Cisco SR2016T-NA Reference Manual page 365

Chapter 2 Cisco CMTS Configuration Commands
cable upstream threshold
To configure the upstream for the carrier-to-noise ratio (CNR) and Forward error correction (FEC)
threshold values to be used in determining the allowable noise levels, use the cable upstream threshold
command in cable interface configuration mode.
This command can be used only on upstreams on the Cisco uBR-MC16S cable interface line cards.
Note
Syntax Description
n
cnr-profile1 threshold1-in-
DB
cnr-profile2 threshold2-in-
DB
corr-fec fec-corrected
uncorr-fec fec-uncorrected
Defaults The CNR threshold for the primary modulation profile defaults to 25 dB. The CNR threshold for the
secondary modulation profile defaults to 15 dB. The correctable FEC error threshold defaults to
3 percent of total packets received, and the uncorrectable FEC error threshold defaults to 1 percent of
total packets received.
The ranges and defaults for the correctable and uncorrectable FEC error thresholds were changed in
Note
Cisco IOS Release 12.2(8)BC2.
Command Modes Interface configuration (cable interface only)
OL-1581-08
cable upstream n threshold cnr-profile1 threshold1-in-dB cnr-profile2 threshold2-in-dB
corr-fec fec-corrected uncorr-fec fec-uncorrected
Specifies the upstream port number. Valid values start with 0 for the
first upstream port on the cable interface line card.
Specifies the CNR threshold for the primary modulation profile
specified for the upstream. The threshold is specified in dB (5–35,
default is 25).
Specifies the CNR threshold for the secondary modulation profile
specified for the upstream. The threshold is specified in dB (5–35,
default is 15 dB and must be less than the primary threshold).
Specifies the allowable number of correctable FEC errors for the
upstream. The fec-corrected parameter is given as a percentage of total
packets received on the upstream during the polling period, with a valid
range of 1 to 30, and a default of 3.
Specifies the allowable number of uncorrectable FEC errors for the
upstream. The fec-uncorrected parameter is given as a percentage of
total packets received on the upstream during the polling period, with a
valid range of 1 to 30, and a default of 1.
For normal plant use, Cisco recommends that the uncorrectable
Note
FEC threshold remain at its default of 1 percent to avoid an
unacceptable number of errors on the channel.
Cisco Broadband Cable Command Reference Guide
cable upstream threshold
2-353