I suspect that it's bed-time in Plazbot's neck of the woods, so I'll have a crack.
Tops looks after the airspace North of Australia which covers all the air routes heading into and out of Asia.
Because it's outside of radar coverage, it relies on procedural techniques to keep aircraft separated - very tricky.
It's at it's busiest around 0300 EST when Internationals are doing their thing.
Check out this link, you'll probably see it at your induction, but none the less, it's pretty cool.
YouTube - airtraffic volume for 24 hour period