mstjohn's profile

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39 Messages

Wednesday, August 5th, 2020 9:00 PM

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Re: Comcast Speed Issue - Help needed!

I have the same exact issue where. I consistently get a speed test of 94 Mbps when I have a 300 Mbps plan. I've tried both SB6183 and MB7621 modems, which are both Docsis 3.0, and they both exhibit the same issue. I'm running these tests with a direct ethernet connection to the modem using a fast ethernet adapter.

 

Similar to the original poster, I was previously able to get the expected speed using my same SB6183 modem. I think that Comcast must somehow be erroneously capping the speed under 100 Mbps for at least some of us that that own our own modems. I have had numerous calls with Comcast tech support regarding this issue, and they always say that the signal is fine and that there must be a problem with my cable modem.

 

I actually had this same problem a couple of years ago, but the problem eventually just resolved itself. Back then I tried upgrading to a Docsis 3.1 modem, but that didn't resolve the issue, so I highly doubt that upgrading to a Docsis 3.1 modem now would fix the issue now.

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Accepted Solution

Contributor

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39 Messages

4 years ago

Following back up on this post, the issue for me was on my end. I fixed it by changing a faulty ethernet cable.

Gold Problem Solver

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26.5K Messages

5 years ago


@mstjohn wrote: ... using a fast ethernet adapter. ...

As stated above, "Fast Ethernet" is only rated for 100 Mbps, and the usual top speed is around 90 Mbps. Speeds above 100 Mbps require a Gigabit Ethernet adapter.

New Poster

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1 Message

5 years ago

We are having the same issues with our MB7621. Comcast tech came out and said it was our modem as well. We are consistently getting speeds of 95MBPS download an 15 MBPS upload when we are paying for up to 600 MBPS.

Expert

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111.4K Messages

4 years ago

Thanks for circling back ! Now re-closing this year old dead thread that was improperly re-opened by the new forum software / platform. A known issue that is being worked on.

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