I've been looking into this pretty seriously today, since I noticed that it happens regularly and on a nearly predictable timetable.
Anyway, I've been monitoring my connection, and I've noticed that each time the latency spikes, the AOC client is attempting to make a connection, on port 80, to this address:
http://aoc-us-control.live.ageofconan.com/
If you go there in your browser you see this message:
"Nothing here, move along citizen."
Pretty funny. I'm not sure what that periodic call is DOING, but it does seem to be what's causing my periodic lag spikes.
The next step I suppose would be to analyze the actual packets being sent to that address.