[Rpm] [Bloat] [Starlink] [LibreQoS] On FiWi

Dave Taht dave.taht at gmail.com
Wed Mar 15 18:04:27 EDT 2023


On Wed, Mar 15, 2023 at 2:52 PM David Lang <david at lang.hm> wrote:
>
> On Wed, 15 Mar 2023, Dave Taht wrote:
>
> > On Wed, Mar 15, 2023 at 12:33 PM David Lang via Rpm
> > <rpm at lists.bufferbloat.net> wrote:
> >>
> >> if you want another example of the failure, look at any conference center, they
> >> have a small number of APs with wide coverage. It works well when the place is
> >> empty and they walk around and test it, but when it fills up with users, the
> >> entire network collapses.
> >>
> >> Part of this is that wifi was really designed for sparse environments, so it's
> >> solution to "I didn't get my message through" is to talk slower (and louder if
> >> possible), which just creates more interference for other users and reduces the
> >> available airtime.
> >>
> >> I just finished the Scale conference in Pasadena, CA. We deployed over 100 APs
> >> for the conference, up to 7 in a room, on the floor (so that the attendees
> >> bodies attenuate the signal) at low power so that the channels could be re-used
> >> more readily.
> >
> > How did it go? You were deploying fq_codel on the wndr3800s there as
> > of a few years ago, and I remember you got rave reviews... (can you
> > repost the link to that old data/blog/podcast?)
>
> no good stats this year. still using the wndr3800s. Lots of people commenting on
> how well the network did, but we were a bit behind this year and didn't get good
> monitoring in place. No cake yet.
>
> I think this is what you mean
> https://www.youtube.com/watch?v=UXvGbEYeWp0


A point I would like to make for the africa contingent here is that
you do not need the latest
technology for africa. We get 300Mbit out of hardware built in the
late 00s, like the wndr3800. The ath9k chipset is STILL manufactured,
the software mature, and for all I know millions of routers
like these are lying in junk bins worldwide, ready to be recycled and
reflashed.

One libreqos customer deployed libreqos, and took a look at the 600+
ubnt AGWs (ath9k based), on the shelf that could be fq_codeled,
especially on the wifi... built a custom openwrt imagebuilder image
for em, reflashed and redistributed them.

The wndr3800s were especially well built. I would expect them to last
decades. I had one failure of one that had been in the field for over
10 years... I thought it was the flash chip... no, it was the power
supply!


> > Did you get any good stats?
> >
> > Run cake anywhere?
> >>
> >> in the cell phone world they discovered 'microcells' years ago, but with wifi
> >> too many people are still trying to cover the max area with the fewest possible
> >> number of radios. As Dan says, it just doesn't work.
> >>
> >> and on mesh radios, you need to not just use a different channel for your
> >> uplink, you need a different band to avoid desense on the connection to your
> >> users. And that uplink is going to have the same hidden transmitter and airtime
> >> problems competing with the other nodes also doing the uplink that it's
> >> scalability is very limited (even with directional antennas). Wire/fiber for the
> >> uplink is much better.
> >>
> >> David Lang
> >>
> >>
> >>
> >>   On Wed, 15 Mar
> >> 2023, dan via Bloat wrote:
> >>
> >>> Trying to do all of what is currently wanted with 1 AP in a house is a huge
> >>> part of the current problems with WiFi networks.  MOAR power to try to
> >>> overcome attenuation and reflections from walls so more power bleeds into
> >>> the next home/suite/apartment etc.
> >>>
> >>> In the MSP space it's been rapidly moving to an AP per room with output
> >>> turned down to minimum.    Doing this we can reused 5Ghz channels 50ft away
> >>> (through 2 walls etc...) without interference.
> >>>
> >>> One issue with the RRH model is that to accomplish this 'light bulb' model,
> >>> ie you put a light bulb in the room you want light, is that it requires
> >>> infrastructure cabling.  1 RRH AP in a house is already a failure today and
> >>> accounts for most access complaints.
> >>>
> >>> Mesh radios have provided a bit of a gap fill, getting the access SSID
> >>> closer to the device and backhauling on a separate channel with better (and
> >>> likely fixed position ) antennas.
> >>>
> >>> regardless of my opinion on the full on failure of moving firewall off prem
> >>> and the associated security risks and liabilities, single AP in a home is
> >>> already a proven failure that has given rise to the mesh systems that are
> >>> top sellers and top performers today.
> >>>
> >>> IMO, there was a scheme that gained a moment of fame and then died out of
> >>> powerline networking and an AP per room off that powerline network.  I have
> >>> some of these deployed with mikrotik PLA adapters and the model works
> >>> fantastically, but the powerline networking has evolved slowly so I'm
> >>> seeing ~200Mbps practical speeds, and the mikrotik units have 802.11n
> >>> radios in them so also a bit of a struggle for modern speeds.   This model,
> >>> with some development to get ~2.5Gbps practical speeds, and WiFi6 or WiFi7
> >>> per room at very low output power, is a very practical and deployable by
> >>> consumers setup.
> >>>
> >>> WiFi7 also solves some pieces of this with AP coordination and
> >>> co-transmission, sort of like a MUMIMO with multiple APs, and that's in
> >>> early devices already (TPLINK just launched an AP).
> >>>
> >>> IMO, too many hurdles for RRH models from massive amounts of unfrastructure
> >>> to build, homes and appartment buildings that need re-wired, security and
> >>> liability concerns of homes and business not being firewall isolated by
> >>> stakeholders of those networks.
> >>>
> >>> On Wed, Mar 15, 2023 at 11:32 AM rjmcmahon <rjmcmahon at rjmcmahon.com> wrote:
> >>>
> >>>> The 6G is a contiguous 1200MhZ. It has low power indoor (LPI) and very
> >>>> low power (VLP) modes. The pluggable transceiver could be color coded to
> >>>> a chanspec, then the four color map problem can be used by installers
> >>>> per those chanspecs. https://en.wikipedia.org/wiki/Four_color_theorem
> >>>>
> >>>> There is no CTS with microwave "interference" The high-speed PHY rates
> >>>> combined with low-density AP/STA ratios, ideally 1/1, decrease the
> >>>> probability of time signal superpositions. The goal with wireless isn't
> >>>> high densities but to unleash humans. A bunch of humans stuck in a dog
> >>>> park isn't really being unleashed. It's the ability to move from block
> >>>> to block so-to-speak. FiWi is cheaper than sidewalks, sanitation
> >>>> systems, etc.
> >>>>
> >>>> The goal now is very low latency. Higher phy rates can achieve that and
> >>>> leave the medium free the vast most of the time and shut down the RRH
> >>>> too. Engineering extra capacity by orders of magnitude is better than
> >>>> AQM. This has been the case in data centers for decades. Congestion? Add
> >>>> a zero (or multiple by 10)
> >>>>
> >>>> Note: None of this is done. This is a 5-10 year project with zero
> >>>> engineering resources assigned.
> >>>>
> >>>> Bob
> >>>>> On Tue, Mar 14, 2023 at 5:11 PM Robert McMahon
> >>>>> <rjmcmahon at rjmcmahon.com> wrote:
> >>>>>
> >>>>>> the AP needs to blast a CTS so every other possible conversation has
> >>>>>> to halt.
> >>>>>
> >>>>> The wireless network is not a bus. This still ignores the hidden
> >>>>> transmitter problem because there is a similar network in the next
> >>>>> room.
> >>>>
> >>> _______________________________________________
> >> Bloat mailing list
> >> Bloat at lists.bufferbloat.net
> >> https://lists.bufferbloat.net/listinfo/bloat
> >> _______________________________________________
> >> Rpm mailing list
> >> Rpm at lists.bufferbloat.net
> >> https://lists.bufferbloat.net/listinfo/rpm
> >
> >
> >
> >



-- 
Come Heckle Mar 6-9 at: https://www.understandinglatency.com/
Dave Täht CEO, TekLibre, LLC


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