Status in source: current.
Technical details
{
"smi_kind": "OBJECT-TYPE",
"definition": [
"docsPnmCmDsHistTable",
"OBJECT-TYPE",
"SYNTAX",
"SEQUENCE",
"OF",
"DocsPnmCmDsHistEntry",
"MAX-ACCESS",
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"STATUS",
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"DESCRIPTION",
"\"The purpose of the downstream histogram is to provide a measurement of nonlinear effects in the channel such as amplifier compression and laser clipping. For example, laser clipping causes one tail of the histogram to be truncated and replaced with a spike. The CM captures the histogram of time domain samples at the wideband front end of the receiver (full downstream band). The histogram is two-sided; that is, it encompasses values from far-negative to far-positive values of the samples. The histogram has either 256 or 255 equally spaced bins. These bins typically correspond to the 8 MSBs of the wideband analog-to-digital converter (ADC). The histogram dwell count, a 32-bit unsigned integer, is the number of samples observed while counting hits for a given bin, and may have the same value for all bins. The histogram hit count, a 32-bit unsigned integer, is the number of samples falling in a given bin. The CM reports the dwell count per bin and the hit count per bin. When enabled, the CM computes a histogram with a dwell of at least 10 million samples at each bin in 30 seconds or less. The CM continues accumulating histogram samples until it is restarted, disabled or times out. If the highest dwell count approaches its 32-bit overflow value, the CM stops counting and sets the docsPnmCmDsHistMeasStatus attribute to 'sampleReady'. The CM reports the start and end time of the histogram measurement using bits 21-52 of the extended timestamp, which provides a 32-bit timestamp value with resolution of 0.4 ms and range of 20 days. This table will have a row for each ifIndex for the modem. \"",
"REFERENCE",
"\"DOCSIS 3.1 Cable Modem Operations Support System Interface Specification CM-SP-CM-OSSIv3.1, PNM section.\"",
"::=",
"{",
"docsPnmCmObjects",
"9",
"}"
],
"syntax_tree": [
[
"conceptualTable",
[
"row",
"DocsPnmCmDsHistEntry"
]
],
null,
[
"MaxAccessPart",
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],
[
"Status",
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],
[
"DESCRIPTION",
"The purpose of the downstream histogram is to provide a measurement of nonlinear effects in the channel such as amplifier compression and laser clipping. For example, laser clipping causes one tail of the histogram to be truncated and replaced with a spike. The CM captures the histogram of time domain samples at the wideband front end of the receiver (full downstream band). The histogram is two-sided; that is, it encompasses values from far-negative to far-positive values of the samples. The histogram has either 256 or 255 equally spaced bins. These bins typically correspond to the 8 MSBs of the wideband analog-to-digital converter (ADC). The histogram dwell count, a 32-bit unsigned integer, is the number of samples observed while counting hits for a given bin, and may have the same value for all bins. The histogram hit count, a 32-bit unsigned integer, is the number of samples falling in a given bin. The CM reports the dwell count per bin and the hit count per bin. When enabled, the CM computes a histogram with a dwell of at least 10 million samples at each bin in 30 seconds or less. The CM continues accumulating histogram samples until it is restarted, disabled or times out. If the highest dwell count approaches its 32-bit overflow value, the CM stops counting and sets the docsPnmCmDsHistMeasStatus attribute to 'sampleReady'. The CM reports the start and end time of the histogram measurement using bits 21-52 of the extended timestamp, which provides a 32-bit timestamp value with resolution of 0.4 ms and range of 20 days. This table will have a row for each ifIndex for the modem."
],
[
"REFERENCE",
"DOCSIS 3.1 Cable Modem Operations Support System Interface Specification CM-SP-CM-OSSIv3.1, PNM section."
],
null,
null,
null
]
}