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cable modulation-profile
seed
diff
pre-len
last-cw
uw-len
Defaults
Modulation profile 1 is defined as a qpsk Time Division Multiple Access (TDMA) profile.
In Cisco IOS Release 12.2(15)CX, Release 12.2(15)BC2 and later releases, additional modulation
profiles are defined as the default mixed TDMA/A-TDMA profile and the default Advanced TDMA (A-
TDMA) profile. The modulation profile numbers for these default values are 1, 41, 101, 121, 201, 221,
or 241, depending on the cable interface line cards being used (see
The default profiles (1, 41, 101, 121, 201, 221, or 241) cannot be deleted. Using the no cable
Note
modulation-profile command on these particular profiles resets them to their original, default values.
Command Modes
Global configuration
Command History
Release
11.3 NA
12.0(7)XR2
12.0(6)SC and 12.1(3a)EC1
12.2(8)BC2
12.2(11)CY
12.2(15)CX
12.2(15)BC2
Cisco Broadband Cable Command Reference Guide
2-170
(Required if scrambler option used) Scrambler seed in hexadecimal
format. Valid values are from 0000 to 7FFF.
Enable or disable differential encoding. Valid entries are diff and no-diff.
Note
In DOCSIS 2.0 mode, differential encoding cannot be enabled for
the 8-QAM, 32-QAM, and 64-QAM modulations.
Preamble length in bits. Valid values are from 2 to 512.
Handling of FEC for last code word. Valid entries are fixed for fixed code-
word length and shortened for shortened last code word.
Upstream unique word length. Enter uw8 for 8-bit unique code words or
uw16 for 16-bit unique code words.
Modification
This command was introduced.
This command was supported.
The mix, qpsk, and qam-16 options were added.
Support was added for the Cisco uBR10012 router.
Support was added for the Cisco uBR-MC5X20S cable interface line
card. This includes creating default modulation profile 21 for the
card.
Support was added for the Cisco uBR-MC16U/X and
Cisco uBR-MC28U/X cable interface line card, including support for
DOCSIS 2.0 A-TDMA and mixed modulation profiles on this card.
The robust predefined modulation profiles were also added for all
modes of operation. The robust profiles use a longer preamble to
provide better handling of noise on the upstream, but they also
consume more bandwidth at the PHY layer than the other profiles.
Support was added for the Cisco uBR-MC5X20S/U cable interface
line cards, including support for DOCSIS 2.0 A-TDMA and mixed
modulation profiles. Support for the IUC-11 burst profile (Advanced
UGS, a-ugs) was also added for mixed TDMA/A-TDMA modulation
profiles.
Chapter 2
Cisco CMTS Configuration Commands
Table 2-5 on page
2-171).
OL-1581-08
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