[Cake] Re: [Rpm] Re: [Bloat] Re: "Fi-Wi is a new forwarding plane for wireless" - Bob McMahon

[dan <dandenson@gmail.com>]

On Sat, May 23, 2026 at 10:36 AM <bob.mcmahon@umbernetworks.com> wrote:

> > I don't have arguments on the technical bits of your reply.
>
> The industry hasn't provided open source tools to analyze 802.11 properly.
> The proprietary ones are tightly coupled to chip firmware, owned by 802.11
> vendors, and not for sale.
>
> You've built solid networks, especially given how little 802.11 MAC-layer
> and MCS observability current tooling exposes. I hope to make open source
> 802.11 MAC telemetry tools available sooner rather than later. These will
> run on both an ESP32-C5 and an RPi5. The inexpensive ESP32 allows monitors
> to be placed throughout a venue at low cost.
>
> A key issue is what's being measured. Your deployment data is a capacity
> analysis. Once baseline capacity is adequate, user experience is driven by
> tail latency and service-time variance rather than throughput. A network
> can saturate aggregate throughput while still showing large service-time
> variance and long per-flow tails under contention. These are different
> measurements.
>
> And CODEL and CAKE are IP-layer mechanisms. They don't operate on 802.11
> TXOPs or airtime sojourn, which is where the contention and service-time
> variance actually live. AQL is closer. It operates on airtime at the
> driver/firmware boundary, but it's still per-AP. There's no coordination
> across APs and no MAC telemetry exposed upward.
>
> Slide 6 of my DPDK Summit Stockholm talk lays out the layering:
> https://www.umbernetworks.com/DPDK_WiFi_Stockholm_Pres.html
>
> Check out iperf2's advanced features around --bounceback, --trip-times,
> and --histograms. These are available as open source. Man page:
> https://iperf2.sourceforge.io/iperf-manpage.html
>
> I'll try to respond with some metrics soon. My rig is down at the moment,
> so give me a few days.
>
> Bob
>

I agree.  However, I'm not actually just measuring throughput, but running
latency sensitive applications without issues.  Frank might attest to my
efforts to reduce latency and I routinely share data on lqos (and another
QoE product's) TCP measurements for latency and among QoE users, I believe
my network is top 1% in latency and jitter and in the WISP space.
Obviously I'm not going to compete with XGSPON operators.. (though I'm only
measuring TCP because that's the 'easiest' to measure passively
practically).  While this is not an engineering adequate benchmark, if my
VoIP handsets work over wireless then the wireless is good is a very
reasonable latency, jitter, loss argument.  And I run a few brands of WiFi
based VoIP phones (Fanvill Wxxx series, Yealink Wxx and AXxx series).
Similarly, if the sonos works and is in sync, the wifi is good.

As a service company and as a user, I don't really care so much where the
goodness is in the system, mac layer or IP having cake work it's magic.
Basically running an AP on OFMDA (as much as possible) and well under the
'red line' capacity delivers great results on WiFi7 radios (and some WiFi6
radios).  I have no doubt that FiWi could get more of the theoretical
throughput delivered at the mac layer.

Deliverables are all that matter to me and I think to buyers and users.
Benchmarks test deliverables which is great and I'm a routing iperf* user.
It's engineering's problem to develop the next tech *AND* solicit funding
to do so.