Contributor
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21 Messages
How can I get rid of continuous CM Errors - Uncorrectable Codewords ?
I'm a brand new Comcast/Xfinity user and I got my internet (300Mbps) installed 10 days ago. Since the beginning I've noticed some intermitent and random packet loss (1% - 2%). I changed the modem 3 times and all 4 modems showed the same CM Errors with Uncorrectable Codewords in all columns.
I connected the modem to the grey box, outside of my house, and I noticed the errors are also happening when I plug it over there, so it doesn't seem to be related to my internal cabling.
I've opened a dozen of tickets with Comcast and a techinician came to my house, but he didn't have the tools nor the knowledge to do anything. He simply left, leving all my wires and cables exposed to the weather, and with the modem connected to the grey box.
I think it is an easy thing over the "last mile" but it seems nobody from Comcast is really trying to help me get it fixed.
Is there anybody from Comcast here that could help me with this issue?
LuizAlexandre
Contributor
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21 Messages
5 years ago
Interesting ... today I got the results of the modem while I had an outage. It seems the upload channels are the ones losing the sync:
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EG
Expert
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111.4K Messages
5 years ago
The downstream power is even weaker now than when you first posted here last November, and it may be intermittently fluctuating even lower to out of spec levels. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, 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.
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LuizAlexandre
Contributor
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21 Messages
5 years ago
Hi EG,
I have this same issue even if I connect my modem to the Comcast box that's outside of my house.
Is there a way to ask Comcast to review their outside cabling knowing it is bad when it gets into my house ?
Thanks,
Luiz
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EG
Expert
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111.4K Messages
5 years ago
A premises facing tech can check the cabling / hardware (including the drop line) up to the tap on the pole / pedestal. From the tap and farther up the line is the responsibility of their line / maintenance dept. techs.
Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.
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