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keith-b600
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Sunday, September 28th, 2025

DS Config Update Messages + MDD Timeouts, Frequent Modem Reboots (Arris T25)

Hello - I am posting this on my dad's behalf on his account because I manage my parent's network stuff. Hope that is ok.

It's been over a year since we switched to our own modem and router to save the rental fee associated with Xfinity the equipment. First we had a Netgear CM1150V (which failed) so we switched to an Arris T25. We went with this model because it was on Xfinity's list of recommended devices at the time and also supports VOIP (a surprising number of new models no longer do??). It was provisioned by an automatic process in the app, I did not speak to anyone to confirm the model, MAC addresses, etc...

Since the switch to the T25, we have been experiencing internet dropouts on average every 2-3 days (sometimes daily) caused by an automatic modem reboot. I don't have the "evidence" from the logs, but basically they looked like this before I started troubleshooting:

DS Profile Config Update -> CM-Status Message Sent -> T3-Timeout No Ranging Response Received (sometimes multiple of these) -> Lost MDD Timeout -> Modem Reboot, MIMO Event.

I noticed that the upstream power levels were far below where they should be according to Arris specifications (I was seeing 30 - 33 dBmv while they specify 45 - 51 dBmv). So it sounds like the power levels are too low to overcome the noise floor at the CMTS and therefore the modem's responses are being lost. I (recently) added a 15 dB return-path attenuator at the cable drop outside the house which has corrected the upstream power levels to around 45-47 dBmv. The result of this is that there are no longer any T3 Timeout messages in the log. Cool, that's good start...

So I thought it was over, but the modem rebooted again two nights ago, so obviously the rebooting issue is still present. Here is what the log looks like. A few DS Profile Config Update messages and lots of CM-Status Messages and MDD Timeouts. Finally at the end there is a MIMO Event, indicating the modem rebooted itself (and just the T3 Timeout, but that seems to be normal after a reboot?).

Date Time Event ID Event Level Description
9/26/2025 21:22 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 74010100 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 74010100 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 43; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 74010100 6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:23 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:24 74010100 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 43; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:24 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:24 74010100 6 CM-STATUS message sent. Event Type Code: 24; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:38 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:38 74010100 6 CM-STATUS message sent. Event Type Code: 4; Chan ID: 13; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:38 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:39 74010100 6 CM-STATUS message sent. Event Type Code: 4; Chan ID: 13; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:39 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:39 74010100 6 CM-STATUS message sent. Event Type Code: 1; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:40 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/26/2025 21:42 90000000 5 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/27/2025 1:44 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Here are the DS and US channels. Note there are not any uncorrectables - very rarely do I ever seen any uncorrectables, maybe 1 or 2 every couple weeks. As far as correctables go, the logged numbers go up a few here and there but always remain low. And the DS channel powers/SNRs are where they should be.

DCID Freq Power SNR Modulation Octets Correcteds Uncorrectables
Downstream 1 28 525.00 MHz 2.70 dBmV 40.95 dB 256QAM 7207357911 0 0
Downstream 2 20 477.00 MHz 3.00 dBmV 43.38 dB 256QAM 3669551944 0 0
Downstream 3 36 573.00 MHz 1.80 dBmV 40.95 dB 256QAM 3751527489 0 0
Downstream 4 44 621.00 MHz 0.60 dBmV 40.37 dB 256QAM 291142239 12 0
Downstream 5 13 435.00 MHz 3.70 dBmV 40.95 dB 256QAM 287762592 0 0
Downstream 6 14 441.00 MHz 3.70 dBmV 43.38 dB 256QAM 289087449 0 0
Downstream 7 15 447.00 MHz 3.70 dBmV 40.95 dB 256QAM 289026362 0 0
Downstream 8 16 453.00 MHz 3.40 dBmV 40.95 dB 256QAM 289349931 0 0
Downstream 9 17 459.00 MHz 3.30 dBmV 40.95 dB 256QAM 290247830 0 0
Downstream 10 18 465.00 MHz 3.30 dBmV 40.95 dB 256QAM 290435905 0 0
Downstream 11 19 471.00 MHz 3.20 dBmV 43.38 dB 256QAM 290414447 0 0
Downstream 12 21 483.00 MHz 2.90 dBmV 40.95 dB 256QAM 261381987 0 0
Downstream 13 22 489.00 MHz 2.70 dBmV 40.95 dB 256QAM 260453264 0 0
Downstream 14 23 495.00 MHz 2.70 dBmV 40.95 dB 256QAM 261389114 0 0
Downstream 15 24 501.00 MHz 2.90 dBmV 40.37 dB 256QAM 260603126 0 0
Downstream 16 25 507.00 MHz 2.70 dBmV 43.38 dB 256QAM 273018649 0 0
Downstream 17 26 513.00 MHz 2.70 dBmV 40.95 dB 256QAM 273784764 0 0
Downstream 18 27 519.00 MHz 2.50 dBmV 40.95 dB 256QAM 274638882 0 0
Downstream 19 29 531.00 MHz 2.50 dBmV 40.95 dB 256QAM 267145441 0 0
Downstream 20 30 537.00 MHz 2.20 dBmV 40.95 dB 256QAM 267326772 0 0
Downstream 21 31 543.00 MHz 2.20 dBmV 40.95 dB 256QAM 266400295 0 0
Downstream 22 32 549.00 MHz 2.00 dBmV 43.38 dB 256QAM 266310797 0 0
Downstream 23 33 555.00 MHz 1.90 dBmV 40.95 dB 256QAM 379605304 0 0
Downstream 24 34 561.00 MHz 1.90 dBmV 40.95 dB 256QAM 378938543 0 0
Downstream 25 35 567.00 MHz 1.80 dBmV 43.38 dB 256QAM 379378236 0 0
Downstream 26 37 579.00 MHz 1.80 dBmV 40.95 dB 256QAM 371575909 0 0
Downstream 27 38 585.00 MHz 1.70 dBmV 40.95 dB 256QAM 371781103 0 0
Downstream 28 39 591.00 MHz 1.50 dBmV 40.95 dB 256QAM 371481849 0 0
Downstream 29 40 597.00 MHz 1.30 dBmV 40.95 dB 256QAM 371654407 0 0
Downstream 30 41 603.00 MHz 1.20 dBmV 40.95 dB 256QAM 371181453 0 0
Downstream 31 42 609.00 MHz 0.80 dBmV 40.95 dB 256QAM 372035593 0 0
Downstream 32 43 615.00 MHz 0.70 dBmV 40.95 dB 256QAM 371932283 11 0

UCID Freq Power Channel Type Symbol Rate Modulation
Upstream 1 1 16.40 MHz 45.75 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 16QAM
Upstream 2 4 35.60 MHz 47.75 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 32QAM
Upstream 3 3 29.20 MHz 46.75 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM
Upstream 4 2 22.80 MHz 46.00 dBmV DOCSIS2.0 (ATDMA) 5120 kSym/s 64QAM

Not sure what needs to happen at this point. Should I call and request that the modem be re-provisioned? It seems like the updates that the CMTS is pushing to the modem might be bugged or incompatible? Everything I'm reading points to this being an issue up the line from us and not a problem with our hardware. Everything else is fine; speeds are great and the VOIP line works perfectly. It's this spontaneous rebooting problem that has me at my wit's end. Any help would be appreciated.

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14 days ago

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XfinityDilary

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14 days ago

 

Thanks for posting on our Community Forums, keith-b600. We appreciate the shared details and the opportunity to help with your connectivity concerns. We can try reprovisioning the device on our end to see if that helps. Could you please send our team a Direct Message with your name and service address? Our team can take a further look at this issue.

 

To send a Direct Message:

Click "Sign In" if necessary

• Click the "Direct Messaging chat" icon

• Click the "New message" (pencil and paper) icon

• Type "Xfinity Support" in the "To:" line and select "Xfinity Support" from the drop-down list that appears. The "Xfinity Support" graphic replaces the "To:" line

• Type your message in the text area near the bottom of the window

• Press Enter to send it

 

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keith-b600

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Hi, thanks for responding, I have sent the message as instructed.

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14 days ago

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keith-b600

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14 days ago

Just want to provide an update, the modem went down again this morning (10/1/2025). This time it was not able to recover, and I had to power cycle it (notice the ~45 minute gap between the last two logged messages). Same cycle of errors again. So the problem is confirmed still present.

Date Time Event ID Event Level Description
9/29/2025 2:12 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
9/29/2025 3:42 82000200 3 No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:21 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:22 74010100 6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:22 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:23 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:23 74010100 6 CM-STATUS message sent. Event Type Code: 4; Chan ID: 193; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:23 67061602 6 DS profile config update. DS Chan ID: 194.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:23 74010100 6 CM-STATUS message sent. Event Type Code: 16; Chan ID: 194; DSID: N/A; MAC Addr: N/A; OFDM/OFDMA Profile ID: 2.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 6:27 84020200 5 Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
10/1/2025 7:11 90000000 5 MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

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XfinityJorge

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Thank you so much for the DM and our team will respond to you there to start working together. We truly appreciate you working with us over this platform, and we will make sure we get this handled. 

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

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14 days ago

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EG

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14 days ago

@keith-b600 @XfinityJorge 

Please circle back here and post any possible solutions for the issue here in these open public forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

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