Guess I should have included the link!
http://www.cisco.com/en/US/docs/wireless/controller/7.3/configuration/guide/b_wlc-cg_chapter_01100.html#ID1197
 
Jeff

>>> On Tuesday, October 08, 2013 at 2:52 PM, in message
<[email protected]>, Jeffrey Sessler
<[email protected]> wrote:

Here is a good reference to the changes made in 6.0 - the whole guide
is a good read if you've not looked at it since the 5.x days, and the
"RF Group Leader" section has information on the changes I mentioned in
my previous email.
 
Jeff

>>> On Tuesday, October 08, 2013 at 12:32 PM, in message
<[email protected]>, Lee H
Badman <[email protected]> wrote:

Thanks for sharing, Don.  Great use of the list, as a lot of people
can't seem to crack these eggs for whatever reason.

-Lee

-----Original Message-----
From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:[email protected]] On Behalf Of Sullivan, Don
Sent: Tuesday, October 08, 2013 3:15 PM
To: [email protected]
Subject: Re: [WIRELESS-LAN] Cisco WLC dynamic channel assignment (DCA)
interval

Ok guys, Here you go. I didn't ask the guy's permission to put on the
list but I think he will be ok with it (at least I hope so).


"My life is RRM, and part of my problem is that there is a lot of
legacy wisdom committed to the world.  Jeff Sessler hit the nail on the
head.  No good reason to change the default interval.  One downside of
this is that DCA only run's when you tell it too - which means if you
are set to 24 hours - and 5 AM as I saw one individual that replied you
will only quantify your channel's at a low load period - once daily.

1 major thing manages DCA's responsiveness - that is the DCA threshold.
 The threshold is set to medium by default which imposes a 10 dB
hysteresis on a potential channel change.  Meaning that a channel needs
to be 10 dB better than the current channel in order for a change to be
processed.  You can increase the sensitivity to 5 db or decrease it to
20 db accordingly.

Other things that will modify DCA behavior are Avoid Foreign AP
Interference - this has to do with rogues and how we treat them. 
Checked it applies a higher Bias for rogue AP's and will work around the
foreign AP to coordinate a channel plan.  Un checked  it gives less
weight and will yield less to the rogues.  The default is for this to be
enabled - since it's a good idea.  However there are use cases where
this can drive a lot of channel changes - our wireless labs building is
a good example as AP's come and go all day long there - channel changes
are frequent if enabled.

The other gotcha is load - this is disabled by default and should
remain that way if channel changes are not desired.  It will react
quickly and the channel plan will change as loads come and go.

Lastly - if you have not rebooted your RF group leader in some time
(there are generally two - one for each band for each RF group) and your
DCA is set to medium - it is possible that you have AP's on the edge of
that 10 dB hysteresis that would be better served by a channel change. 
This is also true if you have added AP's over time.  DCA has a startup
mode where it is very aggressive with no rules applied - simply finding
the best channel plan given the RF.  If the number of AP's has changed
over time this gets stale and re-running this is a very good idea.

You can restart DCA best by using the command line argument in 7.3 and
later code   >config 802.11a/b channel global restart  This must be run
on the RF group leader (you can see which controller is in charge for
the band on the DCA page).  If your code is older than 7.3  - you will
have to reboot the group leader to kick it in.

I hope this helps shed some light.

I am presently writing a guide which encompasses best practices and the
long list of changes including 802.11AC and how DCA handles that
(currently out for a patent by the way).

The change velocity of the RRM feature set has been pretty fast -
wireless as a whole is changing pretty fast - and this is likely to
continue for a while."


Don Sullivan 
Network Administrator | Office: 205.726.2111 | email:
[email protected]





-----Original Message-----
From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:[email protected]] On Behalf Of "Francisco J.
Medina Jiménez"
Sent: Tuesday, October 08, 2013 11:30 AM
To: [email protected]
Subject: Re: [WIRELESS-LAN] Cisco WLC dynamic channel assignment (DCA)
interval

Please, me too, if it's possible.
Thanks.

El 08/10/2013 16:24, Lee H Badman escribió:
> glomming on- hit me, brother.
>
> *Lee H. Badman*
> Network Architect/Wireless TME
> ITS, Syracuse University
> 315.443.3003
>
----------------------------------------------------------------------
> --
> *From:* The EDUCAUSE Wireless Issues Constituent Group Listserv 
> [[email protected]] on behalf of Luis Fernando 
> Valverde [[email protected]]
> *Sent:* Tuesday, October 08, 2013 10:08 AM
> *To:* [email protected]
> *Subject:* Re: [WIRELESS-LAN] Cisco WLC dynamic channel assignment 
> (DCA) interval
>
> Hello,
>
> please send a copy for me too.
>
> Thanks !
>
> *--
> Luis Fernando Valverde /* */Director de Tecnología/
> *
> Dirección de Tecnología de Información y Comunicaciones / *INCAE 
> Business School* Tel +506 2437 23 38 / www.incae.edu 
> <http://www.incae.edu/>
>
> INCAE Business School. La mejor escuela de negocios de América
Latina.
> *N°1* en América Latina. América Economía 2013.
> *Top 10 en el Mundo* en: Estrategia Corporativa,**Clientes
> Internacionales,* y *Participantes Internacionales. Financial Times
2013.
> *Top 50 en el Mundo* en Executive Education.**Financial Times 2013.
>
> Síguenos en: Facebook <http://www.facebook.com/INCAE> / LinkedIn 
> <http://www.linkedin.com/groups?gid=3048169> / Twitter 
> <http://www.twitter.com/incae> / YouTube 
> <http://www.youtube.com/incaemba> / Google+ 
> <https://plus.google.com/113399553262888830636/posts>
> <https://plus.google.com/113399553262888830636/posts>
>
>
> On Tue, Oct 8, 2013 at 8:03 AM, Danny Eaton <[email protected] 
> <mailto:[email protected]>> wrote:
>
>     Me three.
>
>     /Connected by Motorola/
>
>
>     Walter Reynolds <[email protected] <mailto:[email protected]>>
wrote:
>
>     Can you forward me the info as well.
>
>     Thanks.
>
>
>     ------------------------
>     Walter Reynolds
>     Principal Systems Security Development Engineer
>     Information and Technology Services
>     University of Michigan
>     (734) 615-9438
>
>
>     On Mon, Oct 7, 2013 at 10:37 AM, Kent Cummings
<[email protected]
>     <mailto:[email protected]>> wrote:
>
>         Don,  Please forward me this information.
>
>         Thanks, Kent
>
>         Kent Cummings
>         Network Engineer IV
>         ITS Core Network, SSB - 3015
>         Eastern Illinois University
>         (217)-581-8332 <tel:%28217%29-581-8332>
>
>         -----Original Message-----
>         From: The EDUCAUSE Wireless Issues Constituent Group
Listserv
>         [mailto:[email protected]
>         <mailto:[email protected]>] On Behalf Of
>         Sullivan, Don
>         Sent: Friday, October 04, 2013 11:06 AM
>         To: [email protected]
>         <mailto:[email protected]>
>         Subject: Re: [WIRELESS-LAN] Cisco WLC dynamic channel
assignment
>         (DCA)
>         interval
>
>         In response to my question yesterday, a Cisco engineer who
is
>         heavily
>         involved in RRM sent me information in response to my
question
>         which has
>         been very helpful to me in understanding what is occurring
and
>         whether I
>         should be making any changes based on what I am observing.
If
>         you would like
>         for me to forward this information to you please let me know
and
>         I will be
>         happy to. I will tell you that he confirmed what one person
had
>         stated in
>         one of the earlier emails that at code above release 6 there
is
>         no good
>         reason to change the default interval.
>
>
>         Don Sullivan
>         Network Administrator | Office: 205.726.2111
<tel:205.726.2111>
>         | email: [email protected]
<mailto:[email protected]>
>
>
>         -----Original Message-----
>         From: The EDUCAUSE Wireless Issues Constituent Group
Listserv
>         [mailto:[email protected]
>         <mailto:[email protected]>] On Behalf Of
Dennis Xu
>         Sent: Friday, October 04, 2013 10:34 AM
>         To: [email protected]
>         <mailto:[email protected]>
>         Subject: Re: [WIRELESS-LAN] Cisco WLC dynamic channel
assignment
>         (DCA)
>         interval
>
>         There was a post on Cisco support forum about DCA interval
and
>         some senior
>         contributors (not Cisco guys though) suggested to set it to
24
>         hours. I
>         tried to search for it now but could not find it. We did
have
>         the AP channel
>         change issues which affected about 50 APs at once. We
thought
>         the default 10
>         minutes interval is too aggressive and 24 hours is too long.
We
>         started with
>         1 hour to see how it went and we haven't had any issues.
>
>         ---
>         Dennis Xu
>         Analyst 3, Network Infrastructure
>         Computing and Communications Services(CCS) University of 
> Guelph
>
>         519-824-4120 Ext 56217 <tel:519-824-4120%20Ext%2056217>
>         [email protected] <mailto:[email protected]>
>         www.uoguelph.ca/ccs <http://www.uoguelph.ca/ccs>
>
>         ----- Original Message -----
>         From: "Don Sullivan" <[email protected]
>         <mailto:[email protected]>>
>         To: [email protected]
>         <mailto:[email protected]>
>         Sent: Thursday, October 3, 2013 3:48:08 PM
>         Subject: Re: [WIRELESS-LAN] Cisco WLC dynamic channel
assignment
>         (DCA)
>         interval
>
>         Can I ask what led to making this change? I am struggling
trying to
>         understand moving from a default of 10 minutes to 24 hours
and
>         the impact. I
>         have been reading the documentation and reference for this
>         setting in trying
>         to determine if this is something I should implement but
there
>         is very
>         little detail concerning the timer/interval. Based on the
>         replies, 24 hours
>         seems to be the choice and yet I cannot find through a
google
>         search why
>         this is better. Appreciate any feedback given.
>
>         Thanks,
>
>         Don Sullivan
>         Network Administrator | Office: 205.726.2111
<tel:205.726.2111>
>         | email: [email protected]
<mailto:[email protected]>
>
>
>
>         -----Original Message-----
>         From: The EDUCAUSE Wireless Issues Constituent Group
Listserv
>         [mailto:[email protected]
>         <mailto:[email protected]>] On Behalf Of
Mark
>         Duling
>         Sent: Thursday, October 03, 2013 1:00 PM
>         To: [email protected]
>         <mailto:[email protected]>
>         Subject: [WIRELESS-LAN] Cisco WLC dynamic channel assignment
>         (DCA) interval
>
>         A long time ago I increased the interval for this up to a
pretty
>         high
>         setting from the default (I think it was 10 min) at the
>         suggestion of TAC
>         engineer to stop them from changing channels so frequently.
>
>         802.11x > RRM > Dynamic Channel Assignment (DCA)
>
>         I have no evidence that there is any issue with it, but a
lot
>         has changed
>         since then.  What intervals do others use for DCA?
>
>         **********
>         Participation and subscription information for this EDUCAUSE
>         Constituent
>         Group discussion list can be found at
>         http://www.educause.edu/groups/.
>
>         **********
>         Participation and subscription information for this EDUCAUSE
>         Constituent
>         Group discussion list can be found at
>         http://www.educause.edu/groups/.
>
>         **********
>         Participation and subscription information for this EDUCAUSE
>         Constituent
>         Group discussion list can be found at
>         http://www.educause.edu/groups/.
>
>         **********
>         Participation and subscription information for this EDUCAUSE
>         Constituent Group discussion list can be found at
>         http://www.educause.edu/groups/.
>
>
>     ********** Participation and subscription information for this
>     EDUCAUSE Constituent Group discussion list can be found at
>     http://www.educause.edu/groups/.
>
>     !DSPAM:911,52540a1b151581176013478!
>
>
> ********** Participation and subscription information for this 
> EDUCAUSE Constituent Group discussion list can be found at 
> http://www.educause.edu/groups/.
>
> ********** Participation and subscription information for this 
> EDUCAUSE Constituent Group discussion list can be found at 
> http://www.educause.edu/groups/.
>

--
---------------------------------------------------------------------
Francisco J. Medina Jiménez

Área de Redes y Comunicaciones
Universidad de Granada
Centro de Servicios de Informática y Redes de Comunicaciones (CSIRC)
Campus de Fuentenueva. Edificio Mecenas.
18071 Granada (Spain)
E-mail: [email protected]
Tlf: +34 958 241 432
Fax: +34 958 244 221
---------------------------------------------------------------------
Este mensaje se dirige exclusivamente a su destinatario y puede
contener información privilegiada o confidencial. Si no es Ud. el
destinatario indicado, queda notificado de que la utilización,
divulgación o copia sin autorización queda prohibida en virtud de la
legislación Vigente.
Si ha recibido este mensaje por error, le rogamos que nos lo comunique
inmediatamente por esta misma vía y proceda a su destrucción.

This message is intended exclusively for its addressee and may contain
information that is CONFIDENTIAL and protected by professional
privilege.
If you are not the intended recipient you are hereby notified that any
dissemination, copy or disclosure of this communication is strictly
prohibited by law. If this message has been received in error, please
immediately notify us via e-mail and delete it
-------------------------------------------------------------------------

**********
Participation and subscription information for this EDUCAUSE
Constituent Group discussion list can be found at
http://www.educause.edu/groups/.

**********
Participation and subscription information for this EDUCAUSE
Constituent Group discussion list can be found at
http://www.educause.edu/groups/.

**********
Participation and subscription information for this EDUCAUSE
Constituent Group discussion list can be found at
http://www.educause.edu/groups/.
********** Participation and subscription information for this EDUCAUSE
Constituent Group discussion list can be found at
http://www.educause.edu/groups/. 

**********
Participation and subscription information for this EDUCAUSE Constituent Group 
discussion list can be found at http://www.educause.edu/groups/.

Reply via email to