T

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2 Messages

Thursday, May 22nd, 2025 7:34 PM

Upload speed not exceeding 40Mb/s -- Upstream OFDMA Channels not locked

CM2050V modem, achieving about 900Mb/s download speed, but only 40Mb/s upload.

Checked the modem and discovered that --while upstream OFDM channels are locked, downstream OFDMA channels are not (see below)

If they were, I would get higher upload speeds.

What has to happen to get these upstream channels locked ?

Thanks,

Wolf.

 

Downstream OFDM Channels
Channel Lock Status Profile ID Channel ID Frequency Power SNR / MER Active Subcarrier
Number Range
Unerrored
Codewords
Correctable
Codewords
Uncorrectable
Codewords
1 Locked 0 ,1 ,2 ,3 193 690000000 Hz -7.12 dBmV 39.3 dB 628 ~ 3467 3173629300 2969753009 343
2 Locked 0 ,1 ,2 ,3 194 957000000 Hz -13.22 dBmV 38.5 dB 148 ~ 3947 3166256234 2885381064 521104
 
Upstream OFDMA Channels
Channel Lock Status Modulation / Profile ID Channel ID Frequency Power
1 Not Locked 0 0 0 Hz 0 dBmV
2 Not Locked 0 0 0 Hz 0 dBmV

Gold Problem Solver

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1 day ago

... CM2050V modem ... only 40Mb/s upload ...

The CM2050V is compatible with their Internet and home phone services, but is still not compatible with the higher upload speeds they introduced in 2023.

See the "Next Gen" list at the top of the "All Compatible Devices" PDF linked near the bottom of https://www.xfinity.com/support/devices (at the moment it points to https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2025.03.25 Full List of Compatible Devices.pdf, but this changes from time to time).

Comcast could make all of this much simpler and clearer, but they have chosen not to do so.

ETA: The year-old post at https://forums.xfinity.com/conversations/your-home-network/faster-internet-speeds-now-available-until-you-backdated-my-modem/65978b4f2e4f0f284530df88?commentId=659a8be32e4f0f2845312956 is the latest statement I know of from Comcast/Xfinity regarding CM2050V compatibility with higher upload speeds. The post is a vague "we're working on it" statement. You would think that, 12 months later, more would have been accomplished.

When you Comment on a post (by scrolling down to "Comment on this post here...") I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

(edited)

Visitor

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2 Messages

Thank you, Bruce.

Indeed, it is not in the "Next Gen" section, but under "Recommended" -- Specified with download speed "up to 2.33Gbps", but no mentioning of max upload speed. However, it mentioned DOCSIS3.1 (which has a max of 1Gbps for upload).

(and there is no data + voice modem in the NextGen section).

It would be nice if Comcast can address this -- 900 Mbps download, but only 40Mbps is far from satisfying (giving one is paying for high speeds).

 

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