after some investigation here is what I've found:

* without the /throttle switch the game may default to 4 player slots only, regardless of what you set /playerlimit to

* the /throttle switch requires the amount of bandwidth you would like to dedicate to the game (upload) to be specified in KILOBITS. 8 Kilobits = 1 Kilobyte

* with 3 players and no throttling the the bandwidth meter I used (DU Meter) will top out at 24 Kilobytes/s. So that's 8 Kilobytes/s per player and 65.5 KiloBITS/s

* The game however seems to run fine if the 3 players are given half of that (4 Kilobytes/s)

so to find out what you should set your throttle at optimally, decide how many players you would like to have and then multiply that by some number between 4 and 8 (depending on what your hard upper limit is and what kind of experience you'ld like to offer the players) and then multiply again by 8 (to get kiloBITS)

So lets say I want 10 players:

Lower Limit:
10 x 4Kb/s = 40
40kb/s x 8 = 320 KiloBITS/s

Upper Limit:
10 x 8Kb/s = 80
80kb/s x 8 = 640 KiloBITS/s

The /throttle switch should be set between 320-640
the command should be "/throttle 480" or something similar.

Hope this helps.. comments, additions, corrections welcome.

CT