docsIfCmtsChannelUtUtilization
1.3.6.1.2.1.10.127.1.3.9.1.3
The calculated and truncated utilization index for this
physical upstream or downstream channel, accurate as of
the most recent docsIfCmtsChannelUtilizationInterval.
Upstream Channel Utilization Index:
The upstream channel utilization index is expressed as a
percentage of minislots utilized on the physical channel, regardless
of burst type. For an Initial Maintenance region, the minislots
for the complete region are considered utilized if the CMTS
received an upstream burst within the region from any CM on the
physical channel. For contention REQ and REQ/DATA regions, the
minislots for a transmission opportunity within the region are
considered utilized if the CMTS received an upstream burst within
the opportunity from any CM on the physical channel. For all other
regions, utilized minislots are those in which the CMTS granted
bandwidth to any unicast SID on the physical channel.
For an upstream interface that has multiple logical upstream
channels enabled, the utilization index is a weighted sum of
utilization indices for the logical channels. The weight for
each utilization index is the percentage of upstream minislots
allocated for the corresponding logical channel.
Example:
If 75% of bandwidth is allocated to the first logical channel
and 25% to the second, and the utilization indices for each are
60 and 40 respectively, the utilization index for the upstream
physical channel is (60 * 0.75) + (40 * 0.25) = 55. This figure
applies to the most recent utilization interval.
Downstream Channel Utilization Index:
The downstream channel utilization index is a percentage expressing
the ratio between bytes used to transmit data versus the total number
of bytes transmitted in the raw bandwidth of the MPEG channel. As
with the upstream utilization index, the calculated value represents
the most recent utilization interval.
Formula:
Downstream utilization index =
(100 * (data bytes / raw bytes)) =
(100 * ((raw bytes - stuffed bytes) / raw bytes))
Definitions:
Data bytes: Number of bytes transmitted as data in the
docsIfCmtsChannelUtilizationInterval.
Stuffed bytes: Number of filler bytes transmitted as non-data in the
DocsIfCmtsChannelUtilizationInterval.
Raw bandwidth: Total number of bytes available for transmitting data,
not including bytes used for headers and other overhead.
Raw bytes: (raw bandwidth * docsIfCmtsChannelUtilizationInterval).