RFC 3512
Configuring Networks and Devices with Simple Network Management Protocol (SNMP)
Pages: 83
Informational
Informational
Part 4 of 4 – Pages 58 to 83
8. Example MIB Module With Template-based Data
This section defines a MIB module that controls the heating and air conditioning system for a large building. It contains both configuration and counter objects that allow operators to see how much cooling or heating a particular configuration has consumed. Objects that represent the configuration information at a "default" level (as referenced above) are also included. These tables, in combination with the application of the tables' row instance data as templated 'defaults', will allow operators to configure and monitor many rooms at once, change the configuration parameters based on time of day, and make a number of other sophisticated decisions based on the 'policy' implied by these defaults and their application. For this reason, these configuration controls have their instances specified from template object types.
In our simplified Heating Ventilation and Air Conditioning (HVAC)
model we will create three tables based on a simple analysis. More
complicated systems will need more tables, but the principles will be
the same.
Step 1: As with any other MIB module design, the first step
is to determine what objects are necessary for
configuration and control operations. The first table
to be created is a fairly traditional monitoring
table. It includes indices so that we will know what
rooms the counters and status objects are for. It
includes an object that is a RowPointer to a table
that contains configuration information. The objects
for the bldgHVACTable, our first table in the HVAC
MIB module are:
Index objects that identify what floor and office we are
managing:
bldgHVACFloor
bldgHVACOffice
A single index reference to a table that 'glues' configuration
information defaults with descriptive information:
bldgHVACCfgTemplate
A set of objects that show status and units of
work (bldgHVACCoolOrHeatMins) and standard per-row
SnmpAdminString, StorageType, and RowStatus columnar
objects:
bldgHVACFanSpeed
bldgHVACCurrentTemp
bldgHVACCoolOrHeatMins
bldgHVACDiscontinuityTime
bldgHVACOwner
bldgHVACStatus
Step 2: A configuration description table. The purpose of this
table is to provide a unique string identifier for
templates. These may be driven by policies in a
network. If it were necessary to configure devices
to deliver a particular quality of service, the
index string of this table could be the name and the
description part, it could be a brief description of the
underlying motivation such as: "provides extra heat to
corner offices to counteract excessive exterior wind
chill". Standard owner and status objects may also
be helpful and are included here. The row columnar
objects are:
bldgHVACCfgTemplateInfoIndex
bldgHVACCfgTemplateInfoID
bldgHVACCfgTemplateInfoDescr
bldgHVACCfgTemplateInfoOwner
bldgHVACCfgTemplateInfoStatus
Notice that to this point we have provided no
configuration information. That will be in the next
table. Some readers may wonder why this table is not
combined with the configuration template table described
in the next step. In fact, they can be. The reason for
having a separate table is that as systems become more
complex, there may be more than one configuration table
that points to these descriptions. Another reason for
two tables is that this in not reproduced for every
template and instance, which can save some additional
data movement. Every designer will have to evaluate the
tradeoffs between number of objects and data movement
efficiency just as with other MIB modules.
Step 3: The bldgHVACCfgTemplateTable contains the specific
configuration parameters that are pointed to by the
bldgHVACConfigPtr object. Note that many rows in the
bldgHVACTable can point to an entry in this table. It
is also possible for entries to be used by 1 or 0 rows
of the bldgHVACTable. It is the property of allowing
multiple rows (instances) in the bldgHVACTable to
point to a row in this table that can produce such
efficiency gains from policy-based management with
SNMP. Also notice that the configuration data is tied
directly to the counter data so that people can see
how configurations impact behavior.
The objects in this table are all that are necessary
for configuration and connection to the other tables as
well as the usual SnmpAdminString, StorageType, and
RowStatus objects:
A simple index to the table:
bldgHVACCfgTemplateIndex
The configuration objects:
bldgHVACCfgTemplateDesiredTemp
bldgHVACCfgTemplateCoolOrHeat
Administrative objects for SnmpAdminString and
RowStatus:
bldgHVACCfgTemplateInfo
bldgHVACCfgTemplateOwner
bldgHVACCfgTemplateStorage
bldgHVACCfgTemplateStatus
8.1. MIB Module Definition
BLDG-HVAC-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, Counter32,
Gauge32, OBJECT-TYPE, Unsigned32, experimental
FROM SNMPv2-SMI
MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF
TEXTUAL-CONVENTION,
TimeStamp, RowStatus, StorageType
FROM SNMPv2-TC
SnmpAdminString
FROM SNMP-FRAMEWORK-MIB;
bldgHVACMIB MODULE-IDENTITY
LAST-UPDATED "200303270000Z"
ORGANIZATION "SNMPCONF working group
E-mail: snmpconf@snmp.com"
CONTACT-INFO
"Jon Saperia
Postal: JDS Consulting
174 Chapman Street
Watertown, MA 02472
U.S.A.
Phone: +1 617 744 1079
E-mail: saperia@jdscons.com
Wayne Tackabury
Postal: Gold Wire Technology
411 Waverley Oaks Rd.
Waltham, MA 02452
U.S.A.
Phone: +1 781 398 8800
E-mail: wayne@goldwiretech.com
Michael MacFaden
Postal: Riverstone Networks
5200 Great America Pkwy.
Santa Clara, CA 95054
U.S.A.
Phone: +1 408 878 6500
E-mail: mrm@riverstonenet.com
David Partain
Postal: Ericsson AB
P.O. Box 1248
SE-581 12 Linkoping
Sweden
E-mail: David.Partain@ericsson.com"
DESCRIPTION
"This example MIB module defines a set of management objects
for heating ventilation and air conditioning systems. It
also includes objects that can be used to create policies
that are applied to rooms. This eliminates the need to send
per-instance configuration commands to the system.
Copyright (C) The Internet Society (2003). This version of
this MIB module is part of RFC 3512; see the RFC itself for
full legal notices."
REVISION "200303270000Z"
DESCRIPTION
"Initial version of BLDG-HVAC-MIB as published in RFC 3512."
::= { experimental 122 }
bldgHVACObjects OBJECT IDENTIFIER ::= { bldgHVACMIB 1 }
bldgConformance OBJECT IDENTIFIER ::= { bldgHVACMIB 2 }
--
-- Textual Conventions
--
BldgHvacOperation ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"Operations supported by a heating and cooling system.
A reference to underlying general systems would go here."
SYNTAX INTEGER {
heat(1),
cool(2)
}
--
-- HVAC Objects Group
--
bldgHVACTable OBJECT-TYPE
SYNTAX SEQUENCE OF BldgHVACEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table is the representation and data control
for building HVAC by each individual office.
The table has rows for, and is indexed by a specific
floor and office number. Each such row includes
HVAC statistical and current status information for
the associated office. The row also contains a
bldgHVACCfgTemplate columnar object that relates the
bldgHVACTable row to a row in the bldgHVACCfgTemplateTable.
If this value is nonzero, then the instance in the row
that has a value for how the HVAC has been configured
in the associated template (bldgHVACCfgTeplateTable row).
Hence, the bldgHVACCfgTeplateTable row contains the
specific configuration values for the offices as described
in this table."
::= { bldgHVACObjects 1 }
bldgHVACEntry OBJECT-TYPE
SYNTAX BldgHVACEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A row in the bldgHVACTable. Each row represents a particular
office in the building, qualified by its floor and office
number. A given row instance can be created or deleted by
set operations upon its bldgHVACStatus columnar
object instance."
INDEX { bldgHVACFloor, bldgHVACOffice }
::= { bldgHVACTable 1 }
BldgHVACEntry ::= SEQUENCE {
bldgHVACFloor Unsigned32,
bldgHVACOffice Unsigned32,
bldgHVACCfgTemplate Unsigned32,
bldgHVACFanSpeed Gauge32,
bldgHVACCurrentTemp Gauge32,
bldgHVACCoolOrHeatMins Counter32,
bldgHVACDiscontinuityTime TimeStamp,
bldgHVACOwner SnmpAdminString,
bldgHVACStorageType StorageType,
bldgHVACStatus RowStatus
}
bldgHVACFloor OBJECT-TYPE
SYNTAX Unsigned32 (1..1000)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This portion of the index indicates the floor of the
building. The ground floor is considered the
first floor. For the purposes of this example,
floors under the ground floor cannot be
controlled using this MIB module."
::= { bldgHVACEntry 1 }
bldgHVACOffice OBJECT-TYPE
SYNTAX Unsigned32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This second component of the index specifies the
office number."
::= { bldgHVACEntry 2 }
bldgHVACCfgTemplate OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The index (bldgHVACCfgTemplateIndex instance)
of an entry in the 'bldgHVACCfgTemplateTable'.
The bldgHVACCfgTable row instance referenced
is a pre-made configuration 'template'
that represents the configuration described
by the bldgHVACCfgTemplateInfoDescr object. Note
that not all configurations will be under a
defined template. As a result, a row in this
bldgHVACTable may point to an entry in the
bldgHVACCfgTemplateTable that does not in turn
have a reference (bldgHVACCfgTemplateInfo) to an
entry in the bldgHVACCfgTemplateInfoTable. The
benefit of this approach is that all
configuration information is available in one
table whether all elements in the system are
derived from configured templates or not.
Where the instance value for this colunmar object
is zero, this row represents data for an office
whose HVAC status can be monitored using the
read-only columnar object instances of this
row, but is not under the configuration control
of the agent."
::= { bldgHVACEntry 3 }
bldgHVACFanSpeed OBJECT-TYPE
SYNTAX Gauge32
UNITS "revolutions per minute"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"Shows the revolutions per minute of the fan. Fan speed
will vary based on the difference between
bldgHVACCfgTemplateDesiredTemp and bldgHVACCurrentTemp. The
speed is measured in revolutions of the fan blade per minute."
::= { bldgHVACEntry 4 }
bldgHVACCurrentTemp OBJECT-TYPE
SYNTAX Gauge32
UNITS "degrees in celsius"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The current measured temperature in the office. Should
the current temperature be measured at a value of less
than zero degrees celsius, a read of the instance
for this object will return a value of zero."
::= { bldgHVACEntry 5 }
bldgHVACCoolOrHeatMins OBJECT-TYPE
SYNTAX Counter32
UNITS "minutes"
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The total number of heating or cooling minutes that have
been consumed since the row was activated. Notice that
whether the minutes represent heating or cooling is a
function of the configuration of this row. If the system
is re-initialized from a cooling to heating function or
vice versa, then the counter would start over again. This
effect is similar to a reconfiguration of some network
interface cards. When parameters that impact
configuration are changed, the subsystem must be
re-initialized. Discontinuities in the value of this counter
can occur at re-initialization of the management system,
and at other times as indicated by the value of
bldgHVACDiscontinuityTime."
::= { bldgHVACEntry 6 }
bldgHVACDiscontinuityTime OBJECT-TYPE
SYNTAX TimeStamp
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of sysUpTime on the most recent occasion at which
any heating or cooling operation for the office designated
by this row instance experienced a discontinuity. If
no such discontinuities have occurred since the last re-
initialization of the this row, then this object contains a
zero value."
::= { bldgHVACEntry 7 }
bldgHVACOwner OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The identity of the operator/system that
last modified this entry. When a new entry
is created, a valid SnmpAdminString must
be supplied. If, on the other hand, this
entry is populated by the agent 'discovering'
unconfigured rooms, the empty string is a valid
value for this object."
::= { bldgHVACEntry 8 }
bldgHVACStorageType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The persistence of this row of the table in system storage,
as it pertains to permanence across system resets. A columnar
instance of this object with value 'permanent' need not allow
write-access to any of the columnar object instances in the
containing row."
::= { bldgHVACEntry 9 }
bldgHVACStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Controls and reflects the creation and activation status of
a row in this table.
No attempt to modify a row columnar object instance value in
the bldgHVACTable should be issued while the value of
bldgHVACStatus is active(1). Should an agent receive a SET
PDU attempting such a modification in this state, an
inconsistentValue error should be returned as a result of
the SET attempt."
::= { bldgHVACEntry 10 }
--
-- HVAC Configuration Template Table
--
bldgHVACCfgTemplateInfoTable OBJECT-TYPE
SYNTAX SEQUENCE OF BldgHVACCfgTemplateInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table provides unique string identification for
HVAC templates in a network. If it were necessary to
configure rooms to deliver a particular quality of climate
control with regard to cooling or heating, the index string
of a row in this table could be the template name.
The bldgHVACCfgCfgTemplateInfoDescription
contains a brief description of the template service objective
such as: provides summer cooling settings for executive
offices. The bldgHVACCfgTemplateInfo in the
bldgHVACCfgTemplateTable will contain the pointer to the
relevant row in this table if it is intended that items
that point to a row in the bldgHVACCfgTemplateInfoTable be
identifiable as being under template control though this
mechanism."
::= { bldgHVACObjects 2 }
bldgHVACCfgTemplateInfoEntry OBJECT-TYPE
SYNTAX BldgHVACCfgTemplateInfoEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each row represents a particular template and
description. A given row instance can be created or
deleted by set operations upon its
bldgHVACCfgTemplateInfoStatus columnar object
instance."
INDEX { bldgHVACCfgTemplateInfoIndex }
::= { bldgHVACCfgTemplateInfoTable 1 }
BldgHVACCfgTemplateInfoEntry ::= SEQUENCE {
bldgHVACCfgTemplateInfoIndex Unsigned32,
bldgHVACCfgTemplateInfoID SnmpAdminString,
bldgHVACCfgTemplateInfoDescr SnmpAdminString,
bldgHVACCfgTemplateInfoOwner SnmpAdminString,
bldgHVACCfgTemplateInfoStatus RowStatus,
bldgHVACCfgTemplateInfoStorType StorageType
}
bldgHVACCfgTemplateInfoIndex OBJECT-TYPE
SYNTAX Unsigned32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The unique index to a row in this table."
::= { bldgHVACCfgTemplateInfoEntry 1 }
bldgHVACCfgTemplateInfoID OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Textual identifier for this table row, and, consequently
the template. This should be a unique name within
an administrative domain for a particular template so that
all systems in a network that are under the same template
can have the same 'handle' (e.g., 'Executive Offices',
'Lobby Areas')."
::= { bldgHVACCfgTemplateInfoEntry 2 }
bldgHVACCfgTemplateInfoDescr OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A general description of the template. One example might
be - Controls the cooling for offices on higher floors
during the summer."
::= { bldgHVACCfgTemplateInfoEntry 3 }
bldgHVACCfgTemplateInfoOwner OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The identity of the operator/system that last modified
this entry."
::= { bldgHVACCfgTemplateInfoEntry 4 }
bldgHVACCfgTemplateInfoStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The activation status of this row.
No attempt to modify a row columnar object instance value in
the bldgHVACCfgTemplateInfo Table should be issued while the
value of bldgHVACCfgTemplateInfoStatus is active(1).
Should an agent receive a SET PDU attempting such a modification
in this state, an inconsistentValue error should be returned as
a result of the SET attempt."
::= { bldgHVACCfgTemplateInfoEntry 5 }
bldgHVACCfgTemplateInfoStorType OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The persistence of this row of the table in system storage,
as it pertains to permanence across system resets. A columnar
instance of this object with value 'permanent' need not allow
write-access to any of the columnar object instances in the
containing row."
::= { bldgHVACCfgTemplateInfoEntry 6 }
--
-- HVAC Configuration Template Table
--
bldgHVACCfgTemplateTable OBJECT-TYPE
SYNTAX SEQUENCE OF BldgHVACCfgTemplateEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table contains the templates, which
can be used to set defaults that will
be applied to specific offices. The application
of those values is accomplished by having a row
instance of the bldgHVACTable reference a row of
this table (by the value of the former's
bldgHVACCfgTemplate columnar instance). Identifying
information concerning a row instance of this table
can be found in the columnar data of the row instance
of the bldgHVACCfgTemplateInfoTable entry referenced
by the bldgHVACCfgTemplateInfo columnar object of
this table."
::= { bldgHVACObjects 3 }
bldgHVACCfgTemplateEntry OBJECT-TYPE
SYNTAX BldgHVACCfgTemplateEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"Each row represents a single set of template parameters
that can be applied to selected instances - in this case
offices. These policies will be turned on and off by the
policy module through its scheduling facilities.
A given row instance can be created or
deleted by set operations upon its
bldgHVACCfgTemplateStatus columnar object instance."
INDEX { bldgHVACCfgTemplateIndex }
::= { bldgHVACCfgTemplateTable 1 }
BldgHVACCfgTemplateEntry ::= SEQUENCE {
bldgHVACCfgTemplateIndex Unsigned32,
bldgHVACCfgTemplateDesiredTemp Gauge32,
bldgHVACCfgTemplateCoolOrHeat BldgHvacOperation,
bldgHVACCfgTemplateInfo Unsigned32,
bldgHVACCfgTemplateOwner SnmpAdminString,
bldgHVACCfgTemplateStorage StorageType,
bldgHVACCfgTemplateStatus RowStatus
}
bldgHVACCfgTemplateIndex OBJECT-TYPE
SYNTAX Unsigned32 (1..2147483647)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique value for each defined template in this
table. This value can be referenced as a row index
by any MIB module that needs access to this information.
The bldgHVACCfgTemplate will point to entries in this
table."
::= { bldgHVACCfgTemplateEntry 1 }
bldgHVACCfgTemplateDesiredTemp OBJECT-TYPE
SYNTAX Gauge32
UNITS "degrees in celsius"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This is the desired temperature setting. It might be
changed at different times of the day or based on
seasonal conditions. It is permitted to change this value
by first moving the row to an inactive state, making the
change and then reactivating the row."
::= { bldgHVACCfgTemplateEntry 2 }
bldgHVACCfgTemplateCoolOrHeat OBJECT-TYPE
SYNTAX BldgHvacOperation
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This controls the heating and cooling mechanism and is
set-able by building maintenance. It is permitted to
change this value by first moving the row to an inactive
state, making the change and then reactivating the row."
::= { bldgHVACCfgTemplateEntry 3 }
bldgHVACCfgTemplateInfo OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This object points to a row in the
bldgHVACCfgTemplateInfoTable. This controls the
heating and cooling mechanism and is set-able by
building maintenance. It is permissible to change
this value by first moving the row to an inactive
state, making the change and then reactivating
the row. A value of zero means that this entry
is not associated with a named template found
in the bldgHVACCfgTemplateInfoTable."
::= { bldgHVACCfgTemplateEntry 4 }
bldgHVACCfgTemplateOwner OBJECT-TYPE
SYNTAX SnmpAdminString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The identity of the administrative entity
that created this row of the table."
::= { bldgHVACCfgTemplateEntry 5 }
bldgHVACCfgTemplateStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The persistence of this row of the table across
system resets. A columnar instance of this object with
value 'permanent' need not allow write-access to any
of the columnar object instances in the containing row."
::= { bldgHVACCfgTemplateEntry 6 }
bldgHVACCfgTemplateStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The activation status of this row of the table.
No attempt to modify a row columnar object instance value in
the bldgHVACCfgTemplateTable should be issued while the
value of bldgHVACCfgTemplateStatus is active(1).
Should an agent receive a SET PDU attempting such a modification
in this state, an inconsistentValue error should be returned as
a result of the SET attempt."
::= { bldgHVACCfgTemplateEntry 7 }
--
-- Conformance Information
--
bldgCompliances OBJECT IDENTIFIER ::= { bldgConformance 1 }
bldgGroups OBJECT IDENTIFIER ::= { bldgConformance 2 }
-- Compliance Statements
bldgCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The requirements for conformance to the BLDG-HVAC-MIB. The
bldgHVACObjects group must be implemented to conform to the
BLDG-HVAC-MIB."
MODULE -- this module
GROUP bldgHVACObjectsGroup
DESCRIPTION
"The bldgHVACObjects is mandatory for all systems that
support HVAC systems."
::= { bldgCompliances 1 }
bldgHVACObjectsGroup OBJECT-GROUP
OBJECTS {
bldgHVACCfgTemplate,
bldgHVACFanSpeed, bldgHVACCurrentTemp,
bldgHVACCoolOrHeatMins, bldgHVACDiscontinuityTime,
bldgHVACOwner, bldgHVACStatus,
bldgHVACStorageType, bldgHVACCfgTemplateInfoID,
bldgHVACCfgTemplateInfoDescr, bldgHVACCfgTemplateInfoOwner,
bldgHVACCfgTemplateInfoStatus,
bldgHVACCfgTemplateInfoStorType,
bldgHVACCfgTemplateDesiredTemp,
bldgHVACCfgTemplateCoolOrHeat,
bldgHVACCfgTemplateInfo,
bldgHVACCfgTemplateOwner,bldgHVACCfgTemplateStorage,
bldgHVACCfgTemplateStatus
}
STATUS current
DESCRIPTION
"The bldgHVACObjects Group."
::= { bldgGroups 1 }
END
8.2. Notes on MIB Module with Template-based Data
The primary purpose of the example "HVAC" MIB module is to show how
to construct a single module that includes configuration, template,
counter and state information in a single module. If this were a
'real' module we would also have included definitions for
notifications for the configuration change operations as previously
described. We also would have included notifications for faults and
other counter threshold events.
Implementation and Instance Extensions:
Just as with networking technologies, vendors may wish to add
extensions that can distinguish their products from the competition.
If an HVAC vendor also wanted to support humidity control, they could
add that facility to their equipment and use AUGMENTS for the
bldgHVACTemplateTable with two objects, one that indicates the
desired humidity and the other, the actual. The
bldgHVACTemplateTable could also be extended using this same approach
so that HVAC policies could easily be extended to support this
vendor.
8.3. Examples of Usage of the MIB
The following two examples use two templates to configure the temperature in executive offices and in conference rooms. The "conference rooms" template is applied to all conference rooms (which happen to be office 104 on each floor), and the "executive offices" template is applied to executive offices. If offices 24, 25, and 26 on the third floor are executive offices, the values in the bldgHVACTable might be: bldgHVACCfgTemplate.3.24 = 2 bldgHVACFanSpeed.3.24 = 2989 bldgHVACCurrentTemp.3.24 = 24 bldgHVACCoolOrHeatMins.3.24 = 123 bldgHVACDiscontinuityTime.3.24 = sysUpTime + 12h + 21m bldgHVACOwner.3.24 = "policy engine" bldgHVACStorageType.3.24 = nonVolatile(3) bldgHVACStatus.3.24 = active(1) bldgHVACCfgTemplate.3.25 = 2 bldgHVACFanSpeed.3.25 = 0 bldgHVACCurrentTemp.3.25 = 22 bldgHVACCoolOrHeatMins.3.25 = 298 bldgHVACDiscontinuityTime.3.25 = sysUpTime + 4h + 2m bldgHVACOwner.3.25 = "policy engine" bldgHVACStorageType.3.25 = nonVolatile(3) bldgHVACStatus.3.25 = active(1) bldgHVACCfgTemplate.3.26 = 2 bldgHVACFanSpeed.3.26 = 0 bldgHVACCurrentTemp.3.26 = 22 bldgHVACCoolOrHeatMins.3.26 = 982 bldgHVACOwner.3.26 = "policy engine" bldgHVACStorageType.3.26 = nonVolatile(3) bldgHVACStatus.3.26 = active(1) The second entry in the bldgHVACCfgTemplateTable, to which all of the above point, might have the following configuration: bldgHVACCfgTemplateDesiredTemp.2 = 22 bldgHVACCfgTemplateCoolOrHeat.2 = cool(2) bldgHVACCfgTemplateInfo.2 = 2 bldgHVACCfgTemplateOwner.2 = "Senior Executive assistant" bldgHVACCfgTemplateStorage.2 = nonVolatile(3) bldgHVACCfgTemplateStatus.2 = active(1)
and the associated template information ("executive offices") might
be:
bldgHVACCfgTemplateInfoID.2 = "executive offices"
bldgHVACCfgTemplateInfoDescr.2 = "Controls temperature for executive
offices"
bldgHVACCfgTemplateInfoOwner.2 = "Senior Executive assistant"
bldgHVACCfgTemplateInfoStorType.2 = nonVolatile(3)
bldgHVACCfgTemplateInfoStatus.2 = active(1)
The policy engine can now associate instances of executive offices
with the template called "executive offices" and apply the values in
the second entry of the bldgHVACCfgTemplateTable to each of the
instances of the executive offices. This will then attempt to set
the temperature in executive offices to 22 degrees celsius.
It is also possible that there may be an office configured for a
particular temperature, but without using a template. For example,
office 28 on the third floor might look like this:
bldgHVACCfgTemplate.3.28 = 3
bldgHVACFanSpeed.3.28 = 50
bldgHVACCurrentTemp.3.28 = 26
bldgHVACCoolOrHeatMins.3.28 = 0
bldgHVACDiscontinuityTime.3.28 = 0
bldgHVACOwner.3.28 = "Executive with poor circulation"
bldgHVACStorageType.3.28 = nonVolatile(3)
bldgHVACStatus.3.28 = active(1)
The entry in the bldgHVACCfgTemplateTable (to which
bldgHVACCfgTemplate.3.28 points) might instead look like:
bldgHVACCfgTemplateDesiredTemp.3 = 28
bldgHVACCfgTemplateCoolOrHeat.3 = cool(2)
bldgHVACCfgTemplateInfo.3 = 0.0
bldgHVACCfgTemplateOwner.3 = "Executive with poor circulation"
bldgHVACCfgTemplateStorage.3 = nonVolatile(3)
bldgHVACCfgTemplateStatus.3 = active(1)
Note that this entry does not point to a template.
If the executive's circulation improves so that the temperature
should be aligned with other executive offices, this is accomplished
by changing the value of bldgHVACCfgTemplate.3.28 from
bldgHVACCfgTemplateInfoID.3 to bldgHVACCfgTemplateInfoID.2 (shown
above).
Finally, there might be offices for which there is no configured
temperature but management applications can read the current
temperature, fan speed, and cooling or heating minutes from the
bldgHVACTable. In that case, the value of bldgHVACCfgTemplate will
be a zero index ("null"), as will the value of bldgHVACOwner.
bldgHVACCfgTemplate.4.2 = 0
bldgHVACFanSpeed.3.28 = 50
bldgHVACCurrentTemp.3.28 = 26
bldgHVACCoolOrHeatMins.3.28 = 0
bldgHVACDiscontinuityTime.3.28 = 0
bldgHVACOwner.3.28 = ""
bldgHVACStorageType.3.28 = nonVolatile(3)
bldgHVACStatus.3.28 = active(1)
As a second example, the conference rooms on several floors are
configured using the "conference rooms" template. When the values in
the bldgHVACTable pertaining to conference rooms are read, it might
look like:
bldgHVACCfgTemplate.12.104 = bldgHVACCfgTemplateDesiredTemp.1
bldgHVACFanSpeed.12.104 = 1423
bldgHVACCurrentTemp.12.104 = 21
bldgHVACCoolOrHeatMins.12.104 = 2193
bldgHVACDiscontinuityTime.12.104 = sysUpTime + 36h + 15m
bldgHVACOwner.12.104 = = "Bob the Conference Guy"
bldgHVACStorageType.12.104 = nonVolatile(3)
bldgHVACStatus.12.104 = active(1)
bldgHVACCfgTemplate.14.104 = bldgHVACCfgTemplateDesiredTemp.1
bldgHVACFanSpeed.14.104 = 1203
bldgHVACCurrentTemp.14.104 = 20
bldgHVACCoolOrHeatMins.14.104 = 293
bldgHVACDiscontinuityTime.14.104 = sysUpTime + 5h + 54m
bldgHVACOwner.14.104 = = "Bob the Conference Guy"
bldgHVACStorageType.14.104 = nonVolatile(3)
bldgHVACStatus.14.104 = active(1)
bldgHVACCfgTemplate.15.104 = bldgHVACCfgTemplateDesiredTemp.1
bldgHVACFanSpeed.15.104 = 12
bldgHVACCurrentTemp.15.104 = 19
bldgHVACCoolOrHeatMins.15.104 = 1123
bldgHVACDiscontinuityTime.15.103 = sysUpTime + 2d + 2h + 7m
bldgHVACOwner.15.104 = = "Bob the Conference Guy"
bldgHVACStorageType.15.104 = nonVolatile(3)
bldgHVACStatus.15.104 = active(1)
The desired temperature and whether to heat or cool is configured in the first entry of the bldgHVACCfgTemplateTable, which tries to set the temperature to 19 degrees celsius in conference rooms: bldgHVACCfgTemplateDesiredTemp.1 = 19 bldgHVACCfgTemplateCoolOrHeat.1 = cool(2) bldgHVACCfgTemplateInfo.1 = bldgHVACCfgTemplateInfoID.1 bldgHVACCfgTemplateOwner.1 = "Bob the Conference Guy" bldgHVACCfgTemplateStorage.1 = nonVolatile(3) bldgHVACCfgTemplateStatus.1 = active(1) The associated template information would then have: bldgHVACCfgTemplateInfoID.1 = "conference rooms" bldgHVACCfgTemplateInfoDescr.1 = "Controls temperature in conference rooms" bldgHVACCfgTemplateInfoOwner.1 = "Bob the Conference Guy" bldgHVACCfgTemplateInfoStorType.1 = nonVolatile(3) bldgHVACCfgTemplateInfoStatus.1 = active(1) The policy system can then apply this template (cool to 19 degrees Celsius) to its notion of all of the conference rooms in the building.9. Security Considerations
This document discusses practices and methods for using the SNMP for management and distribution of configuration information for network elements. Any effective use of the SNMP in this application must concern itself with issues of authentication of the management entities initiating configuration change and management, in addition to the integrity of the configuration data itself. Other more subtle considerations also exist. To that end, the section of this document entitled "Deployment and Security Issues" covers these security considerations to the extent they affect the current practices described throughout this document. In particular, in the subsection entitled "Secure Agent Considerations", there is a recommendation for the usage of Version 3 of the SNMP, and its essential presumption as a foundation for other practices described throughout. With the exception of a small number of cases where a mention is made to the contrary to illustrate techniques for coexistence with application entities dependent upon earlier versions of the SNMP, that recommendation of usage of Version 3 of the SNMP is reiterated here.
10. Acknowledgments
This document was produced by the SNMPCONF Working Group. In particular, the editors wish to thank: Christopher Anderson Andy Bierman Greg Bruell Dr Jeffrey Case Chris Elliott Joel Halpern Pablo Halpern Wes Hardaker David Harrington Harrie Hazewinkel Thippanna Hongal Bob Moore David T. Perkins Randy Presuhn Dan Romascanu Shawn Routhier Steve Waldbusser Bert Wijnen11. Normative References
[1] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for Describing Simple Network Management Protocol (SNMP) Management Frameworks", STD 62, RFC 3411, December 2002. [2] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Structure of Management Information Version 2 (SMIv2)", STD 58, RFC 2578, April 1999. [3] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Textual Conventions for SMIv2", STD 58, RFC 2579, April 1999. [4] McCloghrie, K., Perkins, D. and J. Schoenwaelder, "Conformance Statements for SMIv2", STD 58, RFC 2580, April 1999. [5] Presuhn, R. (Ed.), "Transport Mappings for the Simple Network Management Protocol (SNMPv2)", STD 62, RFC 3417, December 2002. [6] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message Processing and Dispatching for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3412, December 2002.
[7] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM) for version 3 of the Simple Network Management Protocol (SNMPv3)", STD 62, RFC 3414, December 2002. [8] Presuhn, R. (Ed.), "Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3416, December 2002. [9] Levi, D., Meyer, P., and B. Stewart, "Simple Network Management Protocol Applications", STD 62, RFC 3413, December 2002. [10] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access Control Model (VACM) for the Simple Network Management Protocol (SNMP)", STD 62, RFC 3415, December 2002. [11] Presuhn, R. (Ed.), "Management Information Base for the Simple Network Management Protocol (SNMPv2)", STD 62, RFC 3418, December 2002. [12] Case, J., Mundy, R., Partain, D. and B. Stewart, "Introduction and Applicability Statements for Internet-Standard Management Framework", RFC 3410, December 2002. [13] Daniele, M., Haberman, B., Routhier, S. and J. Schoenwaelder, "Textual Conventions for Internet Network Addresses", RFC 3291, May 2002. [14] McCloghrie, K. (Ed.), "SNMPv2 Management Information Base for the Internet Protocol using SMIv2", RFC 2011, November 1996.12. Informative References
[15] Rose, M. and K. McCloghrie, "Structure and Identification of Management Information for TCP/IP-based Internets", STD 16, RFC 1155, May 1990. [16] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16, RFC 1212, March 1991. [17] Rose, M., "A Convention for Defining Traps for use with the SNMP", RFC 1215, March 1991. [18] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple Network Management Protocol", STD 15, RFC 1157, May 1990. [19] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901, January 1996.
[20] McCloghrie, K. and F. Kastenholz, "The Interfaces Group MIB", RFC 2863, June 2000. [21] Brown, C. and F. Baker, "Management Information Base for Frame Relay DTEs Using SMIv2", RFC 2115, September 1997. [22] Baker, F. (Ed.), "Requirements for IP Version 4 Routers", RFC 1812, June 1995. [23] Hawkinson, J. and T. Bates, "Guidelines for Creation, Selection, and Registration of an Autonomous System (AS)", BCP 6, RFC 1930, March 1996. [24] Decker, E., Langille, P., Rijsinghani, A. and K. McCloghrie, "Definitions of Managed Objects for Bridges", RFC 1493, July 1993. [25] Levi, D. and J. Schoenwaelder "Definitions of Managed Objects for Scheduling Management Operations", RFC 3231, January 2002. [26] Bell, E., Smith, A., Langille, P., Rijsinghani, A. and K. McCloghrie, "Definitions of Managed Objects for Bridges with Traffic Classes, Multicast Filtering and Virtual LAN Extensions", RFC 2674, August 1999. [27] Baker, F., "IP Forwarding Table MIB", RFC 2096, January 1997. [28] St. Johns, M. (Ed.), "Radio Frequency (RF) Interface Management Information Base for MCNS/DOCSIS compliant RF interfaces", RFC 2670, August 1999. [29] Baker, F. and R. Coltun, "OSPF Version 2 Management Information Base", RFC 1850, November 1995. [30] Blake, S., Black, D., Carlson M., Davies, E., Wang, Z. and W. Weiss, "An Architecture for Differentiated Services ", RFC 2475, December 1998. [31] Willis, S., Burruss, J. and J. Chu (Ed.), "Definitions of Managed Objects for the Fourth Version of the Border Gateway Protocol (BGP-4) using SMIv2", RFC 1657, July 1994. [32] Waldbusser, S., "Remote Network Monitoring Management Information Base", RFC 2819, May 2000. [33] McCloghrie, K. and G. Hanson, "The Inverted Stack Table Extension to the Interfaces Group MIB", RFC 2864, June 2000.
[34] McCloghrie, K. and A. Bierman, "Entity MIB (Version 2)", RFC 2737, December 1999. [35] ITU-T,, Recommendation M.3010., PRINCIPLES FOR A TELECOMMUNICATIONS MANAGEMENT NETWORK. February, 2000. [36] Waldbusser, S., Saperia, J., and Hongal, T., "Policy Based Management MIB", Work-in-progress. [37] Heintz, L., "SNMP Row Operations Extensions", Work-in-progress. [38] Zeltserman, D., "A Practical Guide to Snmpv3 and Network Management", Prentice Hall, 1999. [39] Noto, M., Spiegel, E. and K. Tesink, "Definitions of Textual Conventions and OBJECT-IDENTITIES for ATM Management", RFC 2514, February 1999. [40] Kassaveri, R., Editor, "Distributed Management Expression MIB", RFC 2982, October 2000. [41] St. Johns, M., "DOCSIS Cable Device MIB Cable Device Management Information Base for DOCSIS compliant Cable Modems and Cable Modem Termination Systems", RFC 2669, August 1999. [42] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J. and S. Waldbusser, "Terminology for Policy-Based Management", RFC 3198, November 2001. [43] http://wwww.cisco.com/univercd/cc/td/product/software/ios113ed/ 11ed_cr/secur_c/scprt/scacls.pdf. [44] Waldbusser, S., "Remote Network Monitoring Management Information Base Version 2 using SMIv2", RFC 2021, January 1997.13. Intellectual Property
The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to
obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. The IETF invites any interested party to bring to its attention any copyrights, patents or patent applications, or other proprietary rights which may cover technology that may be required to practice this standard. Please address the information to the IETF Executive Director.14. Editors' Addresses
Michael R. MacFaden Riverstone Networks, Inc 5200 Great America Parkway Santa Clara, CA 95054 EMail: mrm@riverstonenet.com David Partain Ericsson AB P.O. Box 1248 SE-581 12 Linkoping Sweden EMail: David.Partain@ericsson.com Jon Saperia JDS Consulting 174 Chapman Street Watertown, MA 02472 EMail: saperia@jdscons.com Wayne F. Tackabury Gold Wire Technology 411 Waverley Oaks Rd. Waltham, MA 02452 EMail: wayne@goldwiretech.com
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