Greg Ferro of Etherealmind writes:
Many people are noticing that part of the Cisco ACI announcement includes mention of 40GbE BiDi optics where a 40GbE SFP needs only two MMF fibre cores for 40GbE connectivity. It’s worth noting that all vendors will also ship BiDi optics in the near future. For example, Arista is promoting a single mode 40G BiDi that uses a single mode pair to achieve less cabling while Cisco has chosen to lead with MMF version to fit it’s customer base better.
Running 40GbE over MMF is going to speed adoption as a backbone interconnect. Greg rightfully points out that everyone will eventually have BiDir optics available for their platforms to reduce CapEx costs. But will that disrupt adoption of 100GbE due to cost?
Read more: Musing: 40GbE BiDir Optics Means Less Cable In The Data Centre