I spoke with a higher-tier rep from AT&T for about 45 minutes tonight.
He was very friendly and helpful, but unfortunately he didn’t have
access to go much deeper than the traceroutes and such we’re already
doing. He suspects that it’s something in the way the traffic is routed
after it leaves the AT&T network, because the response times on the
first few hops are generally good, so the next step is probably
investigating some kind of peering relationship between AT&T and
whatever other ISPs they route traffic through to get to vassalengine.org. He’s checking with his manager tomorrow to see what
next steps we might be able to take; however, he acknowledged that in
order to get attention at a higher level, it will likely take more than
one or two customers reporting an issue and some posts on an internet
message board.
I did get a response, though nothing meaningful yet. Joshua (the tech I worked with) has generated a ticket and sent it on to their IP Network Reliabilty Center, though it’s hard to say when/if it will get any real traction there. (We are, in all honesty, a very small school of fish in a big internet.) He will keep me posted on the fate of that ticket.
I subscribed to hide.me and it fixes the sync problems.
Using a VPN is going to change the route traffic takes between you and
our server. What you’re seeing indicates to me that something is wrong
along the route you would normally have.