Using Wi-Fi roaming with iPhone and iPad
Cisco wireless controller release 8.3 or later supports two wireless network improvements, Adaptive 802.11r and Fastlane. Any device running iOS 10 or later and iPadOS 13.1 or later supports Fastlane.
iPhone and iPad and Cisco networks recognize each other, allowing the devices and network to use the latest Wi-Fi technologies to optimize the experience. Both roaming and device battery life have been improved with features like:
802.11k to deliver the list of neighboring access points
802.11r and Cisco Adaptive 802.11r to help iPhone and iPad quickly and securely roam between access points
802.11u to enable easy and secure Wi-Fi service discovery and connection
802.11v to help identify the optimal wireless access points for roaming
At the end of this chapter is a table listing iOS and iPadOS devices and their supported standards.
802.11k allows your iPhone or iPad to quickly identify nearby access points (APs) that are available for roaming. When the signal strength of the current AP weakens and your device needs to roam to a new AP, it will already know which AP is the best to connect with.
802.11r streamlines the authentication process using a feature called Fast BSS Transition (FT) when your iPhone or iPad roams from one AP to another on the same network. FT allows iPhone or iPad 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.
Adaptive 802.11r allows you to set up a network without explicitly enabling Fast Transition. This configuration still grants the option of FT to devices. iPhone or iPad and Cisco APs mutually signal that adaptive 802.11r is supported by the network and that FT can be used. Legacy wireless clients that don’t support 802.11r can still join the same network but won’t benefit from faster FT roaming.
Organizations use 802.11u (also known as Wi-Fi Certified Passpoint or HotSpot 2.0) to allow their users to automatically move from Wi-Fi network to Wi-Fi network—similar to cellular roaming—without changing any sign-in information. When a device detects an authorized 802.11u AP, the device automatically connects to that network.
802.11v provides additional information about nearby APs that could be optimal candidates to join. When iPhone or iPad decide they need to roam, the BSS transition data (supplied by the network) helps the device quickly decide which APs are best for roaming.
Prioritization of apps
Various standards exist (802.1p, DSCP, 802.11e/WMM) to help network devices agree on how different types of traffic are marked to ensure higher priority. Fastlane greatly simplifies this agreement process between wireless client, wireless network, and wired network so that application packet congestion is minimized and time-sensitive traffic (like voice or video) is delivered on time. Organizations can then install configuration profiles on iPhone or iPad that allow only specific business apps to get priority. The Cisco network looks for these markings and provides the correlated service level.
Roaming optimization support
The table below shows which iPhone or iPad can support 802.11k, 802.11r, and 802.11v. Even if a device doesn’t support 802.11r, all devices support PMKID caching. With this type of caching, the device checks the pairwise master key (PMK) ID sent by the client. You can use PMKID caching with some Cisco equipment to improve roaming between access points. Another form of caching—sticky key caching (SKC)—optimizes roaming back to previously associated access points. SKC isn’t equal to or compatible with opportunistic key caching. Note that if you want to support devices that are FT capable and that have PMKID caching, you may need more service set identifiers.
iPad Pro or later
iPhone 6s or later
FT, PMKID caching
iPad Pro, iPhone 5c/5s or later, iPad Air or later, iPad mini 2 or later
FT, PMKID caching
iPad 5th generation or later
FT, PMKID caching
Note: Refer to the release notes for your installed version of Cisco AireOS to determine 802.11r, 802.11k and 802.11v support.