INTERFACETOPN-MIB

Integer32 (1..65535)

An index that uniquely identifies an entry in the interfaceTopNControl table. Each such entry defines one top N report prepared for a probe.

INTEGER0 = ifInOctets1 = ifInUcastPkts2 = ifInNUcastPkts3 = ifInDiscards4 = ifInErrors5 = ifInUnknownProtos6 = ifOutOctets7 = ifOutUcastPkts8 = ifOutNUcastPkts9 = ifOutDiscards10 = ifOutErrors11 = ifInMulticastPkts12 = ifInBroadcastPkts13 = ifOutMulticastPkts14 = ifOutBroadcastPkts15 = ifHCInOctets16 = ifHCInUcastPkts17 = ifHCInMulticastPkts18 = ifHCInBroadcastPkts19 = ifHCOutOctets20 = ifHCOutUcastPkts21 = ifHCOutMulticastPkts22 = ifHCOutBroadcastPkts23 = dot3StatsAlignmentErrors24 = dot3StatsFCSErrors25 = dot3StatsSingleCollisionFrames26 = dot3StatsMultipleCollisionFrames27 = dot3StatsSQETestErrors28 = dot3StatsDeferredTransmissions29 = dot3StatsLateCollisions30 = dot3StatsExcessiveCollisions31 = dot3StatsInternalMacTxErrors32 = dot3StatsCarrierSenseErrors33 = dot3StatsFrameTooLongs34 = dot3StatsInternalMacRxErrors35 = dot3StatsSymbolErrors36 = dot3InPauseFrames37 = dot3OutPauseFrames38 = dot5StatsLineErrors39 = dot5StatsBurstErrors40 = dot5StatsACErrors41 = dot5StatsAbortTransErrors42 = dot5StatsInternalErrors43 = dot5StatsLostFrameErrors44 = dot5StatsReceiveCongestions45 = dot5StatsFrameCopiedErrors46 = dot5StatsTokenErrors47 = dot5StatsSoftErrors48 = dot5StatsHardErrors49 = dot5StatsSignalLoss50 = dot5StatsTransmitBeacons51 = dot5StatsRecoverys52 = dot5StatsLobeWires53 = dot5StatsRemoves54 = dot5StatsSingles55 = dot5StatsFreqErrors56 = etherStatsDropEvents57 = etherStatsOctets58 = etherStatsPkts59 = etherStatsBroadcastPkts60 = etherStatsMulticastPkts61 = etherStatsCRCAlignErrors62 = etherStatsUndersizePkts63 = etherStatsOversizePkts64 = etherStatsFragments65 = etherStatsJabbers66 = etherStatsCollisions67 = etherStatsPkts64Octets68 = etherStatsPkts65to127Octets69 = etherStatsPkts128to255Octets70 = etherStatsPkts256to511Octets71 = etherStatsPkts512to1023Octets72 = etherStatsPkts1024to1518Octets73 = dot1dTpPortInFrames74 = dot1dTpPortOutFrames75 = dot1dTpPortInDiscards · Integer32

The particular variable to be sampled. Values between 0 and 22, point to MIB objects defined in IF-MIB [RFC2863]. Values between 23 and 37, point to MIB objects defined in EtherLike-MIB [RFC2665]. Values between 38 and 55, point to MIB objects defined in TOKENRING-MIB [RFC1748]. Values between 56 and 72, point to MIB objects defined in RMON-MIB [RFC2819]. Values between 73 and 75, point to MIB objects defined in BRIDGE-MIB [RFC1493]. Because SNMP access control is articulated entirely in terms of the contents of MIB views, no access control mechanism exists that can restrict the value of this object to identify only those objects that exist in a particular MIB view. Because there is thus no acceptable means of restricting the read access that could be obtained through the TopN mechanism, the probe must only grant write access to this object in those views that have read access to all objects on the probe. During a set operation, if the supplied variable name is not available in the selected MIB view, or does not conform the other conditions mentioned above, a badValue error must be returned. This object may not be modified if the associated interfaceTopNControlStatus object is equal to active(1).

INTEGER1 = absoluteValue2 = deltaValue3 = bandwidthPercentage · Integer32

The method of sampling the selected variable for storage in the interfaceTopNTable. If the value of this object is absoluteValue(1), the value of the selected variable will be copied directly into the topNValue. If the value of this object is deltaValue(2), the value of the selected variable at the last sample will be subtracted from the current value, and the difference will be stored in topNValue. If the value of this object is bandwidthPercentage(3), the agent records the total number of octets sent over an interval divided by the total number of octets that represent '100% bandwidth' for that interface. This ratio is multiplied by 1000 to retain a 3 digit integer (0..1000) in units of 'tenth of one percent'. This type of computation is accurate for the octet counters. The usage of this option with respect to packets or error counters is not recommended. This object may not be modified if the associated interfaceTopNControlStatus object is equal to active(1).

TruthValue1 = true2 = falseRepresents a boolean value. · Integer32

This object indicates whether normalization is required in the computation of the selected value. If the value of this object is 'true', the value of the selected variable will be multiplied by a factor equal to the interfaceTopNNormalizationFactor divided by the value of effective speed of the interface If the value of this object is 'false', the value of the selected variable will be taken 'as is' in the TopN computation. If the value of the object interfaceTopNSampleType is bandwidthPercentage(3), the object interfaceTopNNormalizationReq cannot take the value 'true'. The value of this object MUST be false if the effective speed of the interface sub-layer as determined from ifSpeed is zero. This conforms to the ifSpeed definition in [RFC2863]for a sub-layer that has no concept of bandwidth. This object may not be modified if the associated interfaceTopNControlStatus object is equal to active(1).

Integer32 (1..2147483647)

The value used for normalization if interfaceTopNNormalizationReq has the value 'true'. Example: The following set of values is applied to a device with multiple Ethernet interfaces running at 10 Mbps, 100 Mbps, and 1 Gbps. interfaceTopNObjectVariable = 'ifInOctets' interfaceTopNObjectSampleType = 'deltaValue' interfaceTopNNormalizationReq = 'true' interfaceTopNNormalizationFactor = 1000000000 Applying this set of values will result in the sampled delta values to be multiplied by 100 for the 10 Mbps interfaces, and by 10 for the 100 Mbps interfaces, while the sample values for the 1 Gbps interface are left unchanged. The effective speed of the interface is taken from the value of ifSpeed for each interface, if ifSpeed is less than 4,294,967,295, or from ifHighSpeed multiplied by 1,000,000 otherwise. At row creation the agent SHOULD set the value of this object to the effective speed of the interface.

Integer32 (0..2147483647)

The number of seconds left in the report currently being collected. When this object is modified by the management station, a new collection is started, possibly aborting a currently running report. The new value is used as the requested duration of this report, which is loaded into the associated interfaceTopNDuration object. When this object is set to a non-zero value, any associated interfaceTopNEntries shall be made inaccessible by the agent. While the value of this object is non-zero, it decrements by one per second until it reaches zero. During this time, all associated interfaceTopNEntries shall remain inaccessible. At the time that this object decrements to zero, the report is made accessible in the interfaceTopNTable. Thus, the interfaceTopN table needs to be created only at the end of the collection interval. If the value of this object is set to zero while the associated report is running, the running report is aborted and no associated interfaceTopNEntries are created.

Integer32 (0..2147483647)

The number of seconds that this report has collected during the last sampling interval, or if this report is currently being collected, the number of seconds that this report is being collected during this sampling interval. When the associated interfaceTopNTimeRemaining object is set, this object shall be set by the agent to the same value and shall not be modified until the next time the interfaceTopNTimeRemaining is set. This value shall be zero if no reports have been requested for this interfaceTopNControlEntry.

Integer32

The maximum number of interfaces requested for the Top N Table. When this object is created or modified, the agent should set interfaceTopNGrantedSize as close to this object as is possible for the particular implementation and available resources.

Integer32 (0..2147483647)

The maximum number of interfaces in the top N table. When the associated interfaceTopNRequestedSize object is created or modified, the agent should set this object as closely to the requested value as is possible for the particular implementation and available resources. The agent must not lower this value except as a result of a set to the associated interfaceTopNRequestedSize object.

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

The value of sysUpTime when this top N report was last started. In other words, this is the time that the associated interfaceTopNTimeRemaining object was modified to start the requested report. If the report has not yet been started, the value of this object is zero.

OwnerStringThis data type is used to model an administratively assigned name of the owner of a resource. Implementations must accept values composed of well-formed NVT ASCII sequences. In addition, implementations should accept values composed of well-formed UTF-8 sequences. It is suggested that this name contain one or more of the following: IP address, management station name, network manager's name, location, or phone number. In some cases the agent itself will be the owner of an entry. In these cases, this string shall be set to a string starting with 'monitor'. SNMP access control is articulated entirely in terms of the contents of MIB views; access to a particular SNMP object instance depends only upon its presence or absence in a particular MIB view and never upon its value or the value of related object instances. Thus, objects of this type afford resolution of resource contention only among cooperating managers; they realize no access control function with respect to uncooperative parties. SIZE (0..127) · OCTET STRING

The entity that configured this entry and is using the resources assigned to it.

TimeStampThe value of the sysUpTime object at which a specific occurrence happened. The specific occurrence must be defined in the description of any object defined using this type. If sysUpTime is reset to zero as a result of a re- initialization of the network management (sub)system, then the values of all TimeStamp objects are also reset. However, after approximately 497 days without a re- initialization, the sysUpTime object will reach 2^^32-1 and then increment around to zero; in this case, existing values of TimeStamp objects do not change. This can lead to ambiguities in the value of TimeStamp objects. · TimeTicks

The value of sysUpTime when this top N report was last completed. If no report was yet completed, the value of this object is zero.

RowStatus1 = active2 = notInService3 = notReady4 = createAndGo5 = createAndWait6 = destroyThe RowStatus textual convention is used to manage the creation and deletion of conceptual rows, and is used as the value of the SYNTAX clause for the status column of a conceptual row (as described in Section 7.7.1 of [2].) The status column has six defined values: - `active', which indicates that the conceptual row is available for use by the managed device; - `notInService', which indicates that the conceptual row exists in the agent, but is unavailable for use by the managed device (see NOTE below); 'notInService' has no implication regarding the internal consistency of the row, availability of resources, or consistency with the current state of the managed device; - `notReady', which indicates that the conceptual row exists in the agent, but is missing information necessary in order to be available for use by the managed device (i.e., one or more required columns in the conceptual row have not been instanciated); - `createAndGo', which is supplied by a management station wishing to create a new instance of a conceptual row and to have its status automatically set to active, making it available for use by the managed device; - `createAndWait', which is supplied by a management station wishing to create a new instance of a conceptual row (but not make it available for use by the managed device); and, - `destroy', which is supplied by a management station wishing to delete all of the instances associated with an existing conceptual row. Whereas five of the six values (all except `notReady') may be specified in a management protocol set operation, only three values will be returned in response to a management protocol retrieval operation: `notReady', `notInService' or `active'. That is, when queried, an existing conceptual row has only three states: it is either available for use by the managed device (the status column has value `active'); it is not available for use by the managed device, though the agent has sufficient information to attempt to make it so (the status column has value `notInService'); or, it is not available for use by the managed device, and an attempt to make it so would fail because the agent has insufficient information (the state column has value `notReady'). NOTE WELL This textual convention may be used for a MIB table, irrespective of whether the values of that table's conceptual rows are able to be modified while it is active, or whether its conceptual rows must be taken out of service in order to be modified. That is, it is the responsibility of the DESCRIPTION clause of the status column to specify whether the status column must not be `active' in order for the value of some other column of the same conceptual row to be modified. If such a specification is made, affected columns may be changed by an SNMP set PDU if the RowStatus would not be equal to `active' either immediately before or after processing the PDU. In other words, if the PDU also contained a varbind that would change the RowStatus value, the column in question may be changed if the RowStatus was not equal to `active' as the PDU was received, or if the varbind sets the status to a value other than 'active'. Also note that whenever any elements of a row exist, the RowStatus column must also exist. To summarize the effect of having a conceptual row with a status column having a SYNTAX clause value of RowStatus, consider the following state diagram: STATE +--------------+-----------+-------------+------------- | A | B | C | D | |status col.|status column| |status column | is | is |status column ACTION |does not exist| notReady | notInService| is active --------------+--------------+-----------+-------------+------------- set status |noError ->D|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndGo |inconsistent- | | | | Value| | | --------------+--------------+-----------+-------------+------------- set status |noError see 1|inconsist- |inconsistent-|inconsistent- column to | or | entValue| Value| Value createAndWait |wrongValue | | | --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError column to | Value| entValue| | active | | | | | | or | | | | | | | |see 2 ->D|see 8 ->D| ->D --------------+--------------+-----------+-------------+------------- set status |inconsistent- |inconsist- |noError |noError ->C column to | Value| entValue| | notInService | | | | | | or | | or | | | | | |see 3 ->C| ->C|see 6 --------------+--------------+-----------+-------------+------------- set status |noError |noError |noError |noError ->A column to | | | | or destroy | ->A| ->A| ->A|see 7 --------------+--------------+-----------+-------------+------------- set any other |see 4 |noError |noError |see 5 column to some| | | | value | | see 1| ->C| ->D --------------+--------------+-----------+-------------+------------- (1) goto B or C, depending on information available to the agent. (2) if other variable bindings included in the same PDU, provide values for all columns which are missing but required, and all columns have acceptable values, then return noError and goto D. (3) if other variable bindings included in the same PDU, provide legal values for all columns which are missing but required, then return noError and goto C. (4) at the discretion of the agent, the return value may be either: inconsistentName: because the agent does not choose to create such an instance when the corresponding RowStatus instance does not exist, or inconsistentValue: if the supplied value is inconsistent with the state of some other MIB object's value, or noError: because the agent chooses to create the instance. If noError is returned, then the instance of the status column must also be created, and the new state is B or C, depending on the information available to the agent. If inconsistentName or inconsistentValue is returned, the row remains in state A. (5) depending on the MIB definition for the column/table, either noError or inconsistentValue may be returned. (6) the return value can indicate one of the following errors: wrongValue: because the agent does not support notInService (e.g., an agent which does not support createAndWait), or inconsistentValue: because the agent is unable to take the row out of service at this time, perhaps because it is in use and cannot be de-activated. (7) the return value can indicate the following error: inconsistentValue: because the agent is unable to remove the row at this time, perhaps because it is in use and cannot be de-activated. (8) the transition to D can fail, e.g., if the values of the conceptual row are inconsistent, then the error code would be inconsistentValue. NOTE: Other processing of (this and other varbinds of) the set request may result in a response other than noError being returned, e.g., wrongValue, noCreation, etc. Conceptual Row Creation There are four potential interactions when creating a conceptual row: selecting an instance-identifier which is not in use; creating the conceptual row; initializing any objects for which the agent does not supply a default; and, making the conceptual row available for use by the managed device. Interaction 1: Selecting an Instance-Identifier The algorithm used to select an instance-identifier varies for each conceptual row. In some cases, the instance- identifier is semantically significant, e.g., the destination address of a route, and a management station selects the instance-identifier according to the semantics. In other cases, the instance-identifier is used solely to distinguish conceptual rows, and a management station without specific knowledge of the conceptual row might examine the instances present in order to determine an unused instance-identifier. (This approach may be used, but it is often highly sub-optimal; however, it is also a questionable practice for a naive management station to attempt conceptual row creation.) Alternately, the MIB module which defines the conceptual row might provide one or more objects which provide assistance in determining an unused instance-identifier. For example, if the conceptual row is indexed by an integer-value, then an object having an integer-valued SYNTAX clause might be defined for such a purpose, allowing a management station to issue a management protocol retrieval operation. In order to avoid unnecessary collisions between competing management stations, `adjacent' retrievals of this object should be different. Finally, the management station could select a pseudo-random number to use as the index. In the event that this index was already in use and an inconsistentValue was returned in response to the management protocol set operation, the management station should simply select a new pseudo-random number and retry the operation. A MIB designer should choose between the two latter algorithms based on the size of the table (and therefore the efficiency of each algorithm). For tables in which a large number of entries are expected, it is recommended that a MIB object be defined that returns an acceptable index for creation. For tables with small numbers of entries, it is recommended that the latter pseudo-random index mechanism be used. Interaction 2: Creating the Conceptual Row Once an unused instance-identifier has been selected, the management station determines if it wishes to create and activate the conceptual row in one transaction or in a negotiated set of interactions. Interaction 2a: Creating and Activating the Conceptual Row The management station must first determine the column requirements, i.e., it must determine those columns for which it must or must not provide values. Depending on the complexity of the table and the management station's knowledge of the agent's capabilities, this determination can be made locally by the management station. Alternately, the management station issues a management protocol get operation to examine all columns in the conceptual row that it wishes to create. In response, for each column, there are three possible outcomes: - a value is returned, indicating that some other management station has already created this conceptual row. We return to interaction 1. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it should supply a value for this column when the conceptual row is to be created. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. Once the column requirements have been determined, a management protocol set operation is accordingly issued. This operation also sets the new instance of the status column to `createAndGo'. When the agent processes the set operation, it verifies that it has sufficient information to make the conceptual row available for use by the managed device. The information available to the agent is provided by two sources: the management protocol set operation which creates the conceptual row, and, implementation-specific defaults supplied by the agent (note that an agent must provide implementation-specific defaults for at least those objects which it implements as read-only). If there is sufficient information available, then the conceptual row is created, a `noError' response is returned, the status column is set to `active', and no further interactions are necessary (i.e., interactions 3 and 4 are skipped). If there is insufficient information, then the conceptual row is not created, and the set operation fails with an error of `inconsistentValue'. On this error, the management station can issue a management protocol retrieval operation to determine if this was because it failed to specify a value for a required column, or, because the selected instance of the status column already existed. In the latter case, we return to interaction 1. In the former case, the management station can re-issue the set operation with the additional information, or begin interaction 2 again using `createAndWait' in order to negotiate creation of the conceptual row. NOTE WELL Regardless of the method used to determine the column requirements, it is possible that the management station might deem a column necessary when, in fact, the agent will not allow that particular columnar instance to be created or written. In this case, the management protocol set operation will fail with an error such as `noCreation' or `notWritable'. In this case, the management station decides whether it needs to be able to set a value for that particular columnar instance. If not, the management station re-issues the management protocol set operation, but without setting a value for that particular columnar instance; otherwise, the management station aborts the row creation algorithm. Interaction 2b: Negotiating the Creation of the Conceptual Row The management station issues a management protocol set operation which sets the desired instance of the status column to `createAndWait'. If the agent is unwilling to process a request of this sort, the set operation fails with an error of `wrongValue'. (As a consequence, such an agent must be prepared to accept a single management protocol set operation, i.e., interaction 2a above, containing all of the columns indicated by its column requirements.) Otherwise, the conceptual row is created, a `noError' response is returned, and the status column is immediately set to either `notInService' or `notReady', depending on whether it has sufficient information to (attempt to) make the conceptual row available for use by the managed device. If there is sufficient information available, then the status column is set to `notInService'; otherwise, if there is insufficient information, then the status column is set to `notReady'. Regardless, we proceed to interaction 3. Interaction 3: Initializing non-defaulted Objects The management station must now determine the column requirements. It issues a management protocol get operation to examine all columns in the created conceptual row. In the response, for each column, there are three possible outcomes: - a value is returned, indicating that the agent implements the object-type associated with this column and had sufficient information to provide a value. For those columns to which the agent provides read-create access (and for which the agent allows their values to be changed after their creation), a value return tells the management station that it may issue additional management protocol set operations, if it desires, in order to change the value associated with this column. - the exception `noSuchInstance' is returned, indicating that the agent implements the object-type associated with this column, and that this column in at least one conceptual row would be accessible in the MIB view used by the retrieval were it to exist. However, the agent does not have sufficient information to provide a value, and until a value is provided, the conceptual row may not be made available for use by the managed device. For those columns to which the agent provides read-create access, the `noSuchInstance' exception tells the management station that it must issue additional management protocol set operations, in order to provide a value associated with this column. - the exception `noSuchObject' is returned, indicating that the agent does not implement the object-type associated with this column or that there is no conceptual row for which this column would be accessible in the MIB view used by the retrieval. As such, the management station can not issue any management protocol set operations to create an instance of this column. If the value associated with the status column is `notReady', then the management station must first deal with all `noSuchInstance' columns, if any. Having done so, the value of the status column becomes `notInService', and we proceed to interaction 4. Interaction 4: Making the Conceptual Row Available Once the management station is satisfied with the values associated with the columns of the conceptual row, it issues a management protocol set operation to set the status column to `active'. If the agent has sufficient information to make the conceptual row available for use by the managed device, the management protocol set operation succeeds (a `noError' response is returned). Otherwise, the management protocol set operation fails with an error of `inconsistentValue'. NOTE WELL A conceptual row having a status column with value `notInService' or `notReady' is unavailable to the managed device. As such, it is possible for the managed device to create its own instances during the time between the management protocol set operation which sets the status column to `createAndWait' and the management protocol set operation which sets the status column to `active'. In this case, when the management protocol set operation is issued to set the status column to `active', the values held in the agent supersede those used by the managed device. If the management station is prevented from setting the status column to `active' (e.g., due to management station or network failure) the conceptual row will be left in the `notInService' or `notReady' state, consuming resources indefinitely. The agent must detect conceptual rows that have been in either state for an abnormally long period of time and remove them. It is the responsibility of the DESCRIPTION clause of the status column to indicate what an abnormally long period of time would be. This period of time should be long enough to allow for human response time (including `think time') between the creation of the conceptual row and the setting of the status to `active'. In the absence of such information in the DESCRIPTION clause, it is suggested that this period be approximately 5 minutes in length. This removal action applies not only to newly-created rows, but also to previously active rows which are set to, and left in, the notInService state for a prolonged period exceeding that which is considered normal for such a conceptual row. Conceptual Row Suspension When a conceptual row is `active', the management station may issue a management protocol set operation which sets the instance of the status column to `notInService'. If the agent is unwilling to do so, the set operation fails with an error of `wrongValue' or `inconsistentValue'. Otherwise, the conceptual row is taken out of service, and a `noError' response is returned. It is the responsibility of the DESCRIPTION clause of the status column to indicate under what circumstances the status column should be taken out of service (e.g., in order for the value of some other column of the same conceptual row to be modified). Conceptual Row Deletion For deletion of conceptual rows, a management protocol set operation is issued which sets the instance of the status column to `destroy'. This request may be made regardless of the current value of the status column (e.g., it is possible to delete conceptual rows which are either `notReady', `notInService' or `active'.) If the operation succeeds, then all instances associated with the conceptual row are immediately removed. · Integer32

The status of this row. If the value of this object is not equal to active(1), all associated entries in the interfaceTopNTable shall be deleted by the agent.

Integer32 (1..65535)

An index that uniquely identifies an entry in the interfaceTopN table among those in the same report. This index is between 1 and N, where N is the number of entries in this report. Increasing values of interfaceTopNIndex shall be assigned to entries with decreasing values of interfaceTopNValue or interfaceTopNValue64, whichever applies, until index N is assigned to the entry with the lowest value of interfaceTopNValue / interfaceTopNValue64 or there are no more interfaceTopNEntries. No ports are included in a report where their value of interfaceTopNValue would be zero.

Integer32 (1..2147483647)

This object identifies the index corresponding to the dataSource for this entry. For sorted values of variables belonging to the IF-MIB, EtherLike-MIB or TOKENRING-MIB, this value equals the ifIndex of the interface. For sorted values of variables belonging to the RMON-MIB, this value equals the interface corresponding to the data source, pointed to by the value of etherStatsDataSource. For sorted values of variables belonging to the BRIDGE-MIB, this value equals the interface corresponding to the bridge port, pointed to by the value of dot1dBasePortIfIndex.

Gauge32

The value at the end of the sampling interval, or the amount of change in the selected variable during this sampling interval for the identified interface. The selected variable is that interfaces's instance of the object selected by interfaceTopNObjectVariable. This value may be normalized if interfaceTopNNormalization required equals 'true'. This value of this object will be computed for all cases when interfaceTopNObjectVariable points to a 32-bit counter or Gauge or when interfaceTopNObjectSampleType equals bandwidthPercentage(3), and will be zero for all other cases.

CounterBasedGauge64The CounterBasedGauge64 type represents a non-negative integer, which may increase or decrease, but shall never exceed a maximum value, nor fall below a minimum value. The maximum value can not be greater than 2^64-1 (18446744073709551615 decimal), and the minimum value can not be smaller than 0. The value of a CounterBasedGauge64 has its maximum value whenever the information being modeled is greater than or equal to its maximum value, and has its minimum value whenever the information being modeled is smaller than or equal to its minimum value. If the information being modeled subsequently decreases below (increases above) the maximum (minimum) value, the CounterBasedGauge64 also decreases (increases). Note that this TC is not strictly supported in SMIv2, because the 'always increasing' and 'counter wrap' semantics associated with the Counter64 base type are not preserved. It is possible that management applications which rely solely upon the (Counter64) ASN.1 tag to determine object semantics will mistakenly operate upon objects of this type as they would for Counter64 objects. This textual convention represents a limited and short-term solution, and may be deprecated as a long term solution is defined and deployed to replace it. (0..18446744073709551615) · Counter64

The value at the end of the sampling interval, or the amount of change in the selected variable during this sampling interval for the identified interface. The selected variable is that interfaces's instance of the object selected by interfaceTopNObjectVariable. This value may be normalized if interfaceTopNNormalization required equals 'true'. This value of this object will be computed for all cases when interfaceTopNObjectVariable points to a 64-bit counter, and will be zero for all other cases.