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Intermittent dropouts and slow DL speeds

Regular Visitor

Intermittent dropouts and slow DL speeds

For some time now, I have had inconsistent download speeds and inability to browse. The attached screenshot is typical of what I've seen over the past several months when I go into the modem configuration screen. Some downstream channels are non-bonded. Others have a low dB level. And upstream levels are very high (sometimes as high as 54dBmV). What I have noticed is that after I restart the modem and router, the download speed returns to provisioned speeds for a while (an hour, a day). Before long it starts to stutter again, however. DL speed fluctuates between 1 and 90 Mb/s as per Comcast and Ookla speedtests. I also noticed that latency to the Comcast speedtest server fluctuates between 8 and 32 ms. Our dwelling has one wall jack that is live. No splitters are connected to this wire. I run a single cable from the modem to the wall jack. I do not have cable TV; this account is Internet only. I have traced the line outside and it is not split before it heads underground. I can't find anything to disconnect or remove on the line that would help the signal.
Screenshot (2).png
Connection Expert

Re: Intermittent dropouts and slow DL speeds

The downstream power is weak and the upstream power is too high and may be intermittently fluctuating even higher out of spec. 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.





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Cable Expert

Re: Intermittent dropouts and slow DL speeds

I've asked a Comcast employee to help you. You should expect a reply in this thread. 

 

Tip: If you need service, sign up for the Service Protection Plan (SPP). It's around $6 a month and you must keep it for at least 60 days after your service call. If you have SPP, you won't incur a service charge. You can sign up when you schedule an appointment.

 

If you wish to do some more troubleshooting on your own, see the troubleshooting guide.




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Regular Visitor

Re: Intermittent dropouts and slow DL speeds

Yep I'll futz with the connections outside the house. Inside, it's just one cable connected from modem to wall jack. No splitters at all. Thanks!
Connection Expert

Re: Intermittent dropouts and slow DL speeds

If nothing applies, then as stated, it would be best to get a tech out to investigate / correct. Good luck !




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Official Employee

Re: Intermittent dropouts and slow DL speeds

Hello CVINC. I can assist in troubleshooting your internet performance issues. I'd like to start with polling the CMTS for real-time and historical RF signal reports from your modem. I can also check your local Node/Plant for any degradation or error reports. Please send me a private message and include your full name and account primary phone number so I can access your equipment.


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Regular Visitor

Re: Intermittent dropouts and slow DL speeds

I'm clicking on the "Send Message" link under your name but am not getting the option to actually PM you. Is it because I'm still a "new user"? 

Official Employee

Re: Intermittent dropouts and slow DL speeds

To send me a private message click my name (ComcastJoeTru) and click Private Message Me.


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Regular Visitor

Re: Intermittent dropouts and slow DL speeds

I am sad to display my ignorance here, but when I click on your red name and then the "Private Message" link, this is the page that comes up. I am using Microsoft Edge with no ad blockers or NoScript running. 

Screenshot (5).png
Regular Visitor

Re: Intermittent dropouts and slow DL speeds

Any possibility that a forum mod can bump my privileges up so that I can click on the "Private Message Me" button for this Comcast employee? As a new user, I do not have the rights to PM even when the employee initiated the request. My slow Internet speeds and out-of-range modem reports are still happening and I would like to move forward with the modem being polled prior to booking a tech visit.

Official Employee

Re: Intermittent dropouts and slow DL speeds

Hi CVINC. We apologize that we weren't alerted to your responses requesting your Private Messaging issue get corrected. I have received your private message and responded. We look forward to helping you there. Thank you. 


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