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

[bob.mcmahon@umbernetworks.com]

> 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