A method, apparatus, and computer program product for indicating and responding to various congestion levels in a communication system, such as a wireless communication network. A congestion level in the network is determined, and a percentage of data packets to be transmitted to an endpoint, such as user equipment or another network endpoint serving the user, are marked to indicate the congestion level. The endpoint determines the congestion level at the network from the percentage of received data packets that are marked and may initiate an appropriate response behavior in response to the determined congestion level.