best regards.
WebRedes

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