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Star

Dec 03, 2017

Solved

CM1000 Xfinity issues

I am quite frustrated at this point. I had a CM600 modem to support Comcast's Extreme 150 service. I've had it for a few years and was consistently getting 160 to 170mbps speed from it. About thre...

jgnoonan
Mar 12, 2018
Well it is finally fixed. The tech showed up today and I showed him the two frequencies that were having the problem. He checked outside, and then at the tap. He came into the house and said he needed to call a bucket truck in to fix it. I got a recorded call from Comcast that they were working to fix the issue. I got a second call an hour later that the issue was fixed. I ran a speed test and got a consistent 160mbps (yay!). I used the reset button on the modem and let it re-provision. All the signal/noise and power levels were good and there were no uncorrectable codewords. They didn't tell me what they fixed, but at long last, it is fixed.

JonMJones10

Aspirant

Dec 23, 2017

I think I'm having the same issue! It's driving me bonkers. Here is what I posted on the Xfinity forums:

Hardware Info:

Hardware Version	2.02

Firmware Version	V3.01.04



CM certificate	Installed

Here is the event log of the past 24 hours:

2017-12-23, 08:40:56	Warning (5)	REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-12-22, 17:53:40	Critical (3)	Resetting the cable modem due to docsDevResetNow
2017-12-22, 17:49:50	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-12-22, 14:14:06	Critical (3)	Resetting the cable modem due to docsDevResetNow
2017-12-22, 14:11:15	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
2017-12-22, 14:07:01	Critical (3)	REG RSP not received;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-12-22, 13:23:26	Critical (3)	REG RSP not received;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
2017-12-22, 07:11:59	Critical (3)	REG RSP not received;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx:10;CMTS-MAC=xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;

Note: I removed the MAC addresses, but the CM-MAC and CMTS-MAC do not match.

Latest Log after a factory reset on the modem:

2017-12-23, 09:01:46	Critical (3)	Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
2017-12-23, 09:00:19	Notice (6)	CM-STATUS message sent. Event Type Code: 3; Chan ID: N/A; DSID: E; MAC Addr: N/A; OFDM/OFDMA Profile ID: N/A.;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
2017-12-23, 09:00:19	Warning (5)	Unicast DSID PSN startup error
2017-12-23, 08:59:49	Warning (5)	REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Notice (6)	Honoring MDD; IP provisioning mode = IPv6
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:xx:xx:xx:xx:xx;CM-QOS=1.1;CM-VER=3.1;
Time Not Established	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;CM-MAC=xx:xx:xx:xx:xx;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

Here are my current connection stats:

Frequency start Value

This field below allows you to modify the frequency the cable modem start with its scan during initialization and registration. Enter the new start frequency and restart the cable modem for it to take effect.

Starting Frequency

<tabindex=-1>Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	729000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv6 only

<tabindex=-1>Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	21	729000000 Hz	6.2 dBmV	40.3 dB	48754675	0	0
2	Locked	QAM256	1	609000000 Hz	8.1 dBmV	41.0 dB	47253420	0	0
3	Locked	QAM256	2	615000000 Hz	7.7 dBmV	40.9 dB	47261941	0	0
4	Locked	QAM256	3	621000000 Hz	7.9 dBmV	41.0 dB	47271046	0	0
5	Locked	QAM256	4	627000000 Hz	7.4 dBmV	40.9 dB	47280141	0	0
6	Locked	QAM256	5	633000000 Hz	7.4 dBmV	40.6 dB	47285916	0	0
7	Locked	QAM256	6	639000000 Hz	7.2 dBmV	40.7 dB	47299161	0	0
8	Locked	QAM256	7	645000000 Hz	7.1 dBmV	40.6 dB	47307951	0	0
9	Locked	QAM256	8	651000000 Hz	6.9 dBmV	40.5 dB	47317712	0	0
10	Locked	QAM256	9	657000000 Hz	6.9 dBmV	40.5 dB	47326996	0	0
11	Locked	QAM256	10	663000000 Hz	6.9 dBmV	40.4 dB	47336669	0	0
12	Locked	QAM256	11	669000000 Hz	7.0 dBmV	40.6 dB	47345598	0	0
13	Locked	QAM256	12	675000000 Hz	7.1 dBmV	40.1 dB	47355716	0	0
14	Locked	QAM256	13	681000000 Hz	6.9 dBmV	40.3 dB	47363949	0	0
15	Locked	QAM256	14	687000000 Hz	7.2 dBmV	40.6 dB	47373438	0	0
16	Locked	QAM256	15	693000000 Hz	6.9 dBmV	40.2 dB	47382707	0	0
17	Locked	QAM256	16	699000000 Hz	6.8 dBmV	40.2 dB	47380079	0	0
18	Locked	QAM256	17	705000000 Hz	6.7 dBmV	40.5 dB	47410399	0	0
19	Locked	QAM256	18	711000000 Hz	6.4 dBmV	40.4 dB	47419980	0	0
20	Locked	QAM256	19	717000000 Hz	6.2 dBmV	40.3 dB	47428801	0	0
21	Locked	QAM256	20	723000000 Hz	5.9 dBmV	40.3 dB	47430581	0	0
22	Locked	QAM256	22	735000000 Hz	5.5 dBmV	40.2 dB	47438250	0	0
23	Locked	QAM256	23	741000000 Hz	5.9 dBmV	40.2 dB	47444370	0	0
24	Locked	QAM256	24	747000000 Hz	5.3 dBmV	40.1 dB	47449904	0	0
25	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
26	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
27	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
28	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
29	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
30	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
31	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

<tabindex=-1>Upstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	35800000 Hz	49.5 dBmV
2	Locked	ATDMA	2	29400000 Hz	50.0 dBmV
3	Locked	ATDMA	3	23000000 Hz	50.0 dBmV
4	Not Locked	Unknown	0	0 Hz	0.0 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV

<tabindex=-1>Downstream OFDM Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power	SNR / MER	Active Subcarrier Number Range	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Not Locked	Unknown	0	0 Hz	0 dBmV	0 dB	0 ~ 0	0	0	0
2	Not Locked	Unknown	0	0 Hz	0 dBmV	0 dB	0 ~ 0	0	0	0

<tabindex=-1>Upstream OFDMA Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

Current System Time: Sat Dec 23 09:17:13 2017

jgnoonan

Star

Dec 23, 2017

BigQuark OK. I finally got the modem reactivated which took more time that I thought. First, here is the link to the speed test I did. I have 150mbps service and with the Xfinity gateway I was getting a very solid 175mbps. With the CM1000, I'm getting about 80mbps.

http://speedtest.xfinity.com/results/JBJNMFPLV2Q17ZE

I am going to keep the CM1000 connected until we can resolve the issue. Here is the data you requested;

Frequency start Value

Starting Frequency

<tabindex=-1>Startup Procedure

Procedure	Status	Comment
Acquire Downstream Channel	441000000 Hz	Locked
Connectivity State	OK	Operational
Boot State	OK	Operational
Security	Enable	BPI+
IP Provisioning Mode	Honor MDD	IPv6 only

<tabindex=-1>Downstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	4	441000000 Hz	3.1 dBmV	38.0 dB	32255290	8	0
2	Locked	QAM256	1	423000000 Hz	3.7 dBmV	38.4 dB	30759191	16	0
3	Locked	QAM256	2	429000000 Hz	3.8 dBmV	38.6 dB	30769845	9	0
4	Locked	QAM256	3	435000000 Hz	3.6 dBmV	38.4 dB	30778760	10	0
5	Locked	QAM256	5	453000000 Hz	2.3 dBmV	37.5 dB	30788847	25	0
6	Locked	QAM256	6	459000000 Hz	1.9 dBmV	37.1 dB	30797731	29	0
7	Locked	QAM256	7	465000000 Hz	1.7 dBmV	36.6 dB	30807102	16	0
8	Locked	QAM256	8	471000000 Hz	1.3 dBmV	36.1 dB	30816615	27	0
9	Locked	QAM256	9	477000000 Hz	1.1 dBmV	35.8 dB	30825593	29	0
10	Locked	QAM256	10	483000000 Hz	0.7 dBmV	35.6 dB	30834441	41	0
11	Locked	QAM256	11	489000000 Hz	0.6 dBmV	35.9 dB	30844020	28	0
12	Locked	QAM256	12	495000000 Hz	0.8 dBmV	36.2 dB	30853354	19	0
13	Locked	QAM256	13	507000000 Hz	0.9 dBmV	35.8 dB	30861997	23	0
14	Locked	QAM256	14	513000000 Hz	0.8 dBmV	35.5 dB	30871525	25	0
15	Locked	QAM256	15	519000000 Hz	0.7 dBmV	35.8 dB	30881585	39	0
16	Locked	QAM256	16	525000000 Hz	0.3 dBmV	36.6 dB	30890260	36	0
17	Locked	QAM256	17	531000000 Hz	0.5 dBmV	37.1 dB	30909030	38	0
18	Locked	QAM256	18	537000000 Hz	0.2 dBmV	37.3 dB	30918286	36	0
19	Locked	QAM256	19	543000000 Hz	0.4 dBmV	37.1 dB	30927263	32	0
20	Locked	QAM256	20	555000000 Hz	1.0 dBmV	37.2 dB	30936543	46	0
21	Locked	QAM256	21	561000000 Hz	0.9 dBmV	36.9 dB	30765945	172563	7225
22	Locked	QAM256	22	567000000 Hz	1.9 dBmV	34.9 dB	27083751	1244789	2622102
23	Locked	QAM256	23	573000000 Hz	1.2 dBmV	35.9 dB	29799618	731184	428058
24	Locked	QAM256	24	579000000 Hz	0.3 dBmV	36.6 dB	30964961	44	0
25	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
26	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
27	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
28	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
29	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
30	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
31	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
32	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

<tabindex=-1>Upstream Bonded Channels

Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	35600000 Hz	35.5 dBmV
2	Locked	ATDMA	2	29200000 Hz	35.8 dBmV
3	Locked	ATDMA	3	22800000 Hz	33.3 dBmV
4	Not Locked	Unknown	0	0 Hz	0.0 dBmV
5	Not Locked	Unknown	0	0 Hz	0.0 dBmV
6	Not Locked	Unknown	0	0 Hz	0.0 dBmV
7	Not Locked	Unknown	0	0 Hz	0.0 dBmV
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV

<tabindex=-1>Downstream OFDM Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power	SNR / MER	Active Subcarrier Number Range	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	0, 1	25	372000000 Hz	5.2 dBmV	37.8 dB	1108 ~ 2987	898284	9608	0
2	Not Locked	0	0	0 Hz	7.5 dBmV	0.0 dB	0 ~ 4095	0	0	0

<tabindex=-1>Upstream OFDMA Channels

Channel	Lock Status	Modulation / Profile ID	Channel ID	Frequency	Power
1	Not Locked	Unknown	0	0 Hz	0 dBmV
2	Not Locked	Unknown	0	0 Hz	0 dBmV

Current System Time: Sat Dec 23 13:12:17 2017

I attached a pdf with the rest.

Warm regards,

Joe Noonan

xfinity.pdf190 KB

jgnoonan
Star
Dec 28, 2017
DarrenM My Internet speed dropped to 2mbps overnight. In the attached file are the frequencies and the logs BEFORE I sent a reset signal to the model from Xfinity and AFTER. Let me know if you have any questions.

Frequency start Value.pdf431 KB
jgnoonan
Star
Dec 29, 2017
DarrenM BigQuark The same issue this morning as the previous post. My download speed was 1.5mbps. This time I unplugged the modem and waited 60 seconds and plugged it back in and it cleared the issue.
jgnoonan
Star
Jan 05, 2018
DarrenM BigQuark any update on this issue?
irakhlin
Aspirant
Jan 10, 2018
I don't want to hijack your thread but I just want to add that I am having very similar problems. My internet was having identical issues to yours however on Friday my internet stopped working all together. Since then Comcast has replaced all the lines to my house and inside yet the CM1000 still goes not get any internet. What is weirder is that I am getting an external Comcast IP address assignment but Comcast says they cannot see my modem respond. Additionally connecting their rented equipment and provisioning it to the account works without issue, provisioning the CM1000 back to the account results in no service at all. I am really looking forward to seeing a response on this because I am also out of ideas.
martyr444
Apprentice
Jan 11, 2018
I too am havng similar issues with my CM1000. Comcast has tried some of the same changes with my cables but nothing is fixing it. My CM1000 averages 35,000 errors daily both Correctable Codewords and Uncorrectable Codewords. I get error logs and drops daily and my firmware version is v3.01.04. It was doing the same with the previous version but maybe worse now. They just don't seem to know how to fix these issues in our area. Issues with Xfinity just went down hill ever since switching to Docsis 3.1. I have tried a different CM1000 with the same results.
jgnoonan
Star
Jan 11, 2018
martyr444do you think this is an issue with Xfinity or with the Netgear. When their modem was put on, I was getting 175mbps. I am wondering if I should just bring the Netgear back and go with a different vendor. I really don't want to rent a modem from Xfinity.
martyr444
Apprentice
Jan 11, 2018
In my case I feel Xfinity is having issues with Docsis 3 in general as thats when our issues started up. We have tried all the brands on the Xfinity list including a loaner from them. I think the CM1000 got worse with the latest firm ware update.
irakhlin
Aspirant
Jan 12, 2018
I think this is an issue with xfinity and docsis 3.1 modems. I have tested two netgear cm1000 modems and an arris sb8200.. both of these are the top of the line docsis 3.1 modems and all 3 had identical issues at my house. The second I went out and got an arris sb6190 (one of the fastest docsis 3.0 modems) everything worked perfectly. It also worked perfectly with the rental modem which was also docsis 3.0. I think its fair to say this issue is isolated to docsis 3.1 modems.. atleast on my network.
jgnoonan
Star
Jan 12, 2018
irakhlinit makes sense. Xfinity is rolling out gigabit Internet service in our area to compete with EPB. Hopefully Xfinity and Netgear will sort this out soon. I am paying for service I can't use at the speed I am paying for.
BigQuark
Guide
Jan 19, 2018
My log now has bursts of errors. It may be a 1 or 2 or 3 hour time frame that peppers my Cm1000 error logs, then it clears up. After calling Comcast several times I am convinced the customer service reps are starting to hear more and more of CM1000 issues when using D3.1 Mine modem was just fine on the 24x3 D3.0 but went haywire when the firmware was updated and a D3.1 D/S channel was deployed in my area.
I am on a Cisco CMTS judging by my CMTS MAC and I think that is where the problem lies. Comcast had a similar problem whith the Motorola SurfBoard 8200 activating on Gigabit Tier. The problem was the CMTS and a Comcast Engineer had to log into the CMTS and manually activate the 8200's. That issue has largely been resolved but that is what leads me to believe this also is a CMTS issue. Still no resolution, however.