iOS 4.3 breaks Wireless N (802.11n) in 2.4 and 5 GHz bands on iPad, iphone4

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34 points

iOS 4.3 breaks Wireless N (802.11n) in 2.4 and 5 GHz bands on iPad, iphone4

It's not just in the 5ghz band as I first thought.

I put 4.3 back on things and did more tests..

4.3 prevents ANY iDevice , including the ATV2 from using 802.11n in any band.

Many ppl don't see this because their routers are in mixed mode. So for 5ghz ppl , the devices drop to 802.11a, and for 2.4ghz ppl, the devices drop to G.

I hate mixed mode on routers because it degrades performance(so I don't use it). So my 5ghz band is N only and my 2.4 is G only. So I noticed this right away. But once I set my 2.4ghz to n only mode , no idevice running 4.3 could connect to any band. nothing would touch it

This also is not a 40mhz vs 20 issue as my 5ghz was forced to 40 and the iPad and ATV used it just fine under 4.2.1, and i tried 20mhz N only on both bansd and still nothing would connect.

I'm a computer engineer and programmer so I troubleshooted every possible cause with this affecting all idevices, and what I see on the forums this is a HUGE screw up in the release of iOS 4.3

I'm just shocked there are NO press releases. 54Mbit is not enough to stream HD movies to an iPad. The iPad does not buffer to storage like the ATV2, it buffers to ram. So on a G/A network, HD video streams to my iPad then stops every 1-2 mins

However, I was able to downgrade everything to 4.2.1 again because apple is still signing it

I started a new thread , this one, with a better title so search engines, etc can find this info easier

Message was edited by: TallBearNC

Dell XPS 720, Windows 7

Posted on Mar 12, 2011 8:33 AM

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Answer 1

TallBearNC Author

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34 points

Mar 12, 2011 8:46 AM in response to TallBearNC

So if any of u want to test this. Put ur router in Wireless N only mode for 2.4ghz band (and also 5 ghz band if ur router does 5ghz)

So far, my friends with Airport routers ARE affected once they tried the above

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Answer 2

Mar 12, 2011 9:24 AM in response to TallBearNC

I have an Apple Airport Extreme set on 'n' only at 5Gz.

My iPad running iOS4.3 connects to it just fine! Furthermore the transfer speeds since the update seem to be nearly double what I had before.

I don't understand what is happening to other users, but it obviously isn't happening to everyone.

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Answer 3

TallBearNC Author

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Mar 12, 2011 9:33 AM in response to Merged Content 1

It appears that many airport extreme ppl are not affected, but I've yet to see someone with a NON Apple router working in n only mode at 4.3. If apple is trying to force ppl to buy airport routers, they just stepped in a big pile 😉. Tbh, I think this is just a nasty 4.3 bug

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Answer 4

TallBearNC Author

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34 points

Mar 12, 2011 9:35 AM in response to TallBearNC

I just got off the phone with tier 2 apple support. This issue is CONFIRMED. And it's being sent to tier 3 (engineering). Support says this issues affects all non apple routers and "some" airport routers (probably older ones)

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Answer 5

Maro10

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4 points

Mar 12, 2011 9:38 AM in response to TallBearNC

I have my iPad and iPad 2 on a net gear running 5ghz N and they both work fine.

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Answer 6

TallBearNC Author

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34 points

Mar 12, 2011 9:43 AM in response to Maro10

Put ur router in N only mode and see what happens. Many ppl have their routers set to fall back to A at 5 ghz or G at 2.4

I'm using a cisco e4200.

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Answer 7

Maro10

Level 1

4 points

Mar 12, 2011 10:59 AM in response to TallBearNC

My router is in "N" only mode. I checked it again. 5ghz n only mode

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Answer 8

Mar 12, 2011 11:13 AM in response to TallBearNC

My iPhone 4 is plagued by this exact problem, I hope Apple fixes this soon.

*eagerly awaiting 4.3.1*

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Answer 9

TallBearNC Author

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34 points

Mar 12, 2011 2:12 PM in response to TallBearNC

Issue solved. Apparently iOS 4.3 REQUIRES WMM support to be ENABLED or it will refuse connect to a dedicated N router or it will fall back to G on a mixed mode router. I read the final IEEE 802.11n requirements and it hinted WMM is now mandatory.

WHY apple would force this w/o telling ppl is a mystery. But once I enabled it, all my idevices can now do 2.4 and 5gz N again on iOS 4.3

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Answer 10

tgibbs

Level 1

70 points

Mar 12, 2011 2:20 PM in response to TallBearNC

My router (D-Link 825) works just fine with my iPads and my MacBook Pro both on the 5 GHz 802.11 band. Of course, if the router is working properly, there is nothing that one device can do to "kick other devices off." It is, after all, the router's job to manage communications between multiple devices.

So don't expect a fix from Apple. if your router doesn't work properly to manage communication between your iPad and other devices, get another router. Even wireless-N routers are pretty cheap these days. Also, many routers can be re-flashed with open source firmware freely available on the web.

I did encounter one odd problem when I first set up my iPad2, in that I was initially getting "unable to connect" alerts from the iPad2 when I tried to join my 5 GHz 802.11n network. I thought that maybe the iPad2 couldn't handle 5 GHz, so I turned on 2.4 GHz on the router and was then able to connect. But then I switched back to 5 GHz only mode, and the iPad2 re-connected just fine.

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Answer 11

TallBearNC Author

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34 points

Mar 12, 2011 2:25 PM in response to tgibbs

See my prev post. Once I enabled WMM on the router. That solved it

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Answer 12

Mar 12, 2011 2:28 PM in response to TallBearNC

Anyone know how to enable this on a Time Capsule(Airport Extreme)? I took a look through the manual configuration in the Airport Utility but don't see a option to enable/disable WMM.

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Answer 13

TallBearNC Author

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34 points

Mar 12, 2011 2:52 PM in response to TallBearNC

wwm=Wireless Multimedia Support Settings. Some routers call it WME vs WMM

Look under QoS settings

Message was edited by: TallBearNC

Message was edited by: TallBearNC

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Answer 14

Mar 12, 2011 3:18 PM in response to TallBearNC

This may explain why my iPad WLAN performance improved greatly when I set my DIR-655 router to G only mode. This is a single band router and I honestly don't need the N speed for my wireless devices. I'm looking to move up to a dual-band N router later this year.

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Answer 15

Fubar_UK

Level 1

0 points

Mar 13, 2011 1:11 AM in response to TallBearNC

Nice one TallBear - enabling WMM fixes the issue for me too. Why the he'll don't Apple Support know about this and inform us when we call!

This still isn't acceptable as a solution though - what if you want to connect to a public WiFi setup that's N only and they don't have WMM enabled? Say "excuse me, can you change the config on your router please?" Not good Apple - why have you done this?

Message was edited by: Fubar_UK

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