25 APs / Port Anchor WLC versus Guest WLC

Question

Greetings, first timer here.
We're adding public internet access to our existing wireless network. We are using a 4402 WLC for our guest controller, and our secure WLC is a 4404.
Cisco recommends placing a limit of 25 APs per distribution port, and we utilize that practice on our 4404. My question is, once we add the guest controller, which uses the same APs as the Anchor controller, do we have to re-apply the 25 AP/port rule to the guest controller?
The 4404 obviously has 4 distribution ports giving a max of 100 APs, and the 4402 has 2 resulting in only 50 APs. We've got all of our APs covered by the best practice on the 4404, but would exceed that on the 4402.
I thought that because the data is moving between the WLCs via the ether tunnel, I was covered by the 4404.
Thoughts or suggestions?
I can't seem to find anything in the white papers or best practices.
Thanks to all
Larry

Answer 1

I have no factual information to back up what I am about to say and it may be partially incorrect, but this is how I always explained the process of guest anchoring:
So the 25AP suggestion per interface I think is because of the fact that if you had more than 25 APs on one port, you could theoretically be over subscribing the bandwidth than the port could provide (25AP@40mbps = 1000mbps)....
Anyhow, unless you plan on actually sending a gig worth of traffic to your Guest Controller, I don't think there is any real need to split your anchor. I'm pretty sure Guest Controllers are usually for internet access and 1Gb worth of internet bandwidth sure seems like alot to me..
Also, I had always thought of the anchor tunnel similar in nature to an AP LWAPP tunnel. The controller that supports 25 APs is designed to support 25 LWAPP tunnels. The 50AP model, supports 50 LWAPP tunnels. This same logic could be applied to the WLAN Anchor tunnels. Think of each WLAN Anchor Tunnel as an AP connected to a controller.
When a guest is anchored to the Public Controller, it isn't the AP that is tunneled there nor the client, it is the WLAN. So you could have 25 APs with the same guest WLAN, but really it is still just 1 WLAN anchored to the controller. If for some reason you wanted to do more than 25 different WLANs, then I would suggest splitting those WLANS between your interfaces...
I think the bottom line though is that if you aren't worried about over-subscribing your interface on the anchor controller, there shouldn't be any concerns.