A "breakout" cable won't work because CX4 uses 8/10 encoding and SFP+ uses 64/66 encoding. You'd also need to merge four 3.125Gbps lanes into one 10.3125Gbps lane. So this is not simply a passive operation.
We use Active Optical Cables (AOC) for KAT-7, but they don't go up to 3km, so this'd also not work for you. GMRT developed a media converter (CX-4 to SFP+) at a much more reasonable price. It was announced on the CASPER mailing list by Yashwant Gupta on the 18th Sept 2012. ROACH-2 could also be used, if populated with an SFP mezzanine card and an -LR module, but it seems an expensive solution if a ROACH-1 suffices for your processing needs. Jason Manley CBF Team Leader SKA-SA Cell: +27 82 662 7726 Work: +27 21 506 7300 On 12 Aug 2013, at 09:01 , Keith Bannister wrote: > Hi Casperites, > > Can someone recommend a solution for getting as near as possible to 10 > Gbps from a ROACH v1 over a ~ 3km fibre? (unidirectional) > > Options I guess are: > > 1) Roach v2 (rev 2?) > 2) Some kind of CX4/SFP+ breakout cable with our own transceivers (e.g > 10GBASE-LR) > 3) A rather-pricey media converter [1] > > Any advice appreciated. > > - Keith Bannister > > [1] - http://www.elpeus.com/cx4-cables/10gbe-sfp-to-cx4-converter-device/ >
