Bellcore Threshold Crossing Alert Objects December 1993
Definitions of Managed Objects
for Threshold Crossing Alerts
SNMPv2 MIB
bellcore-tcav2.txt
(See bellcore-tcav1.mib for SNMPv1 MIB)
December 1993
Version 1.0
Tracy A. Brown (editor)
Bell Communications Research
331 Newman Springs Road
Red Bank, NJ 07701
tacox@mail.bellcore.com
1. Status of this Memo
This document is a private extension to the SNMP MIB.
Distribution of this memo is unlimited. Please send comments
to the editor.
2. Abstract
This memo defines a private portion of the Management
Information Base (MIB) for use with network management
protocols in TCP/IP-based internets. In particular, it
defines objects for managing Threshold Crossing Alert
information for managed interfaces. An interface can for
example be an SMDS Subscriber-Network Interface or Inter-
Carrier Interface (SNI/ICI), Frame Relay User-Network
Interface or Inter-Carrier Interface (UNI/ICI), or ATM-based
CRS User-Network Interface or Inter-Carrier Interface
(UNI/ICI).
This memo does not specify a standard for the Internet
community.
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3. The Network Management Framework
The SNMPv2 Network Management Framework consists of four major
components. They are:
o RFC 1442 which defines the SMI, the mechanisms used for
describing and naming objects for the purpose of
management.
o RFC 1213 defines MIB-II, the core set of managed objects
for the Internet suite of protocols.
o RFC 1445 which defines the administrative and other
architectural aspects of the framework.
o RFC 1448 which defines the protocol used for network
access to managed objects.
The Framework permits new objects to be defined for the
purpose of experimentation and evaluation.
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4. Object Definitions
Managed objects are accessed via a virtual information store,
termed the Management Information Base or MIB. Objects in the
MIB are defined using the subset of Abstract Syntax Notation
One (ASN.1) defined in the SMI. In particular, each object
object type is named by an OBJECT IDENTIFIER, an
administratively assigned name. The object type together with
an object instance serves to uniquely identify a specific
instantiation of the object. For human convenience, we often
use a textual string, termed the descriptor, to refer to the
object type.
5. Overview
These objects are used in the context of a SNMP-based Customer
Network Management (CNM) service and Exchange Access
Operations Management (XA-OM) that can be provided by networks
supporting SMDS, Frame Relay Service, and Cell Relay Service.
See references [5] - [8].
This MIB provides Threshold Crossing Alert (TCA) information
to a CNM or XA-OM subscriber. A Threshold Crossing Alert is a
message that is sent from a switching system to an OS (e.g.,
SNMP agent) whenever a counter value crosses a predefined
threshold. The switching system collects information over a
15-minute interval, and the threshold value is an absolute
value for the counter over that 15-minute interval.
Therefore, each counter value can only cross a threshold once
over a 15-minute period. This MIB represents what TCAs have
been received for each interface sublayer. An interface
sublayer can be the protocol sublayers of an SMDS Subscriber-
Network Interface or Inter-Carrier Interface (SNI/ICI), Frame
Relay User-Network Interface or Inter-Carrier Interface
(UNI/ICI), or ATM-based CRS User-Network Interface or Inter-
Carrier Interface (UNI/ICI). See References [5] - [8] for the
definitions of the protocol sublayers for each service
interface. Capturing TCA information in this MIB is
necessary, because many Fast Packet Switching Systems are not
capable of meeting the data currency objective of 180 seconds
as described in the Bellcore Technical Advisories/References.
However, the Switching Systems are capable of alerting the
SNMP agent when a counter value exceeds a predefined threshold
via the TCA mechanism. These TCAs can be translated into SNMP
objects that can be provided to the CNM or XA-OM subscriber.
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Therefore, even though CNM or XA-OM subscribers do not have
access to current counter values, they will have access to
information regarding what counters have crossed a threshold
within a 15-minute interval. Therefore, threshold crossing
information provides these subscribers with a timely fault
detection/isolation capability. A CNM subscriber may use this
information for multiple network management functions and
capabilities.
There are two mechanisms in which a CNM and XA-OM subscriber
receives TCA information. One mechanism is by polling the
objects defined in this TCA MIB (primarily the tcaCounts
object), and the other is by being asynchronously alerted of a
TCA via an SNMP trap message called the fyiTrap. See Reference
[10] for a description of the fyiTrap. However, to control
the potential flood of traps being sent to a CNM and XA-OM
subscriber, some TCA information may not cause a trap to be
automatically generated. See the tcaTrapEnabler object. This
object is read-write. However, initially the object has a
minimum access of read-only. It is envisioned that in the
future, the CNM and XA-OM subscriber may change the value of
the tcaTrapEnabler, thus requesting what TCAs should generate
traps.
The counters being thresholded are defined in the following
Bellcore documents:
-- TR-TSV-001062, SMDS CNM Service
-- TA-NWT-001371, Frame Relay PVC CNM Service
-- TA-NWT-001117, CNM Service for Exchange PVC Cell Relay Service
-- TA-TSV-001237, SMDS XA-OM Service
-- TA-NWT-001430, Frame Relay PVC XA-OM Service
Each document will also specify a default value for the
tcaTrapEnabler object for each counter.
When the service is defined, this MIB may also be used for
XA-OM service for Exchange Access PVC Cell Relay Service.
To obtain Bellcore documents, contact:
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Bellcore Threshold Crossing Alert Objects December 1993
Bellcore
Customer Service
8 Corporate Place - Rm. 3C-183
Piscataway, NJ 08854-4156
1 (800) 521-CORE
(908) 699-5800 (For Foreign Calls)
See bellcore-tcav1.mib for the SNMPv1 equivalent of this
SNMPv2 MIB.
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6. Object Definitions
TCAv2-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE,
Counter32, Integer32,
enterprises FROM SNMPv2-SMI
DisplayString, TimeStamp FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF;
bellcore OBJECT IDENTIFIER ::= { enterprises 148 }
requirements OBJECT IDENTIFIER ::= { bellcore 1 }
tcaMIB MODULE-IDENTITY
LAST-UPDATED "9312101200Z"
ORGANIZATION "Bellcore"
CONTACT-INFO
" Tracy A. Brown
Bellcore
331 Newman Springs Rd.
Red Bank, NJ 07701 USA
Tel: 1-908-758-2107
Fax: 1-908-758-4177
E-mail: tacox@mail.bellcore.com."
DESCRIPTION
"The MIB module to describe generic objects for
Threshold Crossing Alerts (TCAs) for CNM
and XA-OM for
SMDS, Frame Relay Service,
and Cell Relay Service."
::= { requirements 5 }
tcaObjects OBJECT IDENTIFIER ::= { tcaMIB 1 }
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-- The Threshold Crossing Alert Group
tcaTable OBJECT-TYPE
SYNTAX SEQUENCE OF TcaEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The Threshold Crossing Alert table."
::= { tcaObjects 1 }
tcaEntry OBJECT-TYPE
SYNTAX TcaEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the Threshold Crossing Alert table."
INDEX { tcaIfIndex, tcaIndex }
::= { tcaTable 1 }
TcaEntry ::=
SEQUENCE {
tcaIfIndex
Integer32,
tcaIndex
Integer32,
tcaObject
OBJECT IDENTIFIER,
tcaObjectDesc
DisplayString,
tcaThreshold
Integer32,
tcaSampleType
INTEGER,
tcaCounts
Counter32,
tcaTimeStamp
TimeStamp,
tcaTrapEnabler
INTEGER
}
tcaIfIndex OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS not-accessible
STATUS current
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DESCRIPTION
"The value of this object is equal to MIB II's
ifIndex value for this interface sublayer
(ifEntry)."
::= { tcaEntry 1 }
tcaIndex OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The value of this object is used as one of the
indices for this table. It is a unique identifier
for this row in the table for this interface
(ifIndex). The value of this object can be from 1
to N, where N is the number of potential TCAs for
this interface sublayer (ifEntry)."
::= { tcaEntry 2 }
tcaObject OBJECT-TYPE
SYNTAX OBJECT IDENTIFIER
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object is the OBJECT IDENTIFIER
of the counter object being thresholded. The
counter objects being thresholded are defined in
other MIB Modules."
::= { tcaEntry 3 }
tcaObjectDesc OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object is a description of the
counter object being thresholded. For example,
DS1 Coding Violations."
::= { tcaEntry 4 }
tcaThreshold OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
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"The value of this object is the threshold value
of the counter object being thresholded."
::= { tcaEntry 5 }
tcaSampleType OBJECT-TYPE
SYNTAX INTEGER {
intervalAbsoluteValue(1),
intervalDeltaValue(2)
}
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object is the sample type of
the counter object being thresholded from the
perspective of the CNM or XA-OM customer. All
counters are thresholded over a 15-minute
interval. However, over this 15-minute interval
the threshold value may be an absolute value
(e.g., used for interval counters) or a delta
value (e.g., used for continuous counters). The
intervals are measured locally at the agent, and
are not visible to the manager. At the agent's
local interval boundary, all threshold crossing
measurements are reset to zero. (A counter value
may cross the predefined threshold and a TCA is
sent only once within a 15-minute interval.)"
::= { tcaEntry 6 }
tcaCounts OBJECT-TYPE
SYNTAX Counter32
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object is the number of times
the threshold was crossed for this counter object,
since sysUpTime was initialized or restarted.
This counter is a continuous counter. It should
be noted that as this object has a SYNTAX of
Counter, that it does not have a defined initial
value. However, it is recommended that this
object be initialized to zero."
::= { tcaEntry 7 }
tcaTimeStamp OBJECT-TYPE
SYNTAX TimeStamp
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MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The value of this object is equal to the value of
MIB-II's sysUpTime object at which last (latest)
threshold was crossed for this counter object.
The value of this object is set to zero at
(re)initialization."
::= { tcaEntry 8 }
tcaTrapEnabler OBJECT-TYPE
SYNTAX INTEGER {
enabled(1),
disabled(2)
}
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Indicates whether fyiTraps should be generated
for this threshold crossing count (tcaObject).
The physical layer counters' and gauges' (e.g.,
DS1, DS3, SONET, and PLCP) TCAs should have a
default value of disabled(2). The SMDS service
violations and higher layer protocol violations
counters' TCAs should have a default value of
enabled(1). A fyiTrap, when generated, shall have
the following varBind list: tcaObject,
tcaObjectDesc, tcaThreshold, and tcaTimeStamp."
::= { tcaEntry 9 }
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-- Conformance Information
tcaConformance OBJECT IDENTIFIER ::= { tcaMIB 2 }
tcaGroups OBJECT IDENTIFIER ::= { tcaConformance 1 }
tcaCompliances OBJECT IDENTIFIER ::= { tcaConformance 2 }
-- Compliance Statements
tcaCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for SNMPv2 entities
which support Threshold Crossing Alert Information.
This MIB module will be used primarily for SMDS,
Frame Relay Service, and Cell Relay CNM and XA-OM Services."
MODULE -- this module
MANDATORY-GROUPS { tcaGroup }
OBJECT tcaTrapEnabler
MIN-ACCESS read-only
DESCRIPTION
"Write access is not required."
::= { tcaCompliances 1 }
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-- Units of Conformance
tcaGroup OBJECT-GROUP
OBJECTS { tcaObject, tcaObjectDesc,
tcaThreshold, tcaSampleType, tcaCounts,
tcaTimeStamp, tcaTrapEnabler }
STATUS current
DESCRIPTION
"A collection of objects providing information
applicable
to Threshold Crossing Alert Information."
::= { tcaGroups 1 }
END
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7. Acknowledgments
This document was produced by the Bellcore CNM/XA-OM Team:
Masuma Ahmed, Ted Brunner, Tracy Brown, Chuck Davin, Taso
Devetzis, Thom Farese, Shannon Hansen, Alan Hermelee, Sherri
Hiller, Deirdre Kostick, Dave Piscitello, Rich Reimer, Cathy
So, and Kaj Tesink.
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8. References
[1] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
"Structure of Management Information for version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1442, SNMP
Research, Inc., Hughes LAN Systems, Dover Beach Consulting,
Inc., Carnegie Mellon University, April 1993.
[2] Galvin, J., and K. McCloghrie, "Administrative Model for
version 2 of the Simple Network Management Protocol
(SNMPv2)", RFC 1445, Trusted Information Systems, Hughes LAN
Systems, April 1993.
[3] Case, J., McCloghrie, K., Rose, M., and S. Waldbusser,
"Protocol Operations for version 2 of the Simple Network
Management Protocol (SNMPv2)", RFC 1448, SNMP Research, Inc.,
Hughes LAN Systems, Dover Beach Consulting, Inc., Carnegie
Mellon University, April 1993.
[4] McCloghrie, K., and M. Rose, "Management Information Base for
Network Management of TCP/IP-based internets - MIB-II", RFC
1213, Hughes LAN Systems, Performance Systems International,
March 1991.
[5] Generic Requirements For Phase 1
SMDS Customer Network Management Service,
Bellcore TR-TSV-001062, Issue 1, March 1993, and Supplement 1,
December 1993.
[6] Generic Requirements for Phase 1 Frame Relay PVC
Customer Network Management Service, Bellcore TA-NWT-001371,
Issue 1, September 1993.
[7] Generic Requirements for Exchange PVC CRS Customer Network
Management Service, Bellcore
TA-NWT-001117, Issue 1, September 1993.
[8] SMDS Generic Requirements for Initial
Operations Management Capabilities in Support of
Exchange Access and Intercompany Service Arrangements,
Bellcore TA-TSV-001237, Issue 1, June 1993.
[8] Generic Requirements for Initial Frame Relay PVC
Exchange Access Operations Management
(XA-OM) Service, Bellcore TA-NWT-001430, Issue 1,
to be published.
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[10] Definition of the Enterprise-specific fyiTrap (SNMPv1), Kaj Tesink (editor),
Bellcore Enterprise-specific MIB (posted on venera.isi.edu as
bellcore-fyitrapv1.txt),
Version 1.0, December 1993.
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Table of Contents
1 Status of this Memo ................................... 1
2 Abstract .............................................. 1
3 The Network Management Framework ...................... 2
4 Object Definitions .................................... 3
5 Overview .............................................. 3
6 Object Definitions .................................... 6
6.1 The Threshold Crossing Alert Group Group ............ 7
6.2 Conformance Information ............................. 11
7 Acknowledgments ....................................... 13
8 References ............................................ 14
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