Chapter 9: Upstream Cable Access Modules (UCAMs)
STANDARD Revision 1.0
C4® CMTS Release 8.3 User Guide
© 2016 ARRIS Enterprises LLC. All Rights Reserved.
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0x3FFF
implies all CMs (broadcast)
0x3FFx
where x is a value of 0x1 to 0xE used to indicate that a data message must fit in x number of minislots. This
can only be used in the Request/Data IE (broadcast).
0x3Exx
This can only be used in the Request IE to allow different priorities to use the request region (broadcast).
If bit 0x01 is set, priority 0 can request
If bit 0x02 is set, priority 1 can request
If bit 0x04 is set, priority 2 can request
If bit 0x08 is set, priority 3 can request
If bit 0x10 is set, priority 4 can request
If bit 0x20 is set, priority 5 can request
If bit 0x40 is set, priority 6 can request
If bit 0x80 is set, priority 7 can request
The following SID values have special meaning for 12U or 24U CAMs:
0x1FFF
used for FFT (fast Fourier Transform) measurements
0x1FFE
used for ingress cancellation
Redefining the values of an upstream modulation profile affects all the upstream channels that are using that modulation
profile. To display what upstream modulation profile is used on an upstream channel, use one of the following CLI
commands:
show controllers cable-upstream <slot>/<port>
configure interface cable-upstream <slot>/<port> cable show
The system response contains a line similar to the following:
Modulation profile id: 2
To redefine the values of an upstream modulation profile, use the following CLI command:
configure cable modulation-profile <id> iuc <interval usage code> [mod <qpsk |qam8
|qam16|qam32|qam64|qam128>] [pre-len <preamble len>] [diff <true|false>] [fec-tbytes <no of
bytes>] [fec-len <FEC code word length>] [seed <scrambler seed>] [burst-len <max burst len>]
[last-cw <true|false>] [scrambler <true|false>] [guard-time-size <0|8
–
96|no>] [int-depth <depth>]
[int-blocksize <blocksize>] [pre-type <preamble type>] [tcm <on|off>] [int-stepsize <stepsize>]
[spreader <on |off>] [subframe-code <subframe size>] [docsis-mode <tdma | atdma | scdma |
tdma-atdma>]
Modulation Profile Values
Default values for the various modulation profile parameters may change according to the IUC selected. To display the
values associated with a modulation profile number 2, for example, use the following command: