Quote Originally Posted by Raist View Post
Very likely a byproduct of how TCP error detection/correction functions (link is to a simplified explanation, if one is curious).

Basically, an expected segment for a given upload/download is not received in time, and a retransmit is ordered. When your latency is climbing through the roof, it just compounds your lag issue even further due to all the increased communication. It happens more often than people are aware of, but if it happens often enough or with ramped up latency, you may start to see the gap in seconds instead of a light jitter (kind of like a hiccup in a video stream once in a while versus flat out pauses for buffering).

Unfortunately, we may be stuck with this rearing it's ugly head periodically under heavy traffic times. The alternative was probably UDP instead of TCP (like with FFXI), but that creates a whole different problem With UDP, dropped packets would cause blocks of data to just be lost for good and things would simply skip forward on you (like in XI, where people would "blink-walk" around you all the time).
FFXIV uses TCP instead of UDP??? .....

For an endgame that is basically designed for twitch style play, they really didn't think about how to implement a twitch style networking layer.