
3-172
Cisco Broadband Cable Command Reference Guide
OL-1581-08
Chapter 3 Cisco CMTS Show Commands
show controllers cable
Interface Cable5/1/4
Hardware is MC520S
JIB version 66
Cable5/1/4 Upconverter is Enabled Output is Enabled
Model: 74-2094-04 Serial Number: 0WAV0649000L CLEI Code: FFFFFFFFFF
HW Rev: PC2D0108 SW Rev: 010, NVRAM Rev: 006 ECI number FFFFFF
Downstream Frequency 255.0000 MHz
RF Power 49.8 dBmv
...
Router#
Table 3-45
describes the fields shown in the
show controllers cable upstream
display.
Table 3-45 show controllers cable upstream Command Field Descriptions
Field
Description
Cable
Slot number/port number indicating the location of the Cisco cable
interface line card.
Upstream is up/administratively
down
Indicates the administrative state of the upstream (whether it is
shutdown or not).
Channel Width
Indicates the width of the RF upstream channel.
QPSK Symbol Rate
Indicates the modulation technique for upstream transmission.
Spectrum Group 4
Indicates the spectrum group associated with this slot and port.
Frequency
Transmission frequency of the RF upstream channel.
Note
Cisco cable interface line cards always program the
upstream’s center frequency in 16 KHz increments, and
this is the frequency displayed by the lines added to the
router’s configuration and by the
show controllers cable
upstream
command. For example, if you use the
cable
upstream frequency
command to specify a center
frequency of 27 MHz (
cable upstream x frequency
27000000
), the actual center frequency will be 27.008
MHz, which is the next highest 16 KHz boundary.
SNR measurement
Estimate for the overall signal-to-noise ratio (SNR) for cable
interfaces that do not include onboard hardware-based spectrum
management. For most cable interface line cards, this value reflects
the Modulation Error Rate (MER) value for the upstream (as
calculated according to the IEEE 802.14 PHY layer specifications).
The MER is sometimes incorrectly referred to as the carrier-to-
noise ratio (CNR), and the SNR value is generally lower than the
CNR value.
Note
In Cisco IOS Release 12.1(10)EC1 and Cisco IOS Release
12.2(4)BC1b, the algorithm for calculating the SNR
estimate was refined for a more accurate value. Depending
on the plant characteristics, the new SNR estimate could be
up to 6 dB lower than the values shown in earlier software
releases. This value is only an estimate—for the most
accurate value, use a spectrum analyzer.
Содержание Broadband Cable
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Страница 1216: ...6 214 Cisco Broadband Cable Command Reference Guide OL 1581 07 Chapter 6 Cable CPE Commands debug usb ...
Страница 1266: ...A 50 Cisco Broadband Cable Command Reference Guide OL 1581 07 Appendix A Using the ROM Monitor unset ...