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 into.amazon 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.

The evolution that will start the revolution


I like Sam’s take on something I demanded early on in the 11ac arc. Have a read, see if you don’t agree.

Originally posted on SC-WiFi:

You’ve heard it all before, evolutionary technology versus revolutionary technology. Everyone wants their newest technology to be revolutionary – expecting it to be life changing and a wide-sweeping, compelling reason to spend tons of money. This is rarely the case and more often than not marketing fluff to try and get you onto the next big thing. Occasionally we get such an unassuming technology announcement that fits squarely in the ‘no big deal’ from a speeds and feeds perspective that it’s easy to overlook. This is clearly the case with the recent multigigabit announcements from Cisco during Cisco Live, Milan. Multigigabit is a technology that allows your existing cabling to support speeds in excess of 1G, without having to make the jump all the way to significantly more costly 10G. Since we already have technology that address speeds and feeds above what we’re talking about here (how many 10G…

View original 529 more words

Ugh- More Misinformation on 802.11ac

There’s enough bad writing out there already when it comes to wireless networking. We see article authors taking gadgets for a ride on their home networks, falling in love with them, and declaring whatever it is to be THE NEXT BIG THING FOR THE BOARDROOM! -With no regard for the fact that boardrooms are usually in corporate settings where business wireless networks are in use that have vastly different operational characteristics than the home networks where they tested said gadget…

Then there’s the crazy, fun, imaginative, truth-stretching WLAN marketing that usually takes a white paper to explain how the claims were arrived at, with methodology that would impress even a dodgy congressmen on the witness stand to the point of blushing.

I guess these aspects of the greater wireless networking paradigm have always been there to different degrees. With 802.11ac, we compound the Fog of Wireless War with Wave 1 and Wave 2 and big numbers in the standard that may or may not ever be realized. So be it… but every now and then something makes it to print that just feels… damaging.  

People read this stuff, and form expectations and plans. Even a cursory look at Wikipedia would have set this right:


I’m not trying to bash the writer personally, as I don’t know him or her. But as a writer, I really have to wince when I see something this off base and I picture the misconceptions it can propagate, and the ripple effects those misconceptions can have when the information presented is taken as factual. 802.11ac is already confusing enough, this sort of thing really doesn’t help.

Don’t Forget to Have Fun With Your Technology!

I count myself among the lucky folks who absolutely love their day jobs. It helps to have a great chain of command, a solid organizational technology foundation to operate from, and some really great (and intelligent) coworkers. But all of those trappings are just bonuses- the real, deep satisfaction comes from geeking out, designing and building networks, researching and recommending solutions, solving problems, learning something every day, etc.

Being immersed in technology brings fulfillment that you either understand, or you don’t. Most of you reading this likely get it.

But when you’re an addict, you always gotta have more. For me, networking is wonderful business- but I also need to do amateur radio and listen to scanners and strain my ears and receivers to hear far-off, arcane aeronautical beacons (nothing whatsoever to do with iBeacons, though some could argue they have a lot in common to the imaginative mind). I have a need to blog, to talk about the good and bad of technology as I see it with anyone willing to engage. Some of my best fun came when I wrote the bi-weekly hobby radio column for the local paper for around five years. Lately, I’ve added another dimension to my technology mania, and it’s proving to be as enjoyable as I hoped it would be.

I’m doing a technology series for my local community, covering these topics:

  • The dangers of public and unknown Wi-Fi
  • Alternatives to Cable TV
  • How to set up your own home network for optimal performance and security
  • The many things you can do with mobile/portable devices beyond Internet and email

Being a long-time professional instructor, I’m having a great time putting the 2-hour sessions together. I have them chock full of demonstrations, and the conversations and reactions to the topics are wonderful. I’m guessing at least 2 hours goes into prep time for each session, and my wife is giving me “that look” as I scurry around the house with a maniacal grin, popping up different test demos before I call each session “ready”.

Here’s a bit more on each topic, as I’m doing them:

  • Dangers of Public/Unknown Wi-Fi: Talking about Social Wi-Fi, how “Engagement” is a double-edged sword. Using the Pineapple in live disussions to show Karma, Randomroll, and Occupineapple as examples of how easy it is to distort perceptions of reality, then SSL Strip to harvest credentials.
  • Cut the Cord! Showing the finer points of OTA reception, with emphasis on the importance of the antenna- using both a TV and a USB TV-tuner stick with Windows Media Center. Then showing all the stuff you can get over the Internet for free (Crackle, YouTube) and the paid offerings like Netflix/Amazon Prime with Chromecast and Firestick Dongles, in live demonstrations.
  • Setting your network up the right way: Setting up a SOHO router with best practices like changing defaults, disabling unused services, finding the best non-overlapping channel, etc. Talk about router placement, how to overcome weak signals in big houses, etc. Discuss interference sources, and the yin and yang of letting visitors onto your home Wi-Fi.
  • Fun stuff to do with your devices: From scanner apps (both kinds- listening to Emergency Comms and scanning documents to PDF) to Geocaching to tracking aircraft live with a $20 dongle to Internet radio, we cover a lot of ground here. I’ve found that many people simply don’t know how multi-dimensional (both online and offline) their devices can be until someone shows them a taste.

For the folks attending, they get a cheap, interesting night out. I have no doubt they are learning a little something along the way. For me, I get to conceive the “curriculum”, put the demos together, challenge myself under the spotlight of dozens of live demos, and basically lug around a bunch of gadgets to play with and talk with people about.

This was a bit of an experiment when I dreamed it up, and now that I’m into it, I’m glad I took the chance in getting buy-in from the local community council. It’s thoroughly fun, and it’s a different way to enjoy a lot of the technology I’m that enamored with. And… I get to hang out with local residents that are at least curious, if not as into it as I am.

I highly recommend doing something like this at least once- give back a little of what you know, and have fun doing it.