Patent ID: 8259716

Claim:
A method for communication, the method comprising: in an Ethernet network comprising link partners that are coupled via an Ethernet link, performing by a first of the link partners: determining, by an energy efficiency control policy, a decision to transition from a first power level operating mode to a second power level operating mode, the decision being based on information received by the energy efficiency control policy from a physical layer device, the information enabling the energy efficiency control policy to make the determination using link utilization traffic measures; communicating the decision that is determined by the energy efficiency control policy to the physical layer device in an inter-packet gap or a data packet preamble on an interface that couples the physical layer device and a media access controller for the first of the link partners; and transitioning the physical layer device from the first power level operating mode to the second power level operating mode in response to receipt by the physical layer device of the communicated decision that is determined by the energy efficiency control policy.