Re: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

[Jake Snyder]

Might try leaving it off and see if that improves things.  Just sounds oddly 
familiar.  Make sure you disable it on all SSIDs to make sure you get a fair 
test with it off.

Sent from my iPhone

> On Mar 8, 2017, at 10:56 PM, Jason Cook  wrote:
> 
> We don’t use it, but yes looking at our SSID config under QOS AVC is enabled 
> on. Is this the only place to enable it? Per SSID?
>  
> This would seem a good thing to kill off, clearly I should have paid more 
> attention to that discussion last year looking at history.
>  
> Thanks Jake
>  
> I’m now cringing a bit if this is the fix. Oh well. Gotta learn one way or 
> another
>  
> --
> Jason Cook
> Technology Services
> 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 Jake Snyder
> Sent: Thursday, 9 March 2017 4:08 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues
>  
> I hate to ask, but do you have AVC enabled?
> 
> Sent from my iPhone
> 
> On Mar 8, 2017, at 9:59 PM, Watters, John  wrote:
> 
> I'll check the load on our most loaded 8510 HA pair in the morning & get back 
> to you. It is about 2300-2500 APs with at least that many concurrent clients. 
> Running 8.0.140.0 though (we moved there from a 7.6 (126 ?) level and Cisco 
> recommended that we move to 8.0.140 before going on up to 8.3).
> 
>  
> 
> We just bought a new 8510HA pair for this same MPLS area to divide the load. 
> It is running, but has no load at all yet. Was thinking of starting it on 8.3 
> code. So, I am very interested in your problem and tghe solution. Please be 
> sure to post it.
> 
>  
> 
>  
> 
>  
> 
>  
> ==
> -jcw
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
>  on behalf of Jason Cook 
> 
> Sent: Wednesday, March 8, 2017 10:28:09 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues
>  
> Hi All,
>  
> Just wondering if anyone has had an similar experiences to the fun we’ve had 
> the last week or so.
>  
> Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we 
> had an issue in testing at the time so grabbed the latest ER release that 
> resolved a crash bug)
> From 5x5508’s in N+1 on 8.0.121.0 code
> We started before the end of term with a small number of locations but didn’t 
> fully load it up until the big break. Now the students are back and needing 
> there internet we have had some real load issues during the day.
>  
> SO it’s 2x 8510’s in HA about 2100 AP’s peaking at about 14k concurrent 
> clients but the issue seems to creep in at about 10k. While ICMP isn’t the 
> greatest tool for performance it does line up here, the graph below show 
> around 10am we see increased delays in response to the vlan42 (client 
> network) interface on the controller and we see this on its management 
> interface too. At this point our clients ICMP to its  own gateway starts to 
> increase  from 1-3ms to 400-600 and even upto 1800 when the big spike shows 
> 800ms to the interface. Iperf testing will also go from 100Mb down to 1-5 and 
> even 0 at times. With users complaining of slowness and it’s worse unable to 
> login.
>  
> CPU/Memory resources, channel util etc all ok. It’s site wide impact to users 
> no matter if it’s HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
> seems in the controller itself. All testing done on 5hz
>  
> Around midday we started migrating AP’s away to our old 5508’s, which saw a 
> significant drop just before 12:30 and things back to normal at 12:40  once 
> 300AP’s were moved off. So for now users are happy, apparently we’ve even had 
> callers in saying how good it is today (must have been bad the last week for 
> that to happen). Controller response to SNMP was so bad it was taking Prime 2 
> minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
> response was not it’s normal self but no problem. The 5508’s have shown no 
> signs of being unhappy with about 150 AP’s each. 
>  
> We are working with TAC who have been good and they are investigating(no like 
> cases found though), shedding the load has worked around the issue but it 
> needs fixing. We upgraded to 8.2.141.0 yesterday evening but won’t be 
> re-loading the 8510’s until next week so confirming it’s fixed is a few days 
> off. There’s a few short upto 30ms delayed ICMP responses today but it’s hard 
> to know if that’s related or just the nature of icmp and network gear 
> priority.
>  
> Interested to know if anyone has seen anything like this in their environment.
> And anyone if anyone out there is using 8510’s in HA what’s your load in AP 
> and concurrent users? I can imagine many places loading their devices up more 
> than us
> Anyone know how to look at other hardware resources (not CPU/memory/system 
> buffers) Something like 

RE: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

[Jason Cook]

We don’t use it, but yes looking at our SSID config under QOS AVC is enabled 
on. Is this the only place to enable it? Per SSID?

This would seem a good thing to kill off, clearly I should have paid more 
attention to that discussion last year looking at history.

Thanks Jake

I’m now cringing a bit if this is the fix. Oh well. Gotta learn one way or 
another

--
Jason Cook
Technology Services
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 Jake Snyder
Sent: Thursday, 9 March 2017 4:08 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

I hate to ask, but do you have AVC enabled?

Sent from my iPhone

On Mar 8, 2017, at 9:59 PM, Watters, John 
mailto:john.watt...@ua.edu>> wrote:

I'll check the load on our most loaded 8510 HA pair in the morning & get back 
to you. It is about 2300-2500 APs with at least that many concurrent clients. 
Running 8.0.140.0 though (we moved there from a 7.6 (126 ?) level and Cisco 
recommended that we move to 8.0.140 before going on up to 8.3).



We just bought a new 8510HA pair for this same MPLS area to divide the load. It 
is running, but has no load at all yet. Was thinking of starting it on 8.3 
code. So, I am very interested in your problem and tghe solution. Please be 
sure to post it.







==
-jcw

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jason Cook 
mailto:jason.c...@adelaide.edu.au>>
Sent: Wednesday, March 8, 2017 10:28:09 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

Hi All,

Just wondering if anyone has had an similar experiences to the fun we’ve had 
the last week or so.

Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we had 
an issue in testing at the time so grabbed the latest ER release that resolved 
a crash bug)
From 5x5508’s in N+1 on 8.0.121.0 code
We started before the end of term with a small number of locations but didn’t 
fully load it up until the big break. Now the students are back and needing 
there internet we have had some real load issues during the day.

SO it’s 2x 8510’s in HA about 2100 AP’s peaking at about 14k concurrent clients 
but the issue seems to creep in at about 10k. While ICMP isn’t the greatest 
tool for performance it does line up here, the graph below show around 10am we 
see increased delays in response to the vlan42 (client network) interface on 
the controller and we see this on its management interface too. At this point 
our clients ICMP to its  own gateway starts to increase  from 1-3ms to 400-600 
and even upto 1800 when the big spike shows 800ms to the interface. Iperf 
testing will also go from 100Mb down to 1-5 and even 0 at times. With users 
complaining of slowness and it’s worse unable to login.

CPU/Memory resources, channel util etc all ok. It’s site wide impact to users 
no matter if it’s HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
seems in the controller itself. All testing done on 5hz

Around midday we started migrating AP’s away to our old 5508’s, which saw a 
significant drop just before 12:30 and things back to normal at 12:40  once 
300AP’s were moved off. So for now users are happy, apparently we’ve even had 
callers in saying how good it is today (must have been bad the last week for 
that to happen). Controller response to SNMP was so bad it was taking Prime 2 
minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
response was not it’s normal self but no problem. The 5508’s have shown no 
signs of being unhappy with about 150 AP’s each.

We are working with TAC who have been good and they are investigating(no like 
cases found though), shedding the load has worked around the issue but it needs 
fixing. We upgraded to 8.2.141.0 yesterday evening but won’t be re-loading the 
8510’s until next week so confirming it’s fixed is a few days off. There’s a 
few short upto 30ms delayed ICMP responses today but it’s hard to know if 
that’s related or just the nature of icmp and network gear priority.

Interested to know if anyone has seen anything like this in their environment.
And anyone if anyone out there is using 8510’s in HA what’s your load in AP and 
concurrent users? I can imagine many places loading their devices up more than 
us
Anyone know how to look at other hardware resources (not CPU/memory/system 
buffers) Something like ASIC on switches if it exists. Surely all this traffic 
isn’t cpu

Thanks

Jason


--
Jason Cook
Technology Services
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8313 4800
e-mail: 
jason.c...@adelaide.edu.au

RE: Cisco 8510 8.2 Load Issues

[Jason Cook]

Thanks John. Will do

--
Jason Cook
Technology Services
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 Watters, John
Sent: Thursday, 9 March 2017 3:29 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues


I'll check the load on our most loaded 8510 HA pair in the morning & get back 
to you. It is about 2300-2500 APs with at least that many concurrent clients. 
Running 8.0.140.0 though (we moved there from a 7.6 (126 ?) level and Cisco 
recommended that we move to 8.0.140 before going on up to 8.3).



We just bought a new 8510HA pair for this same MPLS area to divide the load. It 
is running, but has no load at all yet. Was thinking of starting it on 8.3 
code. So, I am very interested in your problem and tghe solution. Please be 
sure to post it.







==
-jcw

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of Jason Cook 
mailto:jason.c...@adelaide.edu.au>>
Sent: Wednesday, March 8, 2017 10:28:09 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

Hi All,

Just wondering if anyone has had an similar experiences to the fun we've had 
the last week or so.

Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we had 
an issue in testing at the time so grabbed the latest ER release that resolved 
a crash bug)
>From 5x5508's in N+1 on 8.0.121.0 code
We started before the end of term with a small number of locations but didn't 
fully load it up until the big break. Now the students are back and needing 
there internet we have had some real load issues during the day.

SO it's 2x 8510's in HA about 2100 AP's peaking at about 14k concurrent clients 
but the issue seems to creep in at about 10k. While ICMP isn't the greatest 
tool for performance it does line up here, the graph below show around 10am we 
see increased delays in response to the vlan42 (client network) interface on 
the controller and we see this on its management interface too. At this point 
our clients ICMP to its  own gateway starts to increase  from 1-3ms to 400-600 
and even upto 1800 when the big spike shows 800ms to the interface. Iperf 
testing will also go from 100Mb down to 1-5 and even 0 at times. With users 
complaining of slowness and it's worse unable to login.

CPU/Memory resources, channel util etc all ok. It's site wide impact to users 
no matter if it's HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
seems in the controller itself. All testing done on 5hz

Around midday we started migrating AP's away to our old 5508's, which saw a 
significant drop just before 12:30 and things back to normal at 12:40  once 
300AP's were moved off. So for now users are happy, apparently we've even had 
callers in saying how good it is today (must have been bad the last week for 
that to happen). Controller response to SNMP was so bad it was taking Prime 2 
minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
response was not it's normal self but no problem. The 5508's have shown no 
signs of being unhappy with about 150 AP's each.

We are working with TAC who have been good and they are investigating(no like 
cases found though), shedding the load has worked around the issue but it needs 
fixing. We upgraded to 8.2.141.0 yesterday evening but won't be re-loading the 
8510's until next week so confirming it's fixed is a few days off. There's a 
few short upto 30ms delayed ICMP responses today but it's hard to know if 
that's related or just the nature of icmp and network gear priority.

Interested to know if anyone has seen anything like this in their environment.
And anyone if anyone out there is using 8510's in HA what's your load in AP and 
concurrent users? I can imagine many places loading their devices up more than 
us
Anyone know how to look at other hardware resources (not CPU/memory/system 
buffers) Something like ASIC on switches if it exists. Surely all this traffic 
isn't cpu

Thanks

Jason

[cid:image001.jpg@01D298F0.DA491000]
--
Jason Cook
Technology Services
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8313 4800
e-mail: 
jason.c...@adelaide.edu.au>

CRICOS Provider Number 00123M
---
This email message is intended only for the addressee(s) and contains 
information which may be confidential and/or copyright.  If you are not the 
intended recipient please do not read, save, forward, disclose, or copy the 
contents of this email. If this email has been sent to you in error, please 
notify the sender by reply email and de

Re: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

[Jake Snyder]

I hate to ask, but do you have AVC enabled?

Sent from my iPhone

> On Mar 8, 2017, at 9:59 PM, Watters, John  wrote:
> 
> I'll check the load on our most loaded 8510 HA pair in the morning & get back 
> to you. It is about 2300-2500 APs with at least that many concurrent clients. 
> Running 8.0.140.0 though (we moved there from a 7.6 (126 ?) level and Cisco 
> recommended that we move to 8.0.140 before going on up to 8.3). 
> 
> We just bought a new 8510HA pair for this same MPLS area to divide the load. 
> It is running, but has no load at all yet. Was thinking of starting it on 8.3 
> code. So, I am very interested in your problem and tghe solution. Please be 
> sure to post it.
> 
> 
> 
>  
> ==
> -jcw
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
>  on behalf of Jason Cook 
> 
> Sent: Wednesday, March 8, 2017 10:28:09 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues 
>  
> Hi All,
>  
> Just wondering if anyone has had an similar experiences to the fun we’ve had 
> the last week or so.
>  
> Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we 
> had an issue in testing at the time so grabbed the latest ER release that 
> resolved a crash bug)
> From 5x5508’s in N+1 on 8.0.121.0 code
> We started before the end of term with a small number of locations but didn’t 
> fully load it up until the big break. Now the students are back and needing 
> there internet we have had some real load issues during the day.
>  
> SO it’s 2x 8510’s in HA about 2100 AP’s peaking at about 14k concurrent 
> clients but the issue seems to creep in at about 10k. While ICMP isn’t the 
> greatest tool for performance it does line up here, the graph below show 
> around 10am we see increased delays in response to the vlan42 (client 
> network) interface on the controller and we see this on its management 
> interface too. At this point our clients ICMP to its  own gateway starts to 
> increase  from 1-3ms to 400-600 and even upto 1800 when the big spike shows 
> 800ms to the interface. Iperf testing will also go from 100Mb down to 1-5 and 
> even 0 at times. With users complaining of slowness and it’s worse unable to 
> login.
>  
> CPU/Memory resources, channel util etc all ok. It’s site wide impact to users 
> no matter if it’s HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
> seems in the controller itself. All testing done on 5hz
>  
> Around midday we started migrating AP’s away to our old 5508’s, which saw a 
> significant drop just before 12:30 and things back to normal at 12:40  once 
> 300AP’s were moved off. So for now users are happy, apparently we’ve even had 
> callers in saying how good it is today (must have been bad the last week for 
> that to happen). Controller response to SNMP was so bad it was taking Prime 2 
> minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
> response was not it’s normal self but no problem. The 5508’s have shown no 
> signs of being unhappy with about 150 AP’s each. 
>  
> We are working with TAC who have been good and they are investigating(no like 
> cases found though), shedding the load has worked around the issue but it 
> needs fixing. We upgraded to 8.2.141.0 yesterday evening but won’t be 
> re-loading the 8510’s until next week so confirming it’s fixed is a few days 
> off. There’s a few short upto 30ms delayed ICMP responses today but it’s hard 
> to know if that’s related or just the nature of icmp and network gear 
> priority.
>  
> Interested to know if anyone has seen anything like this in their environment.
> And anyone if anyone out there is using 8510’s in HA what’s your load in AP 
> and concurrent users? I can imagine many places loading their devices up more 
> than us
> Anyone know how to look at other hardware resources (not CPU/memory/system 
> buffers) Something like ASIC on switches if it exists. Surely all this 
> traffic isn’t cpu
>  
> Thanks
> 
> Jason
>  
> 
> --
> Jason Cook
> Technology Services
> The University of Adelaide, AUSTRALIA 5005
> Ph: +61 8 8313 4800
> e-mail: jason.c...@adelaide.edu.au
>  
> CRICOS Provider Number 00123M
> ---
> This email message is intended only for the addressee(s) and contains 
> information which may be confidential and/or copyright.  If you are not the 
> intended recipient please do not read, save, forward, disclose, or copy the 
> contents of this email. If this email has been sent to you in error, please 
> notify the sender by reply email and delete this email and any copies or 
> links to this email completely and immediately from your system.  No 
> representation is made that this email is free of viruses.  Virus scanning is 
> recommended and is the responsibility of the recipient.
>  
> ** Participation and subscription information for this EDUCAUSE 
> 

Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jake Snyder]

Power and distance matter greatly in RF.  Could be differences in client TX 
power, distance from the wispy, the client card, or even the filters in the 
card.  Even the same make/model of card can variants in output.  Partially why 
we can't have calibrated cards in wifi.

2.4GHz will look slightly different than 5GHz due to the the non-ofdm nature of 
the preamble. That signature slope away from channel is a good bet that it's 
the wifi from your laptop.  Also, the strength is absurdly high.  If the wispy 
wasn't on top of the source there's no way it would be at -20 without you 
glowing or your hair itching.

Combine that with the fact that it follows him around and I'm reasonably 
convinced.  Not saying there isn't something else, but taking a capture without 
the super high ACI and you'll get a better picture.


Sent from my iPhone

> On Mar 8, 2017, at 9:53 PM, CHARLES ALBERT ENFIELD III  wrote:
> 
> Thanks Jake.  I was aware of the shape of the side band, but I thought I 
> remembered it starting 30 dB below the peak.  I guess it’s more like 20.  
> Jason’s trace seems to corroborate that.  Sean’s trace seems to be 10 to 15 
> dB.
>  
> The sideband emissions on the Revolution Wi-Fi image looks more like Sean’s 
> than Jason’s.  I think this is relevant because the nature of the OFDM 
> sideband emissions is determined by the subcarrier width and channel width.  
> Sean and Jason both have the same parameters for both, but in Jason’s trace 
> the side lobe disappears into the low noise floor within about 35MHz while 
> Sean’s doesn’t disappear into the much higher noise floor until about 55Mhz.  
> Sean’s 20MHz channel looks much more like the 80MHz channel image on Rev Wifi.
>  
> FWIW, I’m increasingly convinced your hunch is right.  Perhaps I’m taking 
> these traces from inexpensive equipment a little too literally.  I know they 
> are approximations at best, but I’m trying to figure out what’s going on.  
> I’m hopeful that thinking this through will improve my understanding.  
> Something in Sean’s trace still doesn’t add up for me.
>  
> From: Jake Snyder
> Sent: Wednesday, March 8, 2017 9:16 PM
> To: Chuck Enfield
> Cc: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>  
> 
> Might check this out: 
> http://revolutionwifi.blogspot.com/2014/08/80211ac-adjacent-channel-interference.html?m=1
> 
> There's and image there you should find similar.
> 
> Sent from my iPhone
> 
>> On Mar 8, 2017, at 4:58 PM, Chuck Enfield  wrote:
>> 
>> Cool images.  I’ve never tried this.  I would have this afternoon, but our 
>> operations guys have the spectrum analyzer in another building.  I’m a 
>> little surprised to see as nice a plot as you got in the second trace.  
>> Between near field effects and the potential to push the Rx amplifiers into 
>> a non-linear region I would have expected something more messy.
>>  
>> Do you know what the max signal strength was in the two traces?  Also, do 
>> you know how to account for the increased duty cycle in the second one?  I’m 
>> wondering if this is due to different iperf behavior or if it’s weirdness 
>> caused by proximity.  I’ve been doing Wi-Fi for 15 years and still find 
>> myself guessing on a regular basis.
>>  
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
>> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jason Cook
>> Sent: Wednesday, March 08, 2017 6:08 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>>  
>> Still learning my way through signatures but I have been caught out before 
>> with the anaylzer being too close to a wifi source
>> Below shows this on channel 132, using iperf  for a data burst in the first 
>> image the anaylzer is 1m away from a Mac Air,
>> In the second it’s a few centimetres away from it. You can really see the 
>> impact on neighbouring channels at that distance  (I think there’s even a 
>> bit in the 36-40 area)
>>  
>> I now keep the anaylzer away from wifi devices as much as possible J
>>  
>> 
>>  
>> 
>>  
>> --
>> Jason Cook
>> Technology Services
>> 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 Gray, Sean
>> Sent: Thursday, 9 March 2017 7:26 AM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>>  
>> Nope, the spectrum analyzer is going directly into a Surface Pro 2.
>>  
>>  
>> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
>> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
>> Sent: March-08-17 1:30 PM
>> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
>> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>>  
>> Are you using a USB 3.0 hub?
>>  
>>  
>> On Mar 8, 2017, at 1:23 PM, Jason Heffner  wrote:
>>  
>> I’ve seen something similar when running some of the older Cisco 
>>

Re: Cisco 8510 8.2 Load Issues

[Watters, John]

I'll check the load on our most loaded 8510 HA pair in the morning & get back 
to you. It is about 2300-2500 APs with at least that many concurrent clients. 
Running 8.0.140.0 though (we moved there from a 7.6 (126 ?) level and Cisco 
recommended that we move to 8.0.140 before going on up to 8.3).


We just bought a new 8510HA pair for this same MPLS area to divide the load. It 
is running, but has no load at all yet. Was thinking of starting it on 8.3 
code. So, I am very interested in your problem and tghe solution. Please be 
sure to post it.





==
-jcw

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
 on behalf of Jason Cook 

Sent: Wednesday, March 8, 2017 10:28:09 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] Cisco 8510 8.2 Load Issues

Hi All,

Just wondering if anyone has had an similar experiences to the fun we’ve had 
the last week or so.

Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we had 
an issue in testing at the time so grabbed the latest ER release that resolved 
a crash bug)
>From 5x5508’s in N+1 on 8.0.121.0 code
We started before the end of term with a small number of locations but didn’t 
fully load it up until the big break. Now the students are back and needing 
there internet we have had some real load issues during the day.

SO it’s 2x 8510’s in HA about 2100 AP’s peaking at about 14k concurrent clients 
but the issue seems to creep in at about 10k. While ICMP isn’t the greatest 
tool for performance it does line up here, the graph below show around 10am we 
see increased delays in response to the vlan42 (client network) interface on 
the controller and we see this on its management interface too. At this point 
our clients ICMP to its  own gateway starts to increase  from 1-3ms to 400-600 
and even upto 1800 when the big spike shows 800ms to the interface. Iperf 
testing will also go from 100Mb down to 1-5 and even 0 at times. With users 
complaining of slowness and it’s worse unable to login.

CPU/Memory resources, channel util etc all ok. It’s site wide impact to users 
no matter if it’s HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
seems in the controller itself. All testing done on 5hz

Around midday we started migrating AP’s away to our old 5508’s, which saw a 
significant drop just before 12:30 and things back to normal at 12:40  once 
300AP’s were moved off. So for now users are happy, apparently we’ve even had 
callers in saying how good it is today (must have been bad the last week for 
that to happen). Controller response to SNMP was so bad it was taking Prime 2 
minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
response was not it’s normal self but no problem. The 5508’s have shown no 
signs of being unhappy with about 150 AP’s each.

We are working with TAC who have been good and they are investigating(no like 
cases found though), shedding the load has worked around the issue but it needs 
fixing. We upgraded to 8.2.141.0 yesterday evening but won’t be re-loading the 
8510’s until next week so confirming it’s fixed is a few days off. There’s a 
few short upto 30ms delayed ICMP responses today but it’s hard to know if 
that’s related or just the nature of icmp and network gear priority.

Interested to know if anyone has seen anything like this in their environment.
And anyone if anyone out there is using 8510’s in HA what’s your load in AP and 
concurrent users? I can imagine many places loading their devices up more than 
us
Anyone know how to look at other hardware resources (not CPU/memory/system 
buffers) Something like ASIC on switches if it exists. Surely all this traffic 
isn’t cpu

Thanks

Jason

[cid:image001.jpg@01D298E3.B5C5C140]
--
Jason Cook
Technology Services
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8313 4800
e-mail: 
jason.c...@adelaide.edu.au>

CRICOS Provider Number 00123M
---
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Cisco 8510 8.2 Load Issues

[Jason Cook]

Hi All,

Just wondering if anyone has had an similar experiences to the fun we've had 
the last week or so.

Towards the end of last year we moved to new 8510 HA pair on 8.2.121.11 (we had 
an issue in testing at the time so grabbed the latest ER release that resolved 
a crash bug)
>From 5x5508's in N+1 on 8.0.121.0 code
We started before the end of term with a small number of locations but didn't 
fully load it up until the big break. Now the students are back and needing 
there internet we have had some real load issues during the day.

SO it's 2x 8510's in HA about 2100 AP's peaking at about 14k concurrent clients 
but the issue seems to creep in at about 10k. While ICMP isn't the greatest 
tool for performance it does line up here, the graph below show around 10am we 
see increased delays in response to the vlan42 (client network) interface on 
the controller and we see this on its management interface too. At this point 
our clients ICMP to its  own gateway starts to increase  from 1-3ms to 400-600 
and even upto 1800 when the big spike shows 800ms to the interface. Iperf 
testing will also go from 100Mb down to 1-5 and even 0 at times. With users 
complaining of slowness and it's worse unable to login.

CPU/Memory resources, channel util etc all ok. It's site wide impact to users 
no matter if it's HD rf design or what AP model (1142, 2702,3702,3502 etc) So 
seems in the controller itself. All testing done on 5hz

Around midday we started migrating AP's away to our old 5508's, which saw a 
significant drop just before 12:30 and things back to normal at 12:40  once 
300AP's were moved off. So for now users are happy, apparently we've even had 
callers in saying how good it is today (must have been bad the last week for 
that to happen). Controller response to SNMP was so bad it was taking Prime 2 
minutes per AP to re-configure primary controller. Did it by hand, ssh/gui 
response was not it's normal self but no problem. The 5508's have shown no 
signs of being unhappy with about 150 AP's each.

We are working with TAC who have been good and they are investigating(no like 
cases found though), shedding the load has worked around the issue but it needs 
fixing. We upgraded to 8.2.141.0 yesterday evening but won't be re-loading the 
8510's until next week so confirming it's fixed is a few days off. There's a 
few short upto 30ms delayed ICMP responses today but it's hard to know if 
that's related or just the nature of icmp and network gear priority.

Interested to know if anyone has seen anything like this in their environment.
And anyone if anyone out there is using 8510's in HA what's your load in AP and 
concurrent users? I can imagine many places loading their devices up more than 
us
Anyone know how to look at other hardware resources (not CPU/memory/system 
buffers) Something like ASIC on switches if it exists. Surely all this traffic 
isn't cpu

Thanks

Jason

[cid:image001.jpg@01D298E3.B5C5C140]
--
Jason Cook
Technology Services
The University of Adelaide, AUSTRALIA 5005
Ph: +61 8 8313 4800
e-mail: 
jason.c...@adelaide.edu.au>

CRICOS Provider Number 00123M
---
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intended recipient please do not read, save, forward, disclose, or copy the 
contents of this email. If this email has been sent to you in error, please 
notify the sender by reply email and delete this email and any copies or links 
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is made that this email is free of viruses.  Virus scanning is recommended and 
is the responsibility of the recipient.


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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Jason Cook]

That is pretty similar, Thanks  for pointing it out. Good read.



Yeah that plot I almost photoshopped for product advertisements ☺ not that I’m 
suggesting that’s done at all

I wasn’t paying attention to max signal at the time. Not sure on the duty 
cycle, It could be just the proximity or perhaps even the throughput was higher 
on test 2…. Proximity seems to be a fair target.  Again I wasn’t paying close 
attention, and I can’t identify which test that was as I’ve been running 
iperf’s flatout out for another reason (post coming soon)

I can replicate this test on my Lenovo(intel 7260) but it’s much less 
pronounced and a bit more messy. This could be because of what side of the 
laptop my adapters on,  different build quality  or I guess even connection 
rate of the different chip. You’ve provided somethings for me to try when I get 
a bit more time


--
Jason Cook
Technology Services
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 Jake Snyder
Sent: Thursday, 9 March 2017 12:46 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Might check this out:
http://revolutionwifi.blogspot.com/2014/08/80211ac-adjacent-channel-interference.html?m=1

There's and image there you should find similar.

Sent from my iPhone

On Mar 8, 2017, at 4:58 PM, Chuck Enfield 
mailto:chu...@psu.edu>> wrote:
Cool images.  I’ve never tried this.  I would have this afternoon, but our 
operations guys have the spectrum analyzer in another building.  I’m a little 
surprised to see as nice a plot as you got in the second trace.  Between near 
field effects and the potential to push the Rx amplifiers into a non-linear 
region I would have expected something more messy.

Do you know what the max signal strength was in the two traces?  Also, do you 
know how to account for the increased duty cycle in the second one?  I’m 
wondering if this is due to different iperf behavior or if it’s weirdness 
caused by proximity.  I’ve been doing Wi-Fi for 15 years and still find myself 
guessing on a regular basis.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jason Cook
Sent: Wednesday, March 08, 2017 6:08 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Still learning my way through signatures but I have been caught out before with 
the anaylzer being too close to a wifi source
Below shows this on channel 132, using iperf  for a data burst in the first 
image the anaylzer is 1m away from a Mac Air,
In the second it’s a few centimetres away from it. You can really see the 
impact on neighbouring channels at that distance  (I think there’s even a bit 
in the 36-40 area)

I now keep the anaylzer away from wifi devices as much as possible ☺





--
Jason Cook
Technology Services
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 Gray, Sean
Sent: Thursday, 9 March 2017 7:26 AM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Nope, the spectrum analyzer is going directly into a Surface Pro 2.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Are you using a USB 3.0 hub?


On Mar 8, 2017, at 1:23 PM, Jason Heffner 
mailto:jdh...@psu.edu>> wrote:

I’ve seen something similar when running some of the older Cisco controllers. 
If you ruled out everything else and are starting to look for devices causing 
interference I'd check out some of your wireless mic systems. We had some 
800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
similar to this on the lower channels.
On Mar 8, 2017, at 2:32 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:

Hi Everyone,

I’ve been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


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


** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
htt

Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jake Snyder]

Might check this out: 
http://revolutionwifi.blogspot.com/2014/08/80211ac-adjacent-channel-interference.html?m=1

There's and image there you should find similar.

Sent from my iPhone

> On Mar 8, 2017, at 4:58 PM, Chuck Enfield  wrote:
> 
> Cool images.  I’ve never tried this.  I would have this afternoon, but our 
> operations guys have the spectrum analyzer in another building.  I’m a little 
> surprised to see as nice a plot as you got in the second trace.  Between near 
> field effects and the potential to push the Rx amplifiers into a non-linear 
> region I would have expected something more messy.
>  
> Do you know what the max signal strength was in the two traces?  Also, do you 
> know how to account for the increased duty cycle in the second one?  I’m 
> wondering if this is due to different iperf behavior or if it’s weirdness 
> caused by proximity.  I’ve been doing Wi-Fi for 15 years and still find 
> myself guessing on a regular basis.
>  
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jason Cook
> Sent: Wednesday, March 08, 2017 6:08 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>  
> Still learning my way through signatures but I have been caught out before 
> with the anaylzer being too close to a wifi source
> Below shows this on channel 132, using iperf  for a data burst in the first 
> image the anaylzer is 1m away from a Mac Air,
> In the second it’s a few centimetres away from it. You can really see the 
> impact on neighbouring channels at that distance  (I think there’s even a bit 
> in the 36-40 area)
>  
> I now keep the anaylzer away from wifi devices as much as possible J
>  
> 
>  
> 
>  
> --
> Jason Cook
> Technology Services
> 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 Gray, Sean
> Sent: Thursday, 9 March 2017 7:26 AM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>  
> Nope, the spectrum analyzer is going directly into a Surface Pro 2.
>  
>  
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
> Sent: March-08-17 1:30 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>  
> Are you using a USB 3.0 hub?
>  
>  
> On Mar 8, 2017, at 1:23 PM, Jason Heffner  wrote:
>  
> I’ve seen something similar when running some of the older Cisco controllers. 
> If you ruled out everything else and are starting to look for devices causing 
> interference I'd check out some of your wireless mic systems. We had some 
> 800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
> similar to this on the lower channels.
> 
> On Mar 8, 2017, at 2:32 PM, Gray, Sean  wrote:
>  
> Hi Everyone,
>  
> I’ve been doing a little spectrum analysis around campus and I keep seeing 
> the same interference signature in different buildings. I was wondering if 
> anyone had seen anything like this before. It is typically visible for well 
> over 10 minutes at a time and then it completely disappears. 
>  
> Thanks
>  
> Sean
>  
>  
> Sean Gray | B.Sc (Hons)
> Voice, Collaboration & Wireless Network Analyst
> ITS, University of Lethbridge
>  
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> 
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
>  
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.

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

RE: [WIRELESS-LAN] 2.4 GHz Interference

[Chuck Enfield]

Cool images.  I’ve never tried this.  I would have this afternoon, but our 
operations guys have the spectrum analyzer in another building.  I’m a 
little surprised to see as nice a plot as you got in the second trace. 
Between near field effects and the potential to push the Rx amplifiers into 
a non-linear region I would have expected something more messy.



Do you know what the max signal strength was in the two traces?  Also, do 
you know how to account for the increased duty cycle in the second one?  I’m 
wondering if this is due to different iperf behavior or if it’s weirdness 
caused by proximity.  I’ve been doing Wi-Fi for 15 years and still find 
myself guessing on a regular basis.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jason Cook
Sent: Wednesday, March 08, 2017 6:08 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Still learning my way through signatures but I have been caught out before 
with the anaylzer being too close to a wifi source

Below shows this on channel 132, using iperf  for a data burst in the first 
image the anaylzer is 1m away from a Mac Air,

In the second it’s a few centimetres away from it. You can really see the 
impact on neighbouring channels at that distance  (I think there’s even a 
bit in the 36-40 area)



I now keep the anaylzer away from wifi devices as much as possible :)











--

Jason Cook

Technology Services

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 Gray, Sean
Sent: Thursday, 9 March 2017 7:26 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 

Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Nope, the spectrum analyzer is going directly into a Surface Pro 2.





From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 

Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Are you using a USB 3.0 hub?





On Mar 8, 2017, at 1:23 PM, Jason Heffner mailto:jdh...@psu.edu> > wrote:



I’ve seen something similar when running some of the older Cisco 
controllers. If you ruled out everything else and are starting to look for 
devices causing interference I'd check out some of your wireless mic 
systems. We had some 800Mhz that we had to salvage that were causing 
harmonic distortion on 2.4GHZ similar to this on the lower channels.

On Mar 8, 2017, at 2:32 PM, Gray, Sean mailto:sean.gr...@uleth.ca> > wrote:



Hi Everyone,



I’ve been doing a little spectrum analysis around campus and I keep seeing 
the same interference signature in different buildings. I was wondering if 
anyone had seen anything like this before. It is typically visible for well 
over 10 minutes at a time and then it completely disappears.



Thanks



Sean





Sean Gray | B.Sc (Hons)

Voice, Collaboration & Wireless Network Analyst

ITS, University of Lethbridge





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





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





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

** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
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** Participation and subscription information for this EDUCAUSE 
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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Jason Cook]

oops, hadn’t seen these responses before sending mine but follows my thoughts 
too for first thing to rule out

--
Jason Cook
Technology Services
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, 9 March 2017 9:13 AM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

The behavior of your radio could vary.  If you’re associated at 2.4GHz the 
channel would be based on the AP you’re associated to and duty cycle would vary 
with the network activity.  If your connection is good you wouldn’t probe much, 
if at all.  If you’re associated at 5GHz you may occasionally probe on 2.4, but 
otherwise you wouldn’t see your 2.4GHz radio.  If you’re not associated your 
laptop would probe frequently on all channels and duty cycle would alternate 
between probing and listening.

FWIW, my first thought was exactly what Jake suggested, but I didn’t think the 
fall-off at the edge of the channel was quite sharp enough to be from a 
properly functioning nearby radio.  That shoulder should be about 30dB down 
instead of 10dB.  It also seems way too strong 65MHz away at channel 14.  Even 
if the noise floor is -70, the interference is clearly still falling off at 
channel 12.  On the other hand, -20dBm is really strong, so either the 
malfunctioning radio is really booming or you’re very close to it.  When our 
Proxim’s failed they behaved as if they were using the full 100mW Tx power, but 
even at that power you would have to be within 15 feet of the radio to get 
-20dBm.

Let us know what you figure out.  It should be a learning opportunity either 
way.

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Gray, Sean
Sent: Wednesday, March 08, 2017 4:54 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Just curious, but if my Surface was the cause of the problem and I always used 
the same set-up for the Wi-Spy, wouldn’t I always see this signature? This is 
something that seems to occur quite randomly so far.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 2:21 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Try putting your laptop in airplane mode.  My guess is the SpecAn is in very 
close proximity to the laptop.  That horizontal slope indicates the wispy is 
VERY close to a wifi device (aka your surface).  That's why it looks like OFDM, 
because it is.  Getting your wispy close to an AP will look the same.



Sent from my iPhone

On Mar 8, 2017, at 1:56 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:
Nope, the spectrum analyzer is going directly into a Surface Pro 2.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Are you using a USB 3.0 hub?


On Mar 8, 2017, at 1:23 PM, Jason Heffner 
mailto:jdh...@psu.edu>> wrote:

I’ve seen something similar when running some of the older Cisco controllers. 
If you ruled out everything else and are starting to look for devices causing 
interference I'd check out some of your wireless mic systems. We had some 
800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
similar to this on the lower channels.
On Mar 8, 2017, at 2:32 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:

Hi Everyone,

I’ve been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


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


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


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

RE: [WIRELESS-LAN] 2.4 GHz Interference

[Chuck Enfield]

The behavior of your radio could vary.  If you’re associated at 2.4GHz the 
channel would be based on the AP you’re associated to and duty cycle would 
vary with the network activity.  If your connection is good you wouldn’t 
probe much, if at all.  If you’re associated at 5GHz you may occasionally 
probe on 2.4, but otherwise you wouldn’t see your 2.4GHz radio.  If you’re 
not associated your laptop would probe frequently on all channels and duty 
cycle would alternate between probing and listening.



FWIW, my first thought was exactly what Jake suggested, but I didn’t think 
the fall-off at the edge of the channel was quite sharp enough to be from a 
properly functioning nearby radio.  That shoulder should be about 30dB down 
instead of 10dB.  It also seems way too strong 65MHz away at channel 14. 
Even if the noise floor is -70, the interference is clearly still falling 
off at channel 12.  On the other hand, -20dBm is really strong, so either 
the malfunctioning radio is really booming or you’re very close to it.  When 
our Proxim’s failed they behaved as if they were using the full 100mW Tx 
power, but even at that power you would have to be within 15 feet of the 
radio to get -20dBm.



Let us know what you figure out.  It should be a learning opportunity either 
way.



From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Gray, Sean
Sent: Wednesday, March 08, 2017 4:54 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Just curious, but if my Surface was the cause of the problem and I always 
used the same set-up for the Wi-Spy, wouldn’t I always see this signature? 
This is something that seems to occur quite randomly so far.





From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 2:21 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 

Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Try putting your laptop in airplane mode.  My guess is the SpecAn is in very 
close proximity to the laptop.  That horizontal slope indicates the wispy is 
VERY close to a wifi device (aka your surface).  That's why it looks like 
OFDM, because it is.  Getting your wispy close to an AP will look the same.






Sent from my iPhone


On Mar 8, 2017, at 1:56 PM, Gray, Sean mailto:sean.gr...@uleth.ca> > wrote:

Nope, the spectrum analyzer is going directly into a Surface Pro 2.





From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU 

Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference



Are you using a USB 3.0 hub?





On Mar 8, 2017, at 1:23 PM, Jason Heffner mailto:jdh...@psu.edu> > wrote:



I’ve seen something similar when running some of the older Cisco 
controllers. If you ruled out everything else and are starting to look for 
devices causing interference I'd check out some of your wireless mic 
systems. We had some 800Mhz that we had to salvage that were causing 
harmonic distortion on 2.4GHZ similar to this on the lower channels.

On Mar 8, 2017, at 2:32 PM, Gray, Sean mailto:sean.gr...@uleth.ca> > wrote:



Hi Everyone,



I’ve been doing a little spectrum analysis around campus and I keep seeing 
the same interference signature in different buildings. I was wondering if 
anyone had seen anything like this before. It is typically visible for well 
over 10 minutes at a time and then it completely disappears.



Thanks



Sean





Sean Gray | B.Sc (Hons)

Voice, Collaboration & Wireless Network Analyst

ITS, University of Lethbridge





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





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





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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Gray, Sean]

Just curious, but if my Surface was the cause of the problem and I always used 
the same set-up for the Wi-Spy, wouldn’t I always see this signature? This is 
something that seems to occur quite randomly so far.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 2:21 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Try putting your laptop in airplane mode.  My guess is the SpecAn is in very 
close proximity to the laptop.  That horizontal slope indicates the wispy is 
VERY close to a wifi device (aka your surface).  That's why it looks like OFDM, 
because it is.  Getting your wispy close to an AP will look the same.



Sent from my iPhone

On Mar 8, 2017, at 1:56 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:
Nope, the spectrum analyzer is going directly into a Surface Pro 2.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Are you using a USB 3.0 hub?


On Mar 8, 2017, at 1:23 PM, Jason Heffner 
mailto:jdh...@psu.edu>> wrote:

I’ve seen something similar when running some of the older Cisco controllers. 
If you ruled out everything else and are starting to look for devices causing 
interference I'd check out some of your wireless mic systems. We had some 
800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
similar to this on the lower channels.
On Mar 8, 2017, at 2:32 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:

Hi Everyone,

I’ve been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


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


** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
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** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
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** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
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**
Participation and subscription information for this EDUCAUSE Constituent Group 
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Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jake Snyder]

Try putting your laptop in airplane mode.  My guess is the SpecAn is in very 
close proximity to the laptop.  That horizontal slope indicates the wispy is 
VERY close to a wifi device (aka your surface).  That's why it looks like OFDM, 
because it is.  Getting your wispy close to an AP will look the same.



Sent from my iPhone

> On Mar 8, 2017, at 1:56 PM, Gray, Sean  wrote:
> 
> Nope, the spectrum analyzer is going directly into a Surface Pro 2.
>  
>  
> From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
> [mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
> Sent: March-08-17 1:30 PM
> To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
> Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference
>  
> Are you using a USB 3.0 hub?
>  
>  
> On Mar 8, 2017, at 1:23 PM, Jason Heffner  wrote:
>  
> I’ve seen something similar when running some of the older Cisco controllers. 
> If you ruled out everything else and are starting to look for devices causing 
> interference I'd check out some of your wireless mic systems. We had some 
> 800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
> similar to this on the lower channels.
> 
> On Mar 8, 2017, at 2:32 PM, Gray, Sean  wrote:
>  
> Hi Everyone,
>  
> I’ve been doing a little spectrum analysis around campus and I keep seeing 
> the same interference signature in different buildings. I was wondering if 
> anyone had seen anything like this before. It is typically visible for well 
> over 10 minutes at a time and then it completely disappears. 
>  
> Thanks
>  
> Sean
>  
>  
> Sean Gray | B.Sc (Hons)
> Voice, Collaboration & Wireless Network Analyst
> ITS, University of Lethbridge
>  
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> 
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
>  
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss.

**
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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Gray, Sean]

Nope, the spectrum analyzer is going directly into a Surface Pro 2.


From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jake Snyder
Sent: March-08-17 1:30 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Are you using a USB 3.0 hub?


On Mar 8, 2017, at 1:23 PM, Jason Heffner 
mailto:jdh...@psu.edu>> wrote:

I’ve seen something similar when running some of the older Cisco controllers. 
If you ruled out everything else and are starting to look for devices causing 
interference I'd check out some of your wireless mic systems. We had some 
800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
similar to this on the lower channels.
On Mar 8, 2017, at 2:32 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:

Hi Everyone,

I’ve been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


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


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


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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Chuck Enfield]

That's consistent with what I saw from the Proxims.  The radios still
partially work, so the noise is centered around whatever channel they are
set to.

 

From: Gray, Sean [mailto:sean.gr...@uleth.ca] 
Sent: Wednesday, March 08, 2017 3:48 PM
To: Chuck Enfield ; WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: RE: [WIRELESS-LAN] 2.4 GHz Interference

 

Hi Chuck,

 

I'm going to run the spectrum analyzer on a different client to rule out
NIC issues. Now you mention it we do have a couple of old Proxims, that
should have been powered off a long, long time ago as they are no longer
used. So I'll look into that as well.

 

Interestingly, I've also seen the signature on channel 11, when in the
same geographical location minutes after seeing it on channel 1 and
shortly before it disappeared.

 

Thanks

 

Sean

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Chuck Enfield
Sent: March-08-17 1:05 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
 
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

 

Hi Sean,

 

Are all of your APs and Wi-Fi NICs in the area working properly?  That
plateau at -20dBm (see image) is almost certainly from an nearby OFDM
source on channel 1.  If that broadband interference is from the same
source, I'd look for a malfunctioning Wi-Fi radio.  It's been a while, but
we had Proxim APs with a rare failure mode that looked like this.  You
could see the OFDM, but there was intermittent, high-intensity, broadband
noise coming from the radio.  Please don't ask me to explain the
intermittent part.  I never did figure that out.

 

Good Luck,

 

Chuck

 

From: The EDUCAUSE Wireless Issues Constituent Group Listserv
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Gray, Sean
Sent: Wednesday, March 08, 2017 2:32 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
 
Subject: [WIRELESS-LAN] 2.4 GHz Interference

 

Hi Everyone,

 

I've been doing a little spectrum analysis around campus and I keep seeing
the same interference signature in different buildings. I was wondering if
anyone had seen anything like this before. It is typically visible for
well over 10 minutes at a time and then it completely disappears. 

 

Thanks

 

Sean

 

 

Sean Gray | B.Sc (Hons)

Voice, Collaboration & Wireless Network Analyst

ITS, University of Lethbridge

 

 

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

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Constituent Group discussion list can be found at
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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Gray, Sean]

Hi Chuck,

I'm going to run the spectrum analyzer on a different client to rule out NIC 
issues. Now you mention it we do have a couple of old Proxims, that should have 
been powered off a long, long time ago as they are no longer used. So I'll look 
into that as well.

Interestingly, I've also seen the signature on channel 11, when in the same 
geographical location minutes after seeing it on channel 1 and shortly before 
it disappeared.

Thanks

Sean

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Chuck Enfield
Sent: March-08-17 1:05 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Hi Sean,

Are all of your APs and Wi-Fi NICs in the area working properly?  That plateau 
at -20dBm (see image) is almost certainly from an nearby OFDM source on channel 
1.  If that broadband interference is from the same source, I'd look for a 
malfunctioning Wi-Fi radio.  It's been a while, but we had Proxim APs with a 
rare failure mode that looked like this.  You could see the OFDM, but there was 
intermittent, high-intensity, broadband noise coming from the radio.  Please 
don't ask me to explain the intermittent part.  I never did figure that out.

Good Luck,

Chuck

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Gray, Sean
Sent: Wednesday, March 08, 2017 2:32 PM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: [WIRELESS-LAN] 2.4 GHz Interference

Hi Everyone,

I've been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


** Participation and subscription information for this EDUCAUSE 
Constituent Group discussion list can be found at 
http://www.educause.edu/discuss.
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Constituent Group discussion list can be found at 
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RE: [WIRELESS-LAN] 2.4 GHz Interference

[Gray, Sean]

Highly likely, the majority of our APs are in classrooms, offices and hallways. 
I’ll start looking around for such things and see what signatures they give off.

Thanks

Sean

From: The EDUCAUSE Wireless Issues Constituent Group Listserv 
[mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU] On Behalf Of Jeremy Gibbs
Sent: March-08-17 12:37 PM
To: WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 GHz Interference

Are there any common items near APs?  Such as a light with a ballast?  You tend 
to see A LOT of stuff on 2.4, especially if you're in a more urban environment.


--

Jeremy L. Gibbs
Sr. Network Engineer
Utica College IITS

T: (315) 223-2383
F: (315) 792-3814
E: jlgi...@utica.edu
http://www.utica.edu

On Wed, Mar 8, 2017 at 2:32 PM, Gray, Sean 
mailto:sean.gr...@uleth.ca>> wrote:
Hi Everyone,

I’ve been doing a little spectrum analysis around campus and I keep seeing the 
same interference signature in different buildings. I was wondering if anyone 
had seen anything like this before. It is typically visible for well over 10 
minutes at a time and then it completely disappears.

Thanks

Sean


Sean Gray | B.Sc (Hons)
Voice, Collaboration & Wireless Network Analyst
ITS, University of Lethbridge


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

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**
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discussion list can be found at http://www.educause.edu/discuss.

Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jake Snyder]

Are you using a USB 3.0 hub?


> On Mar 8, 2017, at 1:23 PM, Jason Heffner  wrote:
> 
> I’ve seen something similar when running some of the older Cisco controllers. 
> If you ruled out everything else and are starting to look for devices causing 
> interference I'd check out some of your wireless mic systems. We had some 
> 800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
> similar to this on the lower channels.
> 
>> On Mar 8, 2017, at 2:32 PM, Gray, Sean > > wrote:
>> 
>> Hi Everyone,
>>  
>> I’ve been doing a little spectrum analysis around campus and I keep seeing 
>> the same interference signature in different buildings. I was wondering if 
>> anyone had seen anything like this before. It is typically visible for well 
>> over 10 minutes at a time and then it completely disappears. 
>>  
>> Thanks
>>  
>> Sean
>>  
>>  
>> Sean Gray | B.Sc (Hons)
>> Voice, Collaboration & Wireless Network Analyst
>> ITS, University of Lethbridge
>>  
>>  
>> ** Participation and subscription information for this EDUCAUSE 
>> Constituent Group discussion list can be found at 
>> http://www.educause.edu/discuss .
>> 
>> 
> 
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss .
> 


**
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smime.p7s
Description: S/MIME cryptographic signature

Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jason Heffner]

I’ve seen something similar when running some of the older Cisco controllers. 
If you ruled out everything else and are starting to look for devices causing 
interference I'd check out some of your wireless mic systems. We had some 
800Mhz that we had to salvage that were causing harmonic distortion on 2.4GHZ 
similar to this on the lower channels.

> On Mar 8, 2017, at 2:32 PM, Gray, Sean  wrote:
> 
> Hi Everyone,
>  
> I’ve been doing a little spectrum analysis around campus and I keep seeing 
> the same interference signature in different buildings. I was wondering if 
> anyone had seen anything like this before. It is typically visible for well 
> over 10 minutes at a time and then it completely disappears. 
>  
> Thanks
>  
> Sean
>  
>  
> Sean Gray | B.Sc (Hons)
> Voice, Collaboration & Wireless Network Analyst
> ITS, University of Lethbridge
>  
>  
> ** Participation and subscription information for this EDUCAUSE 
> Constituent Group discussion list can be found at 
> http://www.educause.edu/discuss .
> 
> 


**
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discussion list can be found at http://www.educause.edu/discuss.

Re: [WIRELESS-LAN] 2.4 vs 5

[Green, William C]

We are seeing many of the congestion issues of 2.4GHz ameliorating themselves 
as clients are self-selecting 5GHz.  Especially in the higher density 
environments where the 2.4GHz congestion was extreme.

On our campus, 5GHz now represents 80% of the data transferred (up from 28% six 
years ago), and 63% of the association time (up from 22%).  Even higher in high 
density environments.  I expected continued increases as we replace more EOL 
WAPs with 802.11ac capable ones (many popular clients are preferring 802.11ac).

Less dire than before.

--
William C. Green  e-mail:  
gr...@austin.utexas.edu
Director, Networking and Telecommunications   phone:   +1 512-475-9295
ITS (Information Technology Services) fax: +1 512-471-2449
University of Texas
1 University Station Stop C3800
Austin, TX  78712


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

Re: [WIRELESS-LAN] 2.4 GHz Interference

[Jeremy Gibbs]

Are there any common items near APs?  Such as a light with a ballast?  You
tend to see A LOT of stuff on 2.4, especially if you're in a more urban
environment.




*--Jeremy L. Gibbs*
Sr. Network Engineer
Utica College IITS

T: (315) 223-2383
F: (315) 792-3814
E: jlgi...@utica.edu
http://www.utica.edu

On Wed, Mar 8, 2017 at 2:32 PM, Gray, Sean  wrote:

> Hi Everyone,
>
>
>
> I’ve been doing a little spectrum analysis around campus and I keep seeing
> the same interference signature in different buildings. I was wondering if
> anyone had seen anything like this before. It is typically visible for well
> over 10 minutes at a time and then it completely disappears.
>
>
>
> Thanks
>
>
>
> Sean
>
>
>
>
>
> *Sean Gray* | B.Sc (Hons)
>
> Voice, Collaboration & Wireless Network Analyst
>
> ITS, University of Lethbridge
>
>
>
>
> ** Participation and subscription information for this EDUCAUSE
> Constituent Group discussion list can be found at http://www.educause.edu/
> discuss.
>
>

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

Re: [WIRELESS-LAN] 2.4 vs 5

[Jeffrey D. Sessler]

I would add that with the forthcoming 802.11ax, improvements are also being 
extended to 2.4, meaning the life-span of 2.4 is being reset in some form. As 
such, we’ll likely see devices continue in 2.4 for many years, especially those 
that benefit from staying anchored to the same AP (less roaming).

Jeff

From: "wireless-lan@listserv.educause.edu"  
on behalf of Jake Snyder 
Reply-To: "wireless-lan@listserv.educause.edu" 

Date: Monday, March 6, 2017 at 6:20 PM
To: "wireless-lan@listserv.educause.edu" 
Subject: Re: [WIRELESS-LAN] 2.4 vs 5

One thing I like in your design is the 5GHz only and dual band.  So many people 
try a 5GHz only and a 2.4Ghz only and it backfires on them.



Sent from my iPhone

On Mar 6, 2017, at 3:17 PM, Jason Cook 
mailto:jason.c...@adelaide.edu.au>> wrote:
We have a dedicated 5ghz SSID but it’s in addition to our standard which is not 
ideal… too many SSID’s doing the same thing
So our dot1x auth’s are
UofA (2.4&5)
UofA 5ghz (5 only)
eduroam (2.4 & 5)

We still see plenty of brand new devices on 2.4 only and I was helping a 
student recently who grabbed an old laptop out of hard rubbish. So we are stuck 
with making them work but in doing so we see 5ghz capable devices sitting on 
2.4 which isn’t so good. The extra SSID was fired up as a test and worked, so 
got stuck there but we  still don’t classify it under our production since it’s 
poorly named.

For end of year I’m proposing the removal of “UofA 5ghz” and making “UofA” a 
5ghz only SSID with eduroam covering both 5 and 2.4. Our users get the same 
service on eduroam anyway as they would on our branded SSID(ip connectivity 
wise).

A few years back I posted a discussion about this where we were considering 
something similar but having a 2.4ghz only network as UofA-legacy or the 5ghz 
network as UofA-Premium etc. since the current “UofA 5ghz” is technical and 
users don’t know what it means.  We never got to a point where we were fully 
happy with the plan but in general we preferred the idea that if your 2.4ghz 
only you go on something called legacy to help drive the idea that they would 
ideally not use such a device.


--
Jason Cook
Technology Services
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 Casey Feskens
Sent: Tuesday, 7 March 2017 4:58 AM
To: 
WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU
Subject: Re: [WIRELESS-LAN] 2.4 vs 5

We are currently using a 5GHz only SSID (as well as 2.4) and have been trying 
to encourage students to use it. We recently conducted a survey of wireless 
performance and asked questions about why people were using 2.4 networks vs. 
5GHz. A surprising number of students replied that their devices could not see 
the 5GHz SSID.

On Mon, Mar 6, 2017 at 10:18 AM, Hunter Fuller 
mailto:hf0...@uah.edu>> wrote:
Similarly, we haven't looked at it. You can walk into Best Buy today and walk 
out with a brand new laptop with no 5GHz wireless.

On Mon, Mar 6, 2017 at 12:13 PM Jeffrey D. Sessler 
mailto:j...@scrippscollege.edu>> wrote:
I don’t think there is a way to get away from 2.4 yet in EDU. For example, 
while most would install high-density 5GHz in every residential room, it’s 
likely cost-prohibitive to accomplish the same in hallways and other areas that 
devices transit but don’t linger. As such, 2.4 is still important for “in 
flight” devices.

Jeff

From: 
"wireless-lan@listserv.educause.edu" 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>> 
on behalf of "Oliver, Jeff" mailto:jeff.oli...@uleth.ca>>
Reply-To: 
"wireless-lan@listserv.educause.edu" 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Date: Monday, March 6, 2017 at 8:42 AM
To: 
"wireless-lan@listserv.educause.edu" 
mailto:WIRELESS-LAN@LISTSERV.EDUCAUSE.EDU>>
Subject: [WIRELESS-LAN] 2.4 vs 5

Folks, just wondering how many PSI’s have successfully turned off your 2.4 and 
gone 5GHz only? And how much blowback?


Cheers,
Jeff

---

Jeffrey L. Oliver
Manager, Network and Telecommunications
Information Technology Services
The University of Lethbridge
4401 University Drive, Lethbridge, Alberta, T1K 3M4

Tel: 403.329.5162
Mob: 403.315.4461

URI:   jeff.oli...@uleth.ca
Web:http://www.uleth.ca/information-technology/

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



--
--

ISE 2.2 How's it going

[Bruce Boardman]

Anybody using ISE2.2? How's the bug factor?

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