Profile photo of Mr-B

I and at least one other use Level 1 Giggabit switches GSW 0841 for the link between the mix rack and surface, have been for about 4 years now.
This unit is pretty cheap and has 1 SFP port on the back which will take either a single mode or a multimode fibre module. I personally use the Multimode Neutrik pre-made fibre cable (150m though other lengths are available) and custom made a connection panel using off the shelf components. Obviously you need one of these switches at each end.
The switch is configured into a number of discrete channels as is required, for me that is Ether-Sound 1, iLive network 2 then a couple of spares. The system works just fine, never missed a beat, I also use Spanning tree protocol so that I can use a standard CAT5e cable below 100m to provide a backup if the fibre fails. Obviously the total bandwith of the link is still only 1 Giggabit, though the internal backbone of the switch is greater.

My whole system cost me less than £1,000, I would recommend putting a UPS at each end, also make sure the switch does not get too hot.

Hope this helps.