Lower speeds after switch to CM1000

[SushiPragmatic]

I can only get 33Mbps up and down after switching to CM1000 firmware V6.01.02 and Comcast Xfinity 1000Mbps plan. I need help interpreting these values to know if my problem is the modem or my service.

[plemans · Accepted solution]

A screen snip will show all the values. I don't quite see them all. But from what I can see, there's issues with your line. To many errors, not all the channels are locked, ofdm issues, and your power is way out of spec. You should be within 3dBmV of each other. 

A couple things you can try. 

1. remove all splitters, amplifiers, attenuators from your line.  

2. preferrably hook up directly where the coax enters your house. This removes the chance that its the wiring internal to your home.

3. inspect your line in the house if you can't move the modem to the entrance. Check for kinks, corrosion, bad/cheap connectors, wear to the coax, and loose connectors. 

If you do all that and your connection is still looking like it is, have your isp inspect your line. You're responsible for it after it enters the home which is why I recommend direct connecting it.It removes the chance of the problem being in your home. ISP's really like to blame the issue on the wiring within the home. 

[SushiPragmatic]

Downstream Bonded Channels (Partial Service)

Channel	Lock Status	Modulation	Channel ID	Frequency	Power	SNR / MER	Unerrored Codewords	Correctable Codewords	Uncorrectable Codewords
1	Locked	QAM256	37	651000000 Hz	-3.6 dBmV	38.8 dB	29043116	80	420
2	Locked	QAM256	9	483000000 Hz	-0.4 dBmV	39.2 dB	25038117	897	0
3	Locked	QAM256	10	489000000 Hz	-0.3 dBmV	38.4 dB	27387075	1481	4950
4	Locked	QAM256	11	495000000 Hz	-0.4 dBmV	33.9 dB	27418418	1616	4874
5	Locked	QAM256	12	501000000 Hz	-0.8 dBmV	35.6 dB	27426064	1087	4917
6	Locked	QAM256	13	507000000 Hz	-1.7 dBmV	33.7 dB	27433031	1164	4869
7	Locked	QAM256	14	513000000 Hz	-2.1 dBmV	34.6 dB	27440052	1110	4864
8	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
9	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
10	Locked	QAM256	17	531000000 Hz	-2.3 dBmV	28.1 dB	27263782	186097	4555
11	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
12	Locked	QAM256	19	543000000 Hz	-1.4 dBmV	31.9 dB	27455832	1087	4981
13	Locked	QAM256	20	549000000 Hz	-1.4 dBmV	39.8 dB	27464252	1282	5757
14	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
15	Locked	QAM256	22	561000000 Hz	-1.1 dBmV	31.9 dB	27381173	83957	4135
16	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0

[SushiPragmatic]

17	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
18	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
19	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
20	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
21	Not Locked	Unknown	0	0 Hz	0.0 dBmV	0.0 dB	0	0	0
22	Locked	QAM256	29	603000000 Hz	-2.9 dBmV	32.4 dB	25221789	107	510
23	Locked	QAM256	30	609000000 Hz	-3.7 dBmV	39.4 dB	27470916	1130	5510
24	Locked	QAM256	31	615000000 Hz	-3.9 dBmV	40.6 dB	25242970	96	465
25	Locked	QAM256	32	621000000 Hz	-3.7 dBmV	37.6 dB	27486381	1204	5375
26	Locked	QAM256	33	627000000 Hz	-3.2 dBmV	38.2 dB	27486259	1063	4902
27	Locked	QAM256	34	633000000 Hz	-3.1 dBmV	40.9 dB	27494924	1111	4759
28	Locked	QAM256	35	639000000 Hz	-3.3 dBmV	40.4 dB	27535724	1219	5314
29	Locked	QAM256	36	645000000 Hz	-3.5 dBmV	39.5 dB	27567960	1006	4867
30	Locked	QAM256	38	657000000 Hz	-4.3 dBmV	38.5 dB	27514176	1121	5343
31	Locked	QAM256	39	663000000 Hz	-5.1 dBmV	37.6 dB	27520979	1059	4916
32	Locked	QAM256	40	669000000 Hz	-6.4 dBmV	38.3 dB	27518723	1174	5292

[SushiPragmatic]

Upstream Bonded Channels
Channel	Lock Status	Modulation	Channel ID	Frequency	Power
1	Locked	ATDMA	1	35800000 Hz	50.5 dBmV
2	Locked	ATDMA	2	29400000 Hz	54.0 dBmV
3	Locked	ATDMA	3	23000000 Hz	50.5 dBmV
4	Locked	ATDMA	4	16600000 Hz	50.0 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
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	159	690000000 Hz	-8.1 dBmV	4.5 dB	1246 ~ 2849	337796	4639	333301
2	Not Locked	0	0	0 Hz	3.2 dBmV	0.0 dB	0 ~ 4095	0	0	0
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

[plemans · Accepted solution]

A screen snip will show all the values. I don't quite see them all. But from what I can see, there's issues with your line. To many errors, not all the channels are locked, ofdm issues, and your power is way out of spec. You should be within 3dBmV of each other. 

A couple things you can try. 

1. remove all splitters, amplifiers, attenuators from your line.  

2. preferrably hook up directly where the coax enters your house. This removes the chance that its the wiring internal to your home.

3. inspect your line in the house if you can't move the modem to the entrance. Check for kinks, corrosion, bad/cheap connectors, wear to the coax, and loose connectors. 

If you do all that and your connection is still looking like it is, have your isp inspect your line. You're responsible for it after it enters the home which is why I recommend direct connecting it.It removes the chance of the problem being in your home. ISP's really like to blame the issue on the wiring within the home. 

[plemans]

This would also be the cable modem forum. You're int he mobile router forum

https://community.netgear.com/t5/Cable-Modems-Routers/bd-p/home-cable-modems-routers

[SushiPragmatic]

I hooked the modem up outside directly to where the line comes to the side of my house and ran an extension cord to it and hooked my laptop directly to it and now I am seeing 300Mbps and all downstream channels locked with lower variance on channels. This is a great improvement and I thank you for your answer but it is still less than a third of what I pay for. With this in mind though I am convinced that the rest of the performance loss is due to cable issues further up the line with Comcast and the modem does work. Thank you again for your advice.