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Docsis 3.1

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Docsis 3.1

I'm experimenting with Docsis 3.1 on a Cisco cbr8 (downstream only at this time). I have a downstream setup and am awaiting a couple of modems to arrive to test my setup. Does anyone know if there is anything specific that needs to be done in the config file for the modem to help out and take advantage of the new carriers?


No, you don't need anything

No, you don't need anything special

Thank you sir!

Thank you sir!
I'm excited to try this out. My modems will be here this week.

I'm also experimenting with

I'm also working with some D3.1 configurations on CBR8. We have a Technicolor and a Ubee device but waiting on some more from vendors to get things moving in lab. Hopefully there will be more devices available soon from various vendors

I just recieved some Arris

I just recieved some Arris modems (8200a), but haven't connected them yet, I just finished delivering 2 more cbr's to a couple of our remote locations.
Hopefully I will get to play a bit later.

I'm expecting to get some of

I'm expecting to get some of those 8200 devices in next week. This week I got Netgear CM1000, Ubee UBC1301, and Technicolor TC4400. Got them all provisioned and connected to the CBR8. Got the preliminary configs done and the devices are online locked on the OFDM carrier. Interested to see what kind of performance I get.

I have been testing a TC4400

I have been testing a TC4400 with cBR8

Bonding group : 32 DOCSIS SC-QAM plus 1 x OFDM

Seemed to work OK with this settings :

max-ofdm-spectrum 192000000, ofdm channel-profile 2 width 192000000

But it was having packet loss problems (pinging the modem from CMTS) with these settings :
max-ofdm-spectrum 192000000, ofdm channel-profile 2 width 96000000
max-ofdm-spectrum 96000000, ofdm channel-profile 2 width 96000000

I'd be very interested to see if you have any similar problems

SW_REV: SR70.12.20; MODEL: TC4400-GEN

Thanks for the heads up.

Thanks for the heads up. Running the same firmware. Interesting the more narrow width caused issues. Will try to reproduce here at some point.

The D3.1 config documents

The D3.1 config documents from Cisco aren't exactly enlightening on how to set this up; for instance, their example in the current "Full Book" won't complete as given (errors out with the 'plc 663000000' statement)

Do you have a sample custom 'controller Integrated-Cable x/x/x' with OFDM, or are you using the IOS defaults?

Enquiring minds with a lab unit would love to try it out.

Thanks for looking


I decided to teach myself via the IOS "?" route, and got an OFDM channel running using the defaults in 03.18.01a.SP. I now have to figure out what this thing is doing, since Web speed tests are unable to give me a straight answer. :-)

A 96mhz wide channel, using the #2 OFDM channel profile, so far has returned 500mb+ downloads on it's own, using a single SC-QAM as the primary. Tying this to a 24-channel SC-QAM bonding group doesn't seem to bother the Arris CM8200A I'm using as the guinea pig, but I don't see increases in the downstream rate. Could be backhaul, could be the laptop, could be the test site ( and their HTML5-based test).

CMTS work just got 'fun' again.

Standard D1.1 config will be

Standard D1.1 config will be perfect. Rest is config on CBr8 . Work quite well.

Very interesting to read what

Very interesting to read what you already did with D3.1.
What you think, stable enough for a rollout to customers?
Anybody of you able to compare D31 DS service with a Casa CMTS with DS8x192 linecards?
I would prefer US D31 service. But I think I have to wait some more months. Any rumors when Cisco starts supporting US D31?

It's stable for rollout -

It's stable for rollout - question for cost of CM there is still issue with that.
D3.1 will consume bandwidth from D3.0 and D3.1 so you can start with smaller channel and still give 1Gbit to customer.
But to be honest - for now it's still better to pump D3.0 into the platform 32DS etc..
US DS3.1 - modems are the issue. Cisco plan is to support this end Q1/Q2 this year.