Download winmtr and set the host to the gaming server, or one of the gaming provider's primary servers (like eu.battle.net) and run the test for a minute or so. Then PM me the results and I'll add it to a ticket for you to investigate.
Can't say I can replicate it on my side though, so we'll need to see some data to work with in the winmtr results.
Unfortunately I can't get WinMTR to run properly. I managed to track down some ips to test and when I run them in WinMTR I get 0 response (some other web pages do work so it's not WinMTR on my pc). I can do a normal tracert, but it hits a certain point on Riot's network and returns no results afterwards.
Here are the ips and the cached pages I got them from.
192.64.170.252
http://webcache.googleusercontent.c...hread.php?t=2070867+&cd=4&hl=en&ct=clnk&gl=za
185.40.65.1
185.40.66.3
http://webcache.googleusercontent.c...hread.php?t=2044485+&cd=6&hl=en&ct=clnk&gl=za
Don't know if you can do anything with that info but that's whats available on the cached pages from the old forums (they recently migrated to a new system and canned the old forum).