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Cisco Broadband Cable Command Reference Guide
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Chapter 2 Cisco CMTS Configuration Commands
cable upstream maintain-psd
cable upstream maintain-psd
To require DOCSIS 2.0 CMs on an A-TDMA-only upstream to maintain a constant power spectral
density (PSD) after a modulation rate change, use the
cable upstream maintain-psd
command in cable
interface configuration mode. To return to the default behavior, so that CMs do not need to maintain their
power spectral density, use the
no
form of this command.
cable upstream
uport
maintain-psd
no cable upstream
uport
maintain-psd
Syntax Description
Defaults
Cable modems are not required to maintain their power spectral density after a modulation rate change
(
no cable upstream maintain-psd
).
Note
In Cisco IOS Release 12.2(15)BC2 and later releases, this command is automatically removed from the
configuration when you configure an upstream for a TDMA-only or mixed TDMA/A-TDMA
configuration.
Command Modes
Interface configuration (cable interface only)
Command History
Usage Guidelines
Use this command to specify whether DOCSIS 2.0 CMs should maintain their power spectral density
when the Cisco CMTS changes their upstream modulation rate in an upstream channel descriptor (UCD)
message. When you configure an upstream with the
cable upstream maintain-psd
command, the
Cisco CMTS sets TLV 15 (Maintain Power Spectral Density) to ON in the UCD messages it sends to the
CMs on that upstream.
When TLV 15 is on, and when the new UCD specifies a new upstream modulation rate for the CM, the
CM must change its transmit power level to keep its power spectral density as close as possible to what
it was before the modulation rate change. The CM must maintain this power spectral density until the
CMTS sends a power adjustment command in a Ranging-Response (RNG-RSP) message.
uport
Specifies the upstream port to be configured. Upstream port values start
with 0 and end with a value that depends on the number of upstream ports
on the cable interface line card.
Release
Modification
12.2(15)CX
This command was introduced to support DOCSIS 2.0 operations on
the Cisco uBR-MC16U/X and Cisco uBR-MC28U/X cable interface
line card.
12.2(15)BC2
Support was added for DOCSIS 2.0 operations on the
Cisco uBR-MC5X20S/U cable interface line cards.
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 ...