This topic is a chance to discuss more about how to deploy a successful and reliable wireless office. Learn more about the good, bad, ugly and hurdles that is needed to overcome for a successful and reliable process. Ask about methods, components, products and best practices to implement an all-wireless office (AWO), which is considered the next evolution of true Wi-Fi mobility in the enterprise.enterprise.
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Ask questions from Tuesday, February 14th to February 24th, 2017
George Stefanick is a Wireless Architect employed by a large healthcare system in the Texas Medical Center. His Wi-Fi engineering experience spans nearly two decades and in that time he has provided consulting to many Fortune 500 companies in industries such as healthcare, mining, and hospitality. He maintains a popular Wi-Fi engineering community, the blog MY80211.com and he holds many vendor and vendor neutral certifications.
Also, he has been Technical Editor for two books related to Wireless Network technology: ”CCNA Wireless Study Guide” by Todd Lammle and ”Designing and Deploying 802.11 Networks: A Practical Guide to Implementing 802.11n and 802.11ac Wireless Networks for Enterprise-Based Applications” by Jim Geier .
As a member of the Cisco Support Community, George has been awarded with a Cisco Designated VIP status, a recognition that Cisco bestows upon the most valuable and influential members of their official technical support community.
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Abraham, Thank you for the kind comments Im really glad you enjoyed it.
Device testing is a very a important consideration when deploying reliable WiFi. Once you have a mental check box that the RF and wireless configuration is optimal and your config is simple and there was no changes on the network you can quickly start looking at the clients.
Back to the testing ... Its not an easy task and it takes time to baseline client devices and drivers. Once you have your data base full of testing data you can then really feel comfortable and compare results.
1) Baseline receive sensitivity of the device. We do this by testing at different distances from the ap and different orientations of the device. We can see quickly for example the iPhone hears the network 7-9 dB lower then say the average device. This is telling and might mean we need to consider a denser deployment.
2) Roaming test - Look at 802.11 and 802.1X roaming - Collect logs on the device, OTAC (Over the air captures), and controller side.
- Make sure 11r, OKC is supported and working
- Baseline the time from the last data frame sent on the old ap to the first data frame sent on the new ap
- Check roaming triggers and baseline
3) QoS markings
- If your device and app is suppose to mark QoS make sure it is and that it is marking correctly.
4) Allow the device to sit for 24-48 hours and see how the device behaves - do a constant ping do we lose pings and if so why
5) Elevator ride / off campus on campus -- take the device on a long elevator ride does it quickly recover when coming back into coverage
6) Does the device / app support Multicast confirm with multicast hammer OTAC, debugs
7) What 5 GHz channels does it support. Test connectivity on all bands UNII1/2/2E/3
8) Does the device UAPSD/PS POLL or some custom power save. Identity this and observe it working and baseline.
9) Does the device probe aggressively -60 or lower you can see this with transmitting probes as the device is building a neighbor list. If a device is off channel probing its not servicing the client
10) Does the device support 11k if so confirm this ...
The list goes on. What is key, after you collect a lot of devices and or device and driver info you will see a pattern. If you test a device that is way out of spec compared to other data you collected you can start to question -- Humm will this device work in my environment. Then test and see.
I hope that helps.
If you are using EAP then either your device will support NO advance roaming features or it will have some flavor of OKC, PMK cache (fast roam back) or 11r. If a device doesn't support advance roaming protocols you are 100% correct. The device will have to do a FULL 802.1X, which is very much like pulling a cable from the wall and plugging it back in. That all said the controller by default supports OKC. In a BYOD environment where there is little control you are really challenged. Apple and some flavors of android support 11r. But I find some vendors who say they do but once we test we find out they dont support or have issues supporting 11r.
You my friend are in one of the most challenging environments. You know all to well and better then most about BYOD. When I think of wireless devices and education I think of the Guns and Roses song - Welcome to the jungle baby ..
My suggestion is this ... You will never be able to control or manage these devices. While we want the best experience for our users. Find out the larger quantity of devices and NICs and test these drivers. When a student calls in and has an issue and they match say a 7265 INTEl NIC you can tell them we suggest driver XYZ.
I hope this helps bud .. Thanks again for spending the hour with me and the cisco team on the webex.
It was a really great presentation and through those live Q&A session valuable info came out.
You mentioned that you did some trial with 3800s. Based on your experience, if you given an opportunity to do a AWO now, what would you pick ? 3702 or 3802 ?
I know from life time perspective we should go with 3802, but not sure technical point of view is that the right choice
Wow great question. I think the inner geek in us want as much as we can. Lets pin the needle in the red so to speak!
What we really need and should understand is what are the user requirements. What applications will be in use and how many users will be using these applications. I can tell you in a normal office environment not everyone is doing FTP file transfers or intensive bandwidth hogging on WiFi. If they are and this is normal for them they would be better serviced with a wire.
You would be surprised, I think, when I tell you we've seen Aps with 25 or more clients and we could still pull 60Mbps up and down with no problem. It was because the applications and users didnt have demanding requirements.
The question is hard to answer. All depends really.
Hi George ,
One of the common complaing we used to get from the BYOD users are ( I am just round off maybe only few users ) , they need to reauthenticate always ?
what is your suggestion ?
Well we can assume these are more consumer grade devices. We know apple iOS and some flavors of Android support 11r. You could enable 11r on your WLAN and see if that helps. I would caution in that some clients, when 11r is enabled, may have connection issues. I would work with specific users and see first hand what devices you are dealing with.
great timing that you had this ask the expert session.
there's a design question raised at work wherein 2504 uplink needs to be redundant on 2 switch. i was able to aggregate (LAG) before on a single switch before but not on 2 separate switch.
is it possible to do have redundant uplinks on a 2504 to 2 cisco switch? my google search is failing me today. thanks in advance!
p.s. - i'm a fan of your site and read some them during my ccna wireless study
i'm looking on one of our 2504 and saw a 'backup port' under management interface. do i just type '2' for port 2 which is connected to another switch?
i just need port 2 to connect to sw2 to be redundant and still have remote access WLC 2504 in case sw1 fails.
brief diagram as below:
port 1 --- Sw1
port 2 --- Sw2
Best practice is to keep both on the same switch.
Hi George, could you let me know what you have in your 'Wireless Essentials Kit' for troubleshooting Cisco Wireless Networks.
Site Survey Tool - i.e. Airmagnet (which you use)/Ekahau
Spectrum Analysis - i.e. Airmagnet Spectrum/Chanalyzer
Packet Capture (On the go) - i.e. AirPcap+EyePA
Anything else you recommend?
Yes there are a number of tools we use.
AirMagnet Survey - Site survey
AirMagnet XT - Spectrum
AirMagnet WiFi Analyzer - 802.11 analysis
OmniPeek - Deep 802.11 analysis
ZAP - Throughput testing
Thanks for the explanation on coverage & troubleshooting..
I have query regarding the AP placement with the new model of Access points. Most of the new 11ac access points advertise higher coverage areas. If I am placing access points in office place( cubicle & gypsum partitions) should I consider more spacing the between the access points; or go with the same rule of 25 meter between access points for voice WLAN & 30 meter for only Data WLAN
Thanks for the kind comment. No the 2500 doesn't LAG. Best practice is to have the controller connected to the same WLC.
I think transparency is important. While we had the opportunity to test he 3800 we have not done any major deployments of the 3800 at this point. You might remember we just got done installing $1M worth of 3700 access points. I will say the micro cell (SDN) radio allowing 2 5GHz radios will allow for higher density where before you would have to consider 2 access points.
Great presentation with some great questions. I learned a lot.
You mentioned you have some Ap's in sniffer mode and I thought you said you have some in monitor mode. Do you do anything with those access points in monitoring mode or are they just to help out the Ap's in production? I have read it is recommended to have one Ap in monitor mode for every 5 to 6. Wondering if there is anything you can do with the data those are collecting. Thanks!