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Wednesday, December 6th, 2023 9:24 AM

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Slow upload speed: 35Mbps vs 200Mbps (plan)

Hello,
 I am on Gigabit Extra Plan that promises Download speeds: up to 1200 Mbps and Upload speeds: up to 200 Mbps. I own Motorola MB8611 modem + UDM Pro. I am getting 1200-1300Mbps and only 35Mbps download speed. How to fix it?

Regards,

German M.

Gold Problem Solver

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7.9K Messages

1 year ago

If the higher upload speeds are actually available, you currently MUST use a Comcast gateway. I don't think they have started allowing customer-owned modems from using the OFDM upstream signals used for the higher upload, yet.

4 Messages

Based on other posts on this forum, having Comcast gateway is no longer a hard requirement. People report 100-200Mbps speed with own modem (e.g. ARRIS S33). Motorola MB8611 is on par with ARRIS S33.

Expert

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109.4K Messages

1 year ago

@user_l44mh6 

These are the compatible customer-owned devices for the next gen. speeds;

4 Messages

@EG​ Thanks for this list! Is having next gen model the only way (apart from renting Comcast gateway) to get plan upload speed (200Mbps)?

(edited)

Expert

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109.4K Messages

@user_l44mh6 

AFAIK, yes.

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Official Employee

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2.1K Messages

1 year ago

Hi there @user_l44mh6!  Thanks so much for taking the time to reach out to Xfinity Support here on out Community Forum to voice your service concerns.  We are so glad to hear from you and want to help in any way that we can to get this taken care of for you.  No worries!  You have reached out to the right team and we are here to ensure that all of our subscribers have the best experience with their services.  Please feel free to shoot us a private message so that we can get to work on this for you.  

 

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109.4K Messages

@user_l44mh6 @XfinityArmand 

Please circle back here and post any possible solutions for the issue here in these open forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

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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

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26.3K Messages

1 year ago

For reference: https://www.reddit.com/r/Comcast_Xfinity/wiki/knowledgebase/next-generation-internet/ 

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(edited)

4 Messages

@BruceW​ Thanks for the reference!
Tried Hitron CODA56 and the upload speed has increased. Unfortunately still lower than 200Mbps advertised. On a good day I am getting 100Mbps max averaging around 70Mbps.
I have also tried ARRIS S33 and as expected no increase in speed.

7 Messages

was looking at those modem as well..thanks for the share...so we are still getting throttled even with a different modem and you went as far to try 2

mine is a Motorola MB8600 and am having same issue tho am at a hard 40mbps upload

7 Messages

1 year ago

AM HAVEING SAME ISSUE

1200 RX / 200 RX

my sppedtest max is 900 rx and a hard 40Mbps

my modem is a Motoroal MB8600.... so i clearly should not have issue

just had a tech here ....cleaned up signal a bit...so now down breaks 900...however the upload still is a hard 40 mbps

tech still wants to say it is my modem...i feel...not possible...we are being throttled....

Gold Problem Solver

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7.9K Messages

1 year ago

The MB8600 is not currently approved for the higher upstream speeds. Only Comcast gateways and a few modems mentioned a few posts back are currently approved. Hitron Coda and Coda56, Netgear CM3000 and CBR750, Arris G54.

7 Messages

@Andyross​ thank you...so that means comcast does not approve modem ?? and why it is throtled to that upload speed...for my specs say it can handle..

7 Messages

1 year ago

https://approvedmodemlist.com/comcast-xfinity-approved-modems/


[Edited: "Amazon link"]

am still finding this issue vary difficult

(edited)

Gold Problem Solver

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7.9K Messages

1 year ago

The high upstream speeds use a new method called OFDM to send the data. Although it has always been part of the DOCSIS 3.1 specifications, it's only now being rolled out into the real world. Comcast requires the manufacturers to submit their modems for testing to verify that they work properly with the new modulation, and don't cause problems for the user, for Comcast, or other users on the same node. Just because something may work in the lab, doesn't mean it will work properly in the real world with real equipment.

If you really need the higher upload speeds, rent a Comcast gateway for awhile. Once more modems are approved, or even the one you current have, you can switch to that. You can always put it in bridge mode if you want to use your own router.

7 Messages

great information...am greatful for the knowledge...i know i was hpeing this modem would be usefull for years to come..i truly thouhgt i bought ahead of the corve..

this now make more sense...tho forgive me...still fells like be throtled..

thank you again...  vary helpful 

Official Employee

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2.4K Messages

Hello, @U9ly We recommend using https://www.xfinity.com/support/devices/#unauth to review recommended next-generation devices. The MB8611 is showing under our recommended devices for compatibility and download speed. Compatible Next Generation speed COAM devices:

 

CommScope G54 Yes No DOCSIS 3.1 Up to 2.34 Gbps Up to 474 Mbps
Hitron Technologies CODA No No DOCSIS 3.1 Up to 934 Mbps Up to 456 Mbps
Hitron Technologies CODA56 No No DOCSIS 3.1 Up to 2.33 Gbps Up to 454 Mbps
Netgear CM2050v No Yes DOCSIS 3.1 Up to 2.33 Gbps Up to 485 Mbps
Netgear CM3000 No No DOCSIS 3.1 Up to 2.3 Gbps Up to 486 Mbps

 

 

I am an Official Xfinity Employee.
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7 Messages

https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2023.11.22%20Full%20List%20of%20Compatible%20Devices.pdf

in short the original poster of this post and myself are still throttled at a hard 35/40 mbps even tho we have authorized modems according to the list provided

we are paying for 200 mbps and only getting 20%

and another has gone through 2 modems to barely or just get 50% with new modems

i do realized testing and such is part of Information Technology.....however...this is a bit different

the tech that came to my home has no knowledge of this issue other than to push getting a xfi modem for 16$ a month

Official Employee

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1.9K Messages

@U9ly I want to make sure you can get the speeds you're subscribed to. Would you like me to review options to get an xFi gateway from us? Please send a direct message by clicking the chat icon in the upper right corner of the page, click on the pen and paper icon, then enter “Xfinity Support” in the “To” section. Please include your name and address and I'll be happy to check :).

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

7 Messages

that is gracious... would prefer that my modem not be throttled since it is an authorized modem

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