Each class is then regarded as having a generic user for analytical purposes. The network then polices the offered traffic and enforces the contract if users misbehave. One way to capture this heterogeneity is to say that users value their network service differently, according to their subjective requirements for the quality of their application. Users are part of the network and in many cases can be thought of as intelligent peripheral devices at the network edges. These intelligent peripherals can regulate how much and when traffic is input, given appropriate indicators of the network status.
Economic efficiency refers to the relative valuations the users attach to their network service.
Feedback signals from the network can help to increase both types of efficiency. In this way many of the congestion problems that can occur if the offered load is regarded as fixed can be avoided . The flexible users absorb the longer delays and do not tie up network resources, which can therefore be used to serve less flexible users. A cost measure can be defined for any level of network operation. If the prices quoted to the users reflect the current costs of operating the network, then those users who value network service more will choose to transmit, and users who value it less will wait for lower prices.