Hmmpff that doesn't mean jack!
You could be on a 200 petabyte connection and LATENCY would still be an issue.
BANDWIDTH doesn't mean jack to network LATENCY.
Edit:
Your best friends looking up network congestion (validate both DNS and IP, NOT one or the other!):
ping
tracert
else, if doubtful, use one of the 3rd party sites hosted on L3 datacenters.
*Obviously, these will NOT tell you if there is a problem between your modem and the questionable site. The above commands will only notify you of this information or calling your ISP.
Code:
http://dnstools.com/
http://www.dnsstuff.com/