• Traffic shaping (also referred to as packet shaping) is the technique of delaying and restricting certain packets traveling through a network to increase the performance of packets that have been given priority.

• Classes are defined to separate the packets into groupings so that they can each be shaped separately allowing some classes to pass through a network more freely than others. Traffic shapers are usually placed at the boundaries of a network to either shape the traffic going entering or leaving a network.

• Traffic shaping is a mechanism to control the amount and rate of the traffic sent to the network. The two traffic shaping techniques are:

i. Leaky Bucket Algorithm

• Leaky bucket is a bucket with a hole at bottom. Flow of the water from bucket is at a constant rate which is independent of water entering the bucket. If bucket is full, any additional water entering in the bucket is thrown out.

• Same technique is applied to control congestion in network traffic.Every host in the network is having a buffer with finite queue length

• Packets which are put in the buffer is full are thrown away.The buffer may drain onto the subnet either by some number of packets per unit time,or by some total number of bytes per unit time.

• A FIFO queue is used for holding the packets.

• If the arriving packets are of fixed size,then the process removes a fixed number of packets from the queue at each tick of the clock.

• If the arriving packets are of different size,then the fixed output rate will not be based on the number of departing packets.

• Instead it will be based on the number of departing bytes or bits.

Comparison Of Token Bucket and Leaky Bucket Algorithm: