Contemplating Auto RF Functions In WLAN Systems

Once upon a time, wireless networks were completely the product of the person or persons who designed, installed, and configured them. The WLAN couldn’t think for itself, per se, and important settings like channel and power were determined by the human hands and minds behind each Wi-Fi network. This was mostly a hallmark of the age of Fat Access Points, when our wireless networks were more about general coverage and less the stuff of carefully weaving high-density signal tapestries that support ever increasing client device counts. Now, there is impressive (or utterly maddening, depending on vendor and code version) magic behind the typical modern business WLAN; access points get their configs from some version of a mothership, and mystical “algorithms” choose what power and channel settings each access point will use. 

If you let them, that is.

After a recent spirited Twitter dialogue with a couple of dozen really smart fellow wireless networkers, I found myself a bit taken aback by the general distrust of “auto RF” functionality that comes with almost any new Wi-Fi gear that uses multiple access points to form a WLAN. After all, these systems are not cheap, and the auto RF stuff is a major feature that adds to the cost. I’m not aware of any system that lets you order system code without auto RF to lower the price, yet a lot of WLAN professionals aren’t really embracing it. Is it a matter of general disdain for something that has caused pain for their end users that have lead my colleagues to speak somewhat unflatteringly about auto RF features, or is there something else at work?

From my own experience, I’ve been *generally* satisfied with Cisco’s Radio Resource Management (RRM) and use it extensively in my extremely large WLAN environment. At the same time, there have been a few cases where I’ve had to manually override RRM’s selected values. Usually, I can look at these exceptions and point out a design trade-off that we were forced to make (the real world is rarely perfect) that probably threw the RRM algorithm for a loop. It’s not that RRM failed me- in fact you could say that at times my design failed RRM.

I think this is some of the essence of skepticism behind auto RF from my wireless homies. Auto RF features are not divine cure-alls for bad design, nor can they be trusted to simply come to life and make everything OK with manufacturer’s default values in all cases. You have to learn how they work in your environments and with your design approaches, and realize that not all vendors are going to implement the same way. For me, I’ve got the most experience with Cisco’s RRM (generally pleased), Meraki’s version (can be weird at times), some Aruba (did a building-wide pilot a few years back, Aruba’s ARM did fine for me back then) and Aerohive on a small scale. Making things even more complicated, vendors can change their algorithms as they choose (potentially negating what you think you understand) and some document the technical underpinnings better than others… it gets tricky, yet I can’t imagine trying to keep my own 4,000 AP network up without it.

Here are some vendor links relating to auto RF functions (No slight intended to anyone I left out, this is just a sampling), and I have no clue whether there are newer versions available :

You get the point… some vendors are more explicit in explaining the theory of operation behind their auto RF mechanisms, others seem to have added it because it’s what you’re supposed to do anymore. Regardless, it’s very interesting.

I’d love to hear your opinions on the notion of auto RF, whether for a specific vendor or in general. What have you found that works? That doesn’t work? What’s your advice for people just getting started with auto RF capabilities? Any good auto-RF links to share?

Thanks for reading!

On Twitter and Wi-Fi Minded? Look for #WIFIQ

I was a Twitter skeptic early on. It was confounding to me how this framework could have any professional or organizational value at first pass, but I caught on quick. After inheriting someone else’s support-oriented Twitter mess to straighten out a few years ago, I learned that there is actually something to this social media thing… it really does have an element of value when it comes to learning from, promoting (and being promoted by), and interacting with other IT professionals of all skills and backgrounds.

OK, enough on the Twitter sales pitch. If you’re not using it, I encourage you to give it a try and discover for yourself a vibrant, active, dynamic community of professionals that share your interests. And if you’re already on Twitter and have a yen for wireless networking, I encourage you to look for the daily #WIFIQ – which is the hashtag for the Daily Wi-Fi Question. This is an informal but interesting discussion on an offered topic that has gained steam of late. It works like this:

Every morning (US eastern time) I throw out a #WIFIQ. It may be of my own making, or come from someone else who has DM’d me to have their question asked. Then anywhere from a few to a few dozen WLAN professionals that are interested in voicing their opinion and experience chime in throughout the day. It’s a pretty interesting exercise, and typically several countries, skill levels, and viewpoints are represented.

This is certainly nothing earth-shaking, nor is it meant to be. There’s already a lot of fantastic, viral discussion happening on Twitter, but the #WIFIQ brings just a little bit of something to spark people into a common discussion thread, and it’s all about respectfully sharing and engaging with a lot of really smart, humorous, and friendly folks with a passion for all things Wi-Fi on a daily basis. If you choose to be a regular, good for you. And if you pop in on occasion, your thoughts are equally as valued for whatever is being talked about that day. And by using the #WIFIQ hashtag, you can search on discussions you missed, if you are so inclined.

Interested? Get on Twitter, and get in on the daily #WIFIQ. It’s a little thing that has sparked great dialogue, and is guaranteed to get you talking with others that you may not have another reason to.

We’re in the business of connecting people, after all…

Another Amazing Crop of Products at Unwired Innovation Expo

Having just got back from the annual Unwired Innovation Expo, my head is spinning a bit from all that I was fortunate enough to see. Once again the event took place in scenic Clovis, New Mexico at the Llano Estacado Convention Center, and it was phenomenal. I remember first attending UIE back in 2012, and I once thought that nothing would top the amazing products I saw back then. This year not only exceeded the previous years’ excitement, but left me feeling nothing short of awestruck.

For those who couldn’t make it to the Expo, here are my top picks from 2015’s event:

  • Cisco’s Braco Access Point Modules.  Cisco has done well with add-on modules for 3600 and 3700 APs that add WIPS and small-cell capabilities. Now, to counter growing workplace BYOD anger and violence, the market leader in WLAN has partnered with The Gazer to produce the Braco Module. In addition to client access, APs can now broadcast a soothing energy force brought out by the new TGP (Transmission Gazing Protocol) that delivers the very essence of Braco’s Gaze throughout their coverage areas.  I stood in a Braco cell for about two minutes, and left it feeling mellow as a cello. This is powerful tech.

  • GlobaStar Barby. This fun product was the hit of the consumer side of the show floor. GlobaStar Barby is an upgrade to last year’s model, with improved dance moves (33% more spin), and she drives the cutest little Corvette around on Channel 14 Wi-Fi SUPERHIGHWAYS (additional licenses required).

  • Fit-Pit. Billed as the ultimate “wearable” for fitness, Pits Inc. has mastered a roll-on version of BLE technology that you apply to your underarms. It gets operating voltage from your sweat, and transmits statistics on your workout to a smartphone app. Need help reaching your goals? Fit-Pit also comes with an electrode that mounts on either side of your posterior under your workout attire that applies a mini-taser blast when you slack off. Elegent, integrated, and effective- Fit-Pit sets the standard for what this sort of technology should be.

  • New 802.11baa components. Though still in beta, a raft of products built on this agri-business-oriented wireless breakthrough was on display at UIE. Given the convention center’s proximity to Eastern New Mexico’s high plains, attendees were able to watch real-world demonstrations of livestock equipped with 802.11baa transceivers extending a network to the undeserved in neighboring enclaves like Ranchvale and Ft. Sumner. Also, a big screen showed a live feed from the Scottish highlands, where 802.11baa is also being combined with the experimental MDP (meshed dung protocol) for even further reach over difficult terrain.

  • Phantom Fi. Sometimes simplicity is the best answer to tough or costly technical problems. Phantom Fi’s CTO Howard Hamilton walked me through his company’s approach to a scenario many of us can relate to: you want visitors to think you have a kick-ass wireless network, even if you really can’t afford it. Phantom Fi delivers the appearance of a robust, well-designed WLAN environment with simulated access points. “It’s all about appearances with a lot of people”, Hamilton informed me.Space-age polymer enclosures house a AA battery, a multi-color LED, and a small circuit that changes the light color at random intervals to create the illusion of wireless activity. Depending on customer requirements, Phantom Fi’s Professional Services will work with your staff on perfecting the “yes, we have Wi-Fi, and it’s quite good. But it’s also very secure, and only for important people” scenario, or alternatively will train the help desk staff to deliver real-world messaging like “look at the AP- the lights are on. Maybe you should update your driver?” to round out the real-world edginess of the ruse. With Gold-level support, customers can use either approach, as well as make use of optional simulated external antennas with double-sided tape included in the licensing.

  • Marley Foundation’s Mon-itization Portal. The whole “engagement” thing really rubs a lot of people the wrong way, with the typical promise of some small discount or targeted marketing in exchange for the mobile client’s soul and whatnot. For those of us in that camp, the Marley Foundation is teaming up with dive bars, party barges, and frats to offer their Mon-Itization portal. You hit the web page, select your favorite reggae tune and herbal supplement (delivered via app on latest mobile devices) and soon We be jammin, mon… 
    I tried figuring out the business model on this one, but after a couple of logins on the demo portal I got so baked that I gave up and went to get some mozzarella sticks.

There was certainly more… much more at the Unwired Innovation Expo. From edible client devices to weird looking things that seemingly had no purpose to the latest generation of high-performance flatulence apps, there was just so, so much to take in at this year’s show. I know by now that next year will be even more impressive, but at this point I’m feeling like I have touched the face of our collective wireless future- and it made me warm and tingly.

Ubiquiti Bridges- Discoveries and Tips

It seems like almost everywhere I go to consult with small networks that have wireless bridge links in use, I run into some model of Ubiquiti gear. My own knowledge with this tier of hardware isn’t all that deep, as I’m used to dealing higher-priced enterprise-grade stuff. That’s not to sound snobby, but more to add context- and I can say that I’m developing a real appreciation for the likes of Ubiquiti Nanostations and such. Now that I’ve inherited a number of these to verify, optimize, or fix, I’ve found a handful of discussion points worthy of sharing.

I’ve had new-to-me customers declare that their links are failing or that the last guy to touch them did something odd to them. In some cases, the bridges are so high up on a building, you have no way to read the model on them, and the customer has no idea whether he’s using 900 Mhz, 2.4 GHz, or 5 GHz. Many of these cases have come to be in their current state from either a shoestring budget, a poor choice of “network guy”, or both. Whether you’re putting in new Ubiquiti bridges or trying to tame existing deployments, here’s some guidance to help you to be successful, based on my own recent experience:

  • Use the Device Discovery Tool. Found at the bottom of the Ubiquiti downloads page, the tool can save a lot of time and frustration for figuring out what model numbers of hardware is in use, firmware version, and IP addresses. One recent use of the tool showed me this:hourigan bridges

Of course, I wasted time and energy trying to get pictures of the labels on the bridges and finding them via arp, etc before I got smart – the discovery tool is a must-have.

  • Use the Latest Firmware. The operating system on Ubiquiti brides is called airOS. Different model numbers use different “latest” releases, and if you look at the picture above, you’ll see these NanoStation M5s are all on v5.5.9. This happens to be the latest available for this model (as I write this). firmware

  • Keep a Spare Handy. For links that don’t cost much, especially when they are deployed off the beaten path, having a spare or two on hand is just good strategy. Again, using the M5 as an example, you can see a spare bridge (and proprietary 24v power injector block) doesn’t take a lot of coin to get M5Remember to backup the configs of all of the bridges you support (found in Device pages of airOS software config pages) so bringing a spare to life can be done quickly.

  • Watch That Mast/Mounting As A Frequent Source of Headache. Ubiquiti bridges like the M5 tend to be lightweight, and are often constructed to be mounted with nothing more than tie-wraps. Though simplicity is nice, mounting these things can get you in trouble. I have found them under metal roofs, on flimsy conduit “masts” that wiggle in the breeze, and put up with no regard for Fresnel zone dimensions. This is one place where the cheap gear and the expensive stuff share commonality: they still have to mount solidly, with proper alignment, and in a way that provides appropriate radio line of sight for the frequency in use. Given that 900 MHz is popular in this space, anyone working with them needs to know the difference when it comes to Fresnel calculations for the different bands. that 8 foot pole that you can get away with for 5 GHz isn’t going to cut it for 900 MHz.

The Ubuiti bridges (excluding the AirFiber products and optional parabolic antennas) are remarkable lightweight and easy to work with. At the same time, best practices and wireless networking craftsmanship are still required for link success and minimal downtime. Don’t let “cheap” overtake your approach because of the product set you’re dealing with.

What Ubiquiti bridge tips do you have to share?

Related Post: In Defense of Little Wireless


UPDATE: Hey Wireless Professionals- Would You Use…

Breaking news: despite my dashing good looks, tireless ambition, and awe-inspiring brilliance, it seems that another bloke has walked this rode slightly before me.

Ladies and gents, it’s my pleasure to share with you the work of Kevin, the craftsman behind

(which gets me off the hook!) Kevin’s discussion board looks well laid out, and I’d encourage you to join it if my original idea caught you interest.


My man Wi-Fi Nigel floated an idea: there’s so much excellent banter among those interested in wireless networking on Twitter that it might be nice to have someplace else to leave bigger comments, and have longer-running discussions. Perhaps a place where wireless’ most vocal can lay down their ideas and knowledge, and where anyone- ANYONE- can get in on the WLAN discussion and share ideas.

This would be a like if Twitter and the Airheads forum had a lovechild kinda thing, except all vendors and wireless technologies would be fair game. Though I’m smitten by the notion, I understand the potential for overload between all the various online niches competing for your attention. So I ask you- would something easy to use and lightly moderated be of interest? Here’s a mock-up:

WLAN Chatter

With live link to it here (it’s really just constructed to show the idea, right now).

To be worth doing, there’d actually have to be interest across the various wireless communities that manifest themselves on Twitter, in Higher Ed (like the Educause folks) etc.

Please leave a comment on whether you think this sort of cross-vendor, all comers-welcome, framework would or wouldn’t be worth bringing to life, and we’ll see what it looks like after a couple of weeks.

Thanks for participating!

Thank Goodness 5 GHz Is Done For American Wi-Fi

When you think about it, the whole 5 GHz thing has been a complete pain in the backside since it came to the Wi-Fi world. Sure, the 802.11a technology worked in cleaner spectrum than 11b and g back in the day- but it was so complicated. We all had to learn some new numbers and acronyms, and that in itself really sucked.  Sometimes 5 GHz rubber ducky antennas were flat or squarish instead of round. It was pretty over-the-top. But looking back, it got worse… MUCH worse.

With 802.11n and 11ac, utter craziness set in. They were doing this “wide channel” thing, and the 2.4 GHz band started losing users. Clients were getting faster speeds and better overall Wi-Fi experience in that ridiculous 5 GHz band. What is THAT? Like seriously- common clients had the gall to adapt to 5 GHz… And the WLAN vendors! Holy crow, those idiots out in the Silicon Valley actually made dual-band access points! What in the name of all things decent and technically prudent were they thinking?

And then there’s Apple. Just shut up about Apple and all of the kick-ass 5 GHz radio hardware they like to use. You can see where all of this is going… some pencil-necks at the IEEE got a wild hair, this 5 GHz debacle gained traction, and a bunch of users and industry muckety-mucks thought life was better with 5 GHz and dense deployments than when range-oriented 2.4 GHz was king.  Idiots…

Just in time, Globalstar has come along to save us from ourselves and our 5 GHz delusions. With keen analysis and the assistance of hyper-astute experts backing the company up, Globalstar has rightly put the ignorant masses in their place when it comes to the silly notion that 5 GHz has any relevance on the American Wi-Fi landscape. Thankfully, the satellite company has prevailed, and is convincing an equally astute media that their seemingly wankerish channel 14 TLPS juju truly is the Holy Grail of Wi-Fi Goodness for data starved Americans. Forget about all of those confusing channels in 5 GHz- THEY DON’T EXIST. Those channels and all of that speed and spectral cleanliness are dead to us. Which makes the TLPS thing that much more sexy.

Back to where we started- between what’s there now and what’s coming, there are freakin’ dozens of channels and a couple hundred confusing MHz in that pesky 5 GHz spectrum. We just don’t need the complexity, and Globalstar is smart to bring us back to like 1993, when things were so much simpler. By spinning it right, we simply disregard 5 GHz! That leads us to the payoff of TLPS:

Full article

Full Article

Forget for a moment that IF 5 GHz was still relevant, Globalstar’s single-channel 14 TLPS play would add some spit in the bucket to TRUE “US Wi-Fi Capacity”.  Those days are evidently behind us, because I read it on the Internet and in Globalstar’s pitch for TLPS approval. The simple elegance of this mindset is easy to appreciate.

I had three channels. Now I got another. Boom! I just added 33%. High fives!

You just have to discipline yourself to forget that 5 GHz exists. Now if you’ll excuse me, I have to go figure out how to tell 65% or better of my thousands of  users (those misguided souls on 5 GHz) that they aren’t using “US Wi-Fi”.

And that’s just un-American.

Handy TDR Capability In Cisco Switches- How Long Is That Attached Cable?

OK, so this isn’t exactly earth-shaking. Nor does it replace the accuracy of the calibrated Time Domain Reflectometer (TDR) functionality found in your garden variety higher-end UTP tester. But at the same time, there is a TDR utility built into certain Cisco Catalyst switches that provides some handy diagnostics of the physical layer. If this is old news to you (and yes, it has been written about in other places through the years), just click on off to more interesting terrain. If you’re not familiar with the notion, please continue reading.

A Real-World Example

This morning, I got an alert from one of my far-off sites that a wireless access point went off-line. I accessed the switch that the AP should have been connected to, and saw that indeed the interface for the AP was down. Looking in the switch’s log, I could see where the port went dead before I got the alert. So… either the AP itself failed hard enough to show no link, the switchport itself died (unlikely), or I was facing a physical layer problem.

So an AP mysteriously went out as verified by the switch log… Now let’s figure out where it got disconnected. First, login to the switch. My issue was on Interface Gig 0/46, so my whiz-bang TDR command looks like the following (with switch feeback shown):

Switch#test cable-diagnos tdr int gig0/46

TDR test started on interface Gi0/46
A TDR test can take a few seconds to run on an interface
Use ‘show cable-diagnostics tdr’ to read the TDR results.

 OK- so the test ran. Then to see the results:

Switch#sh cable-diagnostics tdr int gig0/46

TDR test last run on: March 10 10:18:06

Interface Speed Local pair Pair length        Remote pair Pair status
——— —– ———- —————— ———– ——————–
Gi0/46    Pair A     66   +/- 10 meters N/A         Open
               Pair B     70   +/- 10 meters N/A         Open
               Pair C     70   +/- 10 meters N/A         Open
               Pair D     67   +/- 10 meters N/A         Open

 What’s It Mean?

Given that we see all pairs open at around 70 meters from the switch, it’s a good bet that the AP got disconnected at the field end. Had the length been a meter or two, you’d guess that the problem is closer to the actual switch itself. If this was a new cable with no host device at the end, you’d get a general sense of the characteristics of the overall cable and individual pairs and whether any obvious problems could be afoot.

In this case, I was able to track someone down on the far end via telephone who was able to explain that construction was going on in the vicinity of the problem AP, and that it was in fact disconnected as a result.

Again, this is hardly revolutionary, but certainly is as handy as the likes of “show cdp/lldp neighbors”, “show power inline” etc when trying to figure out why an AP on a Cisco switch may be misbehaving.