About the AU server, I ran tcpdump (actually wireshark) a couple days ago and discovered that no matter if you set "OnlineService.Matchmaking.ServerPool=AU1" or not, it will still go to US server.

Today I ran it again, seem like it's back to normal. During gameplay, it will constantly connect to (for me) 12.130.244.193 and the actual game server depending on server you chose:

US Server: 12.130.245.39
AU Server: 103.4.114.11

Did a traceroute to these IP, I discovered something else. Unifi line actually hop less and faster to US server (today!). Yes 4G still using reroute in Japan and HongKong.

Just for info, you also can use http://us-looking-glass.battle.net/ to see how the packet travel from Blizzard to you. It changes daily! LOL! Yesterday, both Unifi and 4G uses hop in Japan and HongKong. Today, Unifi uses hop in Singapore. 4G Yes still using Japan (which sloooowwww...)

i have the same understanding, that is why i said, those are capture during gameplay.

US Server: 12.130.245.39
AU Server: 103.4.114.11

if you trace those IP, you will see that they are hosting in the respective country, which indicates that this is the game server and not the authentication server. and again, i was checking the network packet during game play not the authentication process.

another thing, contrary to popular believe, D3 game play use TCP connection and not UDP.

ps:
are u indicating that i may not know how to use tcpdump/wireshark? i am just a little, slightly, offended with that comment...