In this blog, Jeff highlights Aerohive’s built-in Spectrum Analysis; one of the tools most helpful to even the most puzzling troubleshooting situations, and available today in most of Aerohive's current access points.
One of the least discussed yet most powerful functions of Aerohive’s HiveManager is the Spectrum Analysis troubleshooting toolkit that is included in the product. As a Pre-Sales Engineer, I constantly tell people that any 
tool or process that we can provide that keeps our customer, the network admin, in their seats makes them more productive and useful to their customer, the end user.
The minute that admin has to leave their desk and walk, drive, or fly to a site, they are singularly focused on this one task. In contrast when working at their desk, they can multitask and handle the myriad of jobs and roles that are thrust upon today’s network administrator.
A great story that illustrates the use of this product (and kept my customer in their chair) happened recently to me while in my home state when I visited a customer to perform a network health check and configuration optimization session.
While we were exploring their maps looking at the channel and power layout that ACSP (Aerohive Channel Selection Protocol) had implemented for them, an infrequent problem came up. The problem shows itself only when they have their all-hands meetings in their large conference room upstairs. Normally they have no problems in the upstairs office spaces nor during the countless meetings in that location, their largest conference room. They usually have a great network experience, but consistently during their all-hands meetings connectivity problems would occur.
Naturally the discussion, and how it was presented, took us into a discussion on user density versus AP (Access Point) density.
It became quickly apparent that the deployment of the AP in that room and the others in the surrounding area provided sufficient coverage for their infrequent high end user density so we moved our investigation to other avenues. We enabled Aerohive’s WIPS (Wireless Intrusion Prevention System) and monitored the environment for sources of 802.11 interference such as rogue APs and, more importantly, ad-hoc rogues (more of this topic in a future blog.) That quickly became apparent as strike two.
My next step was to turn on our spectrum analysis toolto look for non-802.11 interference. This quickly showed us the problem. 
A meeting was happening in that room during our investigation between their office at headquarters (where we were) and one of their satellite offices on the east coast. Being a technology company, they utilize numerous high-end gadgets in their office and one of those was a wireless HDMI kit that allowed an untethered user the ability to display on the large mounted displays in the room without having to attach to an anchored HDMI cable.
Unfortunately this “wireless HDMI” used proprietary protocols and a broad swath of the 5 Ghz U-NII 3 spectrum. This solution was interfering with the Aerohive access points in the area on their 5 Ghz radios. To verify this was the problem we turned off the wireless HDMI solution after the meeting and showed that the source of interference went away. We were able to then move the access points surrounding the room to a different U-NII band and channel and thereby avoid the interference in the future.
Q) Now a critical reader is going to ask, shouldn’t Aerohive’s ACSP and interference detection algorithms have detected and resolved this issue automatically? Let me add some Aerohive science content to answer these questions.
A)ACSP is configured, out of the box, to select the optimal channel and power for a given set of access points or hive, when it is run. Due to the fact that changing channel in the middle of a data stream would be highly disruptive though, ACSP is only configured to run on boot up out of the box. Customers can easily, and it is recommended to, configure ACSP to run at a specific range of times and only when below a threshold of connected users.
Unfortunately many customers do not implement this (and this was one of the many topics that we were discussing before this problem came up.) Further investigation showed that Aerohive’s HiveManager did indeed have alarms showing that we detected the interference but, due to the fact that this display system was usually kept off and only used for remote meetings, these alarms would clear themselves once the interference source, the wireless HDMI, was turned off.
Another interesting addendum to this story is that users in smaller meetings were not affected because they were naturally roaming over to the 2.4 Ghz radio on the access points and thereby avoiding the interference caused by the wireless HDMI when it was on. The problem only became apparent when the user density required the use of both radios in our access points to service the load. Then the segment of the population on the 5 Ghz radios experienced problems and the 2.4 Ghz radios became overcrowded and unusable as well.
I am happy to report that the latest all-hands meeting went great for this company and they have continued their remote Aerohive roll out.
Aerohive’s ability to troubleshoot problems remotely and provide a tool kit that keeps a network admin from having to walk, drive, or fly to a location to debug and understand a problem were a huge part of the success of that particular deal. It’s a wonderful experience to see a customer discover a tool in their toolkit that they already have and watch their productivity soar.