Which Apple devices support OKC (Opportunistic Key Caching aka PKC/Proactive Key Caching)

In enterprise wireless environments, access point roaming/hopping is very common. There exists a couple protocols/methods for making this seamless. That is, to make re-authentication when hopping to the next AP on an SSID smooth. One is called Opportunistic Key Caching or sometimes called Proactive Key Caching, abbreviated OKC or PKC. [Here is a PDF from Aruba Networks describing OKC/PKC](http://community.arubanetworks.com/aruba/attachments/aruba/115/1097/1/Aruba+OKC+Implementation.pdf) [Here is a Cisco page describing PMK Caching vs OKC vs CCKM](http://intermec.custhelp.com/app/answers/detail/a_id/13488/~/what-is-pmk-caching,-and-how-is-it-different-from-either-opportunistic-key) Windows and various Linux OSes support this protocol. Apple OSX supports a similar thing called Pairwise Master Key ID Validation (PMKID Validation). From the Cisco link, we see that OKC is preferable to PMKID Caching when seamless AP hopping is the number 1 goal. Question 1: - Does current OSX support the OKC/PKC protocol/method? How about current iOS? As of 2011, according to Aruba, Apple does not support OKC/PKC. Question 2: - Is PMKID Caching the same as PMKID Validation?