Bukkit

config.yml

BurstFrequency: 8
How much delay between each burst of held packets, in ticks. (20 = 1 second) Lower values mean bursts happen more often and therefore more bandwidth is consumed. If you feel chunks are not filling in fast enough then try lowering this value. If players experience lag when someone logs in, respawns, or enters or leaves a portal, try raising this value. Also see my comments below on picking an initial value.

PacketsPerBurst: 1
Maximum chunk packets to allow to be sent in each burst. You will probably not need to change this unless you feel BurstFrequency is already too low and you still want to send out chunks faster. As there is some overhead to be expected each time a Burst is performed, if the server starts not keeping up then try increasing this (and raise the BurstFrequency value accordingly). Keep it as low as possible as that results in the smoothest outbound stream.

ListenPriority: LOWEST
Changing this may help compatibility with other plugins, or not. Possible values: LOWEST, LOW, NORMAL, HIGH, HIGHEST

BypassEnabled: true
The default state of the BypassList when the plugin is loaded.

BypassList: []
Any player names or subnetworks (eg. 192.168.0.0/16) for those who should not be affected by this plugin, such as LAN users whose traffic will not be crossing the uplink. This is important as the chunk bandwidth of all connected players not in this list is combined together against the configured limit. So if you're playing on the same LAN as the server, if you're not in the BypassList then you're effectively stealing bandwidth from your players, not to mention receiving your chunks at a slower rate for no good reason.

Debug: false
The default debug state when the plugin is loaded.

Comments

For a starting value for BurstFrequency, use this formula and then fine-tune it as needed.

20 * PacketsPerBurst / ( bandwith / average_chunk_packet_size )

So if I want to permit chunk packets to take up to 40kB/s of the upstream the math is:

BurstFrequency = (20 * 1) / (40 / 16) = 8

Note: 16K being the average chunk packet size is a big assumption. The average size will be larger in jungle biomes, and smaller in plains and even smaller in oceans. If you're using Orebfuscator the average size will be larger too. In short, the more complex the chunk, the less well it will compress, resulting in a larger size.