RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Osborne, Bruce W (Network Services)]

I know Aruba is constantly fine tuning this too.  T
he main engineer working on this is sharp. I see he last updated it 22 days ago.

 
Bruce Osborne
Wireless Engineer
IT Infrastructure & Media Solutions
 
(434) 592-4229
 
LIBERTY UNIVERSITY
Training Champions for Christ since 1971

-Original Message-
From: James Michael Keller [mailto:jmkel...@houseofzen.org] 
Sent: Friday, August 14, 2015 10:24 AM
Subject: Re: Exclusive 2.4 Ghz and 5 Ghz SSIDs

On 08/13/2015 05:28 PM, Frank Sweetser wrote:
> I've heard good things about this specific Aruba solution, which at least 
> aims to give a set of environment specific tuning settings:
> 
> https://ase.arubanetworks.com/solutions/id/75
> 
> (I believe an Aruba support login is required to view)
> 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

Lord, I'm out of a job :)

I'll have to compare some of my templates against what it generates and do some 
A/B testing

-- 

-James

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RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Osborne, Bruce W (Network Services)]

I was going to comment that in 2007 or 2008 when we were choosing between Cisco 
& Aruba, Cisaco told us that Aruba's band steering was not possible. Now 
everybody is doing it.

 
Bruce Osborne
Wireless Engineer
IT Infrastructure & Media Solutions
 
(434) 592-4229
 
LIBERTY UNIVERSITY
Training Champions for Christ since 1971

-Original Message-
From: Chuck Enfield [mailto:chu...@psu.edu] 
Sent: Thursday, August 13, 2015 5:25 PM
Subject: Re: Exclusive 2.4 Ghz and 5 Ghz SSIDs

Thanks.  That could be what I was missing.  The Cisco systems I get asked to 
assist with are usually neglected.  It's quite likely I wasn't dealing with all 
the latest features.  It's important to know the product in this business, so 
I'm at a major disadvantage on Cisco.  (I humbly request that those of you who 
know me resist the temptation to comment on just how disadvantaged I am.)

-Original Message-
From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeffrey D. Sessler
Sent: Thursday, August 13, 2015 5:07 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs

On the Cisco, you also have a choice between TPCv1 coverage optimal mode or
TPCv2 Interference Optimal. For dense deployments, you really want to be using 
TPCv2.

Jeff




On 8/13/15, 1:05 PM, "The EDUCAUSE Wireless Issues Constituent Group Listserv 
on behalf of James Michael Keller" 

wrote:

>On 08/13/2015 03:40 PM, Chuck Enfield wrote:
>> Just to be clear, we don’t have to do these things to make wireless 
>> work.  It makes it work better.  But it is sometimes necessary to 
>> make wireless work acceptably in the most challenging environments.  
>> That said, left to defaults Aruba’s ARM also adjusts 2.4 GHz Tx power 
>> way down.  So far down, in fact, that coverage gaps show up.  It also 
>> tends to keep power higher on busy APs and lower on less busy ones.  
>> In some cases the power on the 2.4 radio will be the same as the 
>> power on the 5 GHz radio.  These characteristics forces us to 
>> configure a range of acceptable power levels for ARM to choose from.  
>> Once you’re doing that, why not select the optimum power levels?
>>
>> While I’m no expert on Cisco wireless, I have assisted some 
>> departments with problems on their Cisco infrastructure.  Based on 
>> that limited experience, I have far less confidence in RRM than you seem to.
>>
>
>The main issue is the defaults for Aruba are for coverage networks, not
>high density (30-40 ft) or very high density (30 Ft or less).   You need
>to adjust the coverage index min/ideal for high density deployments so 
>ARM will power down to Min TX powers without shutting down the 2.4 GHz 
>radios due to CCI (even with edge detection for the APs the default will
>still end up with only a few 2.4 GHz APs).   If you set Tx Min/Max to a
>6dBm range the APs can power to around double the cell size for 
>coverage gaps if a radio is down.
>
>I also like to set the 5 GHz Tx Min/Max range at least 3dBm higher then
>2.4 GHz because of the unattenuated propagation distance and better 
>attenuated penetration.  Which also helps duel band devices make better 
>selections.  However most devices have a fairly generous threshold on 
>AP signal drop before they even try and probe for candidate APs to 
>associate to.  That's really where the controller based client stearing 
>solutions come in to play with selective acks or the probes to get the 
>client on the best AP regardless of what the client wants based on just 
>Rx signal.
>
>--
>
>-James
>
>**
>Participation and subscription information for this EDUCAUSE 
>Constituent Group discussion list can be found at 
>http://www.educause.edu/groups/.

**
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RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Osborne, Bruce W (Network Services)]

Aruba's current technical solution is at 
https://ase.arubanetworks.com/solutions/id/75

 
Bruce Osborne
Wireless Engineer
IT Infrastructure & Media Solutions
 
(434) 592-4229
 
LIBERTY UNIVERSITY
Training Champions for Christ since 1971

-Original Message-
From: Chuck Enfield [mailto:chu...@psu.edu] 
Sent: Thursday, August 13, 2015 5:15 PM
Subject: Re: Exclusive 2.4 Ghz and 5 Ghz SSIDs

I suspect you're that ARM can be made to work, but the question is how to do 
it.  Aruba doesn't tell you what the various indices should be, they just say 
that they vary with deployment density.  Ask the question on Airheads and you 
get:

"95% of the time you do not have to change those parameters.  An explanation of 
ARM parameters is here:" and then a link to the users' guide ARM section. 
That from an Aruba employee.

Also, ARM won’t adjust the Tx power down to 0 dBm, which I find is often the 
right 2.4 Tx power for really dense deployments, such as classroom buildings 
where there's an AP in almost every room.  0 dBm must be set in the radio 
profile.

Before Client Match I considered abandoning ARM entirely.  Client Match and 
Mode Aware definitely make it worth keeping though.

-Original Message-
From: James Michael Keller [mailto:jmkel...@houseofzen.org]
Sent: Thursday, August 13, 2015 4:05 PM
To: Chuck Enfield ; WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs

On 08/13/2015 03:40 PM, Chuck Enfield wrote:
> Just to be clear, we don’t have to do these things to make wireless 
> work.  It makes it work better.  But it is sometimes necessary to make 
> wireless work acceptably in the most challenging environments.  That 
> said, left to defaults Aruba’s ARM also adjusts 2.4 GHz Tx power way 
> down.  So far down, in fact, that coverage gaps show up.  It also 
> tends to keep power higher on busy APs and lower on less busy ones.  
> In some cases the power on the 2.4 radio will be the same as the power 
> on the 5 GHz radio.  These characteristics forces us to configure a 
> range of acceptable power levels for ARM to choose from.  Once you’re 
> doing that, why not select the optimum power levels?
>
> While I’m no expert on Cisco wireless, I have assisted some 
> departments with problems on their Cisco infrastructure.  Based on 
> that limited experience, I have far less confidence in RRM than you seem to.
>

The main issue is the defaults for Aruba are for coverage networks, not
high density (30-40 ft) or very high density (30 Ft or less).   You need
to adjust the coverage index min/ideal for high density deployments so ARM will 
power down to Min TX powers without shutting down the 2.4 GHz radios due to CCI 
(even with edge detection for the APs the default will
still end up with only a few 2.4 GHz APs).   If you set Tx Min/Max to a
6dBm range the APs can power to around double the cell size for coverage gaps 
if a radio is down.

I also like to set the 5 GHz Tx Min/Max range at least 3dBm higher then
2.4 GHz because of the unattenuated propagation distance and better attenuated 
penetration.  Which also helps duel band devices make better selections.  
However most devices have a fairly generous threshold on AP signal drop before 
they even try and probe for candidate APs to associate to.  That's really where 
the controller based client stearing solutions come in to play with selective 
acks or the probes to get the client on the best AP regardless of what the 
client wants based on just Rx signal.

-- 

-James

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

**
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RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Chuck Enfield]

Yes, we vary the power by AP, but that’s more to optimize the network than 
it is to push devices to 5 GHz.  That’s why I didn’t mention it.  AP layout 
in dense environments has to be driven by the number of users and RF 
parameters adjusted accordingly.  We also adjust Rx sensitivity.  We do so 
in 3 dB increments to avoid having 15 different RF settings for 20 APs.  We 
may compromise a bit more if it avoids having an insane number of AP groups 
in a building.  So far our most complex building has 106 APs in 4 AP groups.



Regarding powering up to fill in coverage gaps from a failed AP, that really 
only works if you use extra APs, and therefore have very low power settings 
when operating normally.  If in the event of a failure APs go from high 
power to really high power, client devices in the affected area are still 
likely to have problems.



At the risk of inviting criticism, I’ve attached our AP layout and site 
survey strategy.  That said, questions and constructive criticism are 
welcome.  I’ve removed the Aruba AP specific stuff.  You need to develop 
your own minimum coverage standard and figure out home many clients can be 
supported on your AP(s) of choice.  I will say this this design approach has 
resulted in good performance (as measured by positive user feedback) while 
using less hardware than most recommendations I’ve read (up 100 occupants in 
the coverage area of a premium, wave-1 11ac AP.)  I apologize for any 
difficulty understanding the part about choosing the power settings.  It’s 
surprisingly easy to understand if you’re actually doing it, but my staff 
had difficulty following the text in abstract.  Once they understood it they 
didn’t need to refer back to it.  It’s pretty intuitive.



Chuck Enfield

Manager, Wireless Systems & Engineering

Telecommunications & Networking Services

The Pennsylvania State University

110H, USB2, UP, PA 16802

ph: 814.863.8715

fx: 814.865.3988



From: Jason Cook [mailto:jason.c...@adelaide.edu.au]
Sent: Thursday, August 13, 2015 1:38 AM
To: Chuck Enfield ; WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs



Top info Chuck



A few additional things to play with from that list.



Do you have varying power in your set power or is it designed to be all one 
so very even spacing between AP’s?

By varying I guess do you set to X, survey then adjust some.

Or rely more on your testing and design to get it right and have them all 
the same. And double check with a survey

I’m trying to think of any downsides, but really it would only be the lack 
of ability to surrounding devices to up power and cover and AP that’s 
failed. However design and 2.4ghz still might cover this. And we find AP 
failures aren’t common.





--

Jason Cook

The University of Adelaide, AUSTRALIA 5005

Ph: +61 8 8313 4800



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Chuck Enfield
Sent: Thursday, 13 August 2015 1:14 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 
<mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>
Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs



Yes, we use band-steering and I recommend it over the different SSID 
approach. If a device chooses the 2.4 GHz SSID on its own, most people won't 
notice for quite some time.  How often have you found your device on an SSID 
other than the one you intended?  My Netgear router at home won't let me use 
the same SSID on both bands. (I'll resist the temptation to comment on that 
"feature".)  Every now and then I notice that my phone is connecting on the 
2.4 GHz SSID instead of 5 GHz.  It's hard to say how long my phone was 
connecting to the wrong SSID before I noticed.  At work, my phone sometimes 
connects to the wrong SSID, but it ALWAYS connects at 5 GHz



There are design techniques that will result in a significant majority of 
clients connecting to 5 GHz radios.  If you make dual-band devices want to 
connect to 5 GHz I believe you'll end up with a higher percentage of device 
connected in that band than you'll get through the two SSID method.  It's 
possible to get a majority of dual-band devices onto 5 GHz even without 
band-steering.  Band-steering helps for those oddball devices that just 
won't go there by themselves, but that's less than 10%.  At PSU we attempt 
to optimize 5 GHz coverage, then adjust 2.4 GHz to do the best it can within 
that AP layout.  This allows us some flexibility with 2.4 GHz parameters. 
Even with the compromised settings, 2.4 GHz isn't usually too bad.  With 75% 
of the devices on 5 GHz, 2.4 GHz is usually acceptable for the clients that 
remain on it.  In summary, our approach for getting clients onto 5 GHz is:



1. Have good 5 GHz coverage everywhere. >25dB SNR.  Not only will this make 
5 GHz attractive, but most devices won't probe for a better AP once 
connected, which k

RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Jason Cook]

Top info Chuck

A few additional things to play with from that list.

Do you have varying power in your set power or is it designed to be all one so 
very even spacing between AP’s?
By varying I guess do you set to X, survey then adjust some.
Or rely more on your testing and design to get it right and have them all the 
same. And double check with a survey
I’m trying to think of any downsides, but really it would only be the lack of 
ability to surrounding devices to up power and cover and AP that’s failed. 
However design and 2.4ghz still might cover this. And we find AP failures 
aren’t common.


--
Jason Cook
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8313 4800

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Chuck Enfield
Sent: Thursday, 13 August 2015 1:14 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs

Yes, we use band-steering and I recommend it over the different SSID approach. 
If a device chooses the 2.4 GHz SSID on its own, most people won't notice for 
quite some time.  How often have you found your device on an SSID other than 
the one you intended?  My Netgear router at home won't let me use the same SSID 
on both bands. (I'll resist the temptation to comment on that "feature".)  
Every now and then I notice that my phone is connecting on the 2.4 GHz SSID 
instead of 5 GHz.  It's hard to say how long my phone was connecting to the 
wrong SSID before I noticed.  At work, my phone sometimes connects to the wrong 
SSID, but it ALWAYS connects at 5 GHz

There are design techniques that will result in a significant majority of 
clients connecting to 5 GHz radios.  If you make dual-band devices want to 
connect to 5 GHz I believe you'll end up with a higher percentage of device 
connected in that band than you'll get through the two SSID method.  It's 
possible to get a majority of dual-band devices onto 5 GHz even without 
band-steering.  Band-steering helps for those oddball devices that just won't 
go there by themselves, but that's less than 10%.  At PSU we attempt to 
optimize 5 GHz coverage, then adjust 2.4 GHz to do the best it can within that 
AP layout.  This allows us some flexibility with 2.4 GHz parameters.  Even with 
the compromised settings, 2.4 GHz isn't usually too bad.  With 75% of the 
devices on 5 GHz, 2.4 GHz is usually acceptable for the clients that remain on 
it.  In summary, our approach for getting clients onto 5 GHz is:

1. Have good 5 GHz coverage everywhere. >25dB SNR.  Not only will this make 5 
GHz attractive, but most devices won't probe for a better AP once connected, 
which keeps the air cleaner.
2, Turn down power on 2.4 GHz so it is at least 3 dB weaker than 5 GHz 
throughout the coverage area.  This is what makes the devices prefer 5 GHz.  
(It may go without saying given this recommendation, but we configure the AP 
with a fixed Tx power.  RF management only chooses the channel.  The benefits 
of optimizing the power settings of the two radios on an AP easily outweigh the 
benefits of the crappy power adjustment algorithms used by the AP 
manufacturers.)
3. Turn off 2.4 GHz radios only when necessary to avoid egregious CCI.  It's 
usually only needed in locations with a really high AP density, like 
auditoriums or lots of adjacent classrooms, although it's also sometimes needed 
if walls are close together and construction materials have a much higher loss 
at 5 GHz than at 2.4 GHz, as is common in dorms.  Turning off 2.4 GHz radios 
results in uneven coverage, which makes it hard to keep the signal weaker than 
5 GHz everywhere without having gaps in the 2.4 GHz coverage.
4. Enable band steering.
5. Make sure no other settings are undermining band-steering.  (Aruba's default 
settings for "Client Match" undermine band steering when there's a strong 2.4 
GHz signal.  Shout-out to Jason Mueller at Iowa for bringing that one to my 
attention.)
6. Adjust load balancing parameters such that clients are only pushed to 2.4 
GHz if 2.4 GHz utilization is VERY low.

If you do these things almost everybody with a 5 GHz radio will connect at 5 
GHz.  If your AP of choice doesn't support band-steering, adjustment of load 
balancing parameters, or a wide enough range of power settings, maybe two SSIDs 
is the way to go.  But then I'd start shopping for a new AP, because it's not 
the right product for higher ed.

Chuck


From: "Jeremy Gibbs" mailto:jlgi...@utica.edu>>
To: "EDUCAUSE Wireless Issues Constituent Group Listserv" 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Sent: Wednesday, August 12, 2015 7:39:29 PM
Subject: Re: [WIRELESS-LAN] Exclusive 2.4 Ghz and 5 Ghz SSIDs

Does anyone employ band-steering?  When we enabled it, we saw a massive jump of 
users connecting at 5ghz. Obviously if the client doesn't support 5ghz or it 
just prefers 2.4 because of various factors it can stay on 2.4. I have o

RE: Exclusive 2.4 Ghz and 5 Ghz SSIDs

[Osborne, Bruce W (Network Services)]

Why not just deploy the 2.4 GHz with the same SSID on a few of the APs?  With 
our Aruba APs, that is the recommended solution in a dense situation.

​

Bruce Osborne
Wireless Engineer
IT Infrastructure & Media Solutions

(434) 592-4229

LIBERTY UNIVERSITY
Training Champions for Christ since 1971

From: Paul Sedy [mailto:rps...@masters.edu]
Sent: Tuesday, August 11, 2015 4:23 PM
Subject: Exclusive 2.4 Ghz and 5 Ghz SSIDs

Hello everyone,

We are a Cisco shop and have, up until now, employed a single SSID for 
students, supporting both 2.4 Ghz and 5Ghz connections.  During this summer, we 
have been working to develop sufficient AP density to ensure good 5Ghz cells 
throughout our dorms.  In the past, we have seen numerous instances of poorer 
performance on the 2.4 Ghz spectrum, but up to this point, have relied on the 
client to make the decision between these two options.

We are thinking of deploying two separate SSIDs, a 5Ghz network and a 2.4 Ghz 
network, that are exclusive in order to promote a better experience for the 
students with devices capable of 5Ghz connectivity.  We would probably use the 
original SSID name with an appended (5 Ghz) or (2.4 Ghz).

Are any of you currently employing this type of configuration and how well has 
it worked for you?

We would appreciate any insights that anyone might have.

Paul Sedy
The Master’s College
Director of IT Operations
21726 Placerita Canyon Rd, Santa Clarita, CA 91321
661.362.2340 | rps...@masters.edu
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