packetGroupStats
packetGroupStats - retrieve statistics associated with a packet group.
SYNOPSIS
packetGroupStats sub-command options
DESCRIPTION
The packetGroupStats command is used to retrieve the statistics associated with packet groups, such as minimum latency, maximum latency and average latency. Some of the statistics are only available on specific types of ports; an attempt to read an unavailable statistic results in a error. Refer to Appendix B of the Ixia Reference Guide for list of which statistics are available.
Three sub-commands are used to retrieve the actual statistics.
- packetGroupStats get chasID cardID portID [fromPGID toPGID]: this fetches a range of statistics for the indicated port. The range is dictated by the fromPGID to the toPGID; if omitted, only PGID 0 is retrieved.
- packetGroupStats getGroup index: this fetches the statistics for a PGID that is PGID = fromPGID + index, where fromPGID is the value from the last call to packetGroupStats get. That is, index = 0 refers to the fromPGID packet group ID.
- packetGroupStats getFrameCount index: operates in the same manner as getGroup, with respect to the index parameter.
An additional feature available on some port types is the ability to collect latency measurements per packet group. The availability of this feature for a given port can be tested using the port isValidFeature... portFeatureRxLatencyBin. The port must be configured for wide packet groups (the port's receiveMode includes the portRxModeWidePacketGroup bit); the availability of this mode may be tested with port isValidFeature... portFeatureRxWidePacketGroups. (Note: When the port is in PRBS mode, all latency specific stats is removed.)
Latency bin dividing times must be set up with the packetGroup's enableLatencyBins, latencyBinList option. Following a call to packetGroupStats getGroup, the numLatencyBins option is set and the latency bin information is available through calls to getFirstLatencyBin, getNextLatencyBin and getLatencyBin. The latency information is available in the options of the latencyBin command. Note that there is one more latency bin available than the number of dividers set in packetGroup's latencyBinList, due to the implicit creation of a latency bin from the last divider to the maximum possible latency value.
An additional feature available on some port types is the ability to measure latency over time, per packet group. The availability of this feature for a given port can be tested using the port isValidFeature... portFeatureRxTimeBin. The port must be configured for wide packet groups (the port's receiveMode includes the portRxModeWidePacketGroup bit); the availability of this mode may be tested with port isValidFeature... portFeatureRxWidePacketGroups.
Time bins must be set up with the packetGroup's enableTimeBins, numPgidPerTimeBin, numTimeBins and timeBinDuration options. Following a call to packetGroupStats getGroup, the numTimeBins, numPgidPerTimeBin and timeBinDuration options are set. Latency information for a particular time bin can be obtained by using the additional timeBin argument to the getGroup and getGroupFrameCount sub-commands.
STANDARD OPTIONS
averageLatency
Read-only. 64-bit value. Average latency for all frames of this packet group. Updated after packetGroupStats getGroup command is called.
Used for cut-through, store-forward, and inter-arrival statistics.
bigSequenceError
Read-only. 64-bit value. The number of times when the current sequence number minus the previous sequence number is greater than the error threshold. (Also available in PRBS mode, depending on sequence checking settings.)
bitRate
Read-only. 64-bit value. The bit rate for the frames. Note: this value is calculated on the difference between two successive readings; packetGroupStats get must be called at least twice before valid values are obtained. (Also available in PRBS mode.)
byteRate
Read-only. 64-bit value. The byte rate for the frames. Note: this value is calculated on the difference between two successive readings; packetGroupStats get must be called at least twice before valid values are obtained. (Also available in PRBS mode.)
duplicateFrames
Read-only. 64-bit value. The number of duplicate frames when the port is in multi-switched path mode; that is, the sequenceCheckingMode in the packetGroup command is set to seqMultiSwitchedPath. (Also available in PRBS mode, depending on sequence checking settings.)
duplicatePacketCount
Read-only. 64-bit value. Count of packets that were determined to be duplicates. A received test packet is a duplicate if its value falls within the current sequence run. (A sequence run is a series of sequence numbers from the received test packets that is equal to or less than expected. The sequence run ends when the received sequence number is greater than expected, creating a gap in the series, and a new sequence run is initiated). The sequence run contains all of the sequence numbers from the start of the series up to one less than the expected value. Consequently, a received sequence number that falls within the current series must be a duplicate. Received sequence numbers are not checked against previous sequence runs. Therefore, undetected duplicate packets are counted as Reordered or Late.
firstTimeStamp
Read-only. 64-bit value. The time stamp of the first packet received. This is only available when the port is in wide packet group mode; that is, the port's receiveMode includes the portRxModeWidePacketGroup bit. (Also available in PRBS mode.)
frameRate
Read-only. 64-bit value. The frame rate for the frames. Note: this value is calculated on the difference between two successive readings; packetGroupStats get must be called at least twice before valid values are obtained. (Also available in PRBS mode.)
inOrderPacketCount
Read-only. 64-bit value. Count of received packets that contain sequence numbers equal to or greater than expected. The expected value is set to one greater than the largest sequence number received. When packets are in order, the frames are received when expected. The In Order count is derived by software in the following manner: In Order = Received Frames - Duplicate - Reordered – Late.
lastTimeStamp
Read-only. 64-bit value. The time stamp of the last packet received. This is only available when the port is in wide packet group mode; that is, the port's receiveMode includes the portRxModeWidePacketGroup bit. (Also available in PRBS mode.)
latePacketCount
Read-only. 64-bit value. Count of received packets that contain sequence numbers that are less than expected, were not counted Duplicate, and are less than the Late Threshold value. Received sequence numbers that are less than expected are due to packets that arrived later than the adjacent packets of the transmitted packet sequence. The threshold may be adjusted to allow these packets to be classified as Reordered (if they arrive before the Late Threshold) or Late (if they arrive after the Late Threshold).
lostPacketCount
Read-only. 64-bit value. Frames that were counted as Unknown, but later arrive (and counted as Reordered or Late) are referred to as Lost. The Lost count can be derived by software in the following manner: Lost = Unknown - Reordered – Late. It is possible that this equation results in a negative number, which the software treats as 0.
maxDelayVariation
Read-only. 64-bit value. Maximum Delay Variation. The largest of all delay variations measured for a specific flow from the start of statistic collection.
maxLatency
Read-only. 64-bit value. Maximum latency of all frames of this packet group. Updated after packetGroupStats getGroup command is called.
Used for cut-through, store-forward, and inter-arrival statistics.
maxMinDelayVariation
Read-only. 64-bit value. The interval between the Maximum and Minimum Delay Variation. The mathematical subtraction of Min DV from Max DV.
maxminInterval
Read-only. 64-bit value. The interval between the Maximum and Minimum Latency measurement. Updated after packetGroupStats getGroup command is called. Used for cut-through, store-forward, and inter-arrival statistics.
minDelayVariation
Read-only. 64-bit value. Minimum Delay Variation. The smallest of all delay variations measured for a specific flow from the start of statistic collection.
minLatency
Read-only. 64-bit value. Minimum latency of all frames of this packet group. Updated after packetGroupStats getGroup command is called.
Used for cut-through, store-forward, and inter-arrival statistics.
numGroups
Read-only. The total number of groups that were actually received.
numLatencyBins
Read-only. The number of latency bins available for a given packet group. Updated after packetGroupStats getGroup command is called. Note that there is one more latency bin available than the number of dividers set in packetGroup's latencyBinList, due to the implicit creation of a latency bin from the last divider to the maximum possible latency value.
numPgidPerTimeBin
Read-only. The number of packet group IDs that were used for each time bin, if time bins were enabled and configured in the packetGroup command. This is the same as the same named option used in the packetGroup command when time bins were set up for the port.
numTimeBins
Read-only. The number of time bins used, if time bins were enabled and configured in the packetGroup command. This is the same as the same named option used in the packetGroup command when time bins were set up for the port.
prbsBerRatio
Read-only. 64-bit value. Ratio of PRBS errored bits to bits received.
prbsBitsReceived
Read-only. 64-bit value. Number of PRBS bits received.
prbsErroredBits
Read-only. 64-bit value. Number of PRBS errored bits received.
readTimeStamp
Read-only. Reads the timestamp from when the statistics of a packet group were obtained.
reorderedPacketCount
Read-only. 64-bit value. Count of received packets that contain sequence numbers that are less than expected, but were not counted as Duplicate, and are greater than or equal to the Late Threshold value.
reverseSequenceError
Read-only. 64-bit value. The number of times when the current sequence number is less than the previous sequence number. (Also available in PRBS mode, depending on sequence checking settings.)
sequenceGaps
Read-only. 64-bit value. The number of sequence gaps when the port is in multi-switched path mode; that is, the sequenceCheckingMode in the packetGroup command is set to seqMultiSwitchedPath. (Also available in PRBS mode, depending on sequence checking settings.)
smallSequenceError
Read-only. 64-bit value. The number of times when the current sequence number minus the previous sequence number is less than or equal to the error threshold and not negative, or when the current sequence number is equal to the previous sequence number. (Also available in PRBS mode, depending on sequence checking settings.)
standardDeviation
Read-only. 64-bit value. When latency bins are used, this is the standard deviation of the latencies, using each bin's average.
timeBinDuration
Read-only. The time bin duration expressed in nanoseconds, if time bins were enabled and configured in the packetGroup command. This is the same as the same named option used in the packetGroup command when time bins were set up for the port.
totalByteCount
Read-only. 64-bit value. The number of bytes used to calculate the statistics for this packet group.
totalFrames
Read-only. 64-bit value. Total number of frames used to calculate the statistics for this packet group.
totalSequenceError
Read-only. 64-bit value. The sum of the small, bug and reverse sequence errors. (Also available in PRBS mode, depending on sequence checking settings.)
avgDelayVariation
Read only. 64-bit value. Average Delay Variation. The average of all delay variations measured for a specific flow from the start of statistic collection.
COMMANDS
The packetGroupStats command is invoked with the following sub-commands. If no sub-command is specified, returns a list of all sub-commands available.
packetGroupStats cget option
Returns the current value of the configuration option given by option. Option may have any of the values accepted by the packetGroupStats command.
packetGroupStats clear chasID cardID portID groupIdPairList
Clears all packet group stats for the specified Group ID Pair List, where the list consists of ranges expressed with pairs like this: {{1 100} {300 400} {500 500}}
Note: {500 500} can also be written as {500: it selects a single value, which is also understood as the range from 500 to 500.
This command clears the PGIDStats for PGIDs in the Group ID Pair List. To clear individual rows of packet groupstats on the port, the port must either be unowned or you must be logged in as the owner of the port. Specific errors are:
- No connection to a chassis
- The port doesn't support the command: ixTcl_unsupportedFeature
- Invalid port number or port is used by someone else: ixTcl_notAvailable
- Invalid PGIDList
- Failed to execute the clear command
- Any group ID is outside the legal range
packetGroupStats clearTimeStamps chasID cardID portID groupIdPairList
Clears all packet group time stamps for the specified Group ID Pair List, where the list consists of ranges expressed with pairs like this: {{1 100} {300 400} {500 500}}. Specific errors are:
- No connection to a chassis
- The port doesn't support the command: ixTcl_unsupportedFeature
- Invalid port number or port is used by someone else: ixTcl_notAvailable
- Invalid PGIDList
- Failed to execute the clear command
- Any group ID is outside the legal range
packetGroupStats reArmFirstFrameTimeStamp chasID cardID portID groupIDPairList
Gets the timestamp value of the first frame.
packetGroupStats get chasID cardID portID [fromGroupID toGroupID]
Gets the current Packet Group statistics on the port. Call this command before calling packetGroupStats getGroup index and packetGroupStats cget option value to get the value of the configuration option. fromGroupID and toGroupID are optional and default to 0. In order for this command to succeed, the port must either be unowned, or you must be logged in as the owner of the port. Specific errors are:
- No connection to a chassis
- Invalid port number
- The fromGroupID or toGroupID is invalid
- Network error between the client and the chassis
- Either group ID is outside the legal range
packetGroupStats getFirstLatencyBin
Following a call to packetGroupStats getGroup, a call to this sub-command makes the values associated with the first latency bin available through the latencyBin command. Specific errors are:
- No latency bins are available
packetGroupStats getGroup index [timeBin]
Gets the Packet Group statistics for this index and particular timeBin. If timeBin is omitted, a value of 1 is used. Before calling this command, packet group statistics must be retrieved using the packetGroupStats get chasID cardID portID [fromGroupID toGroupID] command. The index is with respect to the range of group IDs retrieved; for example, index = 0 always refers to the data associated with fromGroupID in the last packetGroupStats get call. The last index corresponds to (toGroupID - fromGroupID). Specific errors are:
- No packet groups are defined
- No packets were counted in packet group groupID
- Either groupID is outside the legal range
packetGroupStats getGroupFrameCount index [timeBin]
Gets the Packet Group statistics for this index and timeBin and returns the number of frames in the group / time bin. If timeBin is omitted, a value of 1 is used. Before calling this command, packet group statistics must be retrieved using the packetGroupStats get chasID cardID portID [fromGroupID toGroupID] command. The first group available is always 0 and corresponds to the fromGroupID argument to packetGroupStats get. The last group is (toGroupID - fromGroupID).
packetGroupStats getLatencyBin lbIndex
Following a call to packetGroupStats getFirstLatencyBin, a call to this sub-command makes the values associated with the latency bin specified by lbIndex available through the latencyBin command. Specific errors are:
- Invalid latency bins number
- The specified latency bin number does not exist
packetGroupStats getNextLatencyBin
Following a call to packetGroupStats getFirstLatencyBin, a call to this sub-command makes the values associated with the next latency bin available through the latencyBin command. Specific errors are:
- No more latency bins are available
packetGroupStats setDefault
Zeros all local statistics in the packet group stat list.
EXAMPLES
See examples under packetGroup.