U

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3 Messages

Monday, July 11th, 2022 7:22 PM

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Modem compatibility with 900 Mbps plan

Online there is conflicting information about the Motorola MB7621 compatibility with the 900 Mbps plan. Can someone clarify if this modem will "handle" this speed? Thanks.

Official Solution

Problem Solver

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339 Messages

2 years ago

Hey there! Thanks for reaching out here in our community. We indeed rate this particular make and model for up to 845Mbps download, (https://comca.st/3z5H1Mp), keeping in mind this is using an Ethernet connection. For a wireless connection, it is expected to get half of the download that you subscribe to and closer to the speeds with a wired connection. 

 

What happens is that when you use an incompatible modem for a faster speed tier, the modem will default to using an even slower configuration file, so you will get even slower speeds than before. You need to use a compatible device. You can search for one at that link that I supplied.

 

We can not say for certain that your speeds will be lower than 845Mbps until we test your speeds with the new service levels. 

(edited)

This comment was created from this reply

Accepted Solution

Gold Problem Solver

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26.1K Messages

2 years ago

... If it just slows speed a little ...

The usual result of using a modem that's not approved for a speed tier is not "just slows speed a little", it's more like "slows speed a lot". AFAIK Comcast has never said just how they handle this situation, but users have reported 1/2 subscribed speed or even less. If you proceed please post what speeds you actually receive with this combination.

Gold Problem Solver

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26.1K Messages

2 years ago

Online there is conflicting information about the Motorola MB7621 compatibility with the 900 Mbps plan. Can someone clarify if this modem will "handle" this speed? Thanks.

https://www.xfinity.com/support/devices says the 7621 is approved for "Wired Download Speed Up to 845 Mbps", so not quite enough for 900 Mbps.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. 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.

Visitor

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3 Messages

2 years ago

Thanks. Yes, I saw that. The 845 is close enough to 900. My concern was that switching to the 900 plan without changing to a new modem might in some way make internet access suddenly impossible, for example, because of being DOCSIS 3.0 instead of 3.1. If it just slows speed a little from its theoretical 900 Mbps max, I can live with that or buy a new modem at my leisure. 

Problem Solver

 • 

339 Messages

Hey there! Thanks for reaching out here in our community. We indeed rate this particular make and model for up to 845Mbps download, (https://comca.st/3z5H1Mp), keeping in mind this is using an Ethernet connection. For a wireless connection, it is expected to get half of the download that you subscribe to and closer to the speeds with a wired connection. 

 

What happens is that when you use an incompatible modem for a faster speed tier, the modem will default to using an even slower configuration file, so you will get even slower speeds than before. You need to use a compatible device. You can search for one at that link that I supplied. (Thanks to @EG  for providing this information previously in the forum).

 

We can not say for certain that your speeds will be lower than 845Mbps until we test your speeds with the new service levels. 

(edited)

This reply has been converted into a comment

I no longer work for Comcast.

Visitor

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3 Messages

2 years ago

I appreciate the responses and I'll post results if I upgrade, but am likely to go to only 600 instead of 900Mbps.

Visitor

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1 Message

2 years ago

That link does not work. Three dots forever. There is, conveniently, nowhere to check the compatibility of third party modems with xfinity service. One has to just purchase it and hope for the best and be out of luck if it’s not compatible. The chat assistant is worse than useless and an actual net loss to the universe for existing.

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