Thanks for all the info everyone. I guess my main concern is about the fact that the Qnap switch I have is SFP+ while the Etherregen is SFP. I have read that if you plug in a cable in an SFP+ cage, no matter what the cable is, it will send an SFP+ signal and the SFP-only Etherregen won't see it.
Not sure if that's the case or not. I've also considered having one SFP+ transceiver at one end an SFP at the other. Or maybe the newer SFP/SFP+ dual mode transceivers.
If anyone has had experience with this kind of issue please let me know. Thanks