Specifications

Avg percent minislots lost on
late Maps
Average percent of slots lost because a
MAP interrupt was too late
Total channel bw reserved
Total amount of bandwidth reserved by
all modems sharing this upstream channel
that require bandwidth reservation. The
Class of Service for these modems
specifies some non−zero value for the
guaranteed upstream rate. When one of
these modems is admitted on the
upstream, this field value is incremented
by this guaranteed−upstream rate value.
Note: Check the noise and microreflection counters. They should be very low values and, in a normal cable
plant, increment slowly. If they are at a high value and increment quickly it typically indicates a problem with
the RF plant.
Note: Check for uncorrectable errors. These typically indicate a problem with noise within the RF plant.
Check the received upstream SNR level.
Use the show cable hop command to check the correctable and uncorrectable FEC error counts for a specific
interface or upstream port. Consider that uncorrectable FEC errors result in dropped packets. Correctable FEC
errors are right before uncorrectable FEC errors, and should be considered a warning sign of uncorrectable
errors yet to come. The information from show cable hop describes the frequency hop status of an upstream
port. (Please see the table below for a further information on this output.)
VXR#show cable hop cable 6/1 upstream 0
Upstream Port Poll Missed Min Missed Hop Hop Corr Uncorr
Port Status Rate Poll Poll Poll Thres Period FEC FEC
(ms) Count Sample Pcnt Pcnt (sec) Errors Errors
Cable6/1/U0 20.000 MHz 1000 * * * set to fixed frequency * * * 10 1
VXR#
Upstream
Port
The upstream port for this information line
Port Status
Lists the status of the port. Valid states are down if
frequency is unassigned or administrative down if the port is
shut down. If the port is up, this column shows the center
frequency of the channel.
Poll Rate The rate that station maintenance polls are generated (in
milliseconds).
Missed Poll
Count
The number of missing polls
Min Poll
Sample
The number of polls in the sample.
Missed
PollPcnt The ratio of missing polls to the number of polls, expressed
as a percentage
Hop Thres
Pcnt The level that the missed poll percentage must exceed to
trigger a frequency hop, expressed as a percentage.
Hop Period
Cisco − Determining RF or Configuration Issues On the CMTS