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Sudden reduction in upload speeds -> gigabit connection

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New Poster

Sudden reduction in upload speeds -> gigabit connection

Hi all,

 

I have an Arris SB8200 connected to a pfSense based router - its a pretty hefty (and very reliable) setup.

 

Today, I noticed I observed that my upload speed hovers anywhere between 15 to 20 mbit as opposed to the 40-42 mbit I get (provisioned is 35 mbit but we are always over provisioned so getting 40-42 mbit is the norm). Download speeds are perfect - I consistently get 940 mbit download.

 

I've done the following (keep in mind all testing is done on a wired computer):

 

  • Reboot modem
  • Reset modem to factory defaults
    • Verified also that signal strengths are within spec. 
  • Reboot router
  • Try a backup router
  • Connect directly to the modem 
  • Contact Comcast support via chat where they sent a modem refresh but to no avail -> still having the same issue. 

Due to Corona, Comcast indicated that there's no further testing/troubleshooting that can be done... 

 

Wondering if there is upload throttling going on? Or something else is afoot?

 

Thanks!

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Frequent Visitor

Re: Sudden reduction in upload speeds -> gigabit connection

I'm having the exact same problem - actually a bit worse. My upload speed on Blast Pro + should be 15Mbit, now actually getting 1-2Mbit/day max. Comcast is completely unresponsive.

 

Upload speed issues.jpg

 

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New Poster

Re: Sudden reduction in upload speeds -> gigabit connection

similar problem here. i'm getting 1-2mbps upload during peak, 7-9mpbs during off-peak

 

this basically makes any type of video conferencing unusable.

 

download/streaming/etc. is fine (usually average ~500mpbs).

 

no luck getting any answers from comcast.

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Silver Problem Solver

Re: Sudden reduction in upload speeds -> gigabit connection

If you have Win10, you might try the Speedtest app which does not use a browser.

https://www.microsoft.com/en-us/p/speedtest-by-ookla/9nblggh4z1jc?activetab=pivot:overviewtab


I am not a Comcast Employee.
I am just a customer, volunteering my time to help other customers here in the Forums.
Was your question answered? Mark the post as best answer!
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New Poster

Re: Sudden reduction in upload speeds -> gigabit connection

So things have been pretty consistent on my end - about 12-19 mbit during the day and full 40-42 mbit at night.

Comcast ain’t sayin a thing; techs are always “Welps we need to send someone out but we can’t because of corona.”

However obviously it’s not a problem on my end... so I guess just gonna have to live thru it 😕
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Regular Contributor

Re: Sudden reduction in upload speeds -> gigabit connection

The symptoms are indeed consistent with an oversubscribed link from your cluster of a few hundred homes.   Maybe new hardware is needed, a module-thing in a gray box near side of the road within a mile or so of your residence.    If there are no more slots for module-things in that gray box, an additional gray box may be needed!   Yours and 200 neighbors internet may go out for a couple hours while issue is fixed.     If you keep escalating the issue you can get the "repair" done sooner, probably.    In meantime as workaround consider using cellular-voice network for the audio on your teleconferences wherever possible so at least the audio will be reliable for both listening and speaking? 

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Frequent Visitor

Re: Sudden reduction in upload speeds -> gigabit connection

Thanks for the reply! This seems exactly what has been going on. Indeed, the phone connection reliefs this issue but of course is not ideal. 

 

What is the best way to keep on escalating? The folks at Xfinity really just shut me off and do not seem to do anything. 

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New Poster

Re: Sudden reduction in upload speeds -> gigabit connection

@bald271 - my video conferencing does not suffer - i still get 10-12 mbit which is plenty of upload bandwidth... but plexing to my friends and family does 😛 - although I shouldn't really complain about that I suppose.

 

Interesting tidbit - we had an outage last night which was excused as routine maintenance between midnight and 6 AM. I was down for maybe 5 minutes around 2 AM - once it came back online, I noticed my upload is at about 30 mbit during peak times... so perhaps network capacity improvement for DOCSIS 3.0?

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Regular Contributor

Re: Sudden reduction in upload speeds -> gigabit connection

I recommend delaying further notification to comcast until your region of USA is open for business again, unless the issue is somehow causing a health risk to someone in your home.     

 

 I am seeing evidence of the same sort of thing in past 2 days.     It is consistent with my neighborhods downlink being intentionally throttled or saturated or both.     

 

I am see about 50 megabits/sec down during daytime/peaktime instead of usual 90 or 100.    Uplink looks as-expected at 5 megabit/sec here.  

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Silver Problem Solver

Re: Sudden reduction in upload speeds -> gigabit connection

https://forums.xfinity.com/t5/Your-Home-Network/Gigabit-speed-troubleshooting-video/m-p/3310454#M316...


I am not a Comcast Employee.
I am just a customer, volunteering my time to help other customers here in the Forums.
Was your question answered? Mark the post as best answer!