Why not try ThinkBroadband's Broadband Quality Monitor (BQM)
Free, completely remote and logs a much better picture of your broadband health, storing historical reports in case you want to go back and work out what happened. You can see your latency increase as your ISP or the wider internet gets busier (i.e. people fire up Netflix). Or use it to beat up your ISP for packet loss etc.
Here is my live graph for example:
edit: that bump at 3am is my NAS kicking off it's cloud upload backup job.
FAQ
Ensure that you enable "reply to ICMP requests" on your router.