Signifgicant number of Pre/Post-RS errors on one single channel

[fjama13]

I have a Hub 5, and there are many Pre and Post-RS errors on a single downstream channel. I was wondering if anyone could tell me if there is anything in the house that can cause interference on channel 8 (187000000Hz). I have tightened the cable and checked to see if anything would cause the cable to be deformed etc. 

I have had 2 engineer visits, and they blame modem mode, but I do not know how that can cause it. I have packet loss and reduced speeds (around 300Mbps instead of 350-380Mbps). I have provided the router stats below.

[fjama13]

Hi,

I disagree It is now affecting multiple channels and the upstream modulation is at 32QAM instead of 64QAM. I also see a flood of the same message:

DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	39	14	0
2	Locked	40	1	0
3	Locked	40	3	0
4	Locked	39	3	0
5	Locked	39	4	0
6	Locked	40	1	0
7	Locked	40	1	0
8	Locked	40	9262	11064
9	Locked	40	1	0
10	Locked	40	3	0
11	Locked	40	0	0
12	Locked	40	0	0
13	Locked	40	0	0
14	Locked	40	0	0
15	Locked	40	117	0
16	Locked	40	8	0
17	Locked	40	81	0
18	Locked	40	8	0
19	Locked	40	460	20
20	Locked	40	0	0
21	Locked	40	0	0
22	Locked	40	1	0
23	Locked	40	0	0
24	Locked	40	0	0
25	Locked	40	0	0
26	Locked	40	0	0
27	Locked	40	0	0
28	Locked	40	0	0
29	Locked	40	0	0
30	Locked	40	0	0
31	Locked	40	0	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

0	49600000	41.5	5120	QAM 32	1
1	43100000	41	5120	QAM 32	2
2	36600000	40.8	5120	QAM 32	3
3	30100000	40.5	5120	QAM 32	4
4	23600000	40	5120	QAM 32	5

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

0	ATDMA	0	0	0	0
1	ATDMA	0	0	0	1
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

[Chris_W1]

Hi fjama13

I have looked into this for you and there is a fault in the area - F010605704  and this is due to be resolved on the 14th April. 

Kind regards, Chris. 

[unisoft]

---

@fjama13 wrote:

Hi,

I disagree It is now affecting multiple channels and the upstream modulation is at 32QAM instead of 64QAM. I also see a flood of the same message:

DBC-REQ Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	39	14	0
2	Locked	40	1	0
3	Locked	40	3	0
4	Locked	39	3	0
5	Locked	39	4	0
6	Locked	40	1	0
7	Locked	40	1	0
8	Locked	40	9262	11064
9	Locked	40	1	0
10	Locked	40	3	0
11	Locked	40	0	0
12	Locked	40	0	0
13	Locked	40	0	0
14	Locked	40	0	0
15	Locked	40	117	0
16	Locked	40	8	0
17	Locked	40	81	0
18	Locked	40	8	0
19	Locked	40	460	20
20	Locked	40	0	0
21	Locked	40	0	0
22	Locked	40	1	0
23	Locked	40	0	0
24	Locked	40	0	0
25	Locked	40	0	0
26	Locked	40	0	0
27	Locked	40	0	0
28	Locked	40	0	0
29	Locked	40	0	0
30	Locked	40	0	0
31	Locked	40	0	0

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

0	49600000	41.5	5120	QAM 32	1
1	43100000	41	5120	QAM 32	2
2	36600000	40.8	5120	QAM 32	3
3	30100000	40.5	5120	QAM 32	4
4	23600000	40	5120	QAM 32	5

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

0	ATDMA	0	0	0	0
1	ATDMA	0	0	0	1
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

---

How can you disagree???? At the time I posted, it was based on the output logs of your original post!

If data changes AFTER I post then that is a different scenario to what I was replying on and my original text said if more channels have an issue which clearly you went on to say after the event, that your upstream was fluctuating QAM levels.

If if you had just ONE QAM channel at QAM32 and the others all QAM64 - in a normal area without utilisation issues, your upstream would still be fine as enough capacity with the other bonded upstream channels for the (mean) upstream allowance VM provision. Obviously, they should all be at QAM64 ideally and your screen shot indicates something is clearly wrong now as all your upstream channels are QAM32 - so I agree there...

[fjama13]

Hi,

It's still an issue. Can you provide an update on whether the fault has been fixed, please?

[John_GS]

Hi @fjama13 

Thanks for coming back to the thread.

I am sorry it's not resolved, checking ticket number F010605704 the estimated fix date is tomorrow at 11.45am. Please check back with us after Midday if still having issues.

Best wishes.

[fjama13]

Hi,

I still have issues, whether in router or modem mode: slower upload and download speeds and packet loss. 

Downstream bonded channels

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID

1	259000000	3.2	39	QAM 256	16
2	139000000	7.3	39	QAM 256	1
3	147000000	7.1	39	QAM 256	2
4	155000000	7.1	39	QAM 256	3
5	163000000	6.7	39	QAM 256	4
6	171000000	6.5	40	QAM 256	5
7	179000000	6.5	40	QAM 256	6
8	187000000	6.3	40	QAM 256	7
9	195000000	6	40	QAM 256	8
10	203000000	5.6	40	QAM 256	9
11	211000000	5.5	39	QAM 256	10
12	219000000	5	39	QAM 256	11
13	227000000	4.8	39	QAM 256	12
14	235000000	4.8	40	QAM 256	13
15	243000000	4.6	40	QAM 256	14
16	251000000	4	40	QAM 256	15
17	267000000	3.2	39	QAM 256	17
18	275000000	3.2	39	QAM 256	18
19	283000000	3.7	40	QAM 256	19
20	291000000	4.4	40	QAM 256	20
21	299000000	4.7	40	QAM 256	21
22	307000000	4.8	40	QAM 256	22
23	315000000	4.6	40	QAM 256	23
24	323000000	4.8	40	QAM 256	24
25	331000000	4.7	40	QAM 256	25
26	339000000	4.8	40	QAM 256	26
27	347000000	5	40	QAM 256	27
28	355000000	5.2	40	QAM 256	28
29	363000000	5	40	QAM 256	29
30	371000000	5	40	QAM 256	30
31	379000000	5.4	40	QAM 256	31

Downstream bonded channels

Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors

1	Locked	39	0	0
2	Locked	39	58	0
3	Locked	39	37	0
4	Locked	39	11	0
5	Locked	39	11	0
6	Locked	40	18	0
7	Locked	40	36	0
8	Locked	40	11291	7401
9	Locked	40	78	0
10	Locked	40	6	0
11	Locked	39	2	0
12	Locked	39	1	0
13	Locked	39	0	0
14	Locked	40	1	0
15	Locked	40	3	0
16	Locked	40	0	0
17	Locked	39	0	0
18	Locked	39	0	0
19	Locked	40	0	0
20	Locked	40	0	0
21	Locked	40	1	0
22	Locked	40	0	0
23	Locked	40	1	0
24	Locked	40	0	0
25	Locked	40	0	0
26	Locked	40	0	0
27	Locked	40	0	0
28	Locked	40	2	0
29	Locked	40	0	0
30	Locked	40	0	0
31	Locked	40	0	0

[fjama13]

Upstream bonded channels

Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID

0	49600000	42	5120	QAM 16	1
1	43100000	41.3	5120	QAM 16	2
2	36600000	41	5120	QAM 16	3
3	30100000	40.3	5120	QAM 16	4
4	23600000	39.8	5120	QAM 16	5

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

0	ATDMA	0	2	0	0
1	ATDMA	0	2	3	0
2	ATDMA	0	2	34	0
3	ATDMA	0	2	0	0
4	ATDMA	0	2	4	0

[Steven_L]

Thanks for coming back to us fjama13. I have looked into this and can see that the fault that you have previously been advised of, is still ongoing, the latest estimated fix time for the issues is 3pm on Monday 26th April. We are sorry and our engineers are working hard to resolve this for you.

Kind Regards,

Steven_L

[fjama13]

Hi,

Still not fixed can this be escalated please?

[Kath_F]

Hi fjama13, 

Thanks for coming back to us in the Community. 

We're sorry to hear you're still having an issue with your connection. Checking things this end, I can see that the fault has now closed as resolved. Please reboot your hub to clear things and refresh everything. 

If you are still having an issue with the connection, let us know and we can run through diagnostics with you then. 

Many thanks,