Might be a bit late to the party here, but as of about a month ago I was dealing with what appeared to be a "ISP being lame" issue as I could not connect to anyone.
Until Harzer and Grimplex notified me, I was not aware of an update to ICE which one may configure in the client:
By default, it was set to "US East," which makes sense as I live on the east coast in the US; however, all my games were not connecting and was about to just give up and say "Okay, I guess FAF server just won't work for me now."
Switching to "Germany" instantly solved the problem, and it it still does.
Could someone explain to me why that is? Are others having this issue? Why was something like this not more broadly discussed in a general community message or news post? The effects seem quit bad and I am not alone in those who were scratching their heads as to why this occurred.