U.S. patent application number 12/474557 was filed with the patent office on 2010-05-06 for method and system for managing energy efficiency of a network link via pluggable transceiver modules in an energy efficient network device.
Invention is credited to Wael William Diab.
Application Number | 20100115316 12/474557 |
Document ID | / |
Family ID | 42131331 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100115316 |
Kind Code |
A1 |
Diab; Wael William |
May 6, 2010 |
METHOD AND SYSTEM FOR MANAGING ENERGY EFFICIENCY OF A NETWORK LINK
VIA PLUGGABLE TRANSCEIVER MODULES IN AN ENERGY EFFICIENT NETWORK
DEVICE
Abstract
An Ethernet network may comprise link partners that may be
coupled via an Ethernet link. The link partners may comprise
pluggable PHY devices. The pluggable PHY devices and/or other link
partner devices may determine energy efficient network (EEN)
control policies, may select a power level mode and may configure
the link partners to operate in the power level mode. Some
components may be reconfigured prior to sending an energy efficient
network control signal to a link partner and configuring remaining
components. Hardware, software and/or firmware may execute the
pluggable PHY energy efficient network control policies. Packet
data pending delivery may be buffered in the pluggable PHY. The
pluggable PHY devices may comprise a MAC and/or a SERDES device.
Exemplary form factors for the pluggable PHYs may comprise a SFP, a
SFP+, a XENPAK, a X2, a XFP and/or a XPAK. Low power idle mode
and/or sub-rate mode may be utilized.
Inventors: |
Diab; Wael William; (San
Francisco, CA) |
Correspondence
Address: |
MCANDREWS HELD & MALLOY, LTD
500 WEST MADISON STREET, SUITE 3400
CHICAGO
IL
60661
US
|
Family ID: |
42131331 |
Appl. No.: |
12/474557 |
Filed: |
May 29, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61111653 |
Nov 5, 2008 |
|
|
|
Current U.S.
Class: |
713/323 ;
713/320 |
Current CPC
Class: |
Y02D 30/00 20180101;
Y02D 50/42 20180101; Y02D 30/32 20180101; Y02D 30/30 20180101; Y02D
50/40 20180101; H04L 12/12 20130101; Y02D 30/50 20200801; G06F
1/3234 20130101 |
Class at
Publication: |
713/323 ;
713/320 |
International
Class: |
G06F 1/00 20060101
G06F001/00 |
Claims
1. A method for communication, the method comprising: in an
Ethernet network comprising one or more link partners that are
coupled via an Ethernet link, said one or more link partners
comprising one or more pluggable PHY devices: determining one or
more energy efficient network control policies that specifies a
power level mode for one or more of said link partners and/or said
one or more pluggable PHY devices; and configuring said one or more
link partners and/or said one or more pluggable PHY devices to
operate in said specified power level mode based on said determined
one or more energy efficient network control policies.
2. The method according to claim 1, comprising determining by said
pluggable PHY device said one or more energy efficient network
control policies.
3. The method according to claim 1, comprising selecting a power
level mode of operation for said one or more pluggable PHY devices
based on said one or more energy efficient network control
policies.
4. The method according to claim 3, comprising reconfiguring one or
more components of said one or more pluggable PHY devices based on
said selected power level mode of operation.
5. The method according to claim 4, comprising reconfiguring a
first portion of said one or more components prior to sending an
energy efficient network control signal to said one or more of said
link partners.
6. The method according to claim 5, comprising reconfiguring a
remaining portion of said one or more components after sending said
energy efficient network control signal.
7. The method according to claim 1, comprising executing said one
or more energy efficient network control policies from within said
one or more pluggable PHY devices utilizing hardware, software,
and/or firmware within said one or more PHY devices.
8. The method according to claim 1, comprising buffering packet
data that is pending delivery in said one or more pluggable PHY
devices while transitioning to an active power mode.
9. The method according to claim 1, wherein said one or more
pluggable PHY devices comprises one or both of a media access
controller and/or a serializer de-serializer device.
10. The method according to claim 1, wherein said one or more
pluggable PHY devices comprises one or more of a SFP, a SFP+, a
XENPAK, a X2, a XFP and a XPAK form factor.
11. The method according to claim 1, wherein said power level mode
comprises low power idle mode and/or sub-rate mode.
12. A system for communication, the system comprising: one or more
circuits for use in an Ethernet network comprising link partners
that are coupled via an Ethernet link, said one or more circuits
comprising one or more pluggable PHY devices, wherein said one or
more circuits are operable to: determine one or more energy
efficient network control policies that specifies a power level
mode for one or more of said link partners, and/or said one or more
pluggable PHY devices; and configure said one or more link partners
and/or said one or more pluggable PHY devices to operate in said
specified power level mode based on said determined one or more
energy efficient network control policies.
13. The system according to claim 12, wherein said one or more
pluggable PHY devices determines said one or more energy efficient
network control policies.
14. The system according to claim 12, wherein said one or more
circuits are operable to select a power level mode of operation for
said one or more pluggable PHY devices based on said one or more
energy efficient network control policies.
15. The system according to claim 14, wherein said one or more
circuits are operable to reconfigure one or more components of said
one or more pluggable PHY devices based on said selected power
level mode of operation.
16. The system according to claim 15, wherein said one or more
circuits are operable to reconfigure a first portion of said one or
more components prior to sending an energy efficient network
control signal to said one or more of said link partners.
17. The system according to claim 16, wherein said one or more
circuits are operable to reconfigure a remaining portion of said
one or more components after sending said energy efficient network
control signal.
18. The system according to claim 12, wherein said one or more
circuits are operable to execute said one or more energy efficient
network control policies from within said one or more pluggable PHY
devices utilizing hardware, software, and/or firmware within said
one or more PHY devices.
19. The system according to claim 12, wherein said one or more
circuits are operable to buffer packet data that is pending
delivery in said one or more pluggable PHY devices while
transitioning to an active power mode.
20. The system according to claim 12, wherein said one or more
pluggable PHY devices comprises one or both of a media access
controller and/or a serializer de-serializer device.
21. The system according to claim 12, wherein said one or more
pluggable PHY devices comprises one or more of a SFP, a SFP+, a
XENPAK, a X2, a XFP and a XPAK form factor.
22. The system according to claim 12, wherein said power level mode
comprises low power idle mode and/or sub-rate mode.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY
REFERENCE
[0001] This application makes reference to, claims priority to, and
claims the benefit of U.S. Provisional Application Ser. No.
61/111,653, filed on Nov. 5, 2008.
[0002] This application makes reference to: [0003] U.S. patent
application Ser. No. 12/471,861 (Attorney Docket No. 20367US02)
filed on May 26, 2009; [0004] U.S. patent application Ser. No.
12/470,785 (Attorney Docket No. 20368US02) filed on May 22, 2009;
[0005] U.S. patent application Ser. No. 12/470,970 (Attorney Docket
No. 20369US02) filed on May 22, 2009; [0006] U.S. patent
application Ser. No. 11/685,554 (Attorney Docket No. 18031US01)
filed Mar. 13, 2007; and [0007] U.S. patent application Ser. No.
11/473,205 (Attorney Docket No. 17396US02) filed Jun. 22, 2006.
[0008] Each of the above stated applications is hereby incorporated
herein by reference in its entirety.
FIELD OF THE INVENTION
[0009] Certain embodiments of the invention relate to networking.
More specifically, certain embodiments of the invention relate to a
method and system for managing energy efficiency of a network link
via pluggable transceiver modules in an energy efficient network
device.
BACKGROUND OF THE INVENTION
[0010] Communications networks and in particular Ethernet networks,
are becoming an increasingly popular means of exchanging data of
various types and sizes for a variety of applications. In this
regard, Ethernet networks are increasingly being utilized to carry
voice, data, and multimedia traffic. Accordingly more and more
devices are being equipped to interface to Ethernet networks.
Broadband connectivity including internet, cable, phone and VOIP
offered by service providers has led to increased traffic and more
recently, migration to Ethernet networking. Much of the demand for
Ethernet connectivity is driven by a shift to electronic lifestyles
involving desktop computers, laptop computers, and various handheld
devices such as smart phones and PDA's. Applications such as search
engines, reservation systems and video on demand that may be
offered at all hours of a day and seven days a week, have become
increasingly popular.
[0011] These recent developments have led to increased demand on
datacenters, aggregation, high performance computing (HPC) and core
networking. As the number of devices connected to data networks
increases and higher data rates are required, there is a growing
need for new transmission technologies which enable higher data
rates. Conventionally, however, increased data rates often results
in significant increases in power consumption. In this regard, as
an increasing number of portable and/or handheld devices are
enabled for Ethernet communications, battery life may be a concern
when communicating over Ethernet networks. Accordingly, ways of
reducing power consumption when communicating over Ethernet
networks may be needed.
[0012] Further limitations and disadvantages of conventional and
traditional approaches will become apparent to one of skill in the
art, through comparison of such systems with the present invention
as set forth in the remainder of the present application with
reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
[0013] A system and/or method for managing energy efficiency of a
network link via pluggable transceiver modules in an energy
efficient network device, substantially as shown in and/or
described in connection with at least one of the figures, as set
forth more completely in the claims.
[0014] Various advantages, aspects and novel features of the
present invention, as well as details of an illustrated embodiment
thereof, will be more fully understood from the following
description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0015] FIG. 1 is a block diagram illustrating an exemplary Ethernet
connection between two network devices, in accordance with an
embodiment of the invention.
[0016] FIG. 2 is a block diagram illustrating an exemplary Ethernet
over twisted pair PHY device architecture comprising a multi-rate
capable physical module, in accordance with an embodiment of the
invention.
[0017] FIG. 3 is a block diagram illustrating an exemplary
pluggable PHY device operable to implement an energy efficient
network control policy.
[0018] FIG. 4A is a block diagram illustrating an exemplary copper
based pluggable PHY device, in accordance with an embodiment of the
invention.
[0019] FIG. 4B is a block diagram illustrating an exemplary
pluggable optical PHY device, in accordance with an embodiment of
the invention.
[0020] FIG. 5 is a flow chart illustrating exemplary steps
implementing an energy efficient network control policy in a
pluggable physical layer device, in accordance with an embodiment
of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0021] Certain embodiments of the invention can be found in a
method and system for managing energy efficiency of a network link
via pluggable transceiver modules in an energy efficient network
device. An Ethernet network may comprise one or more link partners
that may be coupled via an Ethernet link. The one or more link
partners may comprise one or more pluggable PHY devices. The
pluggable PHY devices and/or higher layer devices may be operable
to determine one or more energy efficient network control policies
that may specify a power level mode for the one or more link
partners, and the one or more link partners may be configured to
operate in the specified power level mode. In various embodiments
of the invention, a power level mode of operation may be selected
based on the energy efficient network control policies.
Accordingly, one or more components of the pluggable PHY devices
may be reconfigured based on the selected power level mode of
operation. A first portion of the one or more components may be
reconfigured prior to sending an energy efficient network control
signal to one or more of the link partners and reconfiguring a
remaining portion of the one or more components. Hardware, software
and/or firmware within the one or more pluggable PHY devices may be
utilized to execute the one or more energy efficient network
control policies. In some instances, while transitioning to an
active power mode, packet data that may be pending delivery in the
one or more pluggable PHY devices may be buffered. The one or more
pluggable PHY devices may comprise one or both of a media access
controller and/or a serializer de-serializer device. Exemplary form
factors for the one or more pluggable PHY devices may comprise one
or more of a SFP, a SFP+, a XENPAK, a X2, a XFP and a XPAK form
factor. The power level mode may comprise low power idle mode
and/or sub-rate mode.
[0022] FIG. 1 is a block diagram illustrating an exemplary Ethernet
connection between a two network devices, in accordance with an
embodiment of the invention. Referring to FIG. 1, there is shown a
system 100 that comprises a network device 102 and a network device
104. In addition, there is shown two hosts 106a and 106b, two MAC
controllers 108a and 108b, a pluggable PHY device 110a and a PHY
device 110b, interfaces 114a and 114b, bus controller interfaces
116a and 116b and a link 112
[0023] The network devices 102 and 104 may be link partners that
may communicate via the link 112. The Ethernet link 112 is not
limited to any specific medium and may utilize any suitable medium.
Exemplary Ethernet link 112 media may comprise copper, optical
and/or backplane technologies. For example, a copper medium such as
STP, Cat3, Cat 5, Cat 5e, Cat 6, Cat 7 and/or Cat 7a as well as ISO
nomenclature variants may be utilized. Additionally, copper media
technologies such as InfiniBand, Ribbon and backplane may be
utilized. With regard to optical media for the Ethernet link 112,
single mode fiber as well as multi-mode fiber may be utilized. In
various embodiments of the invention, one or both of the network
devices 102 and 104 may be operable to comply with one or more
standards based on IEEE 802.3, for example, 802.3az.
[0024] In an exemplary embodiment of the invention, the link 112
may comprise up to four or more physical channels, each of which
may, for example, comprise an unshielded twisted pair (UTP). The
network device 102 and the network device 104 may communicate via
two or more physical channels comprising the link 112. For example,
Ethernet over twisted pair standards 10 BASE-T and 100 BASE-TX may
utilize two pairs of UTP while Ethernet over twisted pair standards
1000 BASE-T and 10 GBASE-T may utilize four pairs of UTP. In this
regard, however, aspects of the invention may enable varying the
number of physical channels via which data is communicated.
[0025] The network device 102 may comprise a host 106a, a medium
access control (MAC) controller 108a and a pluggable PHY device
110a. The network device 104 may comprise a host 106b, a MAC
controller 108b, and a PHY device 110b. The PHY device(s) 110a
and/or 110b may be pluggable transceiver modules or may be an
integrated PHY device. Notwithstanding, the invention is not
limited in this regard. In various embodiments of the invention,
the network device 102 and/or 104 may comprise, for example, a
network switch, a router, computer systems or audio/video (A/V)
enabled equipment. In this regard, A/V equipment may, for example,
comprise a microphone, an instrument, a sound board, a sound card,
a video camera, a media player, a graphics card, or other audio
and/or video device. Additionally, the network devices 102 and 104
may be enabled to utilize Audio/Video Bridging and/or Audio/video
bridging extensions (collectively referred to herein as audio video
bridging or AVB) for the exchange of multimedia content and
associated control and/or auxiliary data.
[0026] The pluggable PHY device 110a and the PHY device 110b may
each comprise suitable logic, circuitry, interfaces and/or code
that may enable communication, for example, transmission and
reception of data, between the network device 102 and the network
device 104. One or both of the PHY devices 110a and 110b may
comprise pluggable modules. In this regard, the pluggable device(s)
may be a removable or replaceable component within a network
communication device. The pluggable PHY device(s) 110a and/or 110b
may comprise suitable logic, circuitry, interfaces and/or code that
may provide an interface between the network device(s) 102 and/or
104 to an optical and/or copper cable. In some instances, the
pluggable device(s) 110a and/or 110b may enable interfacing host
and/or MAC that are designed to communicate over a copper link to
an optical link or vice versa. Exemplary form factors for the
pluggable device(s) 110a and/or 110b comprise SFP, SFP+, XENPAK,
X2, XFP and XPAK modules. In various embodiments of the invention,
the pluggable PHY device(s) 110a and/or 110b may be enabled to be
replaced without shutting down the entire network device.
[0027] The pluggable PHY device 110a and/or the PHY device 110b may
be operable to support, for example, Ethernet over copper, Ethernet
over fiber, and/or backplane Ethernet operations. The pluggable PHY
device 110a and/or the PHY device 110b may enable multi-rate
communications, such as 10 Mbps, 100 Mbps, 1000 Mbps (or 1 Gbps),
2.5 Gbps, 4 Gbps, 10 Gbps, 40 Gbps or 100 Gbps for example. In this
regard, the pluggable PHY device 110a and/or the PHY device 110b
may support standard-based data rate limits and/or non-standard
data rate limits. Moreover, the pluggable PHY device 110a and/or
the PHY device 110b may support standard Ethernet link lengths or
ranges of operation and/or extended ranges of operation. The
pluggable PHY device 110a and/or the PHY device 110b may enable
communication between the network device 102 and the network device
104 by utilizing a link discovery signaling (LDS) operation that
enables detection of active operations in the other network device.
In this regard the LDS operation may be configured to support a
standard Ethernet operation and/or an extended range Ethernet
operation. The pluggable PHY device 110a and/or the PHY device 110b
may also support autonegotiation for identifying and selecting
communication parameters such as speed and duplex mode.
[0028] The pluggable PHY device 110a and/or the PHY device 110b 10b
may comprise a pluggable twisted pair PHY capable of operating at
one or more standard rates such as 10 Mbps, 100 Mbps, 1 Gbps, and
10 Gbps (10 BASE-T, 100 GBASE-TX, 1 GBASE-T, and/or 10 GBASE-T);
potentially standardized rates such as 40 Gbps and 100 Gbps; and/or
non-standard rates such as 2.5 Gbps and 5 Gbps. The pluggable PHY
device 110a and/or the PHY device 110b may comprise a pluggable
backplane PHY capable of operating at one or more standard rates
such as 10 Gbps (10 GBASE-KX4 and/or 10 GBASE-KR); and/or
non-standard rates such as 2.5 Gbps and 5 Gbps. The pluggable PHY
device 110a and/or the PHY device 110b may comprise a pluggable
optical PHY capable of operating at one or more standard rates such
as 10 Mbps, 100 Mbps, 1 Gbps, and 10 Gbps; potentially standardized
rates such as 40 Gbps and 100 Gbps; and/or non-standardized rates
such as 2.5 Gbps and 5 Gbps. In this regard, the optical PHY may be
a passive optical network (PON) PHY.
[0029] The pluggable PHY device 110a and/or the PHY device 110b may
support multi-lane topologies such as 40 Gbps CR4, ER4, KR4; 100
Gbps CR10, SR10 and/or 10 Gbps LX4 and CX4. Also, serial electrical
and copper single channel technologies such as KX, KR, SR, LR, LRM,
SX, LX, CX, BX10, LX10 may be supported. Non standard speeds and
non-standard technologies, for example, single channel, two channel
or four channels may also be supported. More over, TDM technologies
such as PON at various speeds may be supported by the network
devices 102 and/or 104.
[0030] In various embodiments of the invention, the pluggable PHY
device 110a and/or the PHY device 110b may comprise suitable logic,
circuitry, and/or code that may enable transmission and/or
reception at a high(er) data in one direction and transmission
and/or reception at a low(er) data rate in the other direction. For
example, the network device 102 may comprise a multimedia server
and the network device 104 may comprise a multimedia client. In
this regard, the network device 102 may transmit multimedia data,
for example, to the network device 104 at high(er) data rates while
the network device 104 may transmit control or auxiliary data
associated with the multimedia content at low(er) data rates.
[0031] The data transmitted and/or received by the pluggable PHY
device 110a and/or the PHY device 110b may be formatted in
accordance with the well-known OSI protocol standard. The OSI model
partitions operability and functionality into seven distinct and
hierarchical layers. Generally, each layer in the OSI model is
structured so that it may provide a service to the immediately
higher interfacing layer. For example, layer 1, or physical layer,
may provide services to layer 2 and layer 2 may provide services to
layer 3. The hosts 106a and 106b may implement layer 3 and above,
the MAC controllers 108a and 108b may implement layer 2 and above
and the pluggable PHY device 110a and/or the PHY device 110b may
implement the operability and/or functionality of layer 1 or the
physical layer. In this regard, the pluggable PHY device 110a
and/or the PHY device 110b may be referred to as physical layer
transmitters and/or receivers, physical layer transceivers, PHY
transceivers, PHYceivers, or PHY, for example. The hosts 106a and
106b may comprise suitable logic, circuitry, and/or code that may
enable operability and/or functionality of the five highest
functional layers for data packets that are to be transmitted over
the link 112. Since each layer in the OSI model provides a service
to the immediately higher interfacing layer, the MAC controllers
108a and 108b may provide the necessary services to the hosts 106a
and 106b to ensure that packets are suitably formatted and
communicated to the pluggable PHY device 110a and/or the PHY device
110b. During transmission, a device implementing a layer function
may add its own header to the data passed on from the interfacing
layer above it. However, during reception, a compatible device
having a similar OSI stack may strip off the headers as the message
passes from the lower layers up to the higher layers.
[0032] The pluggable PHY device 110a and/or the PHY device 110b may
be configured to handle physical layer requirements, which include,
but are not limited to, packetization, data transfer and
serialization/deserialization (SERDES), in instances where such an
operation is required. Data packets received by the pluggable PHY
device 110a and/or the PHY device 110b from MAC controllers 108a
and 108b, respectively, may include data and header information for
each of the six functional layers above the PHY layer. The
pluggable PHY device 110a and/or the PHY device 110b may be
configured to encode data packets that are to be transmitted over
the link 112 and/or to decode data packets received from the link
112.
[0033] In various embodiments of the invention, one or both of the
pluggable PHY device 110a and the PHY device 110b, may comprise
suitable logic, circuitry, interfaces, and/or code that may be
operable to implement one or more energy efficient Ethernet (EEE)
techniques in accordance with IEEE 802.3az as well as other energy
efficient network techniques. For example, the pluggable PHY device
110a and/or the PHY device 110b may be operable to support low
power idle (LPI) and/or sub-rating, also referred to as subset PHY,
techniques. LPI may generally refer a family of techniques where,
instead of transmitting conventional IDLE symbols during periods of
inactivity, the pluggable PHY device 110a and/or the PHY device
110b may remain silent and/or communicate signals other than
conventional IDLE symbols. Sub-rating, or sub-set PHY, may
generally refer to a family of techniques where the PHYs are
reconfigurable, in real-time or near real-time, to communicate at
different data rates.
[0034] In various embodiments of the invention, the host 106a
and/or 106b may be operable to communicate LPI control information
with the pluggable PHY devices 110a and/or 110b via an alternate
path. For example, the host 106a and/or the host 106b may be
operable to communicate via a general purpose input output (GPIO)
and/or a peripheral component interconnect express (PCI-E).
[0035] The MAC controller 108a may comprise suitable logic,
circuitry, and/or code that may enable handling of data link layer,
layer 2, operability and/or functionality in the network device
102. Similarly, the MAC controller 108b may comprise suitable
logic, circuitry, and/or code that may enable handling of layer 2
operability and/or functionality in the network device 104. The MAC
controllers 108a and 108b may be configured to implement Ethernet
protocols, such as those based on the IEEE 802.3 standards, for
example. Notwithstanding, the invention is not limited in this
regard.
[0036] The MAC controller 108a may communicate with the pluggable
PHY device 110a via an interface 114a and with the host 106a via a
bus controller interface 116a. The MAC controller 108b may
communicate with the PHY device 110b via an interface 114b and with
the host 106b via a bus controller interface 116b. The interfaces
114a and 114b correspond to Ethernet interfaces that comprise
protocol and/or link management control signals. The interfaces
114a and 114b may be multi-rate capable interfaces and/or media
independent interfaces (MII). The bus controller interfaces 116a
and 116b may correspond to PCI or PCI-X interfaces.
Notwithstanding, the invention is not limited in this regard.
[0037] In operation, one or both of the pluggable PHY device 110a
and/or the PHY device 110b may comprise a pluggable module that may
support one or more energy efficient network (EEN) techniques.
Accordingly, an energy efficient network (EEN) control policy may
be implemented in firmware, hardware, and/or software within the
pluggable module(s). The EEN control policy may determine how
and/or when to configure and/or reconfigure the pluggable PHY
device 110a and/or the PHY device 110b to optimize a tradeoff
between energy efficiency and performance. For LPI, the control
policy may determine, for example, what variant of LPI to utilize,
when to go into a LPI mode and when to come out of a LPI mode. For
subset PHY, the pluggable PHY device 110a may be operable to
determine, for example, how to achieve a desired data rate and/or
when to transition between data rates. Although various aspects of
the invention are described with regard to LPI and subset PHY, the
invention is not so limited and other EEN techniques may be
implemented via a pluggable PHY based control policy. In various
embodiments of the invention, the pluggable PHY device 110 may be
operable to communicate EEN control policy information with the
host 106a via a GPIO and/or a PCI-E for example.
[0038] In instances when the energy efficient network (EEN) control
policy may be implemented at the physical layer (PHY), it may be
transparent to open systems interconnect (OSI) Layer 2 and above. A
pluggable PHY device that implements such an EEN control policy may
thus be a drop-in replacement for a conventional PHY device.
[0039] Accordingly, such a pluggable PHY device, and the energy
efficient network control policy implemented by the PHY device, may
be compatible with a legacy MAC and/or a legacy host. In this
manner, implementing an energy efficient network control policy in
a pluggable PHY device 110a and/or 110b may enable reaping the
benefits of a more energy efficient network while avoiding the need
to redesign or "re-spin" a MAC 108 or a host 106.
[0040] FIG. 2 is a block diagram illustrating an exemplary Ethernet
over twisted pair PHY device architecture comprising a multi-rate
capable physical module, in accordance with an embodiment of the
invention. Referring to FIG. 2, there is shown a network device 200
which may comprises an Ethernet over twisted pair pluggable PHY
device 202, a MAC controller 204, a host 206 and interfaces 116 and
114. The pluggable PHY device 202 may be a pluggable transceiver
device which may comprise a multi-rate capable physical layer
module 212, one or more transmitters 214, one or more receivers
220, a memory 216, a memory interface 218, and one or more
input/output interfaces 222.
[0041] The pluggable PHY device 202 may be a pluggable transceiver
module that may comprise a multi-rate capable physical layer module
212, one or more transmitters 214, one or more receivers 220, a
memory 216, a memory interface 218, and one or more input/output
interfaces 222. The operation of the pluggable PHY device 202 may
be the same as or substantially similar to that of the pluggable
PHY device 110a disclosed in FIG. 1. In this regard, the pluggable
PHY device 202 may provide OSI layer 1 (physical layer) operability
and/or functionality that enables communication with a remote PHY
device. Similarly, the operation of the MAC controller 204, the
host 206 and the interfaces 114 and/or 116 may be the same as or
substantially similar to the respective MAC controllers 108a and
108b, hosts 106a and 106b and interfaces 116a, 116b, 114a and 114b
described with respect to FIG. 1. The MAC controller 204 may
comprise a multi-rate capable interface 204a that may comprise
suitable logic, circuitry, interfaces and/or code to enable
communication with the pluggable PHY device 202 at a plurality of
data rates via the interface 208.
[0042] The interface 114 may be the same as or substantially
similar to the interfaces 114a and 114b described with respect to
FIG. 1. The interface 114 may comprise, for example, a media
independent interface such as XGMII, GMII, or RGMII for
communicating data to and from the pluggable PHY device 202. In
this regard, the interface 114 may comprise a signal to indicate
that data from the MAC 204 to the pluggable PHY 202 is imminent on
the interface 114. Such a signal is referred to herein as a
transmit enable (TX_EN) signal. Similarly, the interface 114 may
utilize a signal to indicate that data from the PHY 202 to the MAC
204 is imminent on the interface 114. Such a signal is referred to
herein as a receive data valid (RX_DV) signal. The interface 114
may also comprise a control interface such as a management data
input/output (MDIO) interface.
[0043] The multi-rate capable physical layer module 212 in the
pluggable PHY device 202 may comprise suitable logic, circuitry,
and/or code that may enable operability and/or functionality of
physical layer requirements. In this regard, the multi-rate capable
physical layer module 212 may enable generating the appropriate
link discovery signaling utilized for establishing communication
with a remote PHY device in a remote network device. The multi-rate
capable physical layer module 212 may communicate with the MAC
controller 204 via the interface 114. In various embodiments of the
invention, the interface 114 may be a media independent interface
(MII) and may be configured to utilize a plurality of serial data
lanes for receiving data from the multi-rate capable physical layer
module 212 and/or for transmitting data to the multi-rate capable
physical layer module 212. The multi-rate capable physical layer
module 212 may be configured to operate in one or more of a
plurality of communication modes, where each communication mode may
implement a different communication protocol. These communication
modes may include, but are not limited to, Ethernet over twisted
pair standards 10 BASE-T, 100 BASE-TX, 1000 BASE-T, 10 GBASE-T, and
other similar protocols that utilize multiple physical channels
between network devices. The multi-rate capable physical layer
module 212 may be configured to operate in a particular mode of
operation upon initialization or during operation. In this regard,
the pluggable PHY device 202 may operate in a normal mode or in one
of a plurality of an energy saving modes. Exemplary energy saving
modes may comprise a low power idle (LPI) mode and one or more
sub-rate modes where the pluggable PHY device 202 may communicate
at less than a maximum supported or initially negotiated data
rate.
[0044] In various embodiments of the invention, the multi-rate
capable physical layer module 212 may comprise suitable logic,
circuitry, interfaces, and/or code for implementing an energy
efficient networking (EEN) control policy. Accordingly, the
multi-rate capable physical layer module 212 may be operable to
monitor one or more conditions and/or signals in the pluggable PHY
device 202 and control mode of operation based on the monitoring.
In this regard, the multi-rate capable physical layer module 212
may generate one or more control signals to configure and/or
reconfigure the various components of the pluggable PHY device
202.
[0045] The multi-rate capable physical layer module 212 may
comprise memory 216a and/or may be coupled to memory 216b through a
memory interface 218. The memories 216a and 216b, referred
collectively herein as memory 216, may comprise suitable logic,
circuitry, and/or code that may enable storage or programming of
information that includes parameters and/or code that may
effectuate the operation of the multi-rate capable physical layer
module 212. In this regard, the memory 216 may, for example,
comprise one or more registers which may be accessed and/or
controlled via a MDIO portion of the interface 114. Additionally,
the memory 216 may buffer data received via the interface 114 prior
to converting the data to physical symbols and transmitting it via
one or more of the interfaces 222. For example, data from the
interface 114 may be buffered while the PHY transitions from an
energy saving mode to a higher performance mode (transitioning out
of LPI mode) or from a higher data rate to a sub-rate, for example.
Also, the memory 216 may buffer data received via one or more of
the interfaces 222 prior to converting the data to physical symbols
and transmitting it via the interface 114. For example, data
received via the link 112 may be buffered in the memory 216 while
higher layer functions and/or circuitry, such as a MAC or PCI bus,
come out of an energy saving mode.
[0046] Each of the transmitters 214a, 214b, 214c, 214d,
collectively referred to herein as transmitters 214 may comprise
suitable logic, circuitry, and/or code that may enable transmission
of data from the network device 200 to a remote network device via,
for example, the link 112 shown in FIG. 1. The receivers 220a,
220b, 220c, 220d may comprise suitable logic, circuitry, and/or
code that may enable receiving data from a remote network device.
Each of the transmitters 214a, 214b, 214c, 214d and receivers 220a,
220b, 220c, 220d in the pluggable PHY device 202 may correspond to
a physical channel that may comprise the link 112. In this manner,
a transmitter/receiver pair may interface with each of the physical
channels 224a, 224b, 224c and 224d. In this regard, the
transmitter/receiver pairs may be enabled to support various
communication rates, modulation schemes, and signal levels for each
physical channel. In this manner, the transmitters 214 and/or
receivers 229 may support various modes of operation that enable
management of energy consumption of the PHY device 202 and energy
consumption on the link 112. Accordingly, one or more of the
transmitters 214 and/or receivers 220 may be powered down and/or
otherwise configured based on a mode of operation of the pluggable
PHY device 202.
[0047] The input/output interfaces 222 may comprise suitable logic
circuitry, and/or code that may enable the pluggable PHY device 202
to impress signal information onto a physical channel, for example
a twisted pair of the link 112 disclosed in FIG. 1. Consequently,
the input/output interfaces 222 may, for example, provide
conversion between differential and single-ended, balanced and
unbalanced, signaling methods. In this regard, the conversion may
depend on the signaling method utilized by the transmitter 214, the
receiver 220, and the type of medium of the physical channel.
Accordingly, the input/output interfaces 222 may comprise one or
more baluns and/or transformers and may, for example, enable
transmission over a twisted pair. Additionally, the input/output
interfaces 222 may be internal or external to the pluggable PHY
device 202. In this regard, if the pluggable PHY device 202
comprises an integrated circuit, then "internal" may, for example,
refer to being "on-chip" and/or sharing the same substrate.
Similarly, if the pluggable PHY device 202 comprises one or more
discrete components, then "internal" may, for example, refer to
being on the same printed circuit board or being within a common
physical package.
[0048] The pluggable PHY device 202 may be enabled to transmit and
receive simultaneously over up to four or more physical links.
Accordingly, the pluggable PHY device 202 may comprise a number of
hybrids 226 corresponding to the number of physical links. Each
hybrid 226 may comprise suitable logic, circuitry, and/or code that
may enable separating transmitted and received signals from a
physical link. For example, the hybrids may comprise echo
cancellers, far-end crosstalk (FEXT) cancellers, and/or near-end
crostalk (NEXT) cancellers. Each hybrid 226 in the network device
300 may be communicatively coupled to an input/output interface
222. One of more of the hybrids 226 may be enabled to support
various modes of operation that enable managing energy consumption
of the pluggable PHY device 202 and energy consumption on the link
112. Accordingly, portions of the hybrids 226 may be powered down
and/or otherwise configured based on a mode of operation of the
pluggable PHY device 202.
[0049] In operation, the network device 200 may communicate with a
remote partner via the link 112. For example, for 10 Gbps Ethernet,
the network device 200 may transmit data to and receive data from a
remote partner via the physical channels 224a, 224b, 224c, and
224d. In this regard, when there is no data for the network device
200 to transmit, then it may transmit IDLE symbols to keep itself
and/or the remote partner "trained". In this manner, power
consumption of a network may be largely independent of the amount
of actual data being transmitted over the network. Accordingly,
controlling the data rate limit on the link 112 may enable the
network devices 200 to transmit fewer IDLE symbols and thus
communicate in a more energy efficient manner. In this regard, the
pluggable PHY device 202 may implement an energy efficient network
control policy to decide when to transition between various modes
of operation. The control policy may affect a tradeoff between
performance and energy consumption. Performance may be measured by
a variety of metrics such as jitter, latency, bandwidth and error
rates, for example.
[0050] In one exemplary embodiment of the invention, the control
policy may determine when and how to utilize sub-rating to improve
energy efficiency. Accordingly, the control policy may determine
what data rate to utilize, how to configure the various components
of the pluggable PHY device 202 to realize a selected data rate,
and when to transition between data rates. In this regard, the
pluggable PHY device 202 may be operable to generate one or more
control signals, based on the control policy, to configure or
reconfigure the transmitters 214, receivers 220, hybrids 226, the
memory 216, and/or one or more portions of the multi-rate capable
PHY module 212. The pluggable PHY device 202 may also be operable
to generate signals for communicating energy efficient network
(EEN) states and/or decisions to a link partner based on the
control policy.
[0051] In another exemplary embodiment of the invention, the
control policy implemented by the pluggable PHY device may make
determinations as to when and how to utilize low power idle (LPI)
to improve energy efficiency. Accordingly, the control policy may
determine when to go into an LPI mode, how to configure the various
components of the PHY device 202 when in LPI mode, and when to come
out of a LPI mode. The PHY device 202 may also be operable to,
based on the control policy, generate signals for communicating EEN
states and/or decisions to a link partner.
[0052] The pluggable PHY device 202 and/or devices implementing
higher OSI layer functions may be placed in a low power idle mode
(LPI) wherein the pluggable PHY device and/or the devices
implementing high layers may be powered down during idle periods.
In some instances, LPI control information regarding when to power
down, may be communicated via a GPIO and/or PCI-E. During power
down, the pluggable PHY device 202 may maintain various
coefficients, for example, adaptive filter and/or block
coefficients and may maintain synchronization to allow for a more
rapid return to an active state. In addition, during LPI mode, a
portion of the receiver circuitry may be turned off. In asymmetric
systems, devices that handle one direction of communication may be
in a quiet state independent of devices that handle communication
in an opposite direction. In synchronous systems, both directions
of a PHY device may enter and/or leave a quiet state together.
Although a PHY device 202 may operate in a synchronous mode,
devices that may handle OSI layers above the PHY layer may operate
in an asymmetric mode.
[0053] FIG. 3 is a block diagram illustrating an exemplary
pluggable PHY device operable to implement an energy efficient
network control policy, in accordance with an embodiment of the
invention. Referring to FIG. 3, there is shown a pluggable PHY
device 302, a MAC 304, a host 306, an interface 350, the interface
114 and the link 112. The PHY device 302 may comprise a PHY and
logic module 308 for implementing the physical coding sublayer
(PCS), the physical media attachment (PMA) sublayer and/or the
physical media dependent (PMD) sublayer; and an optional control
policy assist module 314. The PHY and logic module 308 may comprise
one or more transmit buffers 310a, one or more receive buffers
310b.
[0054] The pluggable PHY device 302 and the MAC 304 may be similar
or substantially the same as the pluggable PHY device 202 and the
MAC 204 respectively, which are described with respect to, for
example, FIG. 2. The host 306 may be similar and/or substantially
the same as the host 106 and/or the host 206 described with respect
to FIG. 1 and FIG. 2 respectfully. The interface 114 and the link
112 are described with respect to, for example, FIG. 1.
[0055] In various embodiments of the invention, the host 306 may be
operable to communicate LPI control information with the control
policy assist module 314 GPIO and/or a PCI-E bus, for example, via
the interface 350. In this regard, the host 306 may indicate when
the control policy assist may go into and/or out of an LPI
mode.
[0056] The pluggable PHY device 302 may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to implement
physical layer functionality. In this regard, the physical coding
sublayer (PCS), physical medium attachment (PMA) sublayer, and
physical medium dependent (PMD) sublayer may be implemented via
hardware, firmware, and/or software represented as the PHY and
logic module 308. The PHY and logic module 308 may be operable to
perform one or more of physical encoding and/or decoding, PMA
framing, and transmitter and/or receiver operations. The PHY and
logic module 308 may comprise one or more transmit buffers 310a
that may be operable to store data received via the interface 114
and destined for transmission on the link 112. The PHY and logic
module 308 may comprise one or more receive buffers 310b that may
be operable to store data received via the link 112 and destined
for the MAC 304 via the interface 114.
[0057] The pluggable PHY device 302 may also comprise an optional
control policy assist module 314 which may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to implement
an energy efficient network control policy. In various exemplary
embodiments of the invention, the pluggable PHY device 302 may
comprise memory 316 and/or one or more counters 318. In various
embodiments of the invention, the optional control policy assist
module 314 may be operable to generate energy efficient network
control information to be communicated to a link partner and/or
process energy efficient network control information received from
a link partner.
[0058] The memory 316 may comprise one or more state registers
and/or configuration registers. The registers may comprise content
that may be read to control transitioning of the pluggable PHY
device 302 into and/or out of low(er) power level modes of
operation. Additionally, the memory 316 may be allocated and
reallocated to supplement the Tx buffer 310a and/or the Rx buffer
310b.
[0059] In various embodiments of the invention, the pluggable PHY
device 302 may comprise suitable logic, circuitry, interfaces
and/or code that may be operable to communicate via a link
comprising an extended range. In this regard, the PHY layer
architecture in the pluggable PHY device 302 may support
signal-processing operations, such as echo cancellation and/or
equalization, which may be applied to a reduced communication rate
to enable range extension. Range extension is described in greater
detail in U.S. patent application Ser. No. 11/473,205 (Attorney
Docket No. 17396US02) filed Jun. 22, 2006 titled "Method and System
for Extended Reach Copper Transceiver," which is hereby
incorporated herein by reference in its entirety.
[0060] The pluggable PHY device 302 may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to support
MACSEC communication. For example, the pluggable PHY device 302 may
support controlled network access wherein network device identities
may be validated and network security policies may be enforced.
MACSEC is described in greater detail in U.S. patent application
Ser. No. 11/685,554 (Attorney Docket No. 18031US01) filed Mar. 13,
2007 titled "Method and System for Tunneling MACSEC Packets Through
Non-MACSEC Nodes," which is hereby incorporated herein by reference
in its entirety.
[0061] In operation, the energy efficient network (EEN) control
policy may make decisions such as when to enter and/or exit a
low(er) power mode. EEN control policy decisions and the resulting
actions, such as reconfiguring the pluggable PHY device 302, may be
determined based on one or more signals and/or conditions monitored
within the pluggable PHY device 302. Several examples of factors
which may be considered by the control policy follow. Many of the
examples are simplified and various embodiments of the invention
may utilize a combination of two or more of them. Nevertheless, the
invention is not limited to the examples provided.
[0062] Management of the energy efficient network (EEN) protocols
and/or techniques may be based, for example, on an amount of data
buffered in the buffers 310 and/or the memory 316. For example, in
instances that the Tx buffer 310a [Rx buffer 310b] is empty, or is
empty for a certain amount of time, portions of the PHY device 302
associated with data transmission [reception] may be reconfigured
into a low(er) power state.
[0063] Management of the energy efficient network protocols and/or
techniques may be based, for example, on one or more counters
and/or registers in the optional control policy assist module 314.
For example, in instances that the TX_EN of the interface 114 has
not been asserted for a determined period of time, portions of the
pluggable PHY device 302 associated with data transmission
[reception] may be reconfigured into a low(er) power state.
Additionally, values of the counter may be stored and historical
values of the counter may be utilized to predict when the pluggable
PHY device 302 may transition to a low(er) power mode without
having a significant negative impact on performance.
[0064] Management of the energy efficient network protocols and/or
techniques may be based, for example, on management signals of an
MDIO bus to the MAC. For example, the MDIO may configure thresholds
such as how long the pluggable PHY device 302 should stay in a
low(er) power mode after entering the low(er) power mode, how long
a buffer should be empty before going into a low(er) power mode,
and how full a buffer should be before waking up from a low(er)
power mode. The MDIO may also be utilized to configure parameters
pertaining to a link partner. Exemplary parameters comprise how
long the link partner takes to wake up and how much buffering is
available in the link partner's buffers. The MDIO may enable
configuration of the control policy by a system designer or
administrator.
[0065] Management of the energy efficient network protocols and/or
techniques may be based, for example, on signals received from a
device implementing layers above the MAC layer, such as signals
generated by a PCI bus controller and/or the host 306. For example,
a signal indicating whether the PCI bus is active may be utilized
to predict whether data will be arriving at the pluggable PHY
device 302 and/or to determine whether the devices implementing
higher layers are ready to receive data from the pluggable PHY
device 302. For another example, signals from the host 306, or
other data processing components, may indicate a type of traffic
communicated to the pluggable PHY device 302 and the control policy
may determine an appropriate mode of operation of the pluggable PHY
device 302 and/or an appropriate allocation of buffering, or other
resources, in the PHY device 302 based on the data type. In this
regard, management of the energy efficient network protocols and/or
techniques may be based, for example, on latency constraints of the
traffic to be transmitted via the link 112 or communicated up to
the MAC 304. In instances when latency is not tolerable, a series
of traffic bursts may be buffered for an acceptable amount of time
before waking the pluggable PHY device 302, the MAC 304, and/or
devices implementing higher layer functions for delivery of the
accumulated traffic bursts.
[0066] Management of the energy efficient network protocols and/or
techniques may be based, for example, on signals received from a
link partner to which the pluggable PHY device 302 is
communicatively coupled. In this regard, going into and coming out
of low(er) power modes may require agreement by the link partner,
or at least awareness of what the link partner is doing. For
example, in instances that the link partner takes longer to wake up
then the pluggable PHY device 302, the pluggable PHY device 302 may
need to plan accordingly and allocate sufficient memory to the Tx
buffer 310a. Conversely, in instances that the link partner wakes
up faster than the pluggable PHY device 302, the pluggable PHY
device 302 may need to plan accordingly and allocate sufficient
memory to the Rx buffer 310b and/or instruct the link partner to
increase its Tx buffer to hold off transmissions. A similar
situation may occur when a link partner has less buffering
available than the pluggable PHY device 302. Accordingly, in some
embodiments of the invention, the control policy may be operable to
dynamically allocate and reallocate as the memory 316, for example,
to supplement the Tx buffer 310 or the Rx buffer 310b.
[0067] FIG. 4A is a block diagram illustrating an exemplary, copper
based pluggable PHY device, in accordance with an embodiment of the
invention. Referring to FIG. 4A, there is shown a MAC 404, a host
406, an interface 450, a serial link 414, a pluggable PHY device
402, the PHY and logic module 308, the control policy assist module
314 and the link 112.
[0068] The MAC 404, the host 406, the interface 450 and pluggable
PHY device 402 may be similar and/or substantially the same as the
MAC 304, the host 306, the interface 350 and pluggable PHY device
302 described with respect to, for example, FIG. 3. The PHY and
logic module 308 and the control policy assist module 314 are
described with respect to FIG. 3. The link 112 is described with
respect to, for example. FIG. 1.
[0069] The pluggable PHY device 402 may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to implement
an energy efficient network (EEN) control policy. The pluggable PHY
device 402 may be a removable or replaceable component within a
network communication device. In various embodiments of the
invention, the pluggable PHY device 402 may be enabled so that it
may be replaced without shutting down the entire network device. In
this regard, the pluggable PHY device 402 may comprise a hot
swappable PHY device. The pluggable PHY device 402 may comprise the
PHY and logic module 308, the control policy assist module 314. In
this regard, the pluggable PHY device 409 may be operable to
determine when to enter and/or exit a low(er) power mode and may be
operable to communicate EEN control policy instructions to one or
more link partners.
[0070] In operation, the MAC 404 may be integrated within a network
device such as a switch, for example.
[0071] In an exemplary embodiment of the invention, the pluggable
PHY device 402 may support 10 GBASE-T. The pluggable PHY device 402
may be coupled to the MAC 404 via the serial link 414. The
pluggable PHY device 402 may monitor the serial link 414 and/or the
link 112 and may determine when data may and/or may not be
available for transmission and/or reception. The pluggable PHY
device 402 may determine when to enter and/or exit an energy
efficient network (EEN) low(er) power mode and may configure the
various components of the pluggable PHY device 402 accordingly. The
pluggable PHY device 402 may also be operable to generate signals
for communicating energy efficient network (EEN) states and/or
decisions to a link partner.
[0072] FIG. 4B is a block diagram illustrating an exemplary
pluggable optical PHY device, in accordance with an embodiment of
the invention. Referring to FIG. 4B, there is shown a MAC 424, a
host 456, an interface 458, a pluggable PHY device 422, the
serializer-deserializer (SerDes) 426, a SerDes 428, a MAC and logic
module 420, the PHY and logic module 308, the control policy assist
module 314 and the link 112.
[0073] The MAC 424, the host 456, the interface 458 and the
pluggable PHY device 422 may be similar and/or substantially the
same as the MAC 304, the host 306, the interface 350 and pluggable
PHY device 302 described with respect to FIG. 3. The PHY and logic
module 308 and the control policy assist module 314 are described
with respect to FIG. 3. The link 112 is described with respect to
FIG. 1.
[0074] The SerDes 426 and SerDes 428 may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to convert
data between serial data and parallel data in forward and/or
reverse directions. In various embodiments of the invention, the
SerDes 426 and/or 428 may be operable to perform line coding and/or
framing functions.
[0075] The MAC and logic module 420 may comprise suitable logic
circuitry interfaces and/or code that may be operable to implement
Ethernet protocols, such as those based on the IEEE 802.3
standards, for example 802.3az. In various embodiments of the
invention, the MAC 420 may be operable to handle MACSEC for secure
communication. For example, the MAC and logic module 420 may
support controlled network access wherein network device identities
may be validated and network security policies may be enforced.
[0076] The pluggable PHY device 422 may comprise suitable logic,
circuitry, interfaces and/or code that may be operable to implement
an energy efficient network control policy. The pluggable PHY
device 422 may be a removable or replaceable component within a
network communication device. In various embodiments of the
invention, the pluggable PHY device 422 may be enabled to be
replaced without shutting down the entire network device. The
pluggable PHY device 422 may comprise the PHY and logic module 308,
the control policy assist module 314. In this regard, the pluggable
PHY device 422 may be operable to determine when to enter and/or
exit a low(er) power mode and may be operable to communicate the
energy efficient network control policy instructions to one or more
link partners.
[0077] In operation, the MAC 424 may be integrated within a network
device comprising, for example, a switching device. The pluggable
PHY device 422 may provide an interface between the MAC 424 and the
link 112 which may comprise a fiber optic medium. In various
embodiments of the invention, the pluggable PHY device 422 may be
operable to interface a MAC that may be designed to communicate via
a fiber optic link, to a copper link such as a twisted pair. The
pluggable PHY device 422 may comprise a form factor similar to, for
example, a small form-factor pluggable (SFP), an SFP+, a GBIC, a
XENPAK, a X2, a XFP and/or a XPAK.
[0078] The SerDes 426 may convert parallel data received from the
MAC 424, to serial data and may convert serial data received from
the pluggable PHY device 422 to parallel data. In this regard, the
pluggable PHY device 422 may be coupled to the SerDes 426 via the
serial link 444. In order to make MAC functionality complicit with
the energy efficient network control policy, the MAC and Logic
module 420 may be integrated within the pluggable PHY device 422.
The SerDes 428 may receive serial data from the SerDes 426 and
convert the data to a parallel format for the MAC and logic module
420. The parallel data may be sent to the MAC and logic module 420
for processing which may then forward data to the pluggable PHY
device 422.
[0079] The pluggable PHY device 422 may determine when to enter
and/or exit an energy efficient network low(er) power mode and may
configure the various components of the pluggable PHY device 422
accordingly. The pluggable PHY device 422 may also be operable to
generate signals for communicating energy efficient network states
and/or decisions to a link partner.
[0080] FIG. 5 is a flow chart illustrating exemplary steps
implementing an energy efficient network (EEN) control policy in a
pluggable physical layer device, in accordance with an embodiment
of the invention. Referring to FIG. 5, the exemplary steps may
begin with step 502 when communications may be established between
a pluggable PHY device 302 described with respect to FIG. 3
(pluggable PHY device 1) of a first link partner and a PHY device
(PHY 2) of a second link partner. PHY 2 may be a pluggable device
or may be an integrated device. Subsequent to step 502, the
exemplary steps may advance to step 504. In step 504, conditions
may be detected for a power mode state transition of at least the
pluggable PHY device 1. It may be determined that pluggable PHY
device 1 should transition to a different mode of operation.
Configuration of the pluggable PHY device 1 for the different mode
and/or when to perform the transition may be determined. In various
embodiments of the invention, an energy efficient network control
policy may determine how to configure the pluggable PHY device 1
for the different mode and when to perform the transition. The
energy efficient network control policy may be implemented in the
pluggable PHY device 1 or in a device that implements a higher
layer protocol. Subsequent to step 504 the exemplary steps may
advance to step 506.
[0081] In step 506, a state transition in at least the pluggable
PHY device 1 may be triggered. For example, an energy efficient
network control policy may trigger the state transition. In this
regard, one or more control signals may be generated in the
pluggable PHY device 1 and/or a higher layer device. For example,
the optional energy efficient network control policy assist module
314 described with respect to FIG. 3, may reconfigure one or more
components of the pluggable PHY device 1 to implement the different
mode of operation. Subsequent to step 506, the exemplary steps may
advance to step 508.
[0082] In step 508, a different mode of operation may be
implemented. In this regard a portion of the pluggable PHY device 1
may be powered up and/or reconfigured to implement the different
mode of operation. Subsequent to step 508, the exemplary steps may
advance to step 510.
[0083] In step 510, pluggable PHY device 1 may transmit a control
signal to PHY 2 to indicate that it desires, and/or has decided, to
transition to a different state of operation. In this regard, the
control signal may cause an energy efficient network control policy
on the PHY 2 to trigger a transition to a new mode of operation
and/or to reallocate resources such as buffers. Subsequent to step
510, the exemplary steps may advance to step 512.
[0084] In step 512, PHY 2 may complete the transition to the
different mode of operation. In this regard, one or more control
signals may be generated in the pluggable PHY device 1, by the
energy efficient network control policy module 314 in FIG. 3, for
example, to reconfigure one or more components of the pluggable PHY
device 1 to implement the different mode of operation. In some
embodiments of the invention, the transition may comprise training
of one or more components such as, NEXT, FEXT, and echo cancellers.
Subsequent to step 512, the pluggable PHY device 1 may operate in
the different mode of operation and until the control policy
determines to transition again.
[0085] In an embodiment of the invention, an Ethernet network 100
may comprise one or more link partners 102 and/or 104 that may be
coupled via an Ethernet link 112. The one or more link partners 102
and/or 104 may comprise one or more pluggable PHY devices 402
and/or 422 for example. The pluggable PHY devices 402 and/or 422
may be operable to determine one or more energy efficient network
control policies that may specify a power level mode for the one or
more link partners 102 and/or 104 and the one or more link partners
may be configured to operate in the specified power level mode. In
various embodiments of the invention, a power level mode of
operation may be selected based on the energy efficient network
control policies. Accordingly one or more components of the
pluggable PHY devices 402 and/or 422 may be reconfigured based on
the selected power level mode of operation. A first portion of the
one or more components may be reconfigured prior to sending an
energy efficient network control signal to one or more of the link
partners 102 and/or 104 and reconfiguring a remaining portion of
the one or more components.
[0086] Hardware, software and/or firmware 314 within the one or
more pluggable PHY devices 402 and/or 422 may be utilized to
execute the one or more energy efficient network control policies.
In some instances, while transitioning to an active power mode,
packet data that may be pending delivery in the one or more
pluggable PHY devices may be buffered in the TX FIFOs 310a. The one
or more pluggable PHY devices 402 and/or 422 may comprise one or
both of a media access controller 414 and/or a serializer
de-serializer device 428. Exemplary form factors of the one or more
pluggable PHY devices 402 and/or 422 may comprise one or more of a
SFP, a SFP+, a XENPAK, a X2, a XFP and a XPAK form factor. The
power level mode may comprise low power idle mode and/or sub-rate
mode.
[0087] Another embodiment of the invention may provide a machine
and/or computer readable storage and/or medium, having stored
thereon, a machine code and/or a computer program having at least
one code section executable by a machine and/or a computer, thereby
causing the machine and/or computer to perform the steps as
described herein for a method and system for managing energy
efficiency of a network link via pluggable transceiver modules in
an energy efficient network device.
[0088] Accordingly, the present invention may be realized in
hardware, software, or a combination of hardware and software. The
present invention may be realized in a centralized fashion in at
least one computer system or in a distributed fashion where
different elements are spread across several interconnected
computer systems. Any kind of computer system or other apparatus
adapted for carrying out the methods described herein is suited. A
typical combination of hardware and software may be a
general-purpose computer system with a computer program that, when
being loaded and executed, controls the computer system such that
it carries out the methods described herein.
[0089] The present invention may also be embedded in a computer
program product, which comprises all the features enabling the
implementation of the methods described herein, and which when
loaded in a computer system is able to carry out these methods.
Computer program in the present context means any expression, in
any language, code or notation, of a set of instructions intended
to cause a system having an information processing capability to
perform a particular function either directly or after either or
both of the following: a) conversion to another language, code or
notation; b) reproduction in a different material form.
[0090] While the present invention has been described with
reference to certain embodiments, it will be understood by those
skilled in the art that various changes may be made and equivalents
may be substituted without departing from the scope of the present
invention. In addition, many modifications may be made to adapt a
particular situation or material to the teachings of the present
invention without departing from its scope. Therefore, it is
intended that the present invention not be limited to the
particular embodiment disclosed, but that the present invention
will include all embodiments falling within the scope of the
appended claims.
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