No, I meant using it with Ethernet connections only and disabling
the wireless. It should be possible to turn off the wireless facility in the router, but leave the router running. If you can do that for a couple of hours, see if the spikes go away. Don't just stop connecting wireless devices, make sure the router isn't providing wifi.
This happens with some Billion and ZyXEL ruters, but not as badly as yours appears. It's worth ruling it out as the cause though, by trying it.
The indispensable man or woman passes from the scene, and what happens next is more or less the same thing as was happening before.
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