System and method for controlling a PHY attached to a MAC interface for energy efficient ethernet

• US 7,930,373 B2
• Filed: 06/30/2008
• Issued: 04/19/2011
• Est. Priority Date: 06/30/2008
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Diab, Wael William
• Primary Examiner(s): Lin; Kenny S
• Application Number:
  US12/165,564
• Publication Number:
  US 20090327506A1
• Time in Patent Office: 1,023 Days
• Field of Search: 709/220, 709/221
• US Class Current: 709/220
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/13 in a LAN segment, e.g. ring or bus
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/30 in combination with information about buffer occupancy at either end or at transit nodes
• CPC Class Codes: Y02D 30/00 Reducing energy consumption in communication networks

Abstract

A system and method for controlling a physical layer device attached to a media access control interface for energy efficient Ethernet. Detecting of a condition that is conducive to a change in a link rate can be performed at either link partner. In one embodiment, a control message based on the detection can be sent to a physical layer device via a media access control layer interface to effect a link rate change in the physical layer device.

Claims

1. An energy efficient Ethernet method, comprising:

detecting a condition that is conducive to a change in a link rate of an Ethernet link;

sending a message to a media access control layer that identifies a change to a link rate of said Ethernet link;

changing a rate of operation of said media access control layer after receipt of said message;

signaling, by said media access control layer to a physical layer device, an instruction to change said link rate of said physical layer device; and

changing an operating state of said physical layer device upon receipt of said instruction.

2. The method of claim 1, wherein said detecting comprises monitoring a buffer or queue.

3. The method of claim 1, wherein said detecting comprises monitoring a subsystem state.

4. The method of claim 1, wherein said signaling is done in band.

5. The method of claim 1, wherein said signaling is done out of band.

6. The method of claim 1, wherein said changing an operating state comprises switching to a subset physical layer device.

7. The method of claim 1, wherein said changing an operating state comprises switching to a low power idle mode.

8. The method of claim 1, wherein said changing an operating state comprises switching from a subset physical layer device to a parent physical layer device.

9. The method of claim 1, wherein said changing an operating state comprises switching from a low power idle mode to an active mode.

10. The method of claim 1, wherein said changing a rate of operation of said media access control layer comprises changing a rate of operation of an interface with said physical layer device.

11. An energy efficient Ethernet method in a physical layer device, comprising:

receiving a link utilization change message via an interface that couples the physical layer device to a media access control layer;

switching from a first link rate to a second link rate in response to a receipt of said link utilization change message, wherein one of said first link rate and said second link rate is lower than the other link rate; and

switching a part of said media access control layer that supports said interface from a first rate to a second rate in response to a condition that produces said link utilization change message.

12. The method of claim 11, wherein said receiving comprises receiving via in band signaling on said interface.

13. The method of claim 11, wherein said receiving comprises receiving via out of band signaling on said interface.

14. An energy efficient Ethernet method, comprising:

detecting, using components in a layer above a media access control layer, a condition that is conducive to a change in a link rate of an Ethernet link;

sending, in response to said detection, a message to said media access control layer that indicates a change a link rate of said Ethernet link;

signaling, by said media access control layer to a physical layer device, an instruction to change said link rate of said physical layer device;

changing, in response to said message, an operating state of a part of said media access control layer that supports an interface between said media access control layer and said physical layer device; and

changing an operating state of said physical layer device upon receipt of said instruction from said media access control layer.

15. The method of claim 14, wherein said detecting comprises monitoring a subsystem status.

16. The method of claim 14, wherein said detecting comprises monitoring in an application layer.

17. The method of claim 14, wherein said detecting comprises monitoring a bandwidth allocation protocol.

18. The method of claim 14, wherein said changing an operating state of said physical layer device comprises changing to a subset mode of operation.

19. The method of claim 14, wherein said changing an operating state of said physical layer device comprises changing to a low power idle mode of operation.

20. The method of claim 14, wherein said signaling comprises signaling using in band communication on said interface.

21. The method of claim 14, wherein said signaling comprises signaling using out of band communication on said interface.