Wireless Access

Can someone walk me through how tunneling on a campus AP works? To me it sounds like every bit of data must travel back to the controller before it makes it out to the rest of the network.  Is that correct? It seems to me like this would be a less than ideal scenerio because the controllers data link would be the bottleneck for all wireless users.

That is correct. In tunnel mode, the AP creates a GRE tunnel for each BSSID and tunnels all traffic back to the controller. This allows for central policy decisions, firewall processing, etc. We have about 10k simultaneous users across two Aruba 7240s each with two 10G uplinks to our distribution switches and we are nowhere near capacity.

We'd be perfectly fine with one 10G uplink but we use two for redundancy.

How do i check for utilization on my controllers network port?

We use a combination of AirWave and SolarWinds.