I've just purchased this 2820n to have wireless N connectivity with my laptop, however I seem to be having problems keeping my iPhone 3GS (I think this only supports wireless G mode, not N) connected over wifi...

So, I've got the 2820n set up as follows:-
Mode: Mixed (11G + 11N)
Tx burst: unchecked
Security mode: Mixed (WPA + WPA2)/PSK

When I try to connect to the Access Point on the iPhone, it asks and accepts my password, connects briefly, then disconnects, connects, then disconnects and so on, until after around 5 mins, it gives up.

The only way I've managed to keep the iPhone connected is to completely turn off security (set up MAC filtering instead for some very basic security) - Even then it goes through connect & disconnect about 10 times before it settles down and remains connected.

I'm probably setting up the security mode incorrectly somehow... If anyone has some recommended settings, I'd be grateful if you could share them...

Oh, and I've upgraded to the latest firmware (3.3.4) as well to see if this fixed the issue, but no it hasn't.

Kind Regards,
PP

It works well for me with a standard 3G but they're similar enough, you're right that the 3GS only does 802.11G - the security mode I use is WPA2/PSK instead of mixed, it could be that the iphone is connecting with WPA and isn't working well with that.

I had no problems with my iPhone 3G using WPA2/PSK.

If you have to use WPA, create a second SSID and lock it down.

Well I tried WPA2 PSK only and that didn't make any difference. Tried factory reset of the router and set it up from scratch and still the connection goes up and down...

Finally, set up a second SSID with only WEP 128 bit only and that seems to work OK. As that's pretty insecure these days I've put on MAC filtering and switched on member separation...

But at least it's usable now

I have started having a similar problem with my 3GS. It had been working fine with both the 4.0 and 4.01 versions of IOS, but a couple of days ago I upgraded the firmware in my 2820N to the latest version - 3.3.4 - having 3.3.2 prior to the upgrade.

The symptoms are that the iPhone appears to connect to the wifi, but doesn't get an ip address or DNS info. If I manually insert the ip address and mask, router and DNS addresses, it connects without problem, so something is up with DHCP and not with the encryption, at least in my case.

I'm going to downgrade to 3.3.3 and see if that makes any difference.

(edit)
Before downgrading, I decided to reboot the router and reload the saved configuration file. So far, it's working as expected, with the DHCP side allocating ip addresses. The strange thing before was that ip addresses were being allocated to several other devices around the house without problem - ipod Touch, laptop, Sonos sound components, PCs, but not the iPhone.

I received a Draytek Vigor 2820n on Friday; setup over the weekend went well.
I updated the firmware to 3.3.4.
I have chose to use WPA2 PSK for wireless which I used previously on a Netgear router, I typed the passphrase into both my iPhone and iPad, both connected and seemed fine, the iPhone and iPad no longer reconnect and have to be manually reconnected each session and have the passphrase retyped.
Does anybody know what the problem might be as the Netgear works fine, I retested on this afterwards. :?