What is Traffic shaping?
Traffic Shaping (a.k.a Bandwidth Shaping or Packet Shaping) is an attempt to control network traffic by prioritizing network resources and guarantee certain bandwidth based on predefined policy rules. Traffic shaping uses concepts of traffic classification, policy rules, queue disciplines and quality of service (QoS).
One of the main causes of congestion is that traffic is often busy. If hosts could be made to transmit at a uniform rate, congestion would be less common. Another open loop method to help manage congestion is forcing the packet to be transmitted at a more predictable rate. This is called traffic shaping.