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Arris CMTS 1500 QAM16

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Arris CMTS 1500 QAM16


I'm working with this CMTS and trying to squeeze the most out of the upstream. I'd like to go from QPSK to QAM16. The docs aren't doing it for me. I can't seem to figure out their modulation profiles and the whole mod-iuc-list thing. By default everything uses modulation profile 1. Here is what the mod-iuc-list shows:

Modulation list

IUC Control Type PreLn DfEnc F-EC F-CL ScrOn ScrSeed BstSz GuardSz LastCW
--- ------- ----- ----- ----- ---- ---- ----- ------- ----- ------- ------
R active qpsk 64 false 0 16 true 338 0 8 false
RD off qpsk 72 false 5 75 true 338 0 8 false
IR active qpsk 128 false 5 34 true 338 0 48 false
PR active qpsk 128 false 5 34 true 338 0 48 false
SD active qpsk 72 false 5 75 true 338 12 8 true
LD active qpsk 80 false 8 220 true 338 0 8 true

I can't get the command: modulation// to work. What's ?


Arris CMTS 1500 QAM16

Eric -

The command (at downstream level) is: mod qam64, or, mod qam256.

He's trying to change the

He's trying to change the upstream modulation, not downstream.

Sorry, I can't help with answer though, don't know anything about Arris CMTS

I would think it easy enough to locate some other example running confs to copy though. Just google for some "Arris words" that appear in the Arris CMTS conf. That should give you some examples.

Figured it out!

Hi all,

Hope this helps someone.

once logged in:
modulation/1/R or modulation/1/RD or modulation/etc (see mod-iuc-list show data)
type qam16

thanks it! It seems way more efficient than QPSK. I'm getting the most of of these boxes for as long as I can.


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