3 Messages
Modem Keeps Dropping From Docsis 3.1 to 3.0, Causing Major Packet Loss
I purchased an Arris SB8200 this past July because my old modem kept resetting itself. The SB8200 worked perfectly up until a month or so ago, but then I started to notice my streaming, gaming and other internet services were starting to lag or stop working completely. The "lag" (mainly packet loss) occurs when my modem is pushed out of docsis 3.1 into 3.0. The packet loss goes on for about 10 seconds as this process takes place. The modem will then stay in docsis 3.0 for varied times (10, 20, 30 minutes etc.) before trying to reconnect to the 3.1. When it does switch back to 3.1, there is no noticeable lag or packet loss. Unplugging and resetting the modem has not worked. A support agent sent "refreshing signals" yesterday to the modem but that has not worked either. A technician was out to check my outdoor connections in June (2023) and saw nothing wrong. I am at a loss when it comes what to do next.
I have seen other people have the same docsis problem I am having. They tried replacing the modem with other brands and even tried Xfinity's Gateway modems, but this did not seem to fix the issue for them. (Modem switching between DOCSIS 3.1 and 3.0, causing brief packet loss/network drop outs : Comcast_Xfinity (reddit.com) The link will take you to a conversation another customer had on reddit about the issue. They ultimately purchased a modem that only supported docsis 3.0, but still receive slight packet loss.
I don't believe the modem is the main problem, as it was working fine for a long time. Looking for other suggestions to fix the problem, because the laggy service is becoming rather annoying.
dr.z
3 Messages
1 year ago
Managed to get my log right after modem was kicked from 3.1 to 3.0
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BruceW
Gold Problem Solver
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26.3K Messages
1 year ago
The SNR value for the OFDM channel is out of spec (too low). You can try the suggestions in Internet Troubleshooting Tips, but may need to have another visit from a premise tech. Either the problem is intermittent and was in spec when the tech checked it, or the tech was incompetent.
Network connection problems like this are often due to poor coax connections or damaged coax cable, usually in or near your home. Running the cable through a surge protector, a defective splitter, or too many splitters can cause signal problems as well. If there is an amplifier in the line make sure it's getting power.
If the tech finds bad coax, splitters, amplifiers, or connections in your home (even if Comcast originally supplied them) you'll probably have to pay for the visit (approx $100) unless you have their Service Protection Plan ( https://www.xfinity.com/support/articles/service-protection-plan, closed to customers that don't already have it). If the trouble is due to a faulty Comcast rental device or anything outside your home you shouldn't be charged.
Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.
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dr.z
3 Messages
1 year ago
(edited)
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EG
Expert
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110K Messages
1 year ago
@dr.z
Please redact all of the CM MAC and the CMTS MAC addresses from your error log entries for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".
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