I actually have the same problem. Here is my story (beware, quite long).
Setup
AC68U
Synology NAS
5 WIFI IP cams (working on 2.4ghz)
When the Synology NAS surveillance station is used it will continuously take the stream from every camera, look for motion and record or dispose it. So with and without motion the NAS is getting all the frames from every camera (by default 15fps per camera). The NAS is connected by wire to the AC68U.
Previously I had an old Linksys which supported wifi G only. It worked fine but when I went from 2 to 5 wifi camera the interface from the router went incredibly slow so I could not change port forwarding settings etc when all the camera's were on. However, the WIFI and camera's did work reasonable.
So since it was quite an old router I decided to upgrade to the best and fastest router available that I could find and went for the AC68U. And looking now at the router, it is a beast and works great! Some fine engineering! Unfortunately except for the problem with the WIFI IP cams...
When all 5 IP cams are connected to WIFI it will get incredibly (=unusable) slow. The signal is fine but the data transfer rate is unusable: loading an internet page could take 10 minutes. When I use a computer/laptop connected with a cable to the AC68U everything loads perfectly fast, so something seems to be happening to the wifi. As a reminder, this did not happen with the old linksys and all 5 cams connected.
After a lot of trying I changed the framerates from the camera's to 1fps so only 5 frames (5 cams) were traveling over wifi every second. And fortunately that worked.
But
One camera is located quite far from the router. It still has decent signal (better than with the previous linksys router) but sometimes - it seems randomly - during the day the WIFI again becomes incredibly slow and the synology nas says after a few minutes that it lost connection with that camera (it emails me automatically when that happens). After 5-30 minutes the camera comes back and the wifi works fine again...
So it seems like a bad signal from a wifi ipcam fills up the wifi spectrum. Again, this does not happen with the old linksys.
So at this moment everything works, but only temporary. Once or twice a day the bad reception camera disconnects and before and after that the internet is unusable through wifi.
Also, recording the IP cams at 1fps is also a temporary solution, of course I would like to record with at least 10fps or 15fps as with the old linksys.
Hopefully the information from above will help solving this problem since I really like the router and all the features it has!
Looking forward to a reply! Thanks.
More info
- The IP cams work on 2.4ghz as do the laptop, mobiles etc which also connect to the router
- Tried quite some different settings on the router as mentioned in this topic
- When I connect 1 or 2 camera's with cable I can increase the fps from the other camera a bit more before the wifi goes incredibly slow again. When a camera is connected by cable it works fine on 15fps and doesn't change the speeds on the network.
- There are no other networks that can be found with clients, neighbors are located quite far away so wifi crowding is not a problem.