I have had fun and games messing around with the Nest / Nest Cam system for hours on end after a very good client of mine was distraught with the various random disconnects on her home system. When the system was installed everything worked OK….for a while…some updates happened and things started to go wrong. Both the Camera’s and Heating controls went offline – a reboot would fix one or two devices temporarily but pretty soon after I’d get an out of hours call to help.
I’d though I’d share my findings as the solution is obscure given that the Nest system is sold as a ‘hands off’, “no tech skill required” “plug and play system” that anyone can install.
If you have a problem with Nest Cameras disconnecting then very simply the problem is probably down to size of the network packets travelling around your home network. The router making the Internet Connection to your home pretty much has authority on information sent round the network, normally you won’t even think about this as the Internet in general is working (so why would you really care how that works behind the scenes?), however, with Nest camera’s IT DOES MATTER in certain circumstances.
My client was using a Virgin Media Super Hub for the Internet into her home. Most things worked pretty well apart from the Nest System. After some updates (presumably to improve performance with multiple cameras) the Nest Cam system just fell over and would hardly work in this home – the Nest solution to this is to reboot/unplug everything run updates if available. This doesn’t fix the issue. The actual fix was to go into the Virgin Media Router and reduce the MTU size from 1500 to around 1350 and hey presto all the nest Camera’s will work again. That’s it. My guess is that Nest reduced the packet size on their cameras to improve performance after some complaints/issues in testing but the Super Hub conflicts with these unless you manually adjust. I expect others may get this issue with other Router brands also and altering the MTU size may just fix it in the same way.
I hope this helps !