Internet speed went from 1 Gbps to 50 Mbps. Got email saying that my modem is incompatible, but it's been working for years.

During COVID, I upgraded to 1 Gbps service. I bought a Motorola MB8600 cable modem, with DOCSIS 3.1, 32x8, etc. I have had no issues for several years.

A few days ago, after noticing slowness, my connection seems now to be only 50 Mbps. Rebooting does not help. Is anyone else seeing this?

I got an email on December 9th saying that faster UPLOAD speeds are available and I should upgrade my modem (to DOCSIS 3.1.....which I already have!), but it's not upgrade speed that is the problem. My speed is now 1/20th what I am paying for. Any help would be appreciated.

Note: I am an engineer with a fully WIRED network. This is a real issue and I've done all the boilerplate troubleshooting already.

Responses

BruceW

Gold Problem Solver

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26.2K Messages

1 month ago

... 1 Gbps service ... MB8600 cable modem ... only 50 Mbps ... faster UPLOAD speeds ...

Note that the MB8600 is not compatible with Gigabit Internet service. Comcast/Xfinity rates it for use with plan speeds "Up to 949 Mbps".

Slow speeds 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 you want to troubleshoot this yourself, please see Internet Troubleshooting Tips. If you still need help, please post the following information from your modem (from http://192.168.100.1):

uptime
downstream: power levels, SNR (or MER), and error countsfor all channels
upstream: power levels for all channels
complete event log, if available (Be sure to remove or blot out any MAC addresses. Forum security processing considers them "personal information" and may prevent the event log from posting if these are present.)

Copy and pasted text is preferred over images. Be aware that, if you post any images, your message will be made Private for a time, as all images must be approved by the Forum Moderators before the messages containing them become generally visible.

If you can't find the problem or you'd rather have Comcast take care of it and an employee does not respond to your message here, call them at the phone number on your bill or 1-800-Comcast, or use one of the options on https://www.xfinity.com/support/contact-us/. It's not likely they can fix the problem remotely. If not, insist they send a tech out to identify the cause and correct it.

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.

Regarding the upload speed, realize that although Comcast calls some devices "Compatible" and some "Recommended", for all but a few devices those designations only mean "compatible/recommended for use with their Internet service", and not necessarily approved for the new upload speeds introduced last year.

The MB8600 is not compatible with those speeds. Only a few retail devices are. See the "Next Gen" list at the top of the "All Compatible Devices" PDF linked near the bottom of https://www.xfinity.com/support/devices (at the moment that link points to https://assets.xfinity.com/assets/dotcom/projects/cix-4997_compatible-devices/2024.09.18%20Full%20List%20of%20Compatible%20Devices.pdf, but this changes from time to time). Also see:

For faster upload you need one of Comcast's newer rental gateways (XB6, XB7, XB8) or one of the few retail devices shown in the "Next Gen Speed Tier" group in the "All Compatible Devices" PDF:

Hitron Technologies CODA or CODA56
Netgear CM2500, CM3000, or CBR750
ARRIS/Surfboard G20, G34, G36, G54, or S34
Ubiquiti UCI

The Reddit link (if they ever get the page back online) lists the approved devices as well as other requirements for faster upload speeds.

Comcast could make all of this much simpler and clearer, but they have chosen not to do so.

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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U

user_n4qdb0

5 Messages

Thanks for responding. I hear you, but what irritates me is that the MB8600 was indeed on the compatibility list when I upgraded a few years back. It's like I'm being forced to upgrade. Considering that it's a DOCSIS 3.1 device already, this seems like it's an artificial limitation.

I might go for a Ubiquiti UCI anyway....the rest of my system is UniFi already anyway.

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1 month ago

BruceW

Gold Problem Solver

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26.2K Messages

1 month ago

Sorry to hear you are a victim of The Great Gigabit Demotion. When Comcast first introduced Gigabit service they approved a bunch of devices for it which were later demoted from Gigabit back to a number around 940. Why? They've never said. Since then, they seem to be requiring all devices they approve for Gig and Gig+ service to have a 2.5 Gb (or higher) Ethernet port.

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EG

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108.2K Messages

1 month ago

@BruceW @user_n4qdb0

My take on that is that they realized the 940 Mbps ethernet overhead limitation associated with 10/100/1000 gig ports. Furthermore, they over provision the gig speed tier by 20% resulting in 1200 Mbps speeds with which you could never achieve with a gig port.

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user_n4qdb0

5 Messages

One would think that the what's on the other side of the cable modem shouldn't be a limiting factor to the speed on the coax side. My MB8600 is on the supported list (still, according to the PDF), with the only limitation that I should be able to pull "only" 949 Mbps.

Suddenly throttling me down to 50 Mbps doesn't seem like a malfunction.

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1 month ago

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EG

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108.2K Messages

1 month ago

@user_n4qdb0

What we've seen happen here is that if you use an incompatible modem (according to them) for a faster speed tier, the modem will default down to using an even slower speed configuration file. I've never understood why this is done..... A compatible device needs to be used.

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BruceW

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26.2K Messages

1 month ago

... I might go for a Ubiquiti UCI anyway ...

That might not help much if there's a problem with your connection to Comcast's network. If you post the information requested above we might be able to tell if that is the case.

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)

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user_n4qdb0

5 Messages

@BruceW Ok... so here it is. Looks like there might be some issues?

Uptime: 2 days 3 hours (I rebooted a few days ago, thinking that would help)

Downstream:

Channel	Lock Status	Modulation	Channel ID	Freq. (MHz)	Pwr (dBmV)	SNR (dB)	Corrected	Uncorrected
1	Locked	QAM256	20	513.0	15.5	44.9	0	0
2	Locked	QAM256	1	399.0	14.9	44.7	0	0
3	Locked	QAM256	2	405.0	14.9	44.8	0	0
4	Locked	QAM256	3	411.0	14.8	44.4	0	0
5	Locked	QAM256	4	417.0	14.8	44.7	0	0
6	Locked	QAM256	5	423.0	14.8	44.7	0	0
7	Locked	QAM256	6	429.0	14.8	44.7	0	0
8	Locked	QAM256	7	435.0	14.9	44.8	0	0
9	Locked	QAM256	8	441.0	14.8	44.7	0	0
10	Locked	QAM256	9	447.0	14.9	44.9	0	0
11	Locked	QAM256	10	453.0	14.9	44.9	0	0
12	Locked	QAM256	11	459.0	15.0	45.0	0	0
13	Locked	QAM256	12	465.0	15.2	44.9	0	0
14	Locked	QAM256	13	471.0	15.2	44.9	0	0
15	Locked	QAM256	14	477.0	15.3	45.0	0	0
16	Locked	QAM256	15	483.0	15.2	44.9	0	0
17	Locked	QAM256	16	489.0	15.3	45.0	0	0
18	Locked	QAM256	17	495.0	15.4	45.0	0	0
19	Locked	QAM256	18	501.0	15.5	45.1	0	0
20	Locked	QAM256	19	507.0	15.6	45.0	0	0
21	Locked	QAM256	21	519.0	15.3	44.7	0	0
22	Locked	QAM256	22	525.0	15.1	44.6	0	0
23	Locked	QAM256	23	531.0	15.0	44.5	0	0
24	Locked	QAM256	24	537.0	15.0	44.6	0	0
25	Locked	QAM256	25	543.0	15.1	44.7	0	0
26	Locked	QAM256	26	549.0	15.2	44.7	0	0
27	Locked	QAM256	27	555.0	15.2	44.7	0	0
28	Locked	QAM256	28	561.0	15.3	44.6	0	0
29	Locked	QAM256	29	567.0	15.1	44.4	0	0
30	Locked	QAM256	30	573.0	14.9	44.3	0	0
31	Locked	QAM256	31	579.0	14.9	44.3	0	0
32	Locked	QAM256	32	585.0	14.9	44.4	0	0
33	Locked	OFDM PLC	193	690.0	15.0	44.0	60498789	0
34	Locked	OFDM PLC	194	957.0	11.0	41.9	133511687	0

Upstream:

Channel	Lock Status	Channel Type	Channel ID	Symb. Rate (Ksym/sec)	Freq. (MHz)	Pwr (dBmV)
1	Locked	SC-QAM	1	5120	16.4	39.0
2	Locked	SC-QAM	2	5120	22.8	39.0
3	Locked	SC-QAM	3	5120	29.2	39.5
4	Locked	SC-QAM	4	5120	35.6	39.3

Event Log:

Time	Priority	Description
17:46:40 Sat Aug 3 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:46:51 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
17:46:51 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
17:46:51 Sat Aug 3 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
17:47:00 Sat Aug 3 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:55:37 Sat Aug 3 2024	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:55:45 Sat Aug 3 2024	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:56:21 Sat Aug 3 2024	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:56:21 Sat Aug 3 2024	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:56:25 Sat Aug 3 2024	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:56:26 Sat Aug 3 2024	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
17:56:31 Sat Aug 3 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
18:00:49 Sat Aug 3 2024	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
18:01:54 Sat Aug 3 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
18:01:55 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
18:01:55 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
18:01:55 Sat Aug 3 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
18:01:57 Sat Aug 3 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx,CM-QOS=1.1;CM-VER=3.1;
18:02:08 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
18:02:08 Sat Aug 3 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
18:02:08 Sat Aug 3 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
18:02:22 Sat Aug 3 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
08:30:51 Wed Aug 28 2024	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
12:26:34 Thu Sep 5 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
12:26:36 Thu Sep 5 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
12:26:36 Thu Sep 5 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
12:26:36 Thu Sep 5 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
12:26:38 Thu Sep 5 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
12:26:50 Thu Sep 5 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
12:26:50 Thu Sep 5 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
12:26:50 Thu Sep 5 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
12:27:04 Thu Sep 5 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
23:43:11 Sun Oct 13 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
23:43:12 Sun Oct 13 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
23:43:12 Sun Oct 13 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
23:43:12 Sun Oct 13 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
23:43:14 Sun Oct 13 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
23:43:25 Sun Oct 13 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
23:43:25 Sun Oct 13 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
23:43:25 Sun Oct 13 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
23:43:38 Sun Oct 13 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
23:43:38 Sun Oct 13 2024	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
23:43:43 Sun Oct 13 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
15:45:11 Sun Nov 24 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
15:45:13 Sun Nov 24 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
15:45:13 Sun Nov 24 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
15:45:13 Sun Nov 24 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
15:45:15 Sun Nov 24 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
15:45:27 Sun Nov 24 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
15:45:27 Sun Nov 24 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
15:45:27 Sun Nov 24 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
15:45:42 Sun Nov 24 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:Fixed Initial, 5-42MHz.
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
Time Not Established	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-21.1, 5-85MHz.
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
Time Not Established	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
12:59:17 Sat Dec 14 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
12:59:17 Sat Dec 14 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.2, 258MHz.
12:59:17 Sat Dec 14 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-21.3, 1002MHz.
12:59:17 Sat Dec 14 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change_Ignored:TLV-21.1, 85MHz.
12:59:19 Sat Dec 14 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
12:59:23 Sat Dec 14 2024	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
12:59:31 Sat Dec 14 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.2, 108MHz.
12:59:31 Sat Dec 14 2024	Critical (3)	CMSTATUS:DS_Diplexer_Mode_Change_Ignored:TLV-84.3, 1002MHz.
12:59:31 Sat Dec 14 2024	Critical (3)	CMSTATUS:US_Diplexer_Mode_Change:TLV-84.1, 5-42MHz.
12:59:37 Sat Dec 14 2024	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
12:59:38 Sat Dec 14 2024	Notice (6)	DS profile assignment change. DS Chan ID: 33; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
12:59:46 Sat Dec 14 2024	Critical (3)	UCD invalid or channel unusable;CM-MAC=xx:xx:xx:xx:xx:xx;CMTS-MAC=xx:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;

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1 month ago

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BruceW

Gold Problem Solver

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26.2K Messages

1 month ago

Hmmmm. Your downstream SNR and error counts look good, but those out of spec (too high) power levels may be over-driving the receiver circuits. If you have an amp in the line try bypassing it. If not, you may want to add about 7dB attenuation to the coax line to see if that helps your speeds. If you happen to have a 3-way splitter handy you might try inserting it to see what the effect is. If that doesn't work, I'm afraid it's "call Comcast time" as described above.

Good luck!

And again:

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U

user_n4qdb0

5 Messages

1 month ago

@BruceW , as far as "calling comcast" goes....you wouldn't happen to have a link or a number, would you? Seems near-impossible to find on the website...just the useless automated assistant.

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XfinityEricB

Official Employee

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1.9K Messages

user_n4qdb0 Our number to get to phone agents is 1 800 Xfinity, and the automated assistant will get you to an agent after a few questions. We can assist you here as well since you have us. I can review your signal levels to see what needs corrected.

Can you send us a direct message with your full name, name of account holder (if different), and service address please?

To send a "Direct Message" to Xfinity Support:

Click "Sign In" if necessary

Click the "Direct Messaging" icon (speech bubble)

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

The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there

- As you are typing a drop-down list appears. Select "Xfinity Support" from that list

- An "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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1 month ago

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Your Home Network

user_n4qdb0

Internet speed went from 1 Gbps to 50 Mbps. Got email saying that my modem is incompatible, but it's been working for years.

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BruceW

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BruceW

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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BruceW

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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BruceW

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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XfinityEricB

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