Visitor

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2 Messages

Tuesday, December 2nd, 2025 9:55 AM

Horrible internet speeds for my plan.

Hi, so my current Router and Modem combo are a TP-Link Archer BE550 and an Arris SB8200. My current wifi plan is the Gigabit X2 which offers up to 2100Mbps down, and 300Mbps up. I know with my current setup I won't be receiving the full benefits, BUT, I should not be seeing only 500-600Mps down and 5-6Mps up. I logged into my Modem's admin page, and my event log shows critical events as follows multiple times

01/12/2025 20:35:43
critical
No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;
27/11/2025 23:58:56
critical
Config File Rejected due to Invalid or Unexpected TLV 11;CM-MAC=[Edited: "Personal Information"]-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1;

30/11/2025 23:46:52
warning
RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.1

I could post the entirety of the event log if requested further, but these are the critical errors that I'm seeing. From some research, the T3 error is what has been causing me upstream issues.

I'm not too sure what TLV 11 is responsible for but I figured it would hurt to post that one as well. 

If anyone could possibly help me I would appreciate it, and if any further information is needed just let me know. Thank you in advance.

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Gold Problem Solver

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26.9K Messages

2 days ago

... Arris SB8200. ... Gigabit X2 2100Mbps down, and 300Mbps up. ...

The SB8200 is not compatible with Gigabit internet service. Comcast/Xfinity rates it for wired download speeds "up to 957, 936, or 934 Mbps" depending on the device version. It isn't compatible with their "enhanced" upload speeds either.

Follow the "See all modems" link near the bottom of https://www.xfinity.com/support/internet/customerowned, and then under the "Compatible Modems" heading click the Arris list. Using devices on Internet speed tiers for which they are not compatible with tends to produce unexpected results, often speeds well below the ones you are paying for. 

AFAIK Comcast/Xfinity has never said how they provision devices operating on speed tiers they're not compatible with. All I can tell you is that many customers who tried it have reported that they don't get full speed. There's a tendency to think the device will operate at the maximum speed it is capable of, but that doesn't seem to be the case. Instead, incompatible devices often seem to be provisioned to run at speeds well below what they should be capable of. 

The T3 and "Commanded Power in Excess" errors may be due to incompatibility, or to faulty coax cable or connections. Please see Internet Troubleshooting Tips

You need to either get a device compatible with X2 Gigabit, or drop back to a plan speed for which the 8200 is compatible. 

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.

(edited)

Visitor

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2 Messages

@BruceW​ I should mention I've always had upstream issues, even with the equipment that Xfinity has provided me, I just never considered digging deeper until I purchased my own equipment. I have considered dropping down to a lower tiered plan, but if I still have issues in regards to upstream, it feels pretty insane. I still have the XB8 that they provided me previously that I was having difficulties with. I'll test it out and see if it's any better, thank you for your help

Official Employee

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2.1K Messages

3 hours ago

@user_b12fd1 Thanks for reaching out about your internet concerns. @BruceW provided great and accurate information. I'm sorry to hear you're having connection issues with our modem and your own device.

Have you had the chance to swap out the ethernet cord?

Can you tell us more about your current setup

Do you have any additional devices connected such as a separate router, any Wi-Fi extenders, amplifiers or splitters connected?

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