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Forum Discussion
CM2050V - Significant packet loss detected - Is my Cable modem failing?
It is suspected that the cable modem may be experiencing a defect and thus necessitate replacement. During the process of backing up substantial video files, ranging in size from 40GB to 80GB, to a cloud storage service, the Ubiquiti UDM-SE router registers a notable occurrence of packet loss.
To facilitate the diagnostic procedure for this issue, a PDF document containing relevant event logs and information regarding downstream/upstream bonded channels has been provided as an attachment.
Requesting a detailed analysis to determine if my cable modem is malfunctioning or if the problem lies with my Comcast internet service. I would appreciate a comprehensive explanation of standard cable modem operation, including typical performance metrics, common failure points, and diagnostic procedures.
Understanding these aspects will be crucial in identifying whether the issue originates with my equipment or the internet service itself. Information regarding troubleshooting steps I can perform on my modem would also be beneficial.
Thanks in advance for your help!
22 Replies
Any Criticals, Errors or Warnings seen in the event logs needs to be reviewed and resolved by the ISP. Indicates a signal issue on the ISP line up to the modem.
Be sure your using a good quality LAN cable between the modem and router. CAT6A STP is recommended.Power levels are on the low side but with in specs.
You've got some correctables and uncorrectabls that should be zeros.
Have the ISP check the signal and line quality UP to the modem. Be sure the ISP provisions the modem correctly.
Be sure there are no coax cable line splitters in the between the modem and ISP service box.
Be sure your using good quality RG6 coax cable up to the modem.
Start with removing any amplifiers, signal attenuators, or splitters from the coax.
From there check the line for kinks, damage, moisture in the line.
Check the connectors for improperly made ends, foil touching the copper coax line, loose connections, bad/old/cheap connectors, or corroded connections. Replace them if you do.
Be sure to power OFF the modem for 1 minute then back ON.
https://community.netgear.com/t5/Cable-Modems-Routers/General-info-and-Troubleshooting-for-Cable-Modems/m-p/1530376#M12853
https://kb.netgear.com/24311/Power-level-guidelines-for-a-NETGEAR-cable-modem-router
https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html
https://highspeed.tips/docsis-events/Thanks for you suggestions. I have already done what was suggested prior to posting.
Comcast has already checked the lines and claimed they are all good. Comcast claims that my modems is "screaming" causing network issue (i.e. brings down the network) in my condo complex. This happens only when uploading files as mention earlier.
As a result, they added a filter to my connection. That is why only one upstream channel is locked and the other 3 do not locked. Also, the power level is above 50 dBmV, when prior to Comcast adding the filter, 4 channels locked and the power levels were between 44 dBmV - 48 dBmV, never above 50 dBmV!
That being all said, my down load speeds and uploads speed are good. The download speed hovers around 1000 Mbps - 1300 Mbps and the uploads speed (with the filter) hovers around 280 Mbps - 350 Mbps.
Attached is a diagnostic status sheet from my CM2050V I am running on Xfinity just outside of Seattle. What area are you located?
The first thing I noticed is you have only one upstream bonded channel and I have four.
Your power levels are closer to normal than mine. The local technicians tell me Xfinity is running the power levels in my area hot. They did not have an explanation as to why.
If you run a throughput test using the Ookla stand alone application, what up/down values do you get? On my setup, I average 1300/42.
Occasionally I upload 30-40 GB files to Microsoft One Drive. I am running an ASUS RT-AX88U Pro router and have not noted any packet loss entries in the logs.
The users that respond here are all volunteers. Detailed analysis and comprehensive explanations are above our pay grade!
My location is Woodbridge, NJ.
My down load speeds and uploads speed are good. The download speed hovers around 1000 Mbps - 1300 Mbps and the uploads speed (with the filter) hovers around 280 Mbps - 350 Mbps.
I use Ubiquiti equipment (router, switches, and APs).
You are connected to an area that has been upgraded to the Xfinity Enhanced Speed Network and your modem has a boot file that provides the full allowed upstream throughput. This is based on your throughput values and your OFDM/OFDMA channels. Xfinity is gradually releasing the boot files for the CM2050V to see if the new firmware has a negative effect on their network.
I would be curious about the specification details on the filter that was installed. A model number or a picture would be helpful if you can get it. It could possibly be an attenuator that the technician called a filter.
Back to the question in your original post, in my opinion there is no indication your modem is failing. Possibly both Xfinity and Netgear are being cautious about the recently released firmware for the CM2050V, and it still may need some fine tuning.
Have there been any changes/updates on this situation?
Is your connection still tagged for Ingress with the filter installed?
Kitsap,
No changes or updates.
The connection is still tagged and has a filter installed. The values from my OP are still the same.
That being said, I have not really pressed Xfinity about it since I really don't know if I have a modem issue or not. Given that Xfinity has already blame my modem as being the source of neighborhood wide triggering outages or source of major congestion, I am not really incline to reach out to them and address the issue.
You'll need to have a tech come visit onsite to check everything up to the modem. The modem would and could not be a source of neighborhood wide outages or congestion. Seems like ISP phone support is not doing there full duty in this. Par for the course.
