Following Blizzard’s advice of asking the forums after googling and opening a ticket:
I think my issue started around pre-patch; whenever starting to play World of Warcraft, I experience unplayable ping upwards of 10,000 ms, with brief periods lasting a few seconds with my “regular” ping of <20ms. While these extreme lag spikes are happening, the internet connection of all other applications on my PC is also interrupted to the point they become almost unusable.
My current “fix” for this is to stand idle for anywhere from 5-30 minutes and eventually the issue dissappears completely and my ping remains flawless at <20ms for the remainder of my play session. If I close the WoW application for more than a minute or two, then the issue re-appears and I have to stand idle until it resolves itself again.
I use this PC for a wide range of personal and professional tasks including other games, file download/upload, accessing remote PCs etc and don’t see anything close to the issues I’ve desribed here with WoW. I have also played WoW with my current set-up for at least a year and didn’t have any issues until roughly a month ago.
Has anyone come across anything like this or have any advice for how to go about continuing to diagnose/fix this?