Token Bucket

A token bucket algorithm is a method of handling packet traffic, by using an analogy of a bucket containing a number of tokens that arrive at a particular rate. Tokens are used to limit when data packets are transmitted.

The depth of the bucket limits the number of tokens, and the rate of arriving tokens limits how quickly packets can be sent.

The concept is as follows:

• Tokens are added to the bucket at a fixed rate.
• If the bucket becomes full, arriving tokens are thrown away.
• Arriving data packets use up tokens from the bucket and are transmitted on the network.

This means that the bucket needs to be deep enough to handle bursts of traffic, and the token rate limits the transmission rate.