I've now had 5 different Xfinity technicians come to my home, and I'm still dealing with persistent latency, packet loss, rubberbanding, and intermittent disconnects.
The issue is most noticeable while gaming, but it isn't limited to gaming. I've also seen packet loss/timeouts when testing against 1.1.1.1, and sometimes devices will completely lose their Internet connection for a few seconds.
Here's what I've already tested:
- Multiple Xfinity gateways/modems
- Different router configurations
- Wi-Fi and Ethernet
- Different Wi-Fi bands, including 5 GHz and 6 GHz
- Different DNS servers
- Rate-limiting my PC's Internet traffic to different speeds
- Multiple technician visits and coax/signal tests
Every technician has tested the coax connection at my house with their equipment and told me the signal looks good. However, the problem continues.
Some of the symptoms I've been seeing:
- Idle latency can be very low (around 2–8 ms)
- Latency increases dramatically under download load, sometimes reaching 90–200+ ms
- Packet loss/lock icons in Overwatch
- Rubberbanding in CS2
- Roblox disconnects
- Occasional timeouts to 1.1.1.1
- More recently, random 2–5 second Internet disconnects
- The modem's error counters have also been increasing
- Modem CM Error Codewords: Channel 28 currently shows 18,931 uncorrectable codewords, while Channels 13–16 show 9,746–30,540 uncorrectable codewords. The modem is also reporting a significant number of correctable codewords on these channels.
The problem doesn't seem to be limited to my PC or Wi-Fi because I've reproduced issues through Ethernet as well, and I've tested different networking equipment.
At this point, I'm wondering whether this could be something upstream of my residence, such as the neighborhood node, CMTS, upstream noise/ingress, congestion, or another plant/network issue.
What I would really like is for someone to investigate the network path beyond my residence rather than sending another technician to repeat the same basic in-home tests.
If there is an Xfinity employee here who can look at the node/CMTS health, utilization, upstream noise, or other network-side diagnostics for my area, I would really appreciate the help.
I'm not trying to blame anyone — I'm just trying to figure out why this has remained unresolved after five technician visits.
Source: r/Comcast_Xfinity · by /u/-H3R1C