Tuesday, September 17, 2013

SMS Authentication- A Nice, Easy Way To Do WLAN Guest Auth

For wireless guest access, there are all kinds of ways to skin the cat. In a perfect world, Hotspot 2.0 will take care of authentication and encryption, and all would be sunny to everyone's satisfaction. But, that ain't happening for a while (if ever). It's becoming more popular to tie guest access to social media "credentials" (a bit of a joke to call 'em that), as there's usually some marketing hook behind that, and some networks really don't care WHO you are, like really.

But when you need to have some level of accountability on your guest network for whatever reason, using SMS-based authentication is not a bad option. You can front it with a WPA2 PSK or leave it open (everyone has different use cases, business drivers, and policy), but for answering the challenge of "make it easy on 'em but still let us have some bit of real, verifiable information to tie to a person", SMS-based auth is hard to beat. 

Years ago, I set off on a quest to find a wireless guest solution that was easy to support, easy for users to self-provision through, and that met our organizational requirement that guest sessions not just be tied to some bogus email account (the joey@asscrack.com thing is funny only so many times in a row) but to use 10-digit cell number as the "User ID". Though we were a Cisco WLAN back then, Cisco couldn't come close to fulfilling our simple requirements. Rumor was that Coloubris had a gateway that might work, but this was around when HP bought them and we literally couldn't find a human being walking the earth that could tell us anything meaningful about that gateway. Then there was Bluesocket (now ADTRAN). When I first approached them with my needs, they- like Cisco- couldn't do the self-provision SMS based thing. And like Cisco, they tried telling me that if I was willing to change my requirements, they could provide a solution. But when I pushed back, Bluesocket was willing to do a little bit of development and was able to provide something that really was ahead of it's time (we're talking like 2006 here):

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Sure, it's not so impressive today given that there are now lots of other guest portals that do SMS, but it still works very well, and is what we continue to use at my University because it does work well. Unfortunately, you have to invest in a full-blown Bluesocket appliance to get the functionality, but even that's not all bad.  The appliance works well as DHCP, firewalling, NAT, rate limiting, quarantine, MAC exception home for odd stuff that fits nowhere else and a handful of other guest-relevant functions, but also has (and is over-priced based on) lots of Bluesocket-specific WLAN stuff you'll never use if you don't have Bluesocket APs. And the appliance hardware is pretty dated. But... on balance, this has been dynamite- and is the only off-the-shelf 3rd party gateway kind of thing  that I'm aware of that you could bolt on to anyone's WLAN and make work if you didn't like what your native solution does for guest access (Sorry Cisco, you still don't get it as far as I can tell).

Then there's Meraki's version. The SMS auth groove is new to Meraki, and they still have some development to do on it before I'll sing it's praises too loudly, but it works well. I'm about to deploy it in a unique situation, and am pretty pleased with it's slick integration to Twilio as the SMS provider, and that I pay nothing extra to Meraki for exactly the SMS auth feature I want:

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No extra appliance needed, no additional fees, and it works so, so nicely with the rest of the magic in the Meraki cloud-managed wireless solution.  Where it is feature-thin, I can work around until they tighten it up (and I did make my wish last week, so I'm assuming the elves on Mount Meraki are almost done already). It only works with Twilio as the SMS service, but that's OK as Twilio is cheaper than cheap, and each texted password costs you a penny. (We use Message Media for the Bluesocket, is more expensive and less snappy in my experience).

Anyhow- If you've never gone the SMS path for guest access, I can vouch for it's effectiveness. Though I personally have no use for social media logins, I understand the appeal in certain markets (but would never use my own accounts for guest access- I'd rather go without). SMS is just another option to consider. Combine it with Personal PSK, and I think users and admins would both win, at least in my wireless world.

Pssst- If you have a Dashboard, Meraki is easy to try- and you get 25 free Twiio interactions so you can feel what the experience is like for texting the auto-generated password from your own easy-to-customize splash page before signing up for a Twilio account.

(I find Twilio almost as much fun to say as LaserFiche, by the way)

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