Upload speed not reaching 23Mbit when it's supposed to be 100Mbit

The modem is capable of up to 800Mbit upload. All 4 channels are locked for the upload stream, but the speed is very limited to 23Mbit at all times.

I'm testing the speed from the router directly connected to the modem.

I've restarted the modem and verified the status of the channels, they all seem fine. Although no OFDM for upstream.

Upstream Bonded Channels

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	SC-QAM	17	5120	35.6	45.0
2	Locked	SC-QAM	18	5120	29.2	44.8
3	Locked	SC-QAM	19	5120	22.8	44.3
4	Locked	SC-QAM	20	5120	16.4	44.5

The plan is supposed to have 100Mbit upload, and directly from the router connected to the modem I can barely pass 22Mbit.

Testing from my computer to Xfinity shows the same numbers for upload.

[2.7.1-RELEASE][admin@pfSense.***]/root: speedtest --no-download --secure
Retrieving speedtest.net configuration...
Testing from Comcast Cable (174.51.***.***)...
Retrieving speedtest.net server list...
Selecting best server based on ping...
Hosted by Springs Hosting (Colorado Springs, CO) [13.21 km]: 18.354 ms
Skipping download test
Testing upload speed......................................................................................................
Upload: 22.52 Mbit/s

Responses

EG

Expert

•

111.1K Messages

1 year ago

What is the exact make and model number of the cable modem ?

1

0

mlagosh

Regular Visitor

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7 Messages

Motorola MB8611 DOCSIS 3.1

1 year ago

0

EG

Expert

•

111.1K Messages

1 year ago

That device is not compatible with their Next Gen speeds. Only these retail devices currently are;

As are their latest rental gateway devices.

(edited)

0

U

user_svi0f8

2 Messages

1 year ago

I have the same issue with the same modem. Motorola MB8611. (800Mbit download 100Mbit upload plan)

My area went through an upgrade about a month ago. (for symmetrical speeds) My plan was listed as 800Mbit DL and 20Mbit UL at that time, but recently switched to 800Mbit DL and 100Mbit UL under the MY PLAN area of the xfinity website. I am getting download speeds between 800 and 900Mbit but upload speeds are between 23 and 25Mbit. The last time I had a speed increase I had to reactivate my modem to get the new speed. I tried reactivation again, but this time it isn't giving me the plan indicated upload speed. The download speed is great, but the upload speed will not go higher than 25Mbit.

0

harmanly

9 Messages

1 year ago

For the "next gen speeds", which rely on Xfinity rolling out DOCSIS Mid-split upgrades to your area, you need to be on a modem certified to operate at those speeds by Xfinity. You can find the current list here: https://www.reddit.com/r/Comcast_Xfinity/wiki/knowledgebase/next-generation-internet/

The gist is, I had the same problem. Ultimately I upgraded to a modem on the list - the CODA56 - and almost immediately was getting the expected 200Mbps upload speeds. (Here's a longer post with more details: https://forums.xfinity.com/conversations/your-home-network/mb8611-upstream-speed-on-new-xfinity-10g-network/657c5e3e2e4f0f28452cb14e?commentId=657e2cefe4ada534519262c4)

5

harmanly

9 Messages

Thanks for the terrible formatting, forum software.

https://forums.xfinity.com/conversations/your-home-network/mb8611-upstream-speed-on-new-xfinity-10g-network/657c5e3e2e4f0f28452cb14e?commentId=657e2cefe4ada534519262c4

1 year ago

0

mlagosh

Regular Visitor

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7 Messages

So you are saying that my certified modem (2y ago) that was giving me 100Mbit up for all of this time, now is restricted on purpose by Xfinity?

And that I need to buy a new modem to get the speed I'm paying for?

That would be the last straw. If that is the case I'm dumping Xfinity and getting anything else but.

1 year ago

0

CCJodie

Problem Solver

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1.3K Messages

@mlagosh I'm very sorry about all of this. The modems listed are the only ones that can work with the new upload speeds. I would really like to see how we can make this right. Please send us a direct message with your full name and service address.

Here are the detailed steps to Direct Message us:
• Click "Sign In" if necessary
• Click the "Direct Message" icon (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message

I no longer work for Comcast.

1 year ago

0

EG

Expert

•

111.1K Messages

@mlagosh wrote;

So you are saying that my certified modem (2y ago) that was giving me 100Mbit up for all of this time,

FWIW. Are you sure about that ? 100 Mbps upload speed didn't even exist 2 years ago.

(edited)

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer! tick

1 year ago

0

U

user_svi0f8

2 Messages

@harmanly Thanks for the info. I picked up the CODA56. Immediately after activation I was getting the same 25Mbit upload speed, but after about ten minutes and a second reboot I'm now getting 100% of my plan upload speed of 100Mbit.

1 year ago

0

Your Home Network

mlagosh

Upload speed not reaching 23Mbit when it's supposed to be 100Mbit

EG

mlagosh

EG

user_svi0f8

harmanly

harmanly

mlagosh

CCJodie

EG

user_svi0f8

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