System and method for enabling energy efficient ethernet networks with time-sensitive protocols
A system and method for enabling energy efficient Ethernet networks with time-sensitive protocols. Time-stamped packets generated by a time-sensitive protocol rely on fixed latency in a transit time through a transmission subsystem. An energy efficiency control policy in a network device governs a transmission of time-stamped packets in accordance with energy efficiency initiatives controlled by the energy efficiency control policy. In one embodiment, time-stamped packets can be dropped or modified to account for transitions by the transmission subsystem into an energy saving state. In another embodiment, transitions by the transmission subsystem into or out of an energy saving state can be impacted by the existence of time-stamped packets scheduled for transmission.
1. A method, comprising:
determining whether a time-stamped packet is scheduled for transmission when a transmission subsystem in a network device is in an energy saving state, the transmission subsystem supporting transitions between an active state and the energy saving state; and
dropping the time-stamped packet when it is determined that the time-stamped packet is scheduled for transmission when the transmission subsystem is in the energy saving state.
2. The method of claim 1 , further comprising transmitting, by the transmission subsystem, the time-stamped packet when it is determined that the time-stamped packet is scheduled for transmission when the transmission subsystem is in the active state.
3. The method of claim 1 , further comprising generating the time-stamped packet in accordance with IEEE 1588.
4. The method of claim 1 , further comprising generating the time-stamped packed by a media access control layer subsystem.
5. The method of claim 1 , wherein the transmission subsystem is a physical layer device.
6. The method of claim 1 , wherein the determining comprises determining by an energy efficiency control policy in the network device.
7. The method of claim 1 , further comprising
determining whether the time-stamped packet is scheduled for transmission when the transmission subsystem is in the process of transitioning from the active state to the energy saving state; and
canceling the process of transitioning of the transmission subsystem from the active state to the energy saving state when it is determined that the time-stamped packet is scheduled for transmission.
8. A network device, comprising:
a transmission subsystem that supports transitions between an active state and an energy saving state; and
an energy efficiency control policy module that determines whether a time-stamped packet is scheduled for transmission when the transmission subsystem is operating in the energy saving state, the energy efficiency control policy module modifying a time stamp contained in the time-stamped packet to account for an increase in latency due to the transmission subsystem operating in the energy saving state.
9. The network device of claim 8 , wherein the time-stamped packet is a packet generated in accordance with IEEE 1588.
10. The network device of claim 8 , further comprising a media access control layer subsystem that generates the time-stamped packet.
11. The network device of claim 8 , wherein the transmission subsystem is a physical layer device.
12. A method, comprising:
generating a time-stamped packet for transmission by a transmission subsystem in a network device, the transmission subsystem supporting transitions between an active state and an energy saving state; and
determining, by an energy efficiency control policy module in the network device, whether a scheduling of a transmission of the time-stamped packet by the transmission subsystem is impacted by the usage of an energy saving state by the transmission subsystem.
13. The method of claim 12 , further comprising transmitting, by the transmission subsystem, the time-stamped packet when it is determined that the time-stamped packet is scheduled for transmission when the transmission subsystem is in the active state.
14. The method of claim 12 , wherein the generating comprises generating a packet in accordance with IEEE 1588.
15. The method of claim 12 , wherein the generating comprises generating by a media access control layer subsystem.
16. The method of claim 12 , wherein the transmission subsystem is a physical layer device.
17. The method of claim 12 , further comprising dropping the time-stamped packet when it is determined that scheduling of the transmission of the time-stamped packet by the transmission subsystem is impacted by the usage of the energy saving state by the transmission subsystem.
18. The method of claim 12 , further comprising correcting a time stamp in the time-stamped packet when it is determined that scheduling of the transmission of the time-stamped packet by the transmission subsystem is impacted by the usage of the energy saving state by the transmission subsystem.