One document matched: draft-claise-power-management-arch-00.txt





     Network Working Group                                   
     Internet-Draft                                         B. Claise 
     Intended Status: Informational                        J. Parello  
     Expires: January 5, 2011                            B. Schoening 
                                                  Cisco Systems, Inc. 
                                                         July 5, 2010 
      
                        Power Management Architecture 
                    draft-claise-power-management-arch-00 


     Status of this Memo 

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        This Internet-Draft will expire on September, 2010.                     



















      
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     Copyright Notice 
      
        Copyright (c) 2010 IETF Trust and the persons identified as the 
        document authors.  All rights reserved. 
         
        This document is subject to BCP 78 and the IETF Trust's Legal 
        Provisions Relating to IETF Documents 
        (http://trustee.ietf.org/license-info) in effect on the date of 
        publication of this document.  Please review these documents 
        carefully, as they describe your rights and restrictions with 
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        document must include Simplified BSD License text as described 
        in Section 4.e of the Trust Legal Provisions and are provided 
        without warranty as described in the Simplified BSD License. 
         
         
     Abstract 

        This document defines the power management architecture.  
         
     Conventions used in this document 

       The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", 
       "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", 
       and "OPTIONAL" in this document are to be interpreted as 
       described in RFC 2119 [RFC2119]. 
      
         
                                            


















      
      
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     Table of Contents 
         
        1. Foreword....................................................4 
        2. Introduction................................................4 
        3. Use Cases & Requirements....................................5 
        4. Terminology.................................................5 
        5. Architecture High Level Concepts............................7 
           5.1. Power Monitor Information..............................8 
           5.2. Power Monitor Meter Domain.............................8 
           5.3. Power Monitor Parent and Child.........................8 
           5.4. Power Monitor Context.................................10 
           5.5. Power Monitor Levels..................................10 
           5.6. Power Monitor Usage Measurement.......................13 
           5.7. Optional Power Usage Quality..........................14 
           5.8. Optional Energy Measurement...........................14 
           5.9. Optional Battery Information..........................15 
           5.10. CO2 Emission.........................................15 
        6. Power Monitor Children Discovery...........................16 
        7. Configuration..............................................16 
        8. Relationship with Other Standard Development 
        Organizations.................................................17 
           8.1. Information Modeling..................................17 
           8.2. Power Levels..........................................17 
        9. Implementation Scenarios...................................18 
           Scenario 1: Switch with PoE endpoints......................18 
           Scenario 2: Switch with PoE endpoints with further connected 
           device(s)..................................................18 
           Scenario 3: A switch with Wireless Access Points...........19 
           Scenario 4: Network connected facilities gateway...........19 
           Scenario 5: Data Center Network............................19 
           Scenario 6: Power Consumption of UPS.......................19 
           Scenario 7: Power Consumption of Battery-based Devices.....20 
        10. Security Considerations...................................20 
        11. IANA Considerations.......................................20 
        12. References................................................20 
           Normative References.......................................20 
           Informative References.....................................20 
        13. Authors' Addresses........................................21 
      








      
      
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     1. Foreword  

        This document stems from the fact that the Power and Energy 
        Monitoring MIB module [POWER-MON-MIB] contains elements of 
        architecture, which should be specified in a separate document 
        dedicated to the architecture concepts.  Therefore, for the time 
        being, this document has a clear overlap with [POWER-MON-MIB].  
        It is foreseen that the IETF meeting in Maastricht will bring 
        consensus on the respective contents of the Power Monitoring 
        Requirements [POWER-MON-REQ], the Power Management Architecture 
        (this document), and the Power and Energy Monitoring MIB [POWER-
        MON-MIB].  
              
         
     2. Introduction 

        Network management is typically divided into areas of concerns 
        according to the ISO Telecommunications Management Network 
        model.  The model defines Fault, Configuration, Accounting, 
        Performance, and Security Management.  Notably missing is an 
        area of concern specifically covering energy management at an 
        equal level to these areas. 
         
        With energy becoming a more critical area of concern, this 
        document defines an architecture for power management for use 
        with devices in and connected to communication networks.  This 
        architecture includes monitoring for power state and energy 
        consumption of networked elements, taking into account the 
        requirements specified in [POWER-MON-REQ].  However, this 
        architecture goes one step further, as it includes elements of 
        elements of configuration.  
         
        Energy management is applicable to devices that comprise and 
        that are connected to a communication network.  Target devices 
        for this specification include (but are not limited to): 
        routers, switches, Power over Ethernet (PoE) endpoints, protocol 
        gateways for building management systems, intelligent meters, 
        home energy gateway, hosts and servers, sensor proxy, etc.   
         
        Where applicable, monitoring of a device is extended to the 
        individual components of the device and/or to any attached 
        dependent device(s).  An example of such a case could be when a 
        device contains components that are independent from a power 
        state point of view (such as line cards, processor cards, hard 
        drives) or when a devices has dependent attached devices (such 

      
      
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        as a switch with PoE endpoints or a power distribution unit with 
        attached endpoints).  
      
         
     3. Use Cases & Requirements  

        The requirements for power and energy monitoring for networking 
        devices are specified in [POWER-MON-REQ].  The requirements in 
        [POWER-MON-REQ] cover devices that typically make up a 
        communications network such as such as switches, routers, and 
        various connected endpoints.  For power monitoring to be useful, 
        a specification should also be applicable to facility meters, 
        power distribution units, gateway proxies for commercial 
        building control, home automation devices and devices that 
        interface with the utility and/or smart grid.  Due to this fact, 
        the scope of the MIB modules in this document is broader than 
        that specified in [POWER-MON-REQ].  Several scenarios that cover 
        these broader use cases are presented later in Section 9.  - 
        Implementation Scenarios. 
         
     4. Terminology 

        This section contains definitions of major terms used in 
        explaining the concepts, examples, and the MIB definitions. 
         
         
        Power Monitor 
         
        A Power Monitor is a system of one or more components that 
        provide power, draws power, or reports energy consumption on 
        behalf of another Power Monitor.  It can be independently 
        managed from a power monitoring and power state configuration 
        point of view.  Examples of Power Monitors are: a router line 
        card, a motherboard with a CPU, an IP phone connected with a 
        switch, etc. 
         
         
        Power Monitor Parent 
         
        A Power Monitor Parent is a Power Monitor that is the root of 
        one or multiple subtending Power Monitors, called Power Monitor 
        Children.  The Power Monitor Parent is able to report the power 
        state and energy consumption for his Power Monitor Child(ren).   
        For example, in case of Power-over-Ethernet (PoE) device such as 
        an IP phone or an access point attached to a switch port, the 
        switch is the source of power for the attached device.  In such 
        a case, the Power Monitor Parent is the port of the switch, 
        while the attached device is the Power Monitor Child.   
      
      
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        Power Monitor Child 
          
        A Power Monitor Child is a Power Monitor associated to a Power 
        Monitor Parent, which draws power from its Power Monitor Parent 
        or reports its power usage and power state to its Power Monitor 
        Parent. 
         
         
        Power Monitor Meter Domain 
         
        A Power Monitor Meter Domain is a name or name space that 
        logically groups together Power Monitors that comprises a zone 
        of manageable power usage.  Typically, this will comprise all 
        Power Monitors that are powered from the same electrical panel 
        or panels for which there is a meter or sub meter.  For example, 
        all Power Monitors receiving power from the same distribution 
        panel of a building, or all Power Monitors in a building for 
        which there is one main meter.  From the point of monitoring 
        power use, it is useful to report the total power usage as the 
        sum of power consumed by all the Power Monitors within a Power 
        Monitor Meter Domain and then correlate that value to the 
        metered usage.  
         
         
        Power Level 
         
        A uniform way to classify power settings on a Power Monitor 
        (e.g., shut, hibernate, sleep, high).  Power Levels can be 
        viewed as an interface for interacting with the underlying 
        device implemented power settings.  
         
         
        User Defined Power Level 
         
        A device specific way to classify power settings implemented on 
        a Power Monitor.  For cases where the implemented power setting 
        cannot be directly mapped to a Power Level(s), the User Defined 
        Power Levels are used to enumerate and show the relationship 
        between the implemented power settings and the Power Level 
        interface. 
         
         




      
      
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     5. Architecture High Level Concepts 

        This section will go over the basic concepts of the 
        architecture.  Each concept is then listed with notable 
        descriptions in subsequent sections.  
         
        Examples will be provided in a later section to show how these 
        concepts can be fulfilled in an implementation.  
         
        Given a Power Monitor, we can describe the information about the 
        Power Monitor through various data.  A Power Monitor will have 
        basic naming and informational descriptors to identify it in the 
        network. 
         
        A Power Monitor can be part of a Power Monitor Meter Domain.  A 
        Power Monitor Meter Domain is a manageable set of devices that 
        has a meter or sub-meter attached and typically corresponds to a 
        power distribution point or panel.  
         
        A Power Monitor can be a parent (Power Monitor Parent) or child 
        (Power Monitor Child) of another Power Monitor.  This allows for 
        devices to aggregate reporting and/or control of power 
        information. 
         
        Each Power Monitor can have information to allow it to be 
        described in the context of the business or ultimate use.  This 
        is in addition to its networked information.  This allows for 
        tagging, grouping and differentiation between Power Monitors for 
        NMS. 
         
        For control and universal monitoring each Power Monitor will 
        implement or declare a set of known Power Levels.  The Power 
        Levels can be mapped to User Defined Power Levels that indicate 
        the specific power setting for the device implementing the Power 
        Monitor.  
         
        Each Power Monitor will have usage information that describes 
        the instantaneous power information along with how that usage 
        was obtained or derived. 
         
        Optionally a Power Monitor can further describe the 
        instantaneous power information with power quality information 
        reflecting the electrical characteristics of the measurement. 
         
        Optionally a Power Monitor can provide power usage over time to 
        describe energy consumption 
         

      
      
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        If a Power Monitor has one or more batteries, it can provide 
        optional Battery information as well. 
      

     5.1. Power Monitor Information 

        Every Power Monitor should have a unique printable name, and a 
        unique Power Monitor index.  
         
            
         
        Possible naming conventions are: textual DNS name, MAC-address 
        of the device, interface ifName, or a text string uniquely 
        identifying the Power Monitor.  As an example, in the case of IP 
        phones, the Power Monitor name can be the device DNS name.  
      
      

     5.2. Power Monitor Meter Domain 

        Each Power Monitor can be a member of a Power Monitor Meter 
        Domain.  The Power Monitor Meter Domain could map 1-1 with a 
        metered or sub-metered portion of the site.  It can be used to 
        further sub divide the deployment down to finer Power Monitor 
        Meter Domains such as a floor, lab, data center, rack, etc.   
        The Power Monitor Meter Domain MUST be configured on the Power 
        Monitor Parent.  The Power Monitor Children may inherit its 
        domain value from the Power Monitor Parent.  Note that the 
        specification of how to communicate this information between the 
        Power Monitor Parent and Children is out of the scope of this 
        document.  One point of the parent/child design is that 
        typically the network is fixed and the endpoints are transient.  
        In some cases, Power Monitor Children may have a static non-
        transient configuration.  In such cases, the Power Monitor Meter 
        Domain MAY be configured directly in Power Monitor Child. 
         
        It should be possible to aggregate energy consumption across all 
        Power Monitors within a Power Monitor Meter Domain.  However, 
        the specification of how to communicate this information between 
        the Power Monitor Parents is out of the scope of this document. 
      

     5.3. Power Monitor Parent and Child 

        A Power Monitor can be connected to another Power Monitor and 
        either draw power from that entity or report power usage to that 
        entity. 
         
      
      
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        The use of a Power Monitor Parent is not limited to just PoE 
        children.  A Power Monitor Child can be fully dependent on the 
        Power Monitor Parent or independent from the parent.  In the 
        dependent case, the Power Monitor Parent provides power for the 
        Power Monitor Child (the PoE case).  In the independent case, 
        the Power Monitor Child draws power from another source 
        (typically a wall outlet).  Since the switch is not the source 
        of power supply, the power usage cannot be measured at the Power 
        Monitor Parent.   However, an independent Power Monitor Child 
        may report Power Monitor information to the Power Monitor 
        Parent.  The Power Monitor Child may listen to the power control 
        settings from a Power Monitor Parent and could react to the 
        control messages.  Note that the communication between the Power 
        Monitor Parent and Power Monitor Child is out of scope of this 
        document. 
         
        A Power Monitor cannot be at the same time a Power Monitor 
        Parent and a Power Monitor Child.  Indeed such configuration 
        would lead to double counting the energy consumed within a 
        specific Power Monitor Domain. 
         
        A mechanism, outside of the scope of this document, should be in 
        place to verify the connectivity between the Power Monitor 
        Parent and its Power Monitor Children.  If the Power Monitor 
        Child is unavailable, the Power Monitor Parent must follow some 
        rules to determine how long it should wait before removing the 
        Power Monitor Child entry, along with all associated statistics, 
        from his database.  In some situations, such as connected 
        building, in which the Power Monitor Children are pretty static, 
        this removal timer might be pretty long.  The persistence across 
        a Power Monitor Parent reload could even make sense.  However, 
        in a networking environment, where endpoints could come and go, 
        there is not much sense to configure a long removal timer.  In 
        all cases, the removal timer or persistence must be clearly 
        specified. 
         
        When a new Power Monitor Parent is added to the Power Monitor 
        Domain, it should advertise himself to the other existing Power 
        Monitor Parents.  The mechanism could be as simple as a static 
        configuration, or more elaborated, in which case, this is 
        outside of the scope of this architecture.  
         
        Further examples of Power Monitor Parent and Child 
        implementations are provided in the Implementation Scenarios 
        section. 
      


      
      
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     5.4. Power Monitor Context 

        Monitored power will ultimately be collected to and reported 
        from a NMS.  In order to aid in the reporting and 
        differentiation between Power Monitors, each Power Monitor will 
        contain information to establish a business or site context.  
        A Power Monitor can provide a importance value in the range of 
        1..100 to help differentiate the use or relative value to the 
        site.  The importance range is from 1 (least important) to 100 
        (most important).  The default importance value is 1.   
         
        For example, a typical office environment has several types of 
        phones, which can be rated according to the business impact: a 
        public desk phone has a lower importance (for example, 10) than 
        a business-critical emergency phone (for example, 100).  As 
        another example, a company can consider that a PC and a phone 
        for a customer-service engineer is more important than a PC and 
        a phone for lobby use.  
        Although network managers must establish their own ranking the 
        following is a broad recommendation: 
          .  
          . 90 to 100 Emergency response  
          . 80 to 90 Executive or business critical  
          . 70 to 79 General or Average  
          . 60 to  69 Staff or support  
          . 40 to  59 Public or guest  
          . 1  to 39 Decorative or hospitality" 
        
        A Power Monitor can provide a set of keywords.  These keywords 
        are a list of tags that can be used for grouping and summary 
        reporting within or between Power Monitor Meter Domains. All 
        alphanumeric characters and symbols such as #, (, $, !, and & 
        are allowed.  Potential examples are: IT, lobby, HumanResources, 
        Accounting, StoreRoom, CustomerSpace, router, phone, floor2, or 
        SoftwareLab.  There is no default value for the keyword. 
         
        Multiple keywords can be assigned to a device.  In such cases, 
        the keywords are separated by commas and no spaces between 
        keywords are allowed.  For example, "HR,Bldg1,Private". 
        Additionally, a Power Monitor can provide a "role description" 
        string that indicates the purpose the Power Monitor serves in 
        the network or to site/business. 


     5.5. Power Monitor Levels 

        Power Levels represent universal states of power management of a 
        Power Monitor.  Each Power Level corresponds to a global, 
        system, and performance state in the ACPI model. 
              
      
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                Level        ACPI Global/System      Name 
                                    State 
         
        Non-operational states: 
         
                  1               G3, S5           Mech Off 
                  2               G2, S5           Soft Off 
                  3               G1, S4           Hibernate 
                  4               G1, S3           Sleep  
                  5               G1, S2           Standby 
                  6               G1, S1           Ready  
         
        Operational states: 
                  7               G0, S0, P5       LowMinus 
                  8               G0, S0, P4       Low 
                  9               G0, S0, P3       MediumMinus 
                 10               G0, S0, P2       Medium 
                 11               G0, S0, P1       HighMinus 
                 12               G0, S0, P0       High   
         
        For example, a Power Monitor with a Power Level of 9 would 
        indicate an operational state with MediumMinus Power Level. 
         
        The Power Levels can be considered as guidelines for an 
        interface in order to promote interoperability across device 
        types.  Realistically, it is foreseen that each specific feature 
        requiring Power Levels will require a complete recommendation of 
        its own.  For example, designing IP phones with consistent Power 
        Levels across vendors requires a specification for IP phone 
        design, along with the Power Levels mapping. 
         
        In some situation, User Defined Power Levels are required, for 
        example, when no mappings with the existing Power Levels are 
        possible or when more levels than the twelve specified Power 
        Levels are required.   
        A first example would be an imaginary device type, with only 
        five levels: "none", "short", "tall", "grande", and "venti".  
         
          User Defined Power Level     Respective Name 
               0                         none 
               1                         short 
               2                         tall 
               3                         grande 
               4                         venti 
         


      
      
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        In the unlikely event of no possible mapping between these User 
        Defined Power Levels and the Power Levels, the Power Level will 
        remain 0 throughout the MIB module, as displayed below.   
         
           Power Level / Name       User Defined Power Level / Name 
               0 / unknown              0 / none 
               0 / unknown              1 / short 
               0 / unknown              2 / tall 
               0 / unknown              3 / grande 
               0 / unknown              4 / venti 
                      
        If a mapping between the User Defined Power Levels and the Power 
        Levels is achievable, both series of levels exist in the MIB 
        module, allowing the NMS to understand the mapping between them 
        by correlating the Power Level with the User Defined Power 
        Level. 
         
           Power Level / Name       User Defined Power Level / Name 
               1 / Mech Off             0 / none 
               2 / Soft Off             0 / none 
               3 / Hibernate            0 / none 
               4 / Sleep, Save-to-RAM   0 / none 
               5 / Standby              0 / none 
               6 / Ready                1 / short 
               7 / LowMinus             1 / short 
               8 / Low                  1 / short 
               9 / MediumMinus          2 / tall 
               10 / Medium              2 / tall 
               11 / HighMinus           3 / grande 
               12 / High                4 / venti 
      
        How the Power Monitor Levels are then mapped, i.e. assigning the 
        directly lower or directly higher level, is an implementation 
        choice.  However, its recommended that the User Defined Power 
        Level maps to the directly lower Power Level, so that setting 
        all Power Meters to a Power Level would be conservative in terms 
        of disabled functionality on the Power Monitor implementing the 
        User Defined Power Levels. 
         
        A second example would be a device type, such as a dimmer or a 
        motor, with a high number of operational levels.  For the sake 
        of the example, 100 operational states are assumed. 
         
           Power Level / Name       User Defined Power Level / Name 
               1 / Mech Off                  0 / off 
               2 / Soft Off                  0 / off 
               3 / Hibernate                 0 / off 
               4 / Sleep, Save-to-RAM        0 / off 
      
      
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               5 / Standby                   0 / off 
               6 / Ready                     0 / off 
               7 / LowMinus                  1 / 1% 
               7 / LowMinus                  2 / 2% 
               7 / LowMinus                  3 / 3% 
               .                             . 
               .                             . 
               .                             . 
               8 / Low                       15 / 15% 
               8 / Low                       16 / 16% 
               8 / Low                       17 / 17% 
               .                             . 
               .                             . 
               .                             . 
               9 / MediumMinus               30 / 30% 
               9 / MediumMinus               31 / 31% 
               9 / MediumMinus               32 / 32% 
               .                             . 
               .                             . 
               .                             . 
               10 / Medium                   45 / 45% 
               10 / Medium                   46 / 46% 
               10 / Medium                   47 / 47% 
               .                             . 
               .                             . 
               .                             . 
               etc... 
         

     5.6. Power Monitor Usage Measurement 

        For a Power Monitor, power usage must be reported, including the 
        magnitude of measurement, as multiple scaling factors can be 
        used.  
        The power usage measurement should conform to the IEC 61850 
        definition of unit multiplier for the SI (System International) 
        units of measure.  Measured values are represented in SI units 
        obtained by BaseValue * 10 raised to the power of scale.  For 
        example, if current power usage of a Power Monitor is 3, it 
        could be 3 W, 3 mW, 3 KW, 3 MW depending on the value of scaling 
        factor (called pmPowerUnitMultiplier in the MIB module).   
                                         
        In addition to knowing the usage and magnitude it is useful to 
        know how a Power Monitor usage measurement was obtained:  

          . whether the measurements were made at the device itself or 
             from a remote source   

      
      
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          . Description of the method that was used to measure the 
             power and can distinguish actual or estimated values.  
              
        An NMS can use these information to account for the accuracy and 
        nature of the reading between different implementations.   
         
        In addition to the instantaneous usage the nameplate power 
        rating of a Power Monitor is typically specified by the vendor 
        as the capacity required to power the device.  Often this label 
        is a conservative number and is the worst-case power draw.  
        While the actual utilization of an entity can be lower, the 
        nameplate power is important for provisioning, capacity planning 
        and billing.   
         
        [POWER-MON-REQ] specifies some requirements about power states 
        such as "the current state - the time of the last change", "the 
        total time spent in each state", "the number of transitions to 
        each state", etc...  Such requirements are fulfilled via the 
        pmPowerLevelChange NOTIFICATION-TYPE, indexed by pmPowerLevel 
        and pmUserDefinedPowerLevel.  This SNMP notification is 
        generated when the value(s) of pmPowerLevel and/or 
        pmUserDefinedPowerLevel has/have changed for the Power Monitor 
        represented by the pmIndex.   
      

     5.7. Optional Power Usage Quality 

        Given a power measurement of a Power Monitor, it may in certain 
        circumstances be desirable to know the power quality associated 
        with that measurement.  The information model must adhere to the 
        IEC 61850 7-2 standard to describe AC measurements.  In some 
        Power Monitor Domains, the power quality may not be needed, 
        available, nor relevant to the Power Monitor.   
      

     5.8. Optional Energy Measurement 

        In addition to reporting the Power Level, an approach to 
        characterize the energy demand is required.  It is well known in 
        commercial electrical utility rates, that demand charges can be 
        on par with actual power charges.  So, it is useful to 
        characterize the demand.  The demand can be described as the 
        average energy of an Power Monitor over a time window, called a 
        demand interval, typically 15 minutes.  The highest peak energy 
        demand measured over a time horizon, say 1 month or 1 year is 
        often the basis for usage charges.  A single window of time of 
        high usage can penalize the energy consumption charges.  
        However, it is relevant to measure the demand only when there 
      
      
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        are actual power measurements from a Power Monitor, and not when 
        the power measurement is assumed or predicted.    
         
         
         
        Several efficiency metrics can be derived and tracked with the 
        demand usage data.   
         
          . For example, per-packet power costs for a networking device 
             (router or switch) can be calculated by an network 
             management system.  The packets count can be determined 
             from the traffic usage in the ifTable [RFC2863] from the 
             forwarding plane figure, or from the platform 
             specifications. 
              
          . Watt-hour power can be combined with utility energy sources 
             to estimate carbon footprint and other emission statistics. 
                 
      

     5.9. Optional Battery Information 
   
         
        Some Power Monitors might be running on batteries.  Therefore 
        information such as the battery status (charging or 
        discharging),remaining capacity, etc... must be available. 


     5.10. CO2 Emission 

        The goal of energy monitoring and optimization is to reduce the 
        greenhouse gases, such as the CO2 emission.  It proves to be 
        difficult to report the CO2 emission directly in the Power 
        Monitors.  Indeed, the CO2 emission is linked to the source of 
        energy: coal, gasoline, fuel oil, natural gas, wind farm, solar 
        panel.  Since the energy source may vary, and will vary more and 
        more in the future with new ideas such as follow-the-sun 
        routing, the logical solution is that each Power Monitor reports 
        his energy consumption, while the NMS makes the translation into 
        the CO2 emission, based on the different energy sources used in 
        the different geographical regions. 

        In this power management architecture, there are no requirements 
        to report the primary energy required to manufacture a product, 
        also known as the "embedded carbon" of an asset.  Currently, 
        there is no way to get an accurate number of life cycles for a 
      
      
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        product.  Indeed, part of the supply chain analysis, there are 
        still a number of complicated steps to go from supplier 
        emissions to component emissions to emissions for a specific 
        product. 
         

     6. Power Monitor Children Discovery 

        There are multiple ways that the Power Monitor Parent can 
        discover its Power Monitor Children, if not present on the same 
        physical network element. 
         
          . In case of PoE, the Power Monitor Parent automatically 
             discovers that a Power Monitor Child requests some power. 
          . The Power Monitor Parent and Children may run the Link 
             Layer Discovery Protocol [LLDP], or any proprietary similar 
             protocols such as Cisco Discovery Protocol (CDP).  The 
             Power Monitor Parent might even support the LLDP-MED MIB 
             [LLDP-MED-MIB], which returns some extra information on the 
             Power Monitor Children.  
          . The Power Monitor Parent might reside on a network 
             connected facilities gateway.  A typical example is a 
             converged building gateway, monitoring several other 
             devices in the building, doing the proxy between SNMP and a 
             protocol such as BACNET.  
      
         
     7. Configuration 

        This power management architecture allows the configuration of a 
        couple of key parameters: 
         
          . Power Monitor name: an unique printable name for the Power 
             Monitor.  
          . Power Monitor Role: an administratively assigned name to 
             indicate the purpose a Power Monitor serves in the network.  
          . Power Monitor Importance: a ranking of how important the 
             Power Monitor is on a scale of 1 to 100 compared to other 
             Power Monitors in the same Power Monitor Meter Domain.  
          . Power Monitor Keywords: a list of keywords that can be used 
             to group Power Monitors for reporting or searching. 
          . Power Monitor Domain: specifies the name of a Power Monitor 
             Meter Domain for the Power Monitor. 
          . The Power Monitor Level: specifies the current Power Level 
             (0..12) for the Power Monitor.  
          . User Defined Power Level and name 


      
      
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          . The energy demand parameters: for example, which interval 
             length to report the energy on, the number of interval to 
             keep, etc... 
         
        Note that the communication specifications between the Power 
        Monitor Parent and Children is out of the scope of this 
        document.  This includes the communication of the power settings 
        and configuration information such as the Power Monitor Domain. 
         
         
     8. Relationship with Other Standard Development Organizations 

     8.1. Information Modeling  

        This power management architecture should reuse as much as 
        possible existing standard efforts and not re-invent something 
        new, specifically in terms of information modeling and data 
        modeling [RFC3444].  
         
        The data model for power, energy related objects is based on the  
        IEC 61850.   
         
        Specific examples include: 
         
          . The scaling factor, which represent the magnitude of Power 
             Monitor usage, conforms to the IEC 61850 definition of unit 
             multiplier for the SI (System International) units of 
             measure.  
         
          . The power accuracy model is based on the ANSI and IEC 
             Standards, which require that we use an accuracy class for 
             power measurement.  ANSI and IEC define the following 
             accuracy classes for power measurement:  
           
             . IEC 62053-22  60044-1 class 0.1, 0.2, 0.5, 1  3.    
             
             . ANSI C12.20 class 0.2, 0.5 
           
          . The powerQualityMIB MIB module adheres closely to the IEC 
             61850 7-2 standard to describe AC measurements.   
         
      
     8.2. Power Levels 

        There are twelve Power Monitor Levels; divided into six 
        operational states, and six non-operational states.  The lowest 

      
      
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        non-operational state is 1 and the highest is six.  Each non-
        operational state corresponds to an ACPI level [ACPI]. 
         

     9. Implementation Scenarios 

        The scope of power and energy monitoring consists of devices 
        that consume power within and connected to a communications 
        network.  These devices include: 
         
        - Network devices and sub-components: devices such as routers 
        and switches and their sub-components. 
         
        - Network attached endpoints: devices that use the 
        communications network such as endpoints, PCs, or facility 
        gateways that proxy energy monitor and control for commercial 
        buildings or home automation,  
         
        - Network attached meters or supplies: devices that can monitor 
        the electrical supply such as smart meters or Universal Power 
        Supplies (UPS) that meter and provide availability.  
        This section provides illustrative examples that model different 
        scenarios for implementation of the Power Monitor including 
        Power Monitor Parent and Power Monitor Child relationships. 
         
        Each of the scenarios below is explained in more details in the 
        Power Monitor MIB document [POWER-MON-MIB], with a mapping to 
        the MIB OIDs. 
         

     Scenario 1: Switch with PoE endpoints  

        Consider a PoE IP phone connected to a switch, as displayed on 
        figure 1.  The IP phone draws power from the PoE switch.   
      

     Scenario 2: Switch with PoE endpoints with further connected 
        device(s)  

        Consider the same scenario as example 1 with an IP phone 
        connected to PoE port of a switch.  Now, in addition, a PC is 
        also daisy-chained from the IP phone for LAN connectivity.  The 
        phone draws power from PoE port of the switch, while the PC 
        draws power from the wall outlet.  
         
      


      
      
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     Scenario 3: A switch with Wireless Access Points 

        Consider a Wireless Access Point connected to the PoE port of a 
        switch.  There are several PCs connected to the Wireless Access 
        Point over Wireless protocols.  All PCs draw power from the wall 
        outlets.  
         
        The switch port is the Power Monitor Parent for the Wireless 
        Access Point (WAP) and the PCs.  There is a distinction, between 
        the Power Monitor Children, as the WAP draws power from the PoE 
        port of the switch and the PCs draw power from the wall outlet.  
         
         

     Scenario 4: Network connected facilities gateway 

        At the top of the network hierarchy of a building network is a 
        gateway device that can perform protocol conversion between many 
        facility management devices, such as BACNET, MODBUS, DALI, LON,  
        etc.  There are power meters associated with power consuming 
        entities (Heating Ventilation & Air Conditioning - HVAC, 
        lighting, electrical, fire control, elevators, etc).  The 
        proposed MIB can be implemented on the gateway device.  The 
        gateway can be considered as the Power Monitor Parent, while the 
        power meters associated with the energy consuming entities such 
        can be considered as Power Monitor Children.   
      

     Scenario 5: Data Center Network 

        A typical data center network consists of a hierarchy of 
        switches.  At the bottom of hierarchy there are servers mounted 
        on a rack, and those are connected to the top of the rack 
        switches.  The top switches are connected to aggregation 
        switches that are in turn connected to core switches.  As an 
        example, Server 1 and Server 2 are connected to different switch 
        ports of the top switch.  
         
        The proposed MIB can be implemented on the switches.  The switch 
        can be considered as the Power Monitor Parent.  The servers can 
        be considered as the Power Monitor Children.  
         
     Scenario 6: Power Consumption of UPS 

        Data centers and commercial buildings can have Uninterruptible 
        Power Supplies (UPS) connected to the network. The Power Monitor 
        can be used to model a UPS as a Power Monitor Parent with the 
        connected devices as Power Monitor Children. 
      
      
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     Scenario 7: Power Consumption of Battery-based Devices 

         
        A PC is typical example of a battery-based device. 
      
         
     10. Security Considerations 

        TO DO 
      
      
     11. IANA Considerations 

        This document has no actions for IANA. 
      
      
     12. References 

     Normative References 

         
        [RFC2119] S. Bradner, Key words for use in RFCs to Indicate 
                Requirement Levels, BCP 14, RFC 2119, March 1997. 
         
        [POWER-MON-REQ] Quittek, J., Winter, R., Dietz, T., Claise, B., 
                and M. Chandramouli, "Requirements for Power 
                Monitoring", draft-quittek-power-monitoring-
                requirements-00 (work in progress), October 2009. 
         
        [POWER-MON-MIB] Claise, B., Chandramouli, M., Parello, J., and 
                Schoening, B., "Power and Energy Monitoring MIB", 
                draft-claise-energy-monitoring-mib-03, (work in 
                progress), May 2010. 
         
         
     Informative References 

         
        [RFC2863]  McCloghrie, K., Kastenholz, F., "The Interfaces Group 
                MIB", RFC 2863, June 2000. 
      
        [RFC3444]  Pras, A., Schoenwaelder, J. "On the Differences 
                between Information Models and Data Models", RFC 3444, 
                January 2003. 
         

      
      
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        [ACPI] "Advanced Configuration and Power Interface 
                Specification", http://www.acpi.info/spec30b.htm 
         
      
        [LLDP]  IEEE Std 802.1AB, "Station and Media Control 
                Connectivity Discovery", 2005. 
      
        [LLDP-MED-MIB]  ANSI/TIA-1057, "The LLDP Management Information 
                Base extension module for TIA-TR41.4 media endpoint 
                discovery information", July 2005. 
          
         
     13. Authors' Addresses 

      Benoit Claise 
      Cisco Systems Inc. 
      De Kleetlaan 6a b1 
      Diegem 1813 
      BE 
          
      Phone: +32 2 704 5622 
      Email: bclaise@cisco.com 
       
       
      John Parello 
      Cisco Systems Inc. 
      3550 Cisco Way  
      San Jose, California 95134  
      US 
          
      Phone: +1 408 525 2339 
      Email: jparello@cisco.com 
       
      
      Brad Schoening 
      Cisco Systems Inc. 
      3550 Cisco Way  
      San Jose, California 95134  
      US 
          
      Phone: +1 408 525 2339 
      Email: braschoe@cisco.com 
       
       
       



      
      
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