Errors 90001 and 90002.

ISP:
NorthState, USA

Type of Internet Connection:
Fiber

Internet Connection Speed:
28mbs

Date & Time:
2/27/15 - 3/1/15 so far. All times of day.

Frequency:
Sometimes? More than a handful of times per day.

Character Name:
Aster Avos

World:
Goblin

Area and Coordinates:
Seemingly anywhere, including The Howling Eye Hard Mode, Battle in the Big Keep, Second Coil Turn 1 and 2, and Ward 1 of the Lavender Beds.

Party or Solo:
Solo and in parties of 4 and 8 members.

NPC Name:
None.

Monster Name:
Garuda HM, Gilgamesh, Rafflesia, Melusine, etc.

In-Game Time:
Haven't kept track.

Steps:
My character rubberbands and my client shows other characters doing the same occasionally, timing doesn't seem to matter. Between pulls, fighting enemies, standing around, whatever. Suddenly, I'll disconnect with a 90001 or 90002 and be able to immediately join back into the game. I have not experienced any problems in other online games or activities. I've been able to sustain Skype calls and Twitch streams. These issues only affect my connection to FFXIV, and only recently, as the date shows.

Desktop computer
Motherboard: ASRock 990FX Professional
CPU: AMD FX-6100 Zambezi
Graphics: 2GB Nvidia GTX-750 Ti
RAM: 8GB