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iOS 6: Wi-Fi network roaming with 802.11k and 802.11r #BYOD

Is it me or is it hard to keep up with all the little details. Add this to your bookmarks, could come in handy!  ~~ Thanks Scott for referencing this ..

Summary

Learn how iOS 6 improves client roaming using the 802.11k and 802.11r Wi-Fi network standards.

Products Affected

iPad, iPhone, iPod touch

iOS 6 introduces support for optimized client roaming on enterprise Wi-Fi networks. The 802.11 Working Group standards k and r were conceived to give wireless clients the ability to more seamlessly roam from access point (AP) to access point within the same network.

802.11k

802.11k allows an iOS 6 device to quickly identify nearby APs that are available for roaming. When the signal strength of the current AP weakens and the iOS device needs to roam to a new AP, it will already know the best candidate AP with which to connect.

802.11r

When an iOS 6 device roams from one AP to another on the same network, 802.11r streamlines the authentication process using a feature called Fast Basic Service Set Transition (FT). FT allows iOS 6 devices to associate with APs more quickly. Depending on your Wi-Fi hardware vendor, FT can work with both preshared key (PSK) and 802.1X authentication methods.

Coupled with 802.11k’s ability to quickly identify the target AP, FT’s faster association method may enhance application performance and aims to provide a better Wi-Fi experience in iOS.

Additional Information

Not every Wi-Fi network hardware vendor currently supports 802.11k and 802.11r. Check with the manufacturer of your Wi-Fi hardware (controllers and APs) to determine if support is available. Once support for both standards is verified, 802.11k and FT functionality must be enabled. Setup methods vary; please consult the current configuration documentation for your Wi-Fi hardware for details.

The table below indicates which iOS devices can support 802.11k and 802.11r with iOS 6. Even if an iOS device does not support 802.11r, iOS 5.1 added support for “pairwise master key identifier caching” (PMKID caching) which can be used with some Cisco equipment to improve roaming between APs. Additional SSIDs may be necessary to support both FT-capable iOS 6 devices and iOS 5.1 devices.

The following table shows which iOS combinations of version and device will support which AP roaming methods.

ios.apple.device.list

 

  • Prior to iOS 5.1, no method for optimized AP roaming existed in iOS.
  • “Sticky key caching” (SKC) is a form of PMKID caching. SKC is not equivalent to, nor compatible with, opportunistic key caching (OKC).

 

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George Stefanick

George Stefanick

5 Comments

  1. March 7, 2013 at 11:40 am — Reply

    Additional SSIDs may be necessary to support both FT-capable iOS 6 devices and iOS 5.1 devices.

    That’s a tall order…

    • March 7, 2013 at 11:58 am — Reply

      Tall order indeed. I didnt say I agree with their recommendations 🙂

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