[Commotion-discuss] HIgh volume performance

Fri Mar 20 13:50:55 EDT 2015

Ben,

Can you elaborate on this prime number beacon timing phenomenon? What
terminology should I use to read more about this? tBeacon interval syncing
among clients?
like this? http://www.dslreports.com/forum/remark,14241618

On Fri, Mar 20, 2015 at 1:45 PM, Ben West <ben at gowasabi.net> wrote:

> Other helpful tips:
>
>    - Conference venue wifi will always suck, per some divine decree and
>    despite mere mortals' best efforts.  It is best to accept this this fact
>    and proceed with humility.
>
>    - Unless other list members indicate otherwise you likely will want to
>    set unique SSIDs (Conference_AP1, Conference_AP2, ...) for all nodes to
>    deter client roaming.  Commotion doesn't presently support moving a
>    client's session from one node to another, so clients will be bounced back
>    to the splash page if they associate with another node (i.e. unwittingly if
>    roaming is permitted).  Making the SSIDs unique lets the clients knowingly
>    associate with a new signal while moving thru the conference venue, so they
>    can know to click thru the splash page again.
>
>    - Per a tip from a McAfee employee unwillingly conscripted to deploy
>    conference wifi, try setting the beacon interval to some prime number, e.g
>    337ms or better yet 97ms.  This is the "beacon_int" option available in
>    advanced wifi config under OpenWRT.  The theory is that having the nodes
>    beacon at a weird interval will deter clients from accidentally
>    synchronizing with each other in their attempts to connect, which can
>    happen in very crowded environments and cause channel collapse.
>
>
> On Fri, Mar 20, 2015 at 12:32 PM, Grady Johnson <
> grady at opentechinstitute.org> wrote:
>
>> Hi David!
>>
>> Totally agree with Adam and Ben's advice.
>>
>> Please let us know how it works out. We'd love to feature your
>> experience on the Commotion site!
>>
>> On 03/20/2015 01:19 PM, David Banks wrote:
>> > This has all been extremely helpful thank you all so much.
>> >
>> > On Fri, Mar 20, 2015 at 1:02 PM, Adam Longwill <adam.longwill at gmail.com
>> >
>> > wrote:
>> >
>> >> Agreed with Mr. West.
>> >>
>> >> On Fri, Mar 20, 2015 at 1:00 PM, Ben West <ben at gowasabi.net> wrote:
>> >>
>> >>> Echoing Adam's recommendation to distribute the load of 100+ clients
>> over
>> >>> multiple nodes set to non-overlapping channels, with each node wired
>> back
>> >>> to whatever gateway device with cat-5 lines.  That is, don't bother
>> with
>> >>> wireless meshing if you can avoid it.  A single 802.11 channel won't
>> >>> sustain that many clients, much less the meshing OLSR traffic.  So,
>> say 10
>> >>> nodes spaced evenly throughout the conference venue, where immediately
>> >>> adjacent nodes are set to furthest possible channels (e.g channel 1
>> and
>> >>> 11).  Apply similar reasoning for dual-band access points; adjacent
>> devices
>> >>> need to not have their radios on adjacent frequencies.
>> >>>
>> >>> Also, you probably will want to turn the TX power on each node *down
>> as
>> >>> much as possible*, as they will be operating in a very noisy
>> environment
>> >>> at close spacing.  RX sensitivity is preferred over trying to drown
>> out
>> >>> noise with TX power.
>> >>>
>> >>> Finally, you'd want generous RAM available on the access points, so
>> that
>> >>> the firmware can service many clients.  Something like UBNT Rocket M2
>> (64MB
>> >>> RAM), UBNT UniFi AP (64MB RAM), or even TP-Link TL-WDR4300 (128MB).
>> The
>> >>> UBNT stuff would permit easier mounting on walls/poles, since the
>> TP-Link
>> >>> is only an indoor consumer-grade unit.
>> >>>
>> >>>
>> >>>
>> >>>
>> >>> On Fri, Mar 20, 2015 at 10:32 AM, Adam Longwill <
>> adam.longwill at gmail.com>
>> >>> wrote:
>> >>>
>> >>>> There will be issues with any device accepting more than 35
>> connection
>> >>>> requests at a time due to the nature on 802.11 in general. You're
>> going to
>> >>>> have plenty of congestion with more than that and probably have
>> hidden node
>> >>>> problem issues without RTS/ CTS in that situation.
>> >>>>
>> >>>> Commotion is is OpenWRT with some configurations and OLSR running on
>> the
>> >>>> mesh interface which will reduce airtime overall. If anything, you
>> should
>> >>>> mitigate this by having multiple radios on multiple channels with
>> ethernet
>> >>>> meshing instead of a wireless mesh interface.
>> >>>> On 20 Mar 2015 11:11, "David Banks" <david.adam.banks at gmail.com>
>> wrote:
>> >>>>
>> >>>>> Hello Everyone,
>> >>>>>
>> >>>>> Has anyone  had experience using routers running commotion in high
>> >>>>> volume, single building settings? I'm organizing a conference set
>> for next
>> >>>>> month and thought this would be an interesting application. Anyone
>> know of
>> >>>>> good commotion-compatible hardware that's capable of accepting 100+
>> >>>>> connection requests at a time?
>> >>>>>
>> >>>>> --
>> >>>>> -db
>> >>>>>
>> >>>>> _______________________________________________
>> >>>>> Commotion-discuss mailing list
>> >>>>> Commotion-discuss at lists.chambana.net
>> >>>>> https://lists.chambana.net/mailman/listinfo/commotion-discuss
>> >>>>>
>> >>>>>
>> >>>> _______________________________________________
>> >>>> Commotion-discuss mailing list
>> >>>> Commotion-discuss at lists.chambana.net
>> >>>> https://lists.chambana.net/mailman/listinfo/commotion-discuss
>> >>>>
>> >>>>
>> >>>
>> >>>
>> >>> --
>> >>> Ben West
>> >>> http://gowasabi.net
>> >>> ben at gowasabi.net
>> >>> 314-246-9434
>> >>>
>> >>
>> >>
>> >
>> >
>> >
>> >
>> > _______________________________________________
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>> > Commotion-discuss at lists.chambana.net
>> > https://lists.chambana.net/mailman/listinfo/commotion-discuss
>> >
>>
>> --
>> Grady Johnson
>> Open Technology Institute | New America
>> @geekwrights
>> D6AE 65CE 141B 8DBC 7B5F 99AA 6BCC 0833 8B28 833B
>> _______________________________________________
>> Commotion-discuss mailing list
>> Commotion-discuss at lists.chambana.net
>> https://lists.chambana.net/mailman/listinfo/commotion-discuss
>>
>
>
>
> --
> Ben West
> http://gowasabi.net
> ben at gowasabi.net
> 314-246-9434
>
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>
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