Hi,
**LOOK ON THE PDF ATTACHED TO THIS POST-ISNT UPDATED SO MUCH - BUT WILL GIVE U SOME CLUE**
IAP is close to a contoller in capabilities but is not eqaul. Depending on your deployment requirements you might need one or the other. Currently these are some of the features that are available in a controller but not on an IAP.
(off the top of my head)
Spectrum analysis
L3 roaming
DHCP fingerprinting
VIA and VPN client termination
Site-Site VPN
This may change in the future.
Normally if customer is looking at security features we would go for the controller base as it comes with PEFNG and RFP etc and support RAP at the end of the day. As for roaming is L2 versus L2 + L3.
Besides some feature difference, also consider the following.
A controller simplifies VLANs at the edge. You do not have to worry about deploying VLANs.
A controller will manage both your wired and wireless Aruba network. All clients, wired and wireless, have the same policy.
A controller provide remote functionality such as VPN and Remote APs to extend your network.
Aruba Instant will scale, now beyond 16APs, but are limited to a L2 subnet. Using basic network architecture rules, A class C subnet is 256 users. It's best to keep a subnet to that limit. For a Class B flat network, while IAP and Controllers will both manage much more than 256 users, you should be careful. Large L2 subnets create a lot of chatter and the network can and will have issues.
ALSO CONTROLLER WILL GIVE YOU:
-an option for HSPA+ backhaul
- flexibility to use the multiple ports as 'legs' into different networks (e.g. admin, guest, internal).
- Assuming you are already trained in Aruba OS (AOS) then == zero learning curve
If you are trying to make this site 'look like' other corporate sites (say HQ) then I would go controller, and do master--local. If on the other hand its a one-off site and never needs/wants to be in sync with other sites than Instant (IMHO) is a good candidate, if you don't need any of the 650 additions that have been mentioned in this thread already.
Hope this info helpd u