I love the scene in Braveheart where William Wallace (Mel Gibson) inspires an outnumbered, tag-team of Scottish country warriors to a major defeat of the English army. So, what does this Academy-award winning movie have to do with the WLAN controller vs. controller-less debate we are seeing today? Sons of Scotland (a.k.a. my fellow Wi-Fi techies), read on!
(To gain some inspiration, see the above-mentioned clip from Braveheart here: http://www.youtube.com/watch?v=lEOOZDbMrgE )
First, a brief history lesson on the WLAN controller (I hesitate even presenting this historical depiction; WLAN controller history is well-documented by other Wi-Fi experts on the web, but I provide this here for unfamiliar readers). The first WLAN access points or APs (circa 1999) were autonomous – meaning each one had to be individually configured and controlled. It became apparent (very quickly to large organizations) that some type of centralized AP control was needed and the WLAN controller was developed (circa 2003). However, as processors evolved and became more powerful (and cheaper!), it was seen that the hardware controller function could be pushed out to the edge (to the AP itself) and a new type of WLAN management was born: the controller-less Wi-Fi solution. These controller-less solutions come in a few different flavors (some do control via a console manager, others are fully cloud-based control), but all these controller-less solutions have one thing in common: no hardware controller device is involved in managing the Wi-Fi network.
The history lesson is over; now, back to the “battle”! Well, honestly, is it a battle? I have not yet seen vendors drawing their swords, ready to lop off someone’s AP external antenna. But some of the rhetoric between controller and controller-less vendors has been quite testy at times! So, as a Wi-Fi professional who has no bias in this conflict, I’m asking myself: today, why is a controller needed? Can WLANs be set up without controllers, no matter the size of the organization? Is the controller-less route the best way to design a WLAN? Can every vertical benefit from a controller-less solution? Or maybe the question I really should be asking is this: do I join the English (controller) or the Scots (controller-less)?
Controllers do perform important functions in the WLAN. The management and control planes need network oversight and data must be forwarded (distributed or centralized); the WLAN controller indeed performs these functions. I work at a large utility vertical that uses controllers which work well and will be around for the foreseeable future. But the controller-less solution can do all the same functions as that of a controller and in addition, it will eliminate latency, complexity, single points of failure and traffic bottlenecks. And did I mention cost? No controller(s) = a huge $$ savings! Moving management to the edge is also becoming a necessity for bandwidth-hungry applications (VoIP, HD video streaming) and for 802.11ac. So after watching the mighty English battle those scrappy Scots over the past few years, I am ready to make a BOLD statement (and here it comes….): For any WLAN, the controller-less solution needs to be the architecture solution of choice. Period. End of discussion.
Wait–what is that noise you hear? It is my Claymore, coming out of its sheath! I am joining the ranks of William Wallace and the Scots!
Recently, a Wi-Fi blogger posted a January 2012 talk from Devin Akin (CWNE #1, now Chief Evangelist with AirTight) about how the controller-less solution will some day become the standard for WLANs everywhere. Since he used the term, I will call this Devin’s “flag in the sand” speech. Watch it and see if Devin is correct – vendors will copy the controller-less solution, or they will die! http://www.vimeo.com/35697535
And, is Devin (or should I say, William “Wi-Fi” Wallace) not right? Look, here is a non exhaustive list of vendors who are controller-less (by design) or have added controller-less solutions to their repertoire: AirTight, Aerohive, Aruba, Cisco (via Meraki), Enterasys (now part of Extreme Networks), Motorola, Xirrus. No, what you are seeing is not adjacent channel interference affecting your bit error rate — indeed, the Scots are gaining ground every day!
Is the “battle” over? Hardly! The English continue to wield their might, installing their controllers all over the inhabited world while the Scots continue to skirmish, installing controller-less solutions hither and yon. But the battle is turning! More and more WLANs are going controller-less. And as 802.11ac becomes the Wi-Fi standard, I predict that there will be a rush of businesses fleeing the English ranks toward the Scottish Highlands.
Sons of Scotland, Alba gu brath (Controller-less forever!)