[AusNOG] 10GBase-T SFP modules?

[James Andrewartha]

On Thu, 10 Jul 2014, Beeson, Ayden wrote:

> > Are you going to upgrade your entire switch infrastructure so people within 6m of the AP can share an extra 5% peak bandwidth?

> The simple answer for us is yes, given we are doing a refresh anyway, 
> it's on the plan. You are spot on, that graph does show 1050mbps @ 80mhz 
> channels (after you factor in overheads etc) on wave 2, however the game 
> changer is that beam forming (with "sounding" that document called it), 
> allowing the radio to share more bandwidth out than it has before to 
> each client. A single client at 1050mbps used to mean two clients would 
> then share that (or near enough) so that was your limit, but the beam 
> forming (as I understand it) will result in a radio being able to allow 
> multiple clients to hit higher to that theoretical maximum each, meaning 
> those two clients may now get 800mbps each, rather than 525 each (not 
> factoring in all the other junk that reduces it even more), at that 
> point you are beyond that single 1gbps connection, even if only by a 
> little bit. Those gains may or may not get better or worse depending on 
> the amount of clients, distance etc. etc., however given it's a 
> possibility we would like to allow for it if possible.

Right, this is where we differ. My understanding is that with a 4SS 
MU-MIMO AP and clients, your total bandwidth is the same whether you have 
one 4SS client, or four 1SS clients. So those two clients can't get 
800mbps each. The gain in MU-MIMO is that if you have two 2SS clients, 
then they can both get 525 each, rather than the 525mbps of 2SS they would 
share without MU-MIMO.

Wave 2 is supposed to top out at 4SS, but having said that, Quantenna 
announced an 8x8 MU-MIMO chip for 2015, which could change things. 
Broadcom also announced a chip with two 3SS 5GHz radios in it.

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