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From: Jonathan Morton <chromatix99@gmail.com>
To: Rich Brown <richb.hanover@gmail.com>
Cc: bloat <bloat@lists.bufferbloat.net>,
	make-wifi-fast-request@lists.bufferbloat.net
Subject: Re: [Bloat] Good Wi-Fi test programs?
Date: Mon, 7 Dec 2020 03:00:15 +0200	[thread overview]
Message-ID: <C3004AE2-1525-4061-9BFF-59AC11A72195@gmail.com> (raw)
In-Reply-To: <F36D8FCF-AB5E-48F2-A2BD-F319BFAD7A5F@gmail.com>

> On 7 Dec, 2020, at 1:00 am, Rich Brown <richb.hanover@gmail.com> wrote:
> 
> I would first do the following "easy tests":
> 
> - Check for conflicting/overlapping Wi-Fi channels. I am fond of the free app, WiFi Analyzer from farproc (http://a.farproc.com/wifi-analyzer) for this test, but there are several similar Android apps. 
> - Compare the signal strength for the DSL modem and the Calix modem, as shown by WiFi Analyzer 
> - Be sure that all computer(s) are using the Calix modem.
> - Use a variety of speed tests: DSLReports, Fast.com, other favorites?
> - Compare speedtest results when the test computer is close to, or far from the router.
> - (If possible) compare the performance for both Wi-Fi and Ethernet
> - Shut off the DSL modem on my way out the door to be sure it's not causing interference or confusing the situation.
> 
> Anything else you'd recommend?

Make sure the customer's devices are using 5GHz rather than 2.4GHz band, where possible.  The Calix devices apparently support both and try to perform "band steering", but it's worth double checking.

https://www.calix.com/content/calix/en/site-prod/library-html/systems-products/prem/op/p-gw-op/eth-gw/800e-gc-spg/index.htm?toc.htm?76518.htm

I also read while briefly scanning the accessible documentation that Calix operates at maximum permitted wifi transmit power and with up to 80MHz RF bandwidth.  While this does maximise the range and throughput of an individual AP, many such APs in close proximity will see the RF channel as "occupied" by each others' transmissions more often than if a lower transmit power were used.  The result is that they all shout so much that they can't hear themselves think, and clients can't get a word in edgewise to send acks (with generally lower transmit power themselves).

You should look for evidence of this while analysing channel occupancy, especially in multi-occupancy buildings.  It's probably less of a concern in detached or semi-detached housing.

I didn't see any mention of Airtime Fairness technology, which is now a highlighted feature on some other manufacturers' products (specifically TP-Link).  Ask whether that is present or can be implemented.  You may be able to test for it, if you have established a case where wifi is clearly the bottleneck, by passing a saturating ECN Capable flow through it and looking for CE marks (and/or ECE feedback), since Airtime Fairness comes with built-in fq_codel.

 - Jonathan Morton

  reply	other threads:[~2020-12-07  1:00 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-06 23:00 Rich Brown
2020-12-07  1:00 ` Jonathan Morton [this message]
2020-12-07 12:34   ` Rich Brown

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