Thanks. Don't think its a problem of iOS as keep alive as if you set the key caching to 600 mins once it has cached the keys it will work for 10 hrs but once the cache has expired then next connection fails. It's not on an active directory network. Have tried using the built in Radius server and Radius server on Qnap NAS. Both the same results.

right I have just downloaded a Radio app to my phone (5S) and walked from one end of the building to another. (that goes via at least 3 Access points) and the radio never stopped playing.
I also tested it on the normal WPA2/PSK network that's not Radius (Separate VLAN) and that still stayed connected throughout - We are not using the keep alive

Do the 900's support 802.11k & 802.11r?

Has this been resolved? I am looking at buying a couple of AP-900s to use with my 2860 and to replace an old 2800VG (which was used as a WAP but has finally died) and a TP-LINK TL-WA801ND. Roaming is one of the features that attracted me to these WAPs.

Not resolved as far as I'm concerned if you have an SSID configured to use the Radius server then I have numerous problems.

I need to find some time to do some more investigations - but due to pressure of getting things out the door have switched to not using Radius server at the moment and the AP's work reasonably well. Although strange you posted this now as I did have a new mobile last week and set it up to use the Roaming but switched it off this morning as it kept losing the WiFi Connection when moving between AP's - Works better without roaming.

Jon

I presume you've checked everything off against the AP-900 - Managed Wireless Knowledgebase Article .