Router A sends a message to Router B. In order to reduce the unnecessary loss of the message, the message can be traffic shaping-processed at the exit of Router A. Messages beyond traffic shaping characteristics are buffered in Router A. When the shaping algorithm allows the next batch of messages to be sent, the messages will be taken out of the buffer queue and sent. In this way, all messages sent to router B will meet the traffic regulations of router B.

The main difference between traffic shaping and traffic supervision is that traffic shaping will cache messages that exceed the traffic specifications in traffic supervision. When the shaping algorithm allows messages to be sent, these buffered messages are sent evenly. Traffic shaping may increase the delay, and flow control will hardly introduce additional delay.