Network Working Group K. McCloghrie

Network Working Group K. McCloghrie
Request for Comments: 2513 Cisco Systems, Inc.
Category: Standards Track J. Heinanen
Telia Finland, Inc.
W. Greene
MCI Telecommunications Corp.
A. Prasad
Cisco Systems, Inc.
February 1999

Managed Objects for Controlling the Collection
and Storage of Accounting Information for
Connection-Oriented Networks

Status of this Memo

This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (1999). All Rights Reserved.

Table of Contents

1 Introduction .................................................... 2
2 The SNMP Network Management Framework ........................... 2
3 Overview ........................................................ 3
3.1 Operational Model ............................................. 3
3.2 Selection of Accounting Data .................................. 5
3.3 Format of Collection File ..................................... 6
4 Definitions ..................................................... 9
5 Acknowledgements ................................................25
6 References ......................................................25
7 Security Considerations .........................................27
8 IANA Considerations .............................................27
9 Authors' Addresses ..............................................28
10 Full Copyright Statement .......................................29

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RFC 2513 Connection-Oriented Accounting MIB February 1999

1. Introduction

This memo defines a portion of the Management Information Base (MIB)
for use with network management protocols in the Internet community.
In particular, it describes managed objects used for controlling the
collection and storage of accounting information for connection-
oriented networks such as ATM. The accounting data is collected into
files for later retrieval via a file transfer protocol. For
information on data which can be collected for ATM networks, see
[19].

2. The SNMP Network Management Framework

The SNMP Management Framework presently consists of five major
components:

o An overall architecture, described in RFC 2271 [1].

o Mechanisms for describing and naming objects and events for the
purpose of management. The first version of this Structure of
Management Information (SMI) is called SMIv1 and described in
STD 16, RFC 1155 [2], STD 16, RFC 1212 [3] and RFC 1215 [4].
The second version, called SMIv2, is described in RFC 1902 [5],
RFC 1903 [6] and RFC 1904 [7].

o Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
described in STD 15, RFC 1157 [8]. A second version of the SNMP
message protocol, which is not an Internet standards track
protocol, is called SNMPv2c and described in RFC 1901 [9] and
RFC 1906 [10]. The third version of the message protocol is
called SNMPv3 and described in RFC 1906 [10], RFC 2272 [11] and
RFC 2274 [12].

o Protocol operations for accessing management information. The
first set of protocol operations and associated PDU formats is
described in STD 15, RFC 1157 [8]. A second set of protocol
operations and associated PDU formats is described in RFC 1905
[13].

o A set of fundamental applications described in RFC 2273 [14] and
the view-based access control mechanism described in RFC 2275
[15].

Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. Objects in the MIB are
defined using the mechanisms defined in the SMI.

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This memo specifies a MIB module that is compliant to the SMIv2. A
MIB conforming to the SMIv1 can be produced through the appropriate
translations. The resulting translated MIB must be semantically
equivalent, except where objects or events are omitted because no
translation is possible (e.g., use of Counter64). Some machine
readable information in SMIv2 will be converted into textual
descriptions in SMIv1 during the translation process. However, this
loss of machine readable information is not considered to change the
semantics of the MIB.

3. Overview

In some connection-oriented network environments, there is a need for
the network administrator to be able to collect accounting data on
the usage of bandwidth/resources by connections (e.g., ATM
connections) within the network. Data collection should be available
for switched virtual connections (SVCs and SVPs), and permanent
virtual connections (PVCs and PVPs), including soft-permanent virtual
connections (SPVCCs and SPVPCs). This need exists for ATM networks,
and may well exist for other connection-oriented networks, such as
Frame Relay.

The potential quantity of such accounting information is such that it
is not, in general, feasible to retrieve the information via SNMP. A
better method is to store the collected accounting information in a
file which can be subsequently retrieved via a file transfer
protocol.

It is, however, appropriate to provide management control of the
selection and collection of such accounting data via SNMP. This memo
describes a MIB module which provides such control in a manner
independent of the type of network. One or more other documents
provide definitions of particular items of accounting data which can
be selected; for example, a particular set of data items which can be
collected for ATM networks is specified in [19].

3.1. Operational Model

The requirement is for switches (e.g., ATM switches) to collect data
concerning the connections which are routed across some subset of
their interfaces (e.g., ATM UNI and/or NNI interfaces). The
collected data is stored into one or more "files". The use of
multiple files allows, for example, the data collected for PVCs to be
different from that collected for SVCs.

In order to retrieve the data currently being stored in a file, the
administrator instructs the switch to terminate the collection of
data into that file, and start collecting data into a new file.

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After this operation, the data in the old file is available for
retrieval via file transfer.

A collection file is defined to have a maximum size. When the size
of the file currently being collected exceeds a threshold percentage
of that maximum size, an SNMP notification (e.g., a trap) can be
optionally generated. An SNMP notification might also be generated
if the file reaches its maximum size.

The accounting data collected for each connection consists of a set
of objects and their values. The set of objects and their values are
collected on one or more of the following occasions:

(1) on the release (termination) of a connection optionally
including failed connection attempts;

(2) for each active connection (having a particular minimum age) on
a periodic basis;

(3) for each active connection (having a particular minimum age)
when so commanded by a management application.

While collecting data to be stored in a particular file, the same set
of objects is collected for each connection on each occasion. Having
the same set of objects stored on each occasion allows the
optimization of storing only the values of those objects. This
results in a significantly smaller file size, since it allows the
names of the objects to be stored once and only once at the beginning
of the file, rather than having to store every value as a (name,
value) pair.

Two modes of agent behaviour are allowed on the event of a file
reaching its maximum size:

(1) management application in control:

The agent does not automatically swap to a new file; rather, it
discards newly collected data until the management application
subsequently instructs it to swap to a new file. Before
swapping to a new file, the name of the file into which data is
currently being collected is an implementation issue of no
concern to an NM application; after swapping to a new file, the
name of the file available for retrieval is as specified by the
controlling MIB objects. This behaviour allows the application
to know exactly how many files need to be retrieved and their
names without having to perform any type of file directory
operation, but also results in the possibility that data will be
discarded if the application does not instruct the agent to swap

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within the required time frame.

(2) agent automatically swaps to new file:

The agent terminates collection into the current (full) file,
and begins collecting data into a new version of the same base
file name. This behaviour aims to avoid loss of data by
assuming that additional storage space is actually available to
create a new version of the file. To support this behaviour,
files are named using suffixes, such that when the current
version of the file becomes full, the agent begins collecting
data into a file with the same base file-name but with an
incremented (or otherwise modified) suffix. This requires the
application to perform file directory operations prior to
retrieving completed files in order to know how many and which
suffixes have been used.

With either behaviour, any completed file must be an integral number
of connection records (see below). When a file reaches its maximum
size, collection into that file is terminated either immediately
before or immediately after storing the whole of the current
connection record into the file. The former causes the file to be
just less than its maximum size, and the latter causes the file to be
just greater than its maximum size.

3.2. Selection of Accounting Data

The items of accounting data to be collected are specified as a set
of objects. Which objects are contained in such a set is selectable
by an administrator through the specification of one or more
(subtree, list) tuples, where the set of objects to be collected is
the union of the subsets specified by each tuple:

'subtree' specifies an OBJECT IDENTIFIER value such that every
object in the subset is named by the subtree's value appended
with a single additional sub-identifier.

'list' specifies an OCTET STRING value, such that if the N-th bit
of the string's value is set then the the subset contains the
object named by appending N as a single additional sub-
identifier to the subtree.

The rationale for defining each subset as a (subtree,list) tuple is
that one and only one OBJECT IDENTIFIER and one OCTET STRING is
needed to define the subset of objects. This simplifies the MIB
mechanisms needed for selection: an NM application needs to create
only one conceptual row in a MIB table for each subset (rather than
needing to create a conceptual row in a table for each and every

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object in the set).

The number of tuples supported by a particular switch is an
implementation choice. One possibility is to support two (subtree,
list) tuples so that one such tuple can specify a standard 'subtree'
(e.g., the atmAcctngDataObjects subtree defined in [19]), and the
second tuple can specify an enterprise-specific 'subtree'; this would
allow the selected set of objects to be the union of a set of
standard objects and a set of enterprise-defined objects.

3.3. Format of Collection File

A collection file generated by this process contains the values of
MIB objects defined using the SMIv2. The standard way to encode the
values of SNMP MIB objects in a device-independent manner is through
the use of ASN.1's Basic Encoding Rules (BER) [18]. Thus, the
standard format of an accounting file is defined here using the same
adapted subset of ASN.1 [17] as the SMIv2.

The file consists of a set of header information followed by a
sequence of zero or more collection records. The header information
identifies (via sysName [16]) the switch which collected the data,
the date and time at which the collection in to this file started,
and the sequence of one or more (subtree, list) tuples identifying
the objects whose values are contained in each connection record.
The header information also includes a textual description of the
data contained in the file.

Each connection record contains a sequence of values for each
identified tuple, in the same order as the tuples are identified in
the header information. For each tuple, the sequence of values are
in ascending order of the sub-identifier which identifies them within
the subtree.

Formally, an accounting file is an ASN.1 value with the following
syntax:

File ::=
[1]
IMPLICIT SEQUENCE {
-- header information
sysName -- name of the switch
DisplayString,

description -- textual description of the collection
DisplayString,

startTime -- start time of the collection

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DateAndTime,

SEQUENCE OF { -- sequence of (subtree, list) tuples
SEQUENCE {
subtree
OBJECT IDENTIFIER,
list
OCTET STRING
}
}
-- sequence of connection records
SEQUENCE OF {
-- each record containing a sequence
SEQUENCE OF { -- per identified tuple

SEQUENCE OF { -- each per-tuple sequence containing
value -- a sequence of object values
ObjectSyntax
}
}
}
}

where:

(1) the value of the sysName component is that of the sysName object
in the System group [16].

(2) each (subtree, list) specifies the set of objects contained in
that tuple's sequence within each and every connection record.

(3) the tuples' sequences within each connection record occur in the
same order as the (subtree, list) tuples occur in the header
information.

(4) the object values within each connection record occur in the
same order as they are represented by the bits in the
corresponding list value.

(5) ObjectSyntax is defined by the SMIv2 [5].

(6) One particular category of object values deserves special
attention: an object defined to hold the checksum value of an
accounting record (e.g., atmAcctngRecordCrc16, defined in [19]).
An object in this category will generally have a SYNTAX of a
fixed-length OCTET STRING, and have its value initialized to the
string of all zeros when composing the accounting record
containing it, with the location of these zeros being saved.

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Once the record is generated, the checksum is calculated over
the whole connection record (including the starting SEQUENCE OF
and the trailing end-of-contents octets, if used), and then the
zeros are overwritten (at the saved location) by the calculated
value of the checksum.

The encoding of the above syntax using the Basic Encoding Rules is
the same as defined by the SNMPv2 [10], with the following exception:

- when encoding the length field for a structured type, i.e., a
SEQUENCE or SEQUENCE OF, the indefinite form encoding is
permitted.

For example, the file containing the data:

[1] IMPLICIT SEQUENCE a1 80
OCTET STRING 04 09 73 77 69 74 63 68 2d 31 32
OCTET STRING 04 0a 41 63 63 6f 75 6e 74 69 6e 67
OCTET STRING 04 08 07 cc 07 14 10 05 00 00
SEQUENCE OF 30 0e
SEQUENCE 30 0c
OBJECT IDENTIFIER 06 07 2b 06 01 03 7f 01 01
OCTET STRING 04 01 c0
SEQUENCE OF 30 80
SEQUENCE OF 30 08
SEQUENCE OF 30 06
INTEGER 02 01 00
INTEGER 02 01 21
SEQUENCE OF 30 08
SEQUENCE OF 30 06
INTEGER 02 01 00
INTEGER 02 01 22
end-of-contents 00 00
end-of-contents 00 00

contains two connection records, each containing one tuple listing
two (integer) data items in a (fictitious) subtree:
1.3.6.1.3.127.1.1. Its header indicates it's for "switch-12", with
description "Accounting", and was collected at 16:05:00 on 20 July
1996.

As well as the standard format defined above, the MIB allows other
enterprise-specific formats to be used.

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4. Definitions

ACCOUNTING-CONTROL-MIB DEFINITIONS ::= BEGIN

IMPORTS
MODULE-IDENTITY, OBJECT-TYPE, NOTIFICATION-TYPE,
mib-2, Integer32 FROM SNMPv2-SMI
TEXTUAL-CONVENTION, RowStatus, TestAndIncr,
DisplayString, TruthValue FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP, NOTIFICATION-GROUP
FROM SNMPv2-CONF
ifIndex FROM IF-MIB;

accountingControlMIB MODULE-IDENTITY
LAST-UPDATED "9809281000Z"
ORGANIZATION "IETF AToM MIB Working Group"
CONTACT-INFO "Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Drive,
San Jose CA 95134-1706.
Phone: +1 408 526 5260
Email: [email protected]"
DESCRIPTION
"The MIB module for managing the collection and storage of
accounting information for connections in a connection-
oriented network such as ATM."
::= { mib-2 60 }

acctngMIBObjects OBJECT IDENTIFIER ::= { accountingControlMIB 1 }

acctngSelectionControl OBJECT IDENTIFIER ::= { acctngMIBObjects 1 }
acctngFileControl OBJECT IDENTIFIER ::= { acctngMIBObjects 2 }
acctngInterfaceControl OBJECT IDENTIFIER ::= { acctngMIBObjects 3 }
acctngTrapControl OBJECT IDENTIFIER ::= { acctngMIBObjects 4 }

-- Textual Conventions

DataCollectionSubtree ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The subtree component of a (subtree, list) tuple. Such a
(subtree, list) tuple defines a set of objects and their
values to be collected as accounting data for a connection.
The subtree specifies a single OBJECT IDENTIFIER value such
that each object in the set is named by the subtree value

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appended with a single additional sub-identifier."
SYNTAX OBJECT IDENTIFIER

DataCollectionList ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The list component of a (subtree, list) tuple. Such a
(subtree, list) tuple defines a set of objects and their
values to be collected as accounting data for a connection.
The subtree specifies a single OBJECT IDENTIFIER value such
that each object in the set is named by the subtree value
appended with a single additional sub-identifier. The list
specifies a set of data items, where the presence of an item
in the list indicates that the item is (to be) present in
the data collected for a connection; the absence of an item
from the list indicates that the item is not (to be) present
in the data collected for a connection. Each data item is
represented by an integer which when appended (as as
additional sub-identifier) to the OBJECT IDENTIFIER value of
the subtree identified by the tuple, is the name of an
object defining that data item (its description and its
syntax).

The list is specified as an OCTET STRING in which each data
item is represented by a single bit, where data items 1
through 8 are represented by the bits in the first octet,
data items 9 through 16 by the bits in the second octet,
etc. In each octet, the lowest numbered data item is
represented by the most significant bit, and the highest
numbered data item by the least significant bit. A data
item is present in the list when its bit is set, and absent
when its bit is reset. If the length of an OCTET STRING
value is too short to represent one or more data items
defined in a subtree, then those data items are absent from
the set identified by the tuple of that subtree and that
OCTET STRING value."
SYNTAX OCTET STRING (SIZE(0..8))

FileIndex ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"An arbitrary integer value identifying a file into which
accounting data is being collected."
SYNTAX Integer32 (1..65535)

-- The Accounting Information Selection table

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acctngSelectionTable OBJECT-TYPE
SYNTAX SEQUENCE OF AcctngSelectionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of accounting information selection entries.

Note that additions, modifications and deletions of entries
in this table can occur at any time, but such changes only
take effect on the next occasion when collection begins into
a new file. Thus, between modification and the next 'swap',
the content of this table does not reflect the current
selection."
::= { acctngSelectionControl 1 }

acctngSelectionEntry OBJECT-TYPE
SYNTAX AcctngSelectionEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry identifying an (subtree, list) tuple used to
select a set of accounting information which is to be
collected."
INDEX { acctngSelectionIndex }
::= { acctngSelectionTable 1 }

AcctngSelectionEntry ::=
SEQUENCE {
acctngSelectionIndex Integer32,
acctngSelectionSubtree DataCollectionSubtree,
acctngSelectionList DataCollectionList,
acctngSelectionFile FileIndex,
acctngSelectionType BITS,
acctngSelectionRowStatus RowStatus
}

acctngSelectionIndex OBJECT-TYPE
SYNTAX Integer32 (1..65535)
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An arbitrary integer value which uniquely identifies a
tuple stored in this table. This value is required to be
the permanent 'handle' for an entry in this table for as
long as that entry exists, including across restarts and
power outages."
::= { acctngSelectionEntry 1 }

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acctngSelectionSubtree OBJECT-TYPE
SYNTAX DataCollectionSubtree
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The combination of acctngSelectionSubtree and
acctngSelectionList specifies one (subtree, list) tuple
which is to be collected."
::= { acctngSelectionEntry 2 }

acctngSelectionList OBJECT-TYPE
SYNTAX DataCollectionList
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The combination of acctngSelectionSubtree and
acctngSelectionList specifies one (subtree, list) tuple
which is to be collected."
::= { acctngSelectionEntry 3 }

acctngSelectionFile OBJECT-TYPE
SYNTAX FileIndex
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An indication of the file into which the accounting
information identified by this entry is to be stored. If
there is no conceptual row in the acctngFileTable for which
the value of acctngFileIndex has the same value as this
object, then the information selected by this entry is not
collected."
::= { acctngSelectionEntry 4 }

acctngSelectionType OBJECT-TYPE
SYNTAX BITS { svcIncoming(0),
svcOutgoing(1),
svpIncoming(2),
svpOutgoing(3),
pvc(4),
pvp(5),
spvcOriginator(6),
spvcTarget(7),
spvpOriginator(8),
spvpTarget(9) }
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"Indicates the types of connections for which the

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information selected by this entry are to be collected."
DEFVAL { { svcIncoming, svcOutgoing,
svpIncoming, svpOutgoing } }
::= { acctngSelectionEntry 5 }

acctngSelectionRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. An agent may refuse to
create new conceptual rows and/or modify existing conceptual
rows, if such creation/modification would cause multiple
rows to have the same values of acctngSelectionSubtree and
acctngSelectionList.

A conceptual row can not have the status of 'active' until
values have been assigned to the acctngSelectionSubtree,
acctngSelectionList and acctngSelectionFile columnar objects
within that row.

An agent must not refuse to change the values of the
acctngSelectionSubtree, acctngSelectionList and
acctngSelectionFile columnar objects within a conceptual row
even while that row's status is 'active'. Similarly, an
agent must not refuse to destroy an existing conceptual row
while the file referenced by that row's instance of
acctngSelectionFile is in active use, i.e., while the
corresponding instance of acctngFileRowStatus has the value
'active'. However, such changes only take effect upon the
next occasion when collection begins into a new (version of
the) file."
::= { acctngSelectionEntry 6 }

-- The Accounting File table

acctngFileTable OBJECT-TYPE
SYNTAX SEQUENCE OF AcctngFileEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A list of files into which accounting information is to be
stored."
::= { acctngFileControl 1 }

acctngFileEntry OBJECT-TYPE
SYNTAX AcctngFileEntry
MAX-ACCESS not-accessible

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STATUS current
DESCRIPTION
"An entry identifying a file into which accounting
information is to be collected."
INDEX { acctngFileIndex }
::= { acctngFileTable 1 }

AcctngFileEntry ::=
SEQUENCE {
acctngFileIndex FileIndex,
acctngFileName DisplayString,
acctngFileNameSuffix DisplayString,
acctngFileDescription DisplayString,
acctngFileCommand INTEGER,
acctngFileMaximumSize Integer32,
acctngFileCurrentSize Integer32,
acctngFileFormat INTEGER,
acctngFileCollectMode BITS,
acctngFileCollectFailedAttempts BITS,
acctngFileInterval Integer32,
acctngFileMinAge Integer32,
acctngFileRowStatus RowStatus
}

acctngFileIndex OBJECT-TYPE
SYNTAX FileIndex
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A unique value identifying a file into which accounting
data is to be stored. This value is required to be the
permanent 'handle' for an entry in this table for as long as
that entry exists, including across restarts and power
outages."
::= { acctngFileEntry 1 }

acctngFileName OBJECT-TYPE
SYNTAX DisplayString (SIZE(1..32))
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The name of the file into which accounting data is to be
stored. If files are named using suffixes, then the name of
the current file is the concatenation of acctngFileName and
acctngFileNameSuffix.

An agent will respond with an error (e.g., 'wrongValue') to
a management set operation which attempts to modify the

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value of this object to the same value as already held by
another instance of acctngFileName. An agent will also
respond with an error (e.g., 'wrongValue') if the new value
is invalid for use as a file name on the local file system
(e.g., many file systems do not support white space embedded
in file names).

The value of this object can not be modified while the
corresponding instance of acctngFileRowStatus is 'active'."
::= { acctngFileEntry 2 }

acctngFileNameSuffix OBJECT-TYPE
SYNTAX DisplayString (SIZE(0..8))
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"The suffix, if any, of the name of a file into which
accounting data is currently being stored. If suffixes are
not used, then the value of this object is the zero-length
string. Note that if a separator, such as a period, is used
in appending the suffix to the file name, then that
separator appears as the first character of this value."
::= { acctngFileEntry 3 }

acctngFileDescription OBJECT-TYPE
SYNTAX DisplayString
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The textual description of the accounting data which will
be stored (on the next occasion) when header information is
stored in the file. The value of this object may be
modified at any time."
DEFVAL { "" }
::= { acctngFileEntry 4 }

acctngFileCommand OBJECT-TYPE
SYNTAX INTEGER {
-- the following two values are states:
-- they may be read but not written
idle(1),
cmdInProgress(2),
-- the following two values are actions:
-- they may be written, but are never read
swapToNewFile(3),
collectNow(4)
}
MAX-ACCESS read-create

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STATUS current
DESCRIPTION
"A control object for the collection of accounting data.
When read the value is either 'idle' or 'cmdInProgress'.
Writing a value is only allowed when the current value is
'idle'. When a value is successfully written, the value
changes to 'cmdInProgress' until completion of the action,
at which time the value reverts to 'idle'. Actions are
invoked by writing the following values:

'swapToNewFile' - the collection of data into the current
file is terminated, and collection continues into
a new (version of the) file.

'collectNow' - the agent creates and stores a connection
record into the current file for each active
connection having a type matching
acctngSelectionType and an age greater than
acctngFileMinAge."
DEFVAL { idle }
::= { acctngFileEntry 5 }

acctngFileMaximumSize OBJECT-TYPE
SYNTAX Integer32 (100..2147483647)
UNITS "bytes"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The maximum size of the file (including header
information). When the file of collected data reaches this
size, either the agent automatically swaps to a new version
(i.e., a new value acctngFileNameSuffix) of the file, or new
records are discarded. Since a file must contain an
integral number of connection records, the actual maximum
size of the file may be just less OR Just greater than the
value of this object.

The value of this object can not be modified while the
corresponding instance of acctngFileRowStatus is 'active'.
The largest value of the maximum file size in some agents
will be less than 2147483647 bytes."
DEFVAL { 5000000 }
::= { acctngFileEntry 6 }

acctngFileCurrentSize OBJECT-TYPE
SYNTAX Integer32 (0..2147483647)
UNITS "bytes"
MAX-ACCESS read-only

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STATUS current
DESCRIPTION
"The current size of the file into which data is currently
being collected, including header information."
::= { acctngFileEntry 7 }

acctngFileFormat OBJECT-TYPE
SYNTAX INTEGER { other(1), ber(2) }
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An indication of the format in which the accounting data is
to be stored in the file. If the value is modified, the new
value takes effect after the next 'swap' to a new file. The
value ber(2) indicates the standard format."
DEFVAL { ber }
::= { acctngFileEntry 8 }

acctngFileCollectMode OBJECT-TYPE
SYNTAX BITS { onRelease(0), periodically(1) }
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An indication of when accounting data is to be written into
this file. Note that in addition to the occasions indicated
by the value of this object, an agent always writes
information on appropriate connections to the file when the
corresponding instance of acctngFileCommand is set to
'collectNow'.

- 'onRelease' - whenever a connection (or possibly,
connection attempt) is terminated, either through
a Release message or through management removal,
information on that connection is written.

- 'periodically' - information on appropriate connections
is written on the expiry of a periodic timer,

This value may be modified at any time."
DEFVAL { { onRelease } }
::= { acctngFileEntry 9 }

acctngFileCollectFailedAttempts OBJECT-TYPE
SYNTAX BITS { soft(0), regular(1) }
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"An indication of whether connection data is to be collected

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for failed connection attempts when the value of the
corresponding instance of acctngFileCollectMode includes
'onRelease'. The individual values have the following
meaning:

'soft' - indicates that connection data is to be collected
for failed Soft PVCs/PVPs which originate or terminate at
the relevant interface.

'regular' - indicates that connection data is to be
collected for failed SVCs, including Soft PVCs/PVPs not
originating or terminating at the relevant interface.

This value may be modified at any time."
DEFVAL { { soft, regular } }
::= { acctngFileEntry 10 }

acctngFileInterval OBJECT-TYPE
SYNTAX Integer32 (60..86400)
UNITS "seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The number of seconds between the periodic collections of
accounting data when the value of the corresponding instance
of acctngFileCollectMode includes 'periodically'. Some
agents may impose restrictions on the range of this
interval. This value may be modified at any time."
DEFVAL { 3600 }
::= { acctngFileEntry 11 }

acctngFileMinAge OBJECT-TYPE
SYNTAX Integer32 (60..86400)
UNITS "seconds"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The minimum age of a connection, as used to determine the
set of connections for which data is to be collected at the
periodic intervals and/or when acctngFileCommand is set to
'collectNow'. The age of a connection is the elapsed time
since it was last installed.

When the periodic interval expires for a file or when
acctngFileCommand is set to 'collectNow', accounting data is
collected and stored in the file for each connection having
a type matching acctngSelectionType and whose age at that
time is greater than the value of acctngFileMinAge

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associated with the file. This value may be modified at any
time."
DEFVAL { 3600 }
::= { acctngFileEntry 12 }

acctngFileRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row.

This object can not be set to 'active' until a value has
been assigned to the corresponding instance of
acctngFileName. Collection of data into the file does not
begin until this object has the value 'active' and one or
more (active) instances of acctngSelectionFile refer to it.
If this value is modified after a collection has begun,
collection into this file terminates and a new (or new
version of the) file is immediately made ready for future
collection (as if acctngFileCommand had been set to
'swapToNewFile'), but collection into the new (or new
version of the) file does not begin until the value is
subsequently set back to active."
::= { acctngFileEntry 13 }

-- Overall Control

acctngAdminStatus OBJECT-TYPE
SYNTAX INTEGER { enabled(1), disabled(2) }
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"A control object to indicate the administratively desired
state of the collection of accounting records across all
interfaces.

Modifying the value of acctngAdminStatus to 'disabled' does
not remove or change the current configuration as
represented by the active rows in the acctngSelectionTable,
acctngFileTable and acctngInterfaceTable tables."
::= { acctngInterfaceControl 1 }

acctngOperStatus OBJECT-TYPE
SYNTAX INTEGER { enabled(1), disabled(2) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION

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"A status object to indicate the operational state of the
collection of accounting records across all interfaces.

When the value of acctngAdminStatus is modified to be
'enabled', the value of this object will change to 'enabled'
providing it is possible to begin collecting accounting
records.

When the value of acctngAdminStatus is modified to be
'disabled', the value of this object will change to
'disabled' as soon as the collection of accounting records
has terminated."
::= { acctngInterfaceControl 2 }

acctngProtection OBJECT-TYPE
SYNTAX TestAndIncr
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"A control object to protect against duplication of control
commands. Over some transport/network protocols, it is
possible for SNMP messages to get duplicated. Such
duplication, if it occurred at just the wrong time could
cause serious disruption to the collection and retrieval of
accounting data, e.g., if a SNMP message setting
acctngFileCommand to 'swapToNewFile' were to be duplicated,
a whole file of accounting data could be lost.

To protect against such duplication, a management
application should retrieve the value of this object, and
include in the Set operation needing protection, a variable
binding which sets this object to the retrieved value."
::= { acctngInterfaceControl 3 }

acctngAgentMode OBJECT-TYPE
SYNTAX INTEGER { swapOnCommand(1), swapOnFull(2) }
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"An indication of the behaviour mode of the agent when a
file becomes full:

'swapOnCommand' - the agent does not automatically swap
to a new file; rather, it discards newly collected
data until a management application subsequently
instructs it to swap to a new file.

'swapOnFull' - the agent terminates collection into the

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current file as and when that file becomes full."
::= { acctngInterfaceControl 4 }

-- Per-interface control table

acctngInterfaceTable OBJECT-TYPE
SYNTAX SEQUENCE OF AcctngInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A table controlling the collection of accounting data on
specific interfaces of the switch."
::= { acctngInterfaceControl 5 }

acctngInterfaceEntry OBJECT-TYPE
SYNTAX AcctngInterfaceEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry which controls whether accounting data is to be
collected on an interface. The types of interfaces which
are represented in this table is implementation-specific."
INDEX { ifIndex }
::= { acctngInterfaceTable 1 }

AcctngInterfaceEntry ::=
SEQUENCE {
acctngInterfaceEnable TruthValue
}

acctngInterfaceEnable OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"Indicates whether the collection of accounting data is
enabled on this interface."
::= { acctngInterfaceEntry 1 }

-- Objects for controlling the use of Notifications

acctngControlTrapThreshold OBJECT-TYPE
SYNTAX INTEGER (0..99)
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"A percentage of the maximum file size at which a 'nearly-

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full' trap is generated. The value of 0 indicates that no
'nearly-full' trap is to be generated."
::= { acctngTrapControl 1 }

acctngControlTrapEnable OBJECT-TYPE
SYNTAX TruthValue
MAX-ACCESS read-write
STATUS current
DESCRIPTION
"An indication of whether the acctngFileNearlyFull and
acctngFileFull traps are enabled."
::= { acctngTrapControl 2 }

-- notifications

acctngNotifications OBJECT IDENTIFIER ::= { accountingControlMIB 2 }

acctngNotifyPrefix OBJECT IDENTIFIER ::= { acctngNotifications 0 }

acctngFileNearlyFull NOTIFICATION-TYPE
OBJECTS { acctngFileName,
acctngFileMaximumSize,
acctngControlTrapThreshold,
acctngFileNameSuffix }
STATUS current
DESCRIPTION
"An indication that the size of the file into which
accounting information is currently being collected has
exceeded the threshold percentage of its maximum file size.
This notification is generated only at the time of the
transition from not-exceeding to exceeding."
::= { acctngNotifyPrefix 1 }

acctngFileFull NOTIFICATION-TYPE
OBJECTS { acctngFileName,
acctngFileMaximumSize,
acctngFileNameSuffix }
STATUS current
DESCRIPTION
"An indication that the size of the file into which
accounting information is currently being collected has
transistioned to its maximum file size. This notification
is generated (for all values of acctngAgentMode) at the time
of the transition from not-full to full. If acctngAgentMode
has the value 'swapOnCommand', it is also generated
periodically thereafter until such time as collection of

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data is no longer inhibited by the file full condition."
::= { acctngNotifyPrefix 2 }

-- conformance information

acctngConformance OBJECT IDENTIFIER ::= { accountingControlMIB 3 }
acctngGroups OBJECT IDENTIFIER ::= { acctngConformance 1 }
acctngCompliances OBJECT IDENTIFIER ::= { acctngConformance 2 }

acctngCompliance MODULE-COMPLIANCE
STATUS current
DESCRIPTION
"The compliance statement for switches which implement the
Accounting Control MIB."

MODULE -- this module
MANDATORY-GROUPS { acctngBasicGroup,
acctngNotificationsGroup }

OBJECT acctngSelectionType
SYNTAX BITS { svcIncoming(0), svcOutgoing(1) }
DESCRIPTION "The minimal requirement is collection for SVCs."

OBJECT acctngSelectionRowStatus
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileName
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileCommand
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileFormat
SYNTAX INTEGER { ber(2) }
MIN-ACCESS read-only
DESCRIPTION "Only the standard format is required, and write
access is not required."

OBJECT acctngFileMaximumSize
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileCollectMode
SYNTAX BITS { onRelease(0) }

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MIN-ACCESS read-only
DESCRIPTION "The minimal requirement is for collection on
connection release."

OBJECT acctngFileInterval
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileCollectFailedAttempts
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

OBJECT acctngFileRowStatus
MIN-ACCESS read-only
DESCRIPTION "Write access is not required."

::= { acctngCompliances 1 }

-- units of conformance

acctngBasicGroup OBJECT-GROUP
OBJECTS { acctngSelectionSubtree, acctngSelectionList,
acctngSelectionFile, acctngSelectionType,
acctngSelectionRowStatus, acctngFileName,
acctngFileNameSuffix, acctngFileDescription,
acctngFileCommand, acctngFileMaximumSize,
acctngFileCurrentSize, acctngFileRowStatus,
acctngFileFormat, acctngFileCollectMode,
acctngFileCollectFailedAttempts, acctngFileInterval,
acctngFileMinAge,
acctngAdminStatus, acctngOperStatus,
acctngProtection, acctngAgentMode,
acctngInterfaceEnable,
acctngControlTrapThreshold,
acctngControlTrapEnable
}
STATUS current
DESCRIPTION
"A collection of objects providing control of the basic
collection of accounting data for connection-oriented
networks."
::= { acctngGroups 1 }

acctngNotificationsGroup NOTIFICATION-GROUP
NOTIFICATIONS { acctngFileNearlyFull, acctngFileFull }
STATUS current
DESCRIPTION

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"The notifications of events relating to controlling the
collection of accounting data."
::= { acctngGroups 2 }

END

5. Acknowledgements

The comments of the IETF's AToM MIB Working Group are acknowledged.

6. References

[1] Harrington, D., Presuhn, R. and B. Wijnen, "An Architecture for
Describing SNMP Management Frameworks", RFC 2271, January 1998.

[2] Rose, M. and K. McCloghrie, "Structure and Identification of
Management Information for TCP/IP-based Internets", STD 16, RFC
1155, May 1990.

[3] Rose, M. and K. McCloghrie, "Concise MIB Definitions", STD 16,
RFC 1212, March 1991.

[4] Rose, M., "A Convention for Defining Traps for use with the
SNMP", RFC 1215, March 1991.

[5] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Structure of Management Information for Version 2
of the Simple Network Management Protocol (SNMPv2)", RFC 1902,
January 1996.

[6] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Textual Conventions for Version 2 of the Simple
Network Management Protocol (SNMPv2)", RFC 1903, January 1996.

[7] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Conformance Statements for Version 2 of the Simple
Network Management Protocol (SNMPv2)", RFC 1904, January 1996.

[8] Case, J., Fedor, M., Schoffstall, M. and J. Davin, "Simple
Network Management Protocol", STD 15, RFC 1157, May 1990.

[9] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Introduction to Community-based SNMPv2", RFC 1901,
January 1996.

[10] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Transport Mappings for Version 2 of the Simple
Network Management Protocol (SNMPv2)", RFC 1906, January 1996.

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RFC 2513 Connection-Oriented Accounting MIB February 1999

[11] Case, J., Harrington D., Presuhn R. and B. Wijnen, "Message
Processing and Dispatching for the Simple Network Management
Protocol (SNMP)", RFC 2272, January 1998.

[12] Blumenthal, U. and B. Wijnen, "User-based Security Model (USM)
for version 3 of the Simple Network Management Protocol
(SNMPv3)", RFC 2274, January 1998.

[13] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Protocol Operations for Version 2 of the Simple
Network Management Protocol (SNMPv2)", RFC 1905, January 1996.

[14] Levi, D., Meyer, P. and B. Stewart, "SNMPv3 Applications", RFC
2273, January 1998.

[15] Wijnen, B., Presuhn, R. and K. McCloghrie, "View-based Access
Control Model (VACM) for the Simple Network Management Protocol
(SNMP)", RFC 2275, January 1998.

[16] SNMPv2 Working Group, Case, J., McCloghrie, K., Rose, M. and S.
Waldbusser, "Management Information Base for version 2 of the
Simple Network Management Protocol (SNMPv2)", RFC 1907, January
1996.

[17] Information processing systems - Open Systems Interconnection,
"Specification of Abstract Syntax Notation One (ASN.1)",
International Organization for Standardization, Internation
Standard 8824, December 1987.

[18] Information processing systems - Open Systems Interconnection,
"Specification of Basic Encoding Rules for Abstract Syntax
Notation One (ASN.1)", International Organization for
Standardization, Internation Standard 8825, December 1987.

[19] McCloghrie, K., Heinanen, J., Greene, W. and A. Prasad,
"Accounting Information for ATM Networks", RFC 2512, February
1999.

[20] Noto, M., Spiegel, E., and K. Tesink, "Definitions of Textual
Conventions and OBJECT-IDENTITIES for ATM Management", RFC 2514,
February 1999.

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7. Security Considerations

The MIB defined in this memo controls and monitors the collection of
accounting data. Care should be taken to prohibit unauthorized
access to this control capability in order to prevent the disruption
of data collection, possibly with fraudulent intent. Example of such
disruption are disabling the collection of data, or causing the wrong
set of data items to be collected.

SNMPv1 by itself is not a secure environment. 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.

It is recommended that the implementers consider the security
features as provided by the SNMPv3 framework. Specifically, the use
of the User-based Security Model RFC 2274 [12] and the View-based
Access Control Model RFC 2275 [15] is recommended.

It is then a customer/user responsibility to ensure that the SNMP
entity giving access to an instance of this MIB, is properly
configured to give access to the objects only to those principals
(users) that have legitimate rights to indeed GET or SET
(change/create/delete) them.

8. IANA Considerations

Prior to publication of this memo as an RFC, IANA is requested to
make a suitable OBJECT IDENTIFIER assignment.

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RFC 2513 Connection-Oriented Accounting MIB February 1999

9. Authors' Addresses

Keith McCloghrie
Cisco Systems, Inc.
170 West Tasman Drive,
San Jose CA 95134

Phone: +1 408 526 5260
EMail: [email protected]

Juha Heinanen
Telia Finland, Inc.
Myyrmaentie 2
01600 VANTAA
Finland

Phone +358 303 944 808
EMail: [email protected]

Wedge Greene
MCI Telecommunications Corporation
901 International Parkway
Richardson, Texas 75081

Phone: 214-498-1232 or 972-729-1232
EMail: [email protected]

Anil Prasad
Cisco Systems, Inc.
170 West Tasman Drive,
San Jose CA 95134

Phone: 408 525-7209
EMail: [email protected]

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RFC 2513 Connection-Oriented Accounting MIB February 1999

10. Full Copyright Statement

Copyright (C) The Internet Society (1999). All Rights Reserved.

This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph are
included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.

The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns.

This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

McCloghrie, et. al. Standards Track [Page 29]