Wednesday, October 4th, 2023 1:23 AM

Packet loss, high latency, low speeds every evening

Apologies for the long post, but I'm trying to be detailed.  I've been having this issue for a few months now, progressively getting worse.  Everyday from about 6pm to 11pm (mountain time) I start getting packet loss, high latency and slower speeds.  Once the problem 'starts' (around 6pm-ish, varies everyday) it seems to ramp up until around 8pm where it peaks and is really bad for 2-3 hours then tapers off over the next hour or two.  This happens for all devices before and after a modem restart during problem hours.  

I pay for 1200Mpbs which I get just fine (and sometimes even faster) during the first half of the day.  When the issue starts it slowly degrades all the way down to about 200Mbps on average (at this point my latency in games, for example, have at least doubled).  On 9-27 it actually got down to just 5Mpbs.  This is when I reached out and talked with live chat support.  They confirmed that they were also seeing about 5Mbit speeds at that time and scheduled a tech.  He came out about 4pm (9-28) before the issues had started and checked stuff (inside and outside).  Replaced something behind a wall plate and replaced the modem with a new model.  A couple hours after he left the problem persisted right on time.

On 9-29, to rule out issues on my end, I disabled all of my wifi networks and uplugged all ethernet cables.  The speed remained slow when tested via the Xfinity app with zero devices on the network.  I added just a laptop over ethernet and confirmed the usual issues were still occuring.  I also moved the modem to the media panel and connected directly to the service-in coax to rule out issues with my house's coax runs.  No change.

On 10-2 during problem hours, I drove a couple blocks over and connected to two different xfinity public hotspots and got the same results as I do at home.  I don't think the issue is just with me. 

I have documented my speeds as well daily graphs showing my ping times (to google.com) and packet loss for the last 2 weeks.  I've also started logs with PingPlotter and have been pointing it at 4 places: google.com, (a Discord IP), one of path of exile's (game) IPs and also an IP of it's login servers. I believe these are good targets that do not deprioritize ICMP packets.

Here are some daily graphs from 9-21 to 10-1. Each graph represents a 24-hour day, midnight to midnight. This tool pings google.com 4 times every 5 mins and logs the average response time and any timeouts.  Note how everything is fine for the first half of the day then gets bad for the second half, consistently.

Here are some PingPlotter screens from 10-1:

Here is two screenshots of downloading the same file during and after the problem timeframe:

Here are screenshots of the modem signals during bad times (various days):

Here are some screenshots of the Xfinity speed tests during problem times:

-Fridays are usually the smoothest days.  Sundays are usually the worst
-There are no splitters being used as well as no other service using coax here.
-Peak problem time is around 8-9pm mountain time.  Problem windows is around 6pm - 11pm
-I've had Xfinity here for years up to this point without issues.
-Speed tests are done with the Xfinity app
-Problem does not improve when all devices (ethernet & wifi) are removed from the network
-All cables/jacks/wall plates/etc have been checked by two different Xfinity techs

I'm open to trying anything else that might help.  Thanks.



101.6K Messages

2 months ago

FWIW. The signal stat values look OK. This sounds typical of being caused by a peak usage time capacity / traffic congestion problem on your local cable segment / node. YMMV. If it is, there is not much that you can do about it except to complain to them persistently and to get your immediate neighbors to join in. Good luck !


3 Messages


Thanks for the reply. This has been my assumption as well.  I'm hoping an employee sees this and is able to help get the correct ball rolling somewhere. Otherwise I don't know what else to do except contact live chat support every evening when it's bad until something changes, but that seems ridiculous and I'm afraid I'll be fighting their $100 tech fees eventually :(

Official Employee


505 Messages

2 months ago

Hello @user_wb0fun we know that it is important for all of our customers to be able to have a reliable and fast connection, so we definitley want to ensure this is addressed. We may need to get a tech sent out to refer your area over to our network maintenance team for review on possible capacity issues. If you send our team a direct message with your full name and address, we'll work with you to find a solution on this! To send us a message, just use the link provided or the direct message icon in the top right-hand corner of the screen. Then, click "new message", type "Xfinity Support" and select that profile to send us a message directly. We look forward to hearing from you!

1 Message

15 days ago

Did the problem ever get fixed for you? have the exact problem and almost similar order smh so frustrating.

3 Messages


It was finally fixed recently, but it took a looooong time.  The problem first started back in May and was just fixed a few days ago.  It was confirmed to be a capacity issue for my area.  If you (or future Googlers) think you're having similar issues here's what I'd recommend based on my experience:

Find a way to log/prove your connection issues.  My very first tech (back in May) didn't really seem to believe my issues were as bad as I described as he showed up too early in the day to experience the issue first hand.  I made a custom Python script and used a program called PingPlotter to create the graphs I posted.  Live chat support was not particularly helpful.  Make a thread here with as much detail as you can.   Your goal will be to get the issue 'escalated to maintenance'.  This can apparently only be done once you have received 3 Xfinity onsite tech visits within a 30 day period without resolution of the issue (this is what they told me).  At this point (late September) I was able to get an estimated fix date.   After the issue was resolved they agreed to credit my account two months worth of my bill.  Good luck and I hope this helps.


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