[HSSG] 10 x 4 = 40
There's been some discussion (!) around the existence of an MSA for a
40G module format. The module is actually based on 4 x 10G channels,
this leaves system implementors 2 choices:
1. Simply define the MSA to use LAG . The MAC & PCS are already defined
for 10GBASE-R, the PMD definitions are already available for SR, LR &
LRM. This could be incorporated into systems being developed
immediately, exploiting existing MAC and fabric silicon. From a
standards perspective, I would classify this as another 10G format (no
fundamental difference to X2, XFP or SFP+).
Additionally, a breakout device could allow compatibility with discrete
10G systems (using SFP+, XFP, X2 etc.) and also would allow the use of a
40G socket to connect to multiple 10G destinations (redundant
connections, multipath routing etc.).
2. Try to push through a new definition in 802.3 for 40G MAC and PCS.
This would almost certainly be tied to the same schedule as the 100G MAC
& PCS definition, it might be available to start development in 3-4
years. It would require new MAC/fabric silicon, that would have to start
development after the standard is in its last stages of development.
A socket using the single 40G approach could not be connected to a
breakout for legacy compatibility.
If #1 happens (almost impossible to "prevent" it) then confusion will
ensue as option #1 & option #2 products mix in the market. It will be
very difficult to distinguish or differentiate between the two. I don't
know how those who commit to the "proper" approach of #2 will be able to
recoup their extra development costs compared to those who get a 3-4
year headstart by implementing #1. Additionally, option #2 based
products will hit the market at the same time as 100G products become
available. They will start with the perception of being "low-end" and
will not be able to command the "early adopter premium" that is often
relied on to recover leading edge development costs.
Frankly, looking at this, I would not recommend to my employer that we
should spend time (and money) to develop the silicon to support option
#2 vs option #1. Of course, others may feel free to spend their
development differently. Additionally, if I was a component vendor, I
know which option I would pursue.