Arris SB8200 Has No DOCSIS 3.1 Upstream

I recently upgraded our modem to take advantage of the 3.1 standard. Consulting Comcast's list of approved equipment we selected the SB8200. We are on the Starter pkg in the Denver area.

The modem indicates 3.1 / blue on the downstream but the upstream is showing 3.0 / green. Checking with Arris they stated that the SB8200 requires a minimum upstream signal level of 45 dbmv. The current levels provided by Comcast are 38 - 42 across the 4-upstream channels.

Regarding resolution of the issue I'm having, Arris points to this minimum requirement and Comcast points to the signal levels as meeting Comcast's specification which leaves me still pointing to the green DOCSIS 3.0 upstream indication. Comcast refuses to adjust the signal level higher and yet still lists the SB8200 on their approved list. They also pretty much have a "who cares" attitude and their solution is, expectedly, to lease one of their modems.

1. Does the failure of the upstream to utilize 3.1 have anything to do with the starter package speeds?

2. Is anyone using a modem that achieves 3.1 on the upstream channels with signal levels at or below 42 dbmv?

Thanks in advance for your reply!

Responses

Accepted Solution

CC_Jessie

Retired Employee

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178 Messages

6 years ago

@ksj,

I apologize for the delayed response and the confusion that you are experiencing. I think I can shed some light to this situation. DOCSIS (Data-Over-Cable Service Interface Specification, is the specification for transmission of data over a cable network that has been approved by the ITU as an international standard) modems with a higher DOCSIS specification (e.g., DOCSIS 3.1) are able to deliver faster Internet upload/download speeds. This only means that DOCSIS 3.1 modems have the capability of handling faster speeds, if you are on our Starter package you would not need a DOCSIS 3.1 compatible modem. At this time DOCSIS 3.1 capabilities are reserved for our 500 Mbps and 1Gbps speed tiers. Additionally, your business location must be in range of a DOCSIS 3.1 enabled headend and have a DOCSIS 3.1 enabled modem (which you do have). If your business does meet all three of these qualifications you will be automatically on our DOCSIS 3.1 network for both upload and download.

If you would like to upgrade your service or discuss more about your account specifically please contact our Engagement Specialist Comcast_Phil.

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DrDeke

New problem solver

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12 Messages

6 years ago

To the best of my knowledge, Comcast has not yet deployed DOCSIS 3.1 upstream channels anywhere in their network. This would explain why you are not seeing DOCSIS 3.1 upstream on your SB8200.

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DrDeke

New problem solver

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12 Messages

6 years ago

@Comcast_Jessie,

Are you sure that Comcast is really using DOCSIS 3.1 (that is, OFDMA) upstream already, even in a few markets? My understanding was that even in markets where Comcast has DOCSIS 3.1 CMTSs/headends, DOCSIS 3.1 OFDM was being used in the downstream link, but DOCSIS 3.0 ATDMA/S-CDMA was still being used in the upstream direction.

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A

Ambigulous

New Contributor

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1 Message

3 years ago

I spent days and days ... weeks really ... trying to get my Arris SB8200 DOCSIS 3.1 cable modem to work. I was online with technicians all over the world, Mexico, Philippines and Guatemala, sometime for hours at a time. I connected it directly to the Xfinity input to the house, it didn't work. I had the Xfinity technician come out, he could not make it work. He added a Viewsonic Q-6-680 equalizer, and replaced some equipment outside m y house. We could never get to work.
There is a bunch of garbage online about the dBmV levels. The level I have are fine.

Just buy the Netgear Nighthawk 32 x 8 DOCSIS 3.1 Cable Modem instead (Model: CM1200-100NAS) - it just works.

(edited)

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