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Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

New Poster

Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

Hi. Equipment includes a CM1000 modem. I'm wondering what you guys can make of this. I just activated my service with Xfinity. I ordered 250Mbs. The line outside goes into one filter and directly to one line in the house into the modem. There are no splitters. The line in the house is only a couple years old with no damage and worked fine with DirecTV. No TV service any longer just xfinity internet. Power levels for downstream/upstream are all seemingly great. After resetting the modem factory or regular it will juggle a couple channels with the vast majority locked but stays on the same channel and gives 50-300Mbs speeds with drastic swings.

 

Then it will lock to the same 15-32Mbs  (32 cap) speeds without anything changing after just a few minutes of up time. Which I assume is some sort of throttle on Xfinity's end because of noise on the line or something? 90% of the channels have nearly the exact same ratio of Correctable and Uncorrectable Codewords and same amounts. The Uncorrectable to correctable ratio for these nearly identical channels is  is 4.15 to 1. 

I'm also not getting any warnings or critical messages in the event log on my modem. Just notices.

 

Is this a local node issue? Or a modem issue? Or a line issue? Can someone offer tips for a new Xfinity customer?

 

Okay. It doesn't seem to want to accept HTML here and it won't let me upload an image here because it shows up as a giant grey triangle. But here is the link to my CM1000 channel/power page

 

https://imgur.com/Pw2jcFl

New Poster

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

xfiModemPage.png

Why do my images turn into giant triangles......

Expert

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

Can't see your pic. Since you are a new poster, it likely needs to be approved by a Forum Admin. That may take some time.

You could try hosting it at one of those free third-party pic hosting sites like Imgur or Photobucket and post the link to it here.



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New Poster

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

Uploaded to imgur here. https://imgur.com/Pw2jcFl If you don't mind could you take a look and tell me what your opinion is?

Expert

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. And the SNR is too low / out of spec on some of the downstream channels. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems. 

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.

 

FWIW, it's really not recommended for a satellite cable system wiring to be re-used for Comcast cable service.



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New Poster

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

I read that 49 is in spec for upstream and it doesn't fluctuate any higher than 49. I only have Xfinity internet so I already removed all the splitters. Just a ground block from the line outside directly to one coax going directly to the modem.

Expert

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

It's borderline..... And again, some of the SNR's are no good... Get a tech out to investigate if you can't get it any better. Good luck with it !



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I am a Customer Expert volunteering my time to help other customers here in the Forums.
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New Poster

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

Okay, well thanks a bunch.

Highlighted
Official Employee

Re: Locked at 30Mbs with 250Mbs service. High Uncorrectable Codewords On All Channels

Hi NewXfinityUser, it looks like I am chiming in late on this thread but if you need assistance with getting your full speeds I am here to help. For further assistance please send me a private message with your full name by clicking on my name (ComcastAmir) and then click "Send a message".


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