The role of the wireless LAN controller appliance is shifting dramatically. The days of the dumb access point are severely numbered. Motorola became just the latest WLAN vendor to deemphasize the role of its controller appliance in its architecture with its new WiNG 5 architecture.
As we know enterprise wireless LAN used to consist of a bunch of independent, “fat” access points that were basically islands of wireless with no centralized control. Then vendors like Aironet (now Cisco), Motorola and Aruba started introducing a controller-based WLAN architecture, which was much more scalable and (eventually) much more secure. This change opened up Wi-Fi’s potential from isolated hot spots to campus-wide, centrally managed deployments.
Now vendors vendors are pulling back the controller’s role in enterprise WLAN. Meraki has moved its controller functionality into the cloud, building access points that are smart enough to survive on their own when contact is lost with Meraki’s cloud. Aerohive has distributed most of the controller functionality throughout its access points, with a simple management and policy piece sitting on a server.
Enterasys-Siemens’ HiPath wireless LAN product line has also deemphasized its controller in recent years. The HiPath access points manage QoS, encryption and RF management on their own, leaving the controller to handle configuration and policy control and roaming.
Now Motorola has committed to smarter access points, too, with its WiNG 5 architecture. With a simple software update, all of the company’s access points will now run the same software package as Motorola’s controller appliance. Apparently Motorola’s access points have enough compute capacity to handle this new functionality.
Like every vendor that has pulled back the controller’s role in WLAN, Motorola says the speeds involved in 802.11n can lead to a bottleneck effect in the controller. Dr. Amit Sinha, Motorola’s WLAN CTO, said that backhauling everything to the controller isn’t practical, especially when it comes to voice and video communications.
In demos in Boston this week, Motorola showed that the access points are capable doing things traditionally reserved for its controllers. In one demo, an access point that was isolated from its controller was able to recognize and adjust to RF interference. In a second demo, the isolated access point was able to detect a rogue media server running unsanctioned streaming video over the wireless network and cut off the access to that server.
Finally, Motorola demonstrated that by making its access points smarter, it can boost performance. It streamed unicast streaming video from a single wireless access point to 80 laptops, which earned it recognition for a new record by an adjudicator from the Guinness Book of World Records.
What remains unclear to me: Why is Motorola keeping the controller at all. I know there’s a need for centralized configuration, policy and other management functions, but why does Motorola need to continue holding onto the standalone controller appliance. Can’t those management functions be run on an industry standard server or as a virtual machine? If the access points are able to run the same code-base as the controller, surely the access points can handle the data and control planes of the WLAN architecture on their own and leave the management plane to some simple software. Motorola probably has a good reason for this but I didn’t hear much from them about it during their announcement of the WiNG 5 announcement.