We've been looking at graphs for a few of our customers last night, all on different access technologies (FTTC, 20CN and 21CN), different endpoints, data centres and geographic locations but they all show the minimum latency increasing for a period last night.
http://www.thinkbroadband.com/ping/share-large/8dec7...
http://www.thinkbroadband.com/ping/share-large/e8367...
Normally if there's an increase in latency you'd see something like this:
http://www.thinkbroadband.com/ping/share-large/82d6b...
We've checked through our network graphing and can't see anything that would be causing this, could it be a graphing issue for those lines?