Error 90000, 90002, 2002 and 3102 since 2.1
Before patch 2.1 I seemed to be one of those blessed players who would get no server disconnection unless it was my own modem/router messing up (meaning, it'd take down all of my internet, not just XIV). But since that update things have changed.
I get disconnected often, even 2, 3 times a hour, and it's always only an XIV server issue, because other programs I sometimes run simultaneously (youtube, FFXI, guildwork etc.) stay unaffected and show no drops in the received/sent data.
I will get error 90,000 or 90,002, followed by a long 3102 (usually up to 3 minutes, which is awesome especially while I'm in a dungeon), if not an error 2002 which reboots my client entirely and forces me to enter my password again to get to the character selection screen (where error 3102 is still waiting for me, too). It seems to be happening only on my characters on the Aether datacenter (Balmung server). I have characters in a Japanese datacenter, Gaia (Zeromus), and am able to run smoothly there.
Regarding situations, it will happen whenever I am actively playing. It won't happen if I, say, go to my innroom and engage the summoning bell to go afk for a hour or even longer. I even made a test and left the game running all night while I was asleep, with my character engaged on the bed, and when I waked up the morning after I was still online. After moving around for about 15 minutes, there comes Error 90002. The Error 90ks all occur while I'm crafting, walking, fishing, fighting, or hell, even just chatting. It's getting really frustrating and I don't know how to fix it.
I'm on Balmung server, playing from Italy. My provider is Fastweb.
Edit: I even checked if the other softwares were somehow causing XIV issues, and they're not. The game keeps disconnecting even when XIV is the only program running at the time.