I have a MacBoook Pro with OS X 10.9.5 connected to my router with a Power Line Connection and Ethernet, which I did because I use the laptop to play an real time online game which needs mostly a stable ping and no ping spikes, and using WiFi at a distance was deteriorating the gaming experience.
The problem is, someone in my house has bought an iPhone 6 (after I installed the PLC, so I'm not quite sure if the problem arises all the same if the MacBook is connected by wifi), and by trial and error I highly suspect that it interacts with the internet connection to other devices. Whenever the phone came home, if I was playing, the connection went nuts. Not that ping went high, but overboard. To the point of not being able to navigate normally either: websites, youtube videos, etc. I mean, charging any light website shouldn't need that much speed, and still it doesn't work.
I would think that it's not possible that an iPhone 6 with a few apps, which sometimes isn't even transmitting any significant data, could take up that much bandwidth (the local connection is supposed to be around 10Mb/s, and I've been able to enjoy 1,5Mb/s download speeds with torrent).
So I don't really know what the cause is, or how to solve it. Is it truly a bandwidth problem? How does the router determine how much bandwidth is allotted to each device/output (wifi/ethernet)? Could I change the router settings (it's a normal low-end router given by my internet provider) to make the computer a priority, so that the iphone only takes reasonable/excess bandwidth?