CSCut93712 - AP does not send RM IE for 11k in association response; no 11k for iOS > 8.1

[Toivo Voll]

Since it seems that currently 802.11k is broken (and TAC is telling me to just turn it off), and it's the #1 recommendation on Apple's enterprise roaming guidelines (https://support.apple.com/en-us/HT203068) -- how are others handling roaming for iPads and such? We have applications where people are attempting to use data connectivity while mobile and dropping the connection for 5-50 seconds just won't work.

[Aaron]

Hi Toivo,

It's true that 802.11k interop between Cisco infrastructure and Apple iOS is broken as of iOS 8.1, so for now you should turn it off.

I'm not convinced that 802.11k (whereby the APs provide the clients with a list of neighbor APs) provides a huge benefit in any case.

Much more useful, for your Apple iOS clients, is to turn on 802.11r ... this provides for fast roaming on SSIDs that use WPA2/EAP (and even speeds up WPA2/PSK.)

Hth,

Aaron

[Toivo Voll]

We did some testing on this, as our current SSID is dual-band and hidden, WPA2 EAP/PEAP MSChapV2, and iPad roams are atrocious, up to 40 second disconnects (iPad doesn't believe it has a working network connection and applications fail as such) as the iPad tries to find another nearby AP and associates/authenticates. This is in areas with fine coverage and at least three overlapping 2.4 and 5 GHz cells at -65 dBm or better.

The biggest gains we saw were from making the SSID 5 GHz only, broadcast and 802.11r. Earlier in the spring with those settings and 802.11k, we went around with a 0.5 second ping interval and roamed (intra-controller, no inter-controller or L3 roams) fine with longest delays on the order of .5 seconds and iPads never losing network.

Once we tried it again after the Apple update, we're seeing roam times of many seconds and dropped packets / failed pings, so 802.11k, or something in Apples behavior, seems to have made the difference between acceptable to unacceptable. Maybe not to the previous point, but still where hurting us and makes justifying rolling out the new SSID hard to justify (why add complexity and major changes if it's not going to properly fix the problem?)

[Aaron]

Toivo,

Thanks for the detailed followup ... I'm now willing to believe that 11k does provide some benefit :)

The good news is that we are actively working on getting 11k working (CSCut93712).  So if you're interested in this, you should definitely have a TAC case open, make sure that the case is linked to the bug ... if you're interested in / able to run some test code, we may be able to get you some (no promises.)  (And no predictions as to where/when the fixed code might show up on CCO.)

You also may be able to make some progress with an AppleCare Enterprise level ticket open, i.e. http://www.apple.com/support/professional/it-departments/ or http://www.apple.com/support/products/pay-per-incident.html ("Cross-Platform Integration").  11k or no 11k, a 40-second disconnect doesn't sound right.

Best,

Aaron

[Aaron]

FYI we soon will have some TAC/BU supported test code with the fix for 11k with Apple iOS devices.  And we do expect to have the fixed 11k implementation available relatively soon in CCO AireOS releases.

[Toivo Voll]

Great news, thank you!

[Alucidnation]

Ive just downloaded and downgraded to 8.0.121.0 (MR2 escalation) and there is no option for 802.11k or .11v now in the advanced tab.

Am i missing something?

[Alucidnation]

Ive just downloaded and downgraded to 8.0.121.0 (MR2 escalation) and there is no option for 802.11k or .11v now in the advanced tab.

Am i missing something?

*** Apologies for all the re-posts. For some reason my replies weren't showing up in the thread! ***

[Ross Weitzner]

Aaron:

I've been working with 802.11r since the introduction in 7.2.115, and the iPhone 4S. The only thing I can say is, proceed with extreme caution. I work for a software company, and we deliver mission critical voice, alarm and text messaging across a variety of handheld devices -- probably 60% of our clients are on some matrix of iOS/iPhone.

The short of it is this: When using iPhone 4S/5/5S with WPA2 FT-PSK or 802.1x-FT with 7.2.115 through 8.0.x code WLC code, we see the iPhone issue a proactive disassociation packet after a time period of 30-37 minutes of idle state. It will not rejoin the 802.11 network *reliably* until there is interaction from the user (press the home button and swipe the unlock screen).

In most cases the impact isn't significant, because APNS tries to deliver any traffic over the baseband radio. Our solution does not use cellular at all -- no SIM cards are present in the phones. So it's a problem for us. We've filed multiple Apple rdar tickets against this condition.

This may not be relevant to your business case; I'm just throwing it out there as informational. As an aside, we have one organization using IOS-XE with WPA2 FT-PSK, and the iPhones are staying connected. But we don't have very many road miles on that configuration.

YMMV

:-)

[Aaron]

Thanks for the heads-up, Ross.  Do you have a Cisco TAC case open on this topic?  And, do you have an enterprise-level Applecare support ticket?  If so, and if you would like to have Cisco TAC work with Apple to get this issue resolved, please let me know.

[Aaron]

Here's the good news - CSCut93712 is now fixed, so we again have 802.11k interoperability between Apple iOS devices and CUWN.

The fix is available in the following releases:

8.0:

• in 8.0MR2 escalation (8.0.120.6 and above), available now from TAC
• in 8.0MR3, to be released in February/March
• fix is in 8.0MR3 beta (8.0.122.21) now; see https://supportforums.cisco.com/discussion/12755726/80mr3-beta-availability

8.1: 8.1.120.0 and above

8.2: all releases

Cheers,

Aaron

[Alucidnation]

Ive just downgraded and uploaded 8.0.121.0 to try to see if iOS devices would be more stable, and there are no settings for 802.11k or .11v in the advanced tab now?

Am i missing something?

[Alucidnation]

Ive just downloaded and downgraded to 8.0.121.0 (MR2 escalation) and there is no option for 802.11k or .11v now in the advanced tab.

Am i missing something?

[Alucidnation]

Ive just downloaded and downgraded to 8.0.121.0 (MR2 escalation) and there is no option for 802.11k or .11v now in the advanced tab.

Am i missing something?