have you change any of the WMM setting or Green field?

sicon wrote: have you change any of the WMM setting or Green field?

No haven't changed any of the WMM setting or Green field.

I'm also having the same problem.
DHCP server is the 2860n with DNS servers on Windows 2008R2.
I have the same configuration on a 2850n which works perfectly well.
Upgrading to 3.7.3.3 didn't fix the problem.

I'm going to try disabling DHCP on the 2860n and using 2008R2 DHCP server instead.

It has nothing to do with DHCP.
Programmed static IP addresses on iPhone. It all works until the iPhone goes idle and then no connectivity.
The wifi symbol is still there at the top of the phone - it still looks connected but there's no traffic.

Same issue with 3 iPads. Have told them to never go to sleep, but same thing, after ten or so minutes connectivity goes - they still say they are connected, but there's nothing happening.
Turn WiFi off and on again and good to go, at least for another ten minutes or so!

There are upwards of 15 or 20 other devices connected, printers, Sonos, Windows devices, phones - not a single one of them has issues, just the 3 iPads (latest version, IOS7).

I recommended this router as I have only ever used Draytek, now left looking a bit daft.

Similar issue here on a 2860n Plus - it appears to be on the 5g side - If connected to SSID 1, SSID 2 signal starts dropping in and out (Can be seen on wifi timed graph)...