Network Working Group J. Quittek
Internet-Draft R. Winter
Intended status: Standards Track T. Dietz
Expires: March 8, 2013 NEC Europe Ltd.
September 4, 2012
Definition of Managed Objects for Battery Monitoring
draft-ietf-eman-battery-mib-06
Abstract
This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
In particular, it defines managed objects that provide information on
the status of batteries in managed devices.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 8, 2013.
Copyright Notice
Copyright (c) 2012 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 respect
to this document. Code Components extracted from this 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.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. The Internet-Standard Management Framework . . . . . . . . . . 4
3. Design of the Battery MIB Module . . . . . . . . . . . . . . . 5
3.1. MIB Module Structure . . . . . . . . . . . . . . . . . . . 5
3.2. Battery Technologies . . . . . . . . . . . . . . . . . . . 6
3.3. Charging Cycles . . . . . . . . . . . . . . . . . . . . . 7
4. Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 25
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
6.1. SMI Object Identifier Registration . . . . . . . . . . . . 27
6.2. Battery Technology Registration . . . . . . . . . . . . . 27
7. Open Issues . . . . . . . . . . . . . . . . . . . . . . . . . 27
7.1. Time estimations . . . . . . . . . . . . . . . . . . . . . 27
7.2. Entity MIB augmentation . . . . . . . . . . . . . . . . . 28
7.3. Units . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7.4. Kind of entity . . . . . . . . . . . . . . . . . . . . . . 28
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 28
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 28
9.1. Normative References . . . . . . . . . . . . . . . . . . . 28
9.2. Informative References . . . . . . . . . . . . . . . . . . 29
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 30
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1. Introduction
Today, more and more managed devices contain batteries that supply
them with power when disconnected from electrical power distribution
grids. Common examples are nomadic and mobile devices, such as
notebook computers, netbooks, and smart phones. The status of
batteries in such a device, particularly the charging status is
typically controlled by automatic functions that act locally on the
device and manually by users of the device.
In addition to this, there is a need to monitor battery status of
these devices by network management systems. This document defines a
portion of the Management Information Base (MIB) that provides a
means for monitoring batteries in or attached to managed devices.
The Battery MIB module defined in Section 4 meets the requirements
for monitoring the status of batteries specified in
[I-D.ietf-eman-requirements].
The Battery MIB module provides for monitoring the battery status.
According to the framework for energy management
[I-D.ietf-eman-framework] it is an Energy Managed Object, and thus,
MIB modules such as the Power and Energy Monitoring MIB
[I-D.ietf-eman-energy-monitoring-mib] could in principle be
implemented for batteries. The Battery MIB extends the more generic
aspects of energy management by adding battery-specific information.
Amongst other things, the Battery MIB enables the monitoring of:
o the current charge of a battery,
o the age of a battery (charging cycles),
o the state of a battery (e.g. being re-charged),
o last usage of a battery,
o maximum energy provided by a battery (remaining and total
capacity).
Further, means are provided for battery-powered devices to send
notifications when the current battery charge has dropped below a
certain threshold in order to inform the management system of needed
replacement. The same applies to the age of a battery.
Many battery-driven devices have existing instrumentation for
monitoring the battery status, because this is already needed for
local control of the battery by the device. This reduces the effort
for implementing the managed objects defined in this document. For
many devices only additional software will be needed but no
additional hardware instrumentation for battery monitoring.
Since there are a lot of devices in use that contain more than one
battery, means for battery monitoring defined in this document
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support addressing multiple batteries within a single device. Also,
batteries today often come in packages that can include
identification and might contain additional hardware and firmware.
The former allows to trace a battery and allows continuous monitoring
even if the battery is e.g. installed in another device. The
firmware version is useful information as the battery behavior might
be different for different firmware versions.
Not explicitly in scope of definitions in this document are very
small backup batteries, such as for example, batteries used on PC
motherboard to run the clock circuit and retain configuration memory
while the system is turned off. Other means may be required for
reporting on these batteries. However, the MIB module defined in
Section 3.1 can be used for this purpose.
A traditional type of managed device containing batteries is an
Uninterruptible Power Supply (UPS) system; these supply other devices
with electrical energy when the main power supply fails. There is
already a MIB module for managing UPS systems defined in RFC 1628
[RFC1628]. This module includes managed objects for monitoring the
batteries contained in an UPS system. However, the information
provided by these objects is limited and tailored the particular
needs of UPS systems.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in RFC
2119 [RFC2119].
2. The Internet-Standard Management Framework
For a detailed overview of the documents that describe the current
Internet-Standard Management Framework, please refer to section 7 of
RFC 3410 [RFC3410].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. MIB objects are generally
accessed through the Simple Network Management Protocol (SNMP).
Objects in the MIB are defined using the mechanisms defined in the
Structure of Management Information (SMI). This memo specifies MIB
modules that are compliant to the SMIv2, which is described in STD
58, RFC 2578 [RFC2578], STD 58, RFC 2579 [RFC2579] and STD 58,RFC
2580 [RFC2580].
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3. Design of the Battery MIB Module
3.1. MIB Module Structure
The Battery MIB module defined in this document defines objects for
reporting information about batteries. All managed objects providing
information of the status of a battery are contained in a single
table called batteryTable. The batteryTable contains one conceptual
row per battery.
If there is an implementation of the Entity MIB module [RFC4133] that
identifies the batteries to be reported on by individual values for
managed object entPhysicalIndex, then it is REQUIRED that these
values are used as index values for the batteryTable.
The kind of entity in the entPhysicalTable of the Entity MIB module
is indicated by the value of enumeration object entPhysicalClass.
Since there is no value called 'battery' defined for this object, it
is RECOMMENDED that for batteries the value of this object is chosen
to be powerSupply(6).
The batteryTable contains three groups of objects. The first group
(OIDs ending with 2-11) provides information on static properties of
the battery. The second group of objects (OIDs ending with 12-19)
provides information on the current battery state, if it is charging
or discharging, how much it is charged, its remaining capacity, the
number of experienced charging cycles, etc.
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batteryTable(1)
+--batteryEntry(1) [batteryIndex]
+-- --- Integer32 batteryIndex(1)
+-- r-n SnmpAdminString batteryIdentifier(2)
+-- r-n SnmpAdminString batteryFirmwareVersion(3)
+-- r-n Enumeration batteryType(4)
+-- r-n Unsigned32 batteryTechnology(5)
+-- r-n Unsigned32 batteryDesignVoltage(6)
+-- r-n Unsigned32 batteryNumberOfCells(7)
+-- r-n Unsigned32 batteryDesignCapacity(8)
+-- r-n Unsigned32 batteryMaxChargingCurrent(9)
+-- r-n Unsigned32 batteryTrickleChargingCurrent(10)
+-- r-n Unsigned32 batteryActualCapacity(11)
+-- r-n Unsigned32 batteryChargingCycleCount(12)
+-- r-n DateAndTime batteryLastChargingCycleTime(13)
+-- r-n Enumeration batteryChargingOperState(14)
+-- rwn Enumeration batteryChargingAdminState(15)
+-- r-n Unsigned32 batteryActualCharge(16)
+-- r-n Unsigned32 batteryActualVoltage(17)
+-- r-n Integer32 batteryActualCurrent(18)
+-- r-n Integer32 batteryTemperature(19)
+-- rwn Unsigned32 batteryAlarmLowCharge(20)
+-- rwn Unsigned32 batteryAlarmLowVoltage(21)
+-- rwn Unsigned32 batteryAlarmLowCapacity(22)
+-- rwn Unsigned32 batteryAlarmHighCycleCount(23)
+-- rwn Integer32 batteryAlarmHighTemperature(24)
+-- rwn Integer32 batteryAlarmLowTemperature(25)
The third group of objects in this table (OIDs ending with 20-25)
indicates thresholds which can be used to raise an alarm if a
property of the battery exceeds one of them. Raising an alarm may
include sending a notification.
The Battery MIB defines four notifications. One indicating a low
battery charging state, one indicating an aged battery that may need
to be replaced and two dealing with battery temperature. The
temperature-related notifications are either indicating the battery
temperature to have risen above or fallen below a predefined value.
3.2. Battery Technologies
Static information in the batteryTable includes battery type and
technology. The battery type distinguishes primary (not
rechargeable) batteries from rechargeable (secondary) batteries and
capacitors. The battery technology describes the actual technology
of a battery, which typically is a chemical technology.
Since battery technologies are subject of intensive research and
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widely used technologies are often replaced by successor technologies
within an few years, the list of battery technologies was not chosen
as a fixed list. Instead, IANA has created a registry for battery
technologies at http://www.iana.org/assignments/eman where numbers
are assigned to battery technologies (TBD).
The table below shows battery technologies known today that are in
commercial use with the numbers assigned to them by IANA. New
entries can be added to the IANA registry if new technologies are
developed or if missing technologies are identified. Note that there
exists a huge number of battery types that are not listed in the IANA
registry. Many of them are experimental or cannot be used in an
economically useful way. New entries should be added to the IANA
registry only if the respective technologies are in commercial use
and relevant to standardized battery monitoring over the Internet.
+----------------------------+----------+
| battery technology | assigned |
| | number |
+----------------------------+----------+
| Unknown | 1 |
| Other | 2 |
| Zinc-carbon | 3 |
| Zinc chloride | 4 |
| Nickel oxyhydroxide | 5 |
| Lithium-copper oxide | 6 |
| Lithium-iron disulfide | 7 |
| Lithium-manganese dioxide | 8 |
| Zinc-air | 9 |
| Silver oxide | 10 |
| Alkaline | 11 |
| Lead acid | 12 |
| Nickel-cadmium | 13 |
| Nickel-metal hybride | 14 |
| Nickel-zinc | 15 |
| Lithium-ion | 16 |
| Lithium polymer | 17 |
| Double layer capacitor | 18 |
+----------------------------+----------+
3.3. Charging Cycles
The lifetime of a battery can be approximated using the measure of
charging cycles. A commonly used definition of a charging cycle is
the amount of discharge equal to the design (or nominal) capacity of
the battery [SBS]. This means that a single charging cycle may
include several steps of partial charging and discharging until the
amount of discharging has reached the design capacity of the battery.
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After that the next charging cycle immediately starts.
4. Definitions
BATTERY-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
mib-2, Integer32, Unsigned32
FROM SNMPv2-SMI -- RFC2578
SnmpAdminString
FROM SNMP-FRAMEWORK-MIB -- RFC3411
DateAndTime
FROM SNMPv2-TC -- RFC2579
MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
FROM SNMPv2-CONF; -- RFC2580
batteryMIB MODULE-IDENTITY
LAST-UPDATED "201106261200Z" -- 26 june 2010
ORGANIZATION "IETF EMAN Working Group"
CONTACT-INFO
"General Discussion: eman@ietf.org
To Subscribe: http://www.ietf.org/mailman/listinfo/eman
Archive: http://www.ietf.org/mail-archive/web/eman
Editor:
Juergen Quittek
NEC Europe Ltd.
NEC Laboratories Europe
Kurfuersten-Anlage 36
69115 Heidelberg
Germany
Tel: +49 6221 4342-115
Email: quittek@neclab.eu"
DESCRIPTION
"This MIB module defines a set of objects for monitoring
batteries of networked devices and of their components.
Copyright (c) 2010 IETF Trust and the persons identified as
authors of the code. All rights reserved.
Redistribution and use in source and binary forms, with or
without modification, is permitted pursuant to, and subject
to the license terms contained in, the Simplified BSD
License set forth in Section 4.c of the IETF Trust's Legal
Provisions Relating to IETF Documents
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(http://trustee.ietf.org/license-info).
This version of this MIB module is part of RFC yyyy; see
the RFC itself for full legal notices."
-- replace yyyy with actual RFC number & remove this notice
-- Revision history
REVISION "201106261200Z" -- 26 June 2010
DESCRIPTION
"Initial version, published as RFC yyyy."
-- replace yyyy with actual RFC number & remove this notice
::= { mib-2 zzz }
-- zzz to be assigned by IANA.
--******************************************************************
-- Top Level Structure of the MIB module
--******************************************************************
batteryNotifications OBJECT IDENTIFIER ::= { batteryMIB 0 }
batteryObjects OBJECT IDENTIFIER ::= { batteryMIB 1 }
batteryConformance OBJECT IDENTIFIER ::= { batteryMIB 2 }
--==================================================================
-- 1. Object Definitions
--==================================================================
--------------------------------------------------------------------
-- 1.1. Battery Table
--------------------------------------------------------------------
batteryTable OBJECT-TYPE
SYNTAX SEQUENCE OF BatteryEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table provides information on batteries.
It contains one conceptual row per battery."
::= { batteryObjects 1 }
batteryEntry OBJECT-TYPE
SYNTAX BatteryEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry providing information on a battery."
INDEX { batteryIndex }
::= { batteryTable 1 }
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BatteryEntry ::=
SEQUENCE {
batteryIndex Integer32,
batteryIdentifier SnmpAdminString,
batteryFirmwareVersion SnmpAdminString,
batteryType INTEGER,
batteryTechnology Unsigned32,
batteryDesignVoltage Unsigned32,
batteryNumberOfCells Unsigned32,
batteryDesignCapacity Unsigned32,
batteryMaxChargingCurrent Unsigned32,
batteryTrickleChargingCurrent Unsigned32,
batteryActualCapacity Unsigned32,
batteryChargingCycleCount Unsigned32,
batteryLastChargingCycleTime DateAndTime,
batteryChargingOperState INTEGER,
batteryChargingAdminState INTEGER,
batteryActualCharge Unsigned64,
batteryActualVoltage Unsigned32,
batteryActualCurrent Integer32,
batteryTemperature Integer32,
batteryAlarmLowCharge Unsigned32,
batteryAlarmLowVoltage Unsigned32,
batteryAlarmLowCapacity Unsigned32,
batteryAlarmHighCycleCount Unsigned32,
batteryAlarmHighTemperature Integer32,
batteryAlarmLowTemperature Integer32
}
batteryIndex OBJECT-TYPE
SYNTAX Integer32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This object identifies a battery for which status is
reported. Index values MUST be locally unique.
If there is an instance of the entPhysicalTable (defined in
the ENTITY-MIB module, see RFC 4133) with an individual
entry for each battery, then it is REQUIRED that values of
batteryIndex match the corresponding values of
entPhysicalIndex for the batteries. Otherwise, index values
may be chosen arbitrarily."
::= { batteryEntry 1 }
batteryIdentifier OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-only
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STATUS current
DESCRIPTION
"This object contains an identifier for the battery.
Many manufacturers deliver not pure batteries but battery
packages including additional hardware and firmware.
Typically, these modules include an identifier that can be
retrieved by a device at which a battery has been installed.
The identifier is useful when batteries are removed and
re-installed at the same or other devices. Then the device
or the network management system can trace batteries and
achieve continuity of battery monitoring.
If the battery identifier cannot be represented using the
ISO/IEC IS 10646-1 character set, then a hexadecimal
encoding of a binary representation of the battery
identifier must be used.
The value of this object must be an empty string if there
is no battery identifier or if the battery idenitfier is
unknown."
::= { batteryEntry 2 }
batteryFirmwareVersion OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the version number of the firmware
that is included in a battery module.
Many manufacturers deliver not pure batteries but battery
packages including additional hardware and firmware.
Since the bahavior of the battery may change with the
firmware, it may be useful to retrieve the firmware version
number.
The value of this object must be an empty string if there
is no firmware or if the version number of the firware is
unknown."
::= { batteryEntry 3 }
batteryType OBJECT-TYPE
SYNTAX INTEGER {
unknown(1),
other(2),
primary(3),
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rechargeable(4),
capacitor(5)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the type of battery.
It distinguishes between primary (not rechargeable)
batteries, rechargeable (secondary) batteries and capacitors
which are not really batteries but often used in the same
way as a battery.
The value other(2) can be used if the battery type is known
but none of the ones above. Value unknown(1) is to be used
if the type of battery cannot be determined."
::= { batteryEntry 4 }
batteryTechnology OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the technology used by the battery.
Numbers identifying battery types are registered at IANA.
A current list of assignments can be found at
<http://www.iana.org/assignments/eman>.
Value 0 (unknown) MUST be used if the type of battery
cannot be determined.
Value 1 (other) can be used if the battery type is known
but not one of the types already registered at IANA."
::= { batteryEntry 5 }
batteryDesignVoltage OBJECT-TYPE
SYNTAX Unsigned32
UNITS "millivolt"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the design (or nominal) voltage of the
battery in units of millivolt (mV).
Note that the design voltage is a constant value and
typically different from the actual voltage of the battery.
A value of 0 indicates that the design voltage is unknown."
::= { batteryEntry 6 }
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batteryNumberOfCells OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the number of cells contained in the
battery.
A value of 0 indicates that the number of cells is unknown."
::= { batteryEntry 7 }
batteryDesignCapacity OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliampere hours"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the design (or nominal) capacity of the
battery in units of milliampere hours (mAh).
Note that the design capacity is a constant value and
typically different from the actual capacity of the battery.
Usually, this is a value provided by the manufacturer of the
battery.
A value of 0 indicates that the design capacity is
unknown."
::= { batteryEntry 8 }
batteryMaxChargingCurrent OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliampere"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the maximal current to be used for
charging the battery in units of milliampere (mA).
Note that the maximal charging current may not lead to
optimal charge of the battery and that some batteries can
only be charged with the maximal current for a limited
amount of time.
A value of 0 indicates that the maximal charging current is
unknown."
::= { batteryEntry 9 }
batteryTrickleChargingCurrent OBJECT-TYPE
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SYNTAX Unsigned32
UNITS "milliampere"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the recommended current to be used for
trickle charging the battery in units of milliampere (mA).
Typically, this is a value recommended by the manufacturer
of the battery or by the manufacturer of the charging
circuit.
A value of 0 indicates that the recommended trickle charging
current is unknown."
::= { batteryEntry 10 }
batteryActualCapacity OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliampere hours"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the actual capacity of the
battery in units of milliampere hours (mAh).
Typically, the actual capacity of a battery decreases
with time and with usage of the battery. It is usually
lower than the design capacity
Note that the actual capacity needs to be measured and is
typically an estimate based on observed discharging and
charging cycles of the battery.
A value of 'ffffffff'H indicates that the actual capacity
cannot be determined."
::= { batteryEntry 11 }
batteryChargingCycleCount OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the number of completed charging
cycles that the battery underwent. In line with the
Smart Battery Data Specification Revision 1.1, a charging
cycle is defined as the process of discharging the battery
by a total amount equal to the battery design capacity as
given by object batteryDesignCapacity. A charging cycle
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may include several steps of charging and discharging the
battery until the discharging amount given by
batteryDesignCapacity has been reached. As soon as a
charging cycle has been completed the next one starts
immediately independent of the battery's current charge at
the end of the cycle.
For batteries of type primary(1) the value of this object is
always 0.
A value of 'ffffffff'H indicates that the number of charging
cycles cannot be determined."
::= { batteryEntry 12 }
batteryLastChargingCycleTime OBJECT-TYPE
SYNTAX DateAndTime
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The date and time of the last charging cycle. The value
'0000000000000000'H is returned if the battery has not been
charged yet or if the last charging time cannot be
determined.
For batteries of type primary(1) the value of this object is
always '0000000000000000'H."
::= { batteryEntry 13 }
batteryChargingOperState OBJECT-TYPE
SYNTAX INTEGER {
unknown(1),
charging(2),
fastCharging(3),
maintainingCharge(4),
noCharging(5),
discharging(6)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object indicates the current charging state of the
battery.
Value unknown(1) indicates that the charging state of the
battery cannot be determined.
Value charging(2) indicates that the battery is being
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charged in a way that the charge of the battery increases.
Value fastCharging(3) indicated that the battery is being
charged rapidly, i.e. faster than in the charging(2) state.
If multiple fast charging states exist, all of these
states are indicated by fastCharging(3).
Value maintainingCharge(4) indicates that the battery is
being charged with a low current that compensates
self-discharging. This includes trickle charging, float
charging and other methods for maintaining the current
charge of a battery.
Value noCharging(5) indicates that the battery is not being
charged or discharged by electric current between the
battery and electric circuits external to the battery.
Note that the battery may still be subject to
self-discharging.
Value discharging(6) indicates that the battery is being
discharged and that the charge of the battery decreases."
::= { batteryEntry 14 }
batteryChargingAdminState OBJECT-TYPE
SYNTAX INTEGER {
charging(2),
fastCharging(3),
maintainingCharge(4),
noCharging(5),
discharging(6),
notSet(7)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"The value of this object indicates the desired status of
the charging state of the battery. The real state is
indicated by object batteryChargingOperState. See the
definition of object batteryChargingOperState for a
description of the values.
When this object is initialized by an implementation of the
BATTERY-MIB module, its value is set to notSet(7).
However, a SET request can only set this object to either
charging(2), fastCharging(3), maintainingCharge(4),
noCharging(5), or discharging(6). Attempts to set this
object to notSet(7) will always fail with an
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'inconsistentValue' error. In case multiple fast charging
states exist, the battery logic can choose an appropriate
fast charging state - preferably the fastest.
When the batteryChargingAdminState object is set, then the
BATTERY-MIB implementation must try to set the battery
to the indicated state. The result will be indicated by
object batteryChargingOperState.
Due to operational conditions and limitations of the
implementation of the BATTERY-MIB module, changing the
battery status according to a set value of object
batteryChargingAdminState may not be possible.
Setting the value of object batteryChargingAdminState
may result in not changing the state of the battery
to this value or even in setting the charging state
to another value. For example, setting
batteryChargingAdminState to value fastCharging(3) may
have no effect when the battery logic is not allowing
fast charging due to temperature constraints."
::= { batteryEntry 15 }
batteryActualCharge OBJECT-TYPE
SYNTAX Unsigned64
UNITS "milliampere hours"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the actual charge of the battery
in units of milliampere hours (mAh).
Note that the actual charge needs to be measured and is
typically an estimate based on observed discharging and
charging cycles of the battery.
A value of 'ffffffff'H indicates that the actual charge
cannot be determined."
::= { batteryEntry 16 }
batteryActualVoltage OBJECT-TYPE
SYNTAX Unsigned32
UNITS "millivolt"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the actual voltage of the battery
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in units of millivolt (mV).
A value of 'ffffffff'H indicates that the actual voltage
cannot be determined."
::= { batteryEntry 17 }
batteryActualCurrent OBJECT-TYPE
SYNTAX Integer32
UNITS "milliampere"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object provides the actual charging or discharging
current of the battery in units of milliampere (mA).
Charging current is represented by positive values,
discharging current is represented by negative values.
A value of '7fffffff'H indicates that the actual current
cannot be determined."
::= { batteryEntry 18 }
batteryTemperature OBJECT-TYPE
SYNTAX Integer32
UNITS "deci-degrees Celsius"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The ambient temperature at or near the battery.
A value of '7fffffff'H indicates that the temperature
cannot be determined."
::= { batteryEntry 19 }
batteryAlarmLowCharge OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliampere hours"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the lower threshold value for object
batteryActualCharge. If the value of object
batteryActualCharge falls below this threshold,
a low battery alarm will be raised. The alarm procedure may
include generating a batteryLowNotification.
A value of 0 indicates that no alarm will be raised for any
value of object batteryActualCharge."
::= { batteryEntry 20 }
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batteryAlarmLowVoltage OBJECT-TYPE
SYNTAX Unsigned32
UNITS "millivolt"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the lower threshold value for object
batteryActualVoltage. If the value of object
batteryActualVoltage falls below this threshold,
a low battery alarm will be raised. The alarm procedure may
include generating a batteryLowNotification.
A value of 0 indicates that no alarm will be raised for any
value of object batteryActualVoltage."
::= { batteryEntry 21 }
batteryAlarmLowCapacity OBJECT-TYPE
SYNTAX Unsigned32
UNITS "milliampere hours"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the lower threshold value for object
batteryActualCapacity. If the value of object
batteryActualCapacity falls below this threshold,
a battery aging alarm will be raised. The alarm procedure
may include generating a batteryAgingNotification.
A value of 0 indicates that no alarm will be raised for any
value of object batteryActualCapacity."
::= { batteryEntry 22 }
batteryAlarmHighCycleCount OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the upper threshold value for object
batteryChargingCycleCount. If the value of object
batteryChargingCycleCount rises above this threshold,
a battery aging alarm will be raised. The alarm procedure
may include generating a batteryAgingtNotification.
A value of 0 indicates that no alarm will be raised for any
value of object batteryChargingCycleCount."
::= { batteryEntry 23 }
batteryAlarmHighTemperature OBJECT-TYPE
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SYNTAX Integer32
UNITS "deci-degrees Celsius"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the upper threshold value for object
batteryTemperature. If the value of object
batteryTemperature rises above this threshold, a battery
high temperature alarm will be raised. The alarm procedure
may include generating a batteryHighTemperatNotification.
A value of '7fffffff'H indicates that no alarm will be
raised for any value of object batteryTemperature."
::= { batteryEntry 24 }
batteryAlarmLowTemperature OBJECT-TYPE
SYNTAX Integer32
UNITS "deci-degrees Celsius"
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"This object provides the lower threshold value for object
batteryTemperature. If the value of object
batteryTemperature rises above this threshold, a battery
low temperature alarm will be raised. The alarm procedure
may include generating a batteryLowTemperatNotification.
A value of '7fffffff'H indicates that no alarm will be
raised for any value of object batteryTemperature."
::= { batteryEntry 25 }
--==================================================================
-- 2. Notifications
--==================================================================
batteryLowNotification NOTIFICATION-TYPE
OBJECTS {
batteryActualCharge,
batteryActualVoltage
}
STATUS current
DESCRIPTION
"This notification can be generated when the current charge
(batteryActualCharge) or the current voltage
(batteryActualVoltage) of the battery falls below a
threshold defined by object batteryAlarmLowCharge or object
batteryAlarmLowVoltage, respectively. The notification can
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only be sent again when the current voltage or the current
charge become higher than the respective thresholds
through charging before falling below the thresholds again
(to avoid fluctuations through e.g. temperature). The
notification can also be sent again when a charging process
is interrupted and either the battery charge
(batteryActualCharge) or battery voltage
(batteryActualVoltage) is still below either the value of
the object batteryAlarmLowCharge or the value of object
batteryAlarmLowVoltage."
::= { batteryNotifications 1 }
batteryAgingNotification NOTIFICATION-TYPE
OBJECTS {
batteryActualCapacity,
batteryChargingCycleCount
}
STATUS current
DESCRIPTION
"This notification can be generated when the actual
capacity (batteryActualCapacity) falls below a threshold
defined by object batteryAlarmLowCapacity
or when the charging cycle count of the battery
(batteryChargingCycleCount) exceeds the threshold defined
by object batteryAlarmHighCycleCount."
::= { batteryNotifications 2 }
batteryHighTemperatNotification NOTIFICATION-TYPE
OBJECTS {
batteryTemperature
}
STATUS current
DESCRIPTION
"This notification can be generated when the measured
temperature (batteryTemperature) rises above a threshold
defined by object batteryAlarmHighTemperature."
::= { batteryNotifications 3 }
batteryLowTemperatNotification NOTIFICATION-TYPE
OBJECTS {
batteryTemperature
}
STATUS current
DESCRIPTION
"This notification can be generated when the measured
temperature (batteryTemperature) falls below a threshold
defined by object batteryAlarmLowTemperature."
::= { batteryNotifications 4 }
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--==================================================================
-- 3. Conformance Information
--==================================================================
batteryCompliances OBJECT IDENTIFIER ::= { batteryConformance 1 }
batteryGroups OBJECT IDENTIFIER ::= { batteryConformance 2 }
--------------------------------------------------------------------
-- 3.1. Compliance Statements
--------------------------------------------------------------------
batteryCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for implementations of the
POWER-STATE-MIB module.
A compliant implementation MUST implement the objects
defined in the mandatory groups batteryDescriptionGroup
and batteryStatusGroup."
MODULE -- this module
MANDATORY-GROUPS {
batteryDescriptionGroup,
batteryStatusGroup
}
GROUP batteryAlarmThresholdsGroup
DESCRIPTION
"A compliant implementation does not have to implement
the batteryAlarmThresholdsGroup."
GROUP batteryNotificationsGroup
DESCRIPTION
"A compliant implementation does not have to implement
the batteryNotificationsGroup."
GROUP batteryAdminGroup
DESCRIPTION
"A compliant implementation does not have to implement
the batteryAdminGroup."
OBJECT batteryAlarmLowCharge
MIN-ACCESS read-only
DESCRIPTION
"The agent is not required to support set
operations to this object."
OBJECT batteryAlarmLowVoltage
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MIN-ACCESS read-only
DESCRIPTION
"The agent is not required to support set
operations to this object."
OBJECT batteryAlarmLowCapacity
MIN-ACCESS read-only
DESCRIPTION
"The agent is not required to support set
operations to this object."
OBJECT batteryAlarmHighCycleCount
MIN-ACCESS read-only
DESCRIPTION
"The agent is not required to support set
operations to this object."
OBJECT batteryHighTemperatNotification
MIN-ACCESS read-only
DESCRIPTION
"The agent is not required to support set
operations to this object."
::= { batteryCompliances 1 }
--------------------------------------------------------------------
-- 3.2. MIB Grouping
--------------------------------------------------------------------
batteryDescriptionGroup OBJECT-GROUP
OBJECTS {
batteryIdentifier,
batteryFirmwareVersion,
batteryType,
batteryTechnology,
batteryDesignVoltage,
batteryNumberOfCells,
batteryDesignCapacity,
batteryMaxChargingCurrent,
batteryTrickleChargingCurrent
}
STATUS current
DESCRIPTION
"A compliant implementation MUST implement the objects
contained in this group."
::= { batteryGroups 1 }
batteryStatusGroup OBJECT-GROUP
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OBJECTS {
batteryActualCapacity,
batteryChargingCycleCount,
batteryLastChargingCycleTime,
batteryChargingOperState,
batteryActualCharge,
batteryActualVoltage,
batteryActualCurrent,
batteryTemperature
}
STATUS current
DESCRIPTION
"A compliant implementation MUST implement the objects
contained in this group."
::= { batteryGroups 2 }
batteryAdminGroup OBJECT-GROUP
OBJECTS {
batteryChargingAdminState
}
STATUS current
DESCRIPTION
"A compliant implementation does not have to implement the
object contained in this group."
::= { batteryGroups 3 }
batteryAlarmThresholdsGroup OBJECT-GROUP
OBJECTS {
batteryAlarmLowCharge,
batteryAlarmLowVoltage,
batteryAlarmLowCapacity,
batteryAlarmHighCycleCount,
batteryAlarmHighTemperature,
batteryAlarmLowTemperature
}
STATUS current
DESCRIPTION
"A compliant implementation does not have to implement the
objects contained in this group."
::= { batteryGroups 4 }
batteryNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS {
batteryLowNotification,
batteryAgingNotification,
batteryHighTemperatNotification,
batteryLowTemperatNotification
}
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STATUS current
DESCRIPTION
"A compliant implementation does not have to implement the
notifications contained in this group."
::= { batteryGroups 5 }
END
5. Security Considerations
There are a number of management objects defined in this MIB module
with a MAX-ACCESS clause of read-write. Such objects may be
considered sensitive or vulnerable in some network environments. The
support for SET operations in a non-secure environment without proper
protection can have a negative effect on network operations. These
are the tables and objects and their sensitivity/vulnerability:
o batteryChargingAdminState
Setting the battery charging state can be beneficial for an
operator for various reasons such as charging batteries when the
price of electricity is low. However, setting the charging state
can e.g. be used by an attacker to discharge batteries of devices
and thereby swiching these devices off if they are powered solely
by batteries. In particular, if the batteryAlarmLowCharge and
batteryAlarmLowVoltage can also be set, this attack will go
unnoticed (i.e. no notifications are sent).
o batteryAlarmLowCharge and batteryAlarmLowVoltage
These objects set the threshold for an alarm to be raised when the
battery charge or voltage falls below the corresponding one of
them. An attacker setting one of these alarm values can switch
off the alarm by setting it to the 'off' value 0 or modify the
alarm behavior by setting it to any other value. The result may
be loss of data if the battery runs empty without warning to a
receipient expecting such a notification.
o batteryAlarmLowCapacity and batteryAlarmHighCycleCount
These objects set the threshold for an alarm to be raised when the
battery becomes older and less performant than required for stable
operation. An attacker setting this alarm value can switch off
the alarm by setting it to the 'off' value 0 or modify the alarm
behavior by setting it to any other value. This may either lead
to a costly replacement of a working battery or too old or too
weak batteries are used. The consequence of the latter could e.g.
be that a battery cannot provide power long enough between two
scheduled charging actions causing the powered device to shut down
and potentially loose data.
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o batteryAlarmHighTemperature and batteryAlarmLowTemperature
These objects set thresholds for an alarm to be raised when the
battery rises above/falls below them. An attacker setting one of
these alarm values can switch off these alarms by setting them to
the 'off' value '7fffffff'H or modify the alarm behavior by
setting them to any other value. The result may e.g. be an
unnecessary shutdown of a device if batteryAlarmHighTemperature is
set to too low or damage to the device by too high temperatures if
switched off or set to too high values or by damage to the battery
when it e.g. is being charged. Batteries can also be damaged e.g.
in an attempt to charge them at too low temperatures.
Some of the readable objects in this MIB module (i.e., objects with a
MAX-ACCESS other than not-accessible) may be considered sensitive or
vulnerable in some network environments. It is thus important to
control even GET and/or NOTIFY access to these objects and possibly
to even encrypt the values of these objects when sending them over
the network via SNMP. These are the tables and objects and their
sensitivity/vulnerability:
All potentially sensible or vulnerable objects of this MIB modules
are in the batteryTable. In general, there are no serious
operational vulnerabilities foreseen in case of an unauthorized read
access to this table. However, privacy issues need to be considered.
It may be a trade secret of the operator
o how many batteries are installed in a managed node (batteryIndex)
o how old these batteries are (batteryActualCapacity and
batteryChargingCycleCount)
o when the next replacement cycle for batteries can be expected
(batteryAlarmLowCapacity and batteryAlarmHighCycleCount)
o what battery type and make are used with which firmware version
(batteryIdentifier, batteryFirmwareVersion, batteryType, and
batteryTechnology)
SNMP versions prior to SNMPv3 did not include adequate security.
Even if the network itself is secure (for example by using IPsec),
even then, there is no control as to who on the secure network is
allowed to access and GET/SET (read/change/create/delete) the objects
in this MIB module.
It is RECOMMENDED that implementers consider the security features as
provided by the SNMPv3 framework (see [RFC3410], section 8),
including full support for the SNMPv3 cryptographic mechanisms (for
authentication and privacy).
Further, deployment of SNMP versions prior to SNMPv3 is NOT
RECOMMENDED. Instead, it is RECOMMENDED to deploy SNMPv3 and to
enable cryptographic security. It is then a customer/operator
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responsibility to ensure that the SNMP entity giving access to an
instance of this MIB module is properly configured to give access to
the objects only to those principals (users) that have legitimate
rights to GET or SET (change/create/delete) them.
6. IANA Considerations
6.1. SMI Object Identifier Registration
The Battery MIB module defined in this document uses the following
IANA-assigned OBJECT IDENTIFIER value recorded in the SMI Numbers
registry:
Descriptor OBJECT IDENTIFIER value
---------- -----------------------
batteryMIB { mib-2 xxx }
[NOTE for IANA: Please allocate an object identifier at
http://www.iana.org/assignments/smi-numbers for object batteryMIB.]
6.2. Battery Technology Registration
Object batteryTechnology defined in Section 4 reports battery
technologies. Eighteen values for battery technologies have
initially been defined. They are listed in a table in Section 3.2.
For ensuring extensibility of this list, IANA has created a registry
for battery technologies at http://www.iana.org/assignments/eman and
filled it with the initial list given in Section 3.2.
New assignments of numbers for battery technologies will be
administered by IANA through Expert Review ([RFC5226]). Experts must
check for sufficient relevance of a battery technology to be added.
[NOTE for IANA: Please create a new registry under
http://www.iana.org/assignments/eman for battery types. Please fill
the registry with values from the table in Section 3.2]
7. Open Issues
7.1. Time estimations
Shall we add managed objects and notifications that are based on the
estimated time that the battery will be able to provide power (time-
to-empty) or will need until it is fully charged (time-to-full). In
general this is useful and desired information. However, this
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information is not reliable. It is based on the assumption that the
actual current will be continuous drawn from the battery or used to
charge the battery. Additionally, it is assumed that the battery
chemistry works as expected. Both may not be the case.
The list of time estimations and related alarms on the table include:
RemainingTimeAlarm, AtRateTimeToFull, AtRateTimeToEmpty, AtRateOK,
RunTimeToEmpty, AverageTimeToEmpty, AverageTimeToFull.
From previous discussions it seems that the AtRate ones will be more
difficult to implement and it is questionable whether the effort is
worth the gain. The RunTimeToEmpty and AverageTimeToEmpty and
AverageTimeToFull might be interesting but needs to be decided on the
list. With the objects we have so far, this could also be
implemented in the NMS.
7.2. Entity MIB augmentation
Should the batteryTable augment the entPhysicalTable from the Entity
MIB?
7.3. Units
Which unit shall we use for batteryDesignVoltage and
batteryActualVoltage? Currently we use millivolt. The UPS MIB uses
"0.1 Volt DC".
7.4. Kind of entity
In section 3.1 we recommend to use a value of powerSupply(6) for
object entPhysicalClass, if the entity is a battery. This sections
needs to be updates once we have values for entPhysicalClass
maintained by IANA. We should then register a new value
"battery(xy)" at IANA and replace "powerSupply(6) in this section.
8. Acknowledgements
We would like to thank Steven Chew and Bill Mielke for their valuable
input.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
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[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC2578] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Structure of Management Information
Version 2 (SMIv2)", STD 58, RFC 2578, April 1999.
[RFC2579] McCloghrie, K., Ed., Perkins, D., Ed., and J.
Schoenwaelder, Ed., "Textual Conventions for SMIv2",
STD 58, RFC 2579, April 1999.
[RFC2580] McCloghrie, K., Perkins, D., and J. Schoenwaelder,
"Conformance Statements for SMIv2", STD 58, RFC 2580,
April 1999.
[RFC4133] Bierman, A. and K. McCloghrie, "Entity MIB (Version 3)",
RFC 4133, August 2005.
9.2. Informative References
[I-D.ietf-eman-requirements]
Quittek, J., Chandramouli, M., Winter, R., Dietz, T., and
B. Claise, "Requirements for Energy Management",
draft-ietf-eman-requirements-08 (work in progress),
July 2012.
[I-D.ietf-eman-framework]
Claise, B., Parello, J., Silver, L., Quittek, J., and B.
Nordman, "Energy Management Framework",
draft-ietf-eman-framework-05 (work in progress),
July 2012.
[I-D.ietf-eman-energy-monitoring-mib]
Chandramouli, M., Silver, L., Quittek, J., Dietz, T., and
B. Claise, "Power and Energy Monitoring MIB",
draft-ietf-eman-energy-monitoring-mib-03 (work in
progress), July 2012.
[RFC1628] Case, J., "UPS Management Information Base", RFC 1628,
May 1994.
[RFC3410] Case, J., Mundy, R., Partain, D., and B. Stewart,
"Introduction and Applicability Statements for Internet-
Standard Management Framework", RFC 3410, December 2002.
[SBS] "Smart Battery Data Specification", Revision 1.1,
December 1998.
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Authors' Addresses
Juergen Quittek
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-115
Email: quittek@neclab.eu
Rolf Winter
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-121
Email: Rolf.Winter@neclab.eu
Thomas Dietz
NEC Europe Ltd.
NEC Laboratories Europe
Network Research Division
Kurfuersten-Anlage 36
Heidelberg 69115
DE
Phone: +49 6221 4342-128
Email: Thomas.Dietz@neclab.eu
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