Command-line ping command shows 81ms to eu.newerth.com server 24/7. However for the last few days my in-game ping is 135 during the day, and 95 during the night (correlates with times of low server activity.)
It's normal to have about 15ms extra ingame (as I do at night), but the jump during the day is puzzling because it doesn't translate in the icmp ping measure.
The game itself uses UDP, although I think the game measures ping with TCP.
I'm in USA on a very fast university ISP and the server is in London, the problem seems to be affecting other american clients but I'm not sure. It is not affecting players from Europe.
My in-game latency to other servers in the same game, for example one in Germany, do not experience the same night/day cycle and are staying stable.
What could be the cause of the in-game increase without corresponding icmp increase?