Sorry for the long message but hopefully this information will be of some help to people..
Today my brother-in-law called in to help my mother in the UK. He ran some speed tests using the Speedtest-X app. The results definitely point to the upload speed on the iPad being an issue, however also the wifi router seemed to be part of the problem.
It is to much of a coincidence that the router has never required a reboot/power-cycle until we updated to IOS6 - I think somehow IOS6 screwed with the router.
Equipment used..
In the UK:
Windows8 Laptop
iPad2 running IOS 6
iPad3 running IOS 6.0.1
Thompson 585 modem/router (wireless b/g)
In Canada:
iPad3 running IOS 6.0.1
Thompson Speedtouch modem connected to Netgear R6300 wifi router (using wireless-N connection to iPad3)
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Speedtest Results:
Test conditions:
Speed tests performed using server located in London, unless mentioned otherwise
All tests performed with laptop/iPad in close proximity to the router (within a few feet)
BEFORE power-cycling router..
Using Win8 laptop CONNECTED TO ROUTER USING ETHERNET CABLE..
Server: Milton Keynes
Ping: 15ms
Download: 5.5mbps
Upload: 380 Kbps (note, service provider (Plusnet) say that best we can expect is 400)
Using Win8 laptop connected using wifi..
Ping: 15
Download: 5.6mbps
Upload: 150kbps !!
Using iPad2 running IOS 6..
Ping: 41
Download: 5.03mbps
Upload: 150kbps
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AFTER power-cycling router..
Using Win8 laptop connected using wifi..
Ping: (not recorded)
Download: 5.5 Mbps
Upload: 350kbps - i.e TWICE as fast as it was before!
Using iPad3 running IOS 6.0.1..
Ping: 281
Download: 5mbps
Upload: 250kbps .. much faster but STILL much slower than the laptop
Next we updated my Mothers iPad2 to IOS 6.0.1 but it did not help, upload performance is still noticeably worse than the iPad3
Using iPad2 running IOS 6.0.1..
Ping: 473
Download: 5.5mbps
Upload: 150kbps
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Notes,
a) the poor/unstable ping may be an issue with the server in London, or some issue on the route to getting to that server. I don't know whether the ping time is relevant to Facetime, upload speed seems to be the critical factor here.
b) My brother-in-law changed the wifi setting to WPA2-only for the security setting. The channel was already set to Auto. The router was changed to mode b/g. Changing these setting had no effect (on the iPad in Canada I was still seeing the frozen picture and also black screen with 'Poor connection' message)
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CONCLUSION:
1. iPad2 upload performance is almost 1/2 that of iPad3 (both running IOS 6.0.1)
2. Thompson modem/router had become bogged down, possibly as a consequence of updating the iPad2 to IOS 6. Power-cycling fixed this.
3. Changing security setting and channel (to auto) didn't help.
4. Upload performance of iPad3 is still noticeably poor compared to Windows8 laptop
I think that Apple still have some work to do. Upload is poor on iPad3, and even worse on iPad2. I wonder if the hardware is different on iPad2 and if they will be able to fix this - or maybe they don't even care about iPad2 users any more??