I've an AP900 that's setup in dual mode with a 5ghz and 2.4ghz network running. I could write an essay on all the things I've tried over the last few weeks, but the following pretty much sums it up...

Sat <10m from the AP900, with no objects between, I connect to either network and get a strong signal (5ghz gets -50dBm while 2.4ghz gets -40dBm).

There are several other 2.4ghz networks around but none on the same channel and the next strongest is -80dBm. There are no other 5ghz networks.

On the 5ghz network Speedtest.net shows ~50Mbps, and a file transfer to a wired server shows ~10MB/s.

However every few minutes the connection will drop. Sometimes Windows manages to simply reconnect and a few times it just sits there not connected, but showing the network as available to connect to. This happens on 4 different laptops using Windows 7 and Windows 8/8.1.

All FW up to date. All drivers up to date.

I don't think I could make the conditions any better. I'm lost as to the problem, unless there's an issue in the AP900 (I have tried a second AP900 with the same issues).

Help

Quick update....after trying a Skype call, it seems the connection dies every 3 minutes.

Another update:

I have a 2860 router on this network (non-WiFi version). After reading http://www.forum.draytek.co.uk/viewtopic.php?f=19&t=19313&start=80#p80325 and seeing diarens post, I set its ARP cache to 10 minutes.

I've been connected to the AP900's 5ghz network for almost an hour since, and I've had zero drop outs so, so far its seems fixed!

There is a new firmware for the ap900, 1.1.4 here
http://www.draytek.com/index.php?option=com_jumi&view=application&fileid=15&Itemid=583&lang=en
Not sure if will help your case (have a look the released notes) but maybe worth to try, my guess after load the firmware (if you do) perform a master reset if you don't have many settings to do back from the begin

babis3g wrote: There is a new firmware for the ap900, 1.1.4 here
http://www.draytek.com/index.php?option=com_jumi&view=application&fileid=15&Itemid=583&lang=en
Not sure if will help your case (have a look the released notes) but maybe worth to try, my guess after load the firmware (if you do) perform a master reset if you don't have many settings to do back from the begin

Thanks! I checked again for FW yesterday on the .co.uk website but it still lists 1.1.3 as the latest even now. Must not be updated yet. I'll try the FW, but theres nothing interesting in the release note.

I'm still having problems after setting the ARP cache life on the 2860, although not as often.

a member has fixed the apr issue here
http://www.forum.draytek.co.uk/viewtopic.php?f=19&t=19313&start=80#p80325
but the beta should fix the issue for the 2860
http://www.forum.draytek.co.uk/viewtopic.php?f=19&t=19313&start=80#p80330
is this the one you still have issues?