Patent ID: 8009695

Claim:
An energy efficient Ethernet method, comprising: communicating between a first physical layer device and a second physical layer device via a network cable, said first physical layer device operating in a master mode and said second physical layer device operating in a slave mode, wherein a physical layer device operating in said slave mode recovers a clock from a received signal; after a determination that a first direction of transmission between a transmitter in said first physical layer device and a receiver in said second physical layer device should enter an outage interval, transmitting a control message from said first physical layer device to said second physical layer device, wherein during said outage interval a second direction of transmission between a transmitter in said second physical layer device and a receiver in said first physical layer device remains operative; switching said first physical layer device from said master mode to said slave mode, wherein said slave mode is responsive to said second physical layer device that has switched from said slave mode to said master mode in response to said transmitted control message; and following said switching, transitioning said first direction of transmission into an outage interval.