What is Burst mean in Limit Bridge Filter Rule?
and is it true set 'Burst' value at least as high as 'Rate' value?

hello
if bandwidth has been free then client can use it to burst size

The burst limit is how much the user can pull, IF the average usage is less the "burst threshold" for the last "burst time" seconds.
The queue will allow the client to have more bandwidth, until the average hits the threshold.