It seems that having an independent system (AirMagnet) provides a truly independent view of the network regardless of the AP supplier. However, the Cisco approach only works if it's used with Cisco APs (I assume).
This also could lead to a follow-up on economics. Which is the more cost-effective method?
What are the pros and cons?
Can CleanAir work in conjunction with non-Cisco APs?
Integrated vs. separate management?
Along with the clear advantage of being vendor independent to allow spectrum management for any infrastructure vendor, the AirMagnet solution also offers top value to the user at the most affordable price. The 24 X 7 distributed solution uses spectrum sensors deployed as an overlay solution. In contrast, infrastructure vendors may offer a couple of options like Neil mentioned: 1) part-time scanning or 2) the overlay option when the requirement is for full-time RF spectrum monitoring. For reducing equipment and deployment costs, part-time scanning may be a desired solution for a certain group of users. Part-time monitoring solutions scan the RF environment (or only part of the spectrum on which the AP is operating) on a part-time basis (re-using services of the same AP providing data client access), but may not be able to efficiently monitor and detect a variety of interference issues occurring in the environment as they are not monitoring the entire spectrum continuously. Basically you can only see when and where you are looking! For example, a hopping device could be missed easily. So, dependent on the importance of RF spectrum analysis and management for the IT organization to ensuring top performance of the network, the overlay architecture must be the ideal mode of deployment. In the case of an AirMagnet overlay architecture for spectrum management, you need spectrum sensors that plug into any switch in your network and the centralized server/its associated software. While in the case of infrastructure vendor solutions, there are huge hidden costs, especially with regards to all the controllers to which these APs need to be connected. Additionally, I would also focus on the other pros of the independent solution in the “Is it adequate for an enterprise to scan only the channels that it is using? Why or why not?” section.
With the Cisco solution, you can acutally deploy in three ways:
1) Deploy 3500 APs in Local Mode, where they serve traffic and monitor spectrum on the active channel.
2) Deploy an overlay of 3500 APs in Monitor Mode, where they monitor spectrum on all channels.
3) Do both (1) and (2).
In terms of capability, option (3) is the best.
In terms of cost, option (1) is very cost effective.
If you have an existing network that you don't want to replace, then option (2) can make a lot of sense. And to your question, the existing network does not necessarily need to be Cisco.
Thanks, Neil.
Can you say a bit more about "Local Mode" versus "Monitor Mode"?
In "Local Mode," are only selective channels monitored? (Why would I ever want to do this?)
Is there a price differential depending on which modes are activated?
If not, then if I were to choose option (2) then wouldn't I be essentially "wasting" the capability to serve traffic?
In "Local Mode", the AP does 2 things at the same time: 1) serves traffic, and 2) monitors for interference on the current (active) channel. The reason a Local Mode AP does not perform spectrum scanning on other channels is because this would impact the ability of the AP to serve traffic.
In "Monitor Mode", the AP is dedicated to scanning. Since it is not serving traffic, it is free to scan on all channels without impacting performance.
There is no price difference depending on which mode is activated. But since Monitor Mode APs do no serve traffic, they are typically "extra" APs that are added to the deployment (in addition to the traffic-serving APs).
Thanks for the clarification!