Re: [Make-wifi-fast] I used to dream of a single wifi cpu, memory, and I/O

[Aaron Wood <woody77@gmail.com>]

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On Sun, Jul 9, 2023 at 10:40 PM Bob McMahon via Make-wifi-fast <
make-wifi-fast@lists.bufferbloat.net> wrote:

> I wonder if treating WiFi like a transceiver is the better approach,
> separating "the computer abstraction" from the remote radio head.
>
> Then it's a RF Front End(s) / CMOS Radios / PHY(s) / 802.11 MAC(s) (lower)
> / 802.3 PAM4 / 100G SERDES / 4 1x25G VCSELs. Pluggable like an SFP.
>
> The virtualized APs could support at least 10 and maybe 100s of these via
> merchant switching silicon and could be kilometers away. The MACs lower
> could be simplified to dual queue a la L4S. No need for 4 AC queues per
> MAC. Might be able to throw away 802.11 retries too and let the upper
> layers handle it.
>

Isn't this how the commercial APs that use a combined
backhaul/control-plane operate?

I've often wanted to use something like OpenVSwitch to combine all the
layer-2 broadcast domains without actually making them a single broadcast
domain (central ARP responder/router, multicast-to-singlecast conversion,
mDNS routing instead of always using broadcasts, etc).  I know that we were
looking at that with CeroWRT, early on, using routing between separate
subnets, but that required a bunch of proxies that never seemed to really
work as well as I wanted (or I wasn't very good at getting them set up
correctly).  I think we're maybe in a better place for that now.

Given that wifi stations must associate with APs, there's so much
knowledgeable state that can be centrally (and distributedly) cached and
then used to move a bunch of broadcast traffic to single-cast.  With the
huge difference in encoding rates between broadcast and singlecast traffic,
especially as the number of STAs increases, it seems like it would be very
beneficial.

And if you were in the 1:1 AP<->STA situation that has floated across this
list a few times (I do find the micro-AP idea fascinating), then all
"broadcast" traffic should hopefully become limited-transmit-power
single-cast, with minimal use of spectrum (both in terms of time and
physical space).

One issue that I've seen with many APs in the same space, is that many
client stations are very aggressive enumerators of the available APs, much
to the detriment of the operation of the system.  I've seen clients DoS all
the available spectrum with wildcard probe requests and their responses,
which sound like exactly the sort problems seen with ARP in very dense
server racks that the vswitch and central ARP server model was meant to
solve:  have a single "best" response instead of flooding the network with
responses (or requests, in the ARP case).

May be a good time to simplify.
>

It seems like perhaps a little more hierarchy/coordination could result in
more simple operation at scale.


>
> Bob
>
> On Fri, Jul 7, 2023 at 2:25 PM Dave Taht via Make-wifi-fast <
> make-wifi-fast@lists.bufferbloat.net> wrote:
>
>> preferably using some sort of async circuitry for minimum interference
>> and power consumption. I figured, oh, 256MB would be more than enough
>> for a 10Gbit router.
>>
>> Instead, we can now layer 64GB on die.
>>
>> https://blocksandfiles.com/2023/07/05/3d-stacked-dram-and-processor-cube/
>>
>> --
>> Podcast:
>> https://www.linkedin.com/feed/update/urn:li:activity:7058793910227111937/
>> Dave Täht CSO, LibreQos
>> _______________________________________________
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>
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