From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-x22e.google.com (mail-ig0-x22e.google.com [IPv6:2607:f8b0:4001:c05::22e]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by huchra.bufferbloat.net (Postfix) with ESMTPS id B4C1E21F27E for ; Sat, 7 Feb 2015 18:36:53 -0800 (PST) Received: by mail-ig0-f174.google.com with SMTP id b16so10299259igk.1 for ; Sat, 07 Feb 2015 18:36:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=Xssodgsut1hv/UmWqSMvjHNvsF6QvasA6LopNKj+Bio=; b=vb6/hyEQehKus+RnCPnqu1zYr5MB68pctWWew6Dgg/SGsZFmvvqnLGxwQYYuNhgKiS +s2g4Zm0wDPBbsmoiqfsWrshOK8fa6pkh3hf4Z+g7WTDvLiaDSD5jMpnxt3m2D67hNzz mg7TBCmgfP58udGeuyXmNE7POerDegfbTe1hDFw5bGPX4MMR1ruF7j+sCk09IPBLVQq2 Mf5F70zJNiGNg/c9kDEnm6jyItXhSbOa3DSAKUZeIshkXgVY3CJRmln0uj5IJ8QhxNjp zAZF14pezczNTZx4wfWUo7xkCdJlU3B46y2XU49vb1MSucdVafr/7fdGWhnsYZwqd+q+ Y4XQ== MIME-Version: 1.0 X-Received: by 10.50.39.65 with SMTP id n1mr9955577igk.37.1423363012545; Sat, 07 Feb 2015 18:36:52 -0800 (PST) Received: by 10.64.142.42 with HTTP; Sat, 7 Feb 2015 18:36:52 -0800 (PST) In-Reply-To: References: Date: Sat, 7 Feb 2015 18:36:52 -0800 Message-ID: From: Aaron Wood To: David Lang Content-Type: multipart/alternative; boundary=047d7bdc1438bfd0e8050e8a8614 Cc: cerowrt-devel Subject: Re: [Cerowrt-devel] what stats do people want from conference wifi? X-BeenThere: cerowrt-devel@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: Development issues regarding the cerowrt test router project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 08 Feb 2015 02:37:22 -0000 --047d7bdc1438bfd0e8050e8a8614 Content-Type: text/plain; charset=UTF-8 I would love to see this data, especially since insights into dense wifi environments is rare. It seems like this might be a fascinating time to get stats from Minstrel, for which rates clients are connected at: Do they connect at high rates at all? Do they stay stable at high rates, or do they see all the noise of other APs and drop to slower rates accordingly? -Aaron On Sat, Feb 7, 2015 at 6:02 PM, David Lang wrote: > In the next few days I'm going to be building the openwrt images to use at > the SCaLE conference. I will have ~50 APs deployed supporting ~3k > attendees. This will be running on WNDR3700v2 and WNDR3800 APs. Since I am > compiling the firmware myself, I can add in patches to gather and log stats > for things that are not normally reported > > The wireless network architecture is: > > separate ESSIDs for 2.4 vs 5. > each band gets bridged to a different VLAN > the APs are configured not to forward broadcast traffic from one wireless > client to another on the same AP (although broadcast traffic from one AP > probably goes out others after hitting the wire now that I think about it) > I have all logs from the APs sent to a central logserver > I have use rrdtool to catpture normal bandwith/cpu/etc stats > I also have rrdtool capture how many clients are connected to each ESSID > every minute. > > > What else can I gather related to the wifi? > > I think it would be useful if we could gather info along the lines of > > amount of airtime used > > how much latency is added to packets while waiting to transmit because > it's hearing something else transmit? > > amount of unused airtime available > > average effective bit rate > > percentage of time spent doing broadcasts (things required to operate at > the lowest bit rate) > > > > > Part of the reason that I compile my own firmware images is that I > completely disable connection tracking in the kernel (because clients may > move from one AP to another in the middle of a connection it's a waste of > cpu and memory to track), and as a result of these optimizations, there is > actually quite a bit of CPU available. The boxes almost never hit 20% cpu > utilization, so there's quite a bit available to gather other stats. > > some of the stats I gather are in messages spit out by the kernel, others > from scrips running on the box querying things in /proc or /sys, and others > from watching logs and summarizing them once a minute. I even have a > process that goes threough all the connection logs for the duration of the > show and graph how many unique MAC addresses we've seen and a breakdown > into the different vendor prefixes. If there's a way to get the data, I can > support it. > > If there are fq_codel stats that people would find interesting in this > environment, I can gather those as well (both on the APs and on the Debian > based firewall/gateway) > > David Lang > _______________________________________________ > Cerowrt-devel mailing list > Cerowrt-devel@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/cerowrt-devel > --047d7bdc1438bfd0e8050e8a8614 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I would love to see this data, especially since insig= hts into dense wifi environments is rare.

It seems like= this might be a fascinating time to get stats from Minstrel, for which rat= es clients are connected at:

Do they connect at high rat= es at all?
Do they stay stable at high rates, or do they see all = the noise of other APs and drop to slower rates accordingly?

=
-Aaron

On Sat, Feb 7, 2015 at 6:02 PM, David Lang &l= t;david@lang.hm><= /span> wrote:
In the next few days I'= m going to be building the openwrt images to use at the SCaLE conference. I= will have ~50 APs deployed supporting ~3k attendees. This will be running = on WNDR3700v2 and WNDR3800 APs. Since I am compiling the firmware myself, I= can add in patches to gather and log stats for things that are not normall= y reported

The wireless network architecture is:

separate ESSIDs for 2.4 vs 5.
each band gets bridged to a different VLAN
the APs are configured not to forward broadcast traffic from one wireless c= lient to another on the same AP (although broadcast traffic from one AP pro= bably goes out others after hitting the wire now that I think about it)
I have all logs from the APs sent to a central logserver
I have use rrdtool to catpture normal bandwith/cpu/etc stats
I also have rrdtool capture how many clients are connected to each ESSID ev= ery minute.


What else can I gather related to the wifi?

I think it would be useful if we could gather info along the lines of

amount of airtime used

how much latency is added to packets while waiting to transmit because it&#= 39;s hearing something else transmit?

amount of unused airtime available

average effective bit rate

percentage of time spent doing broadcasts (things required to operate at th= e lowest bit rate)




Part of the reason that I compile my own firmware images is that I complete= ly disable connection tracking in the kernel (because clients may move from= one AP to another in the middle of a connection it's a waste of cpu an= d memory to track), and as a result of these optimizations, there is actual= ly quite a bit of CPU available. The boxes almost never hit 20% cpu utiliza= tion, so there's quite a bit available to gather other stats.

some of the stats I gather are in messages spit out by the kernel, others f= rom scrips running on the box querying things in /proc or /sys, and others = from watching logs and summarizing them once a minute. I even have a proces= s that goes threough all the connection logs for the duration of the show a= nd graph how many unique MAC addresses we've seen and a breakdown into = the different vendor prefixes. If there's a way to get the data, I can = support it.

If there are fq_codel stats that people would find interesting in this envi= ronment, I can gather those as well (both on the APs and on the Debian base= d firewall/gateway)

David Lang
_______________________________________________
Cerowrt-devel mailing list
Ce= rowrt-devel@lists.bufferbloat.net
https://lists.bufferbloat.net/listinfo/cerowrt-devel

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