Dropping QAM on upload channels

[risc19]

I'm starting a new thread as not to confuse staff on previous problems.

For the last 2 weeks my upload speed has been suffering.

QAM on all four upload channels has been fluctuating between the normal 64 QAM and 16 QAM.

As a result latency and upload speed has been a problem.

I was told at one point there was a problem in my area however that member of staff will not reply as to the progress of the fault.

Could someone please check of there are any issues that could be causing it?

All of my other stats are within spec and yes I'm using an ethernet cable.

I have also done several factory resets but it has not helped.

3.0 Upstream channels

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

1	39400000	38.3	5120 KSym/sec	16QAM	4
2	25800000	37.8	5120 KSym/sec	64QAM	6
3	32600000	38.3	5120 KSym/sec	32QAM	5
4	46200000	38.3	5120 KSym/sec	32QAM	3

[legacy1]

VM should lock QAM even if you get packet loss it shows it needs fixing.

[risc19]

Hummmmm.

Of course as soon as I post it here, they fix themselves.

3.0 Upstream channels

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

1	39400000	38	5120 KSym/sec	64QAM	4
2	25800000	37.8	5120 KSym/sec	64QAM	6
3	32600000	38	5120 KSym/sec	64QAM	5
4	46200000	38.5	5120 KSym/sec	64QAM	3

We'll see if it lasts.

[jem101]

---

@legacy1 wrote:
VM should lock QAM even if you get packet loss it shows it needs fixing.

---

What?

Do you actually know how DOCSIS works?

[risc19]

3.0 Upstream channels

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

1	39400000	38	5120 KSym/sec	32QAM	4
2	25800000	37.8	5120 KSym/sec	64QAM	6
3	32600000	38.3	5120 KSym/sec	64QAM	5
4	46200000	38.3	5120 KSym/sec	64QAM	3

Spoke too soon.

[Roger_Gooner]

Post your downstream stats as well as the network logs.

[risc19]

---

@Roger_Gooner wrote:

Post your downstream stats as well as the network logs.

---

I will mate, but they are all fine.

I thought I would do one better and show what the experience is like when trying to game tonight.

Here are the highlights...

https://youtu.be/d9JwLRrZXrs

After 20 mins I had enough as it was impossible.

The area of packetloss was when I was trying to play...

[risc19]

3.0 Downstream channels

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

1	411000000	4.1	40.9	QAM256	1
2	419000000	4.2	40.4	QAM256	2
3	427000000	4.5	40.4	QAM256	3
4	435000000	4.3	40.4	QAM256	4
5	443000000	4.7	40.4	QAM256	5
6	451000000	4.6	40.9	QAM256	6
7	459000000	4.3	40.4	QAM256	7
8	467000000	4.1	40.4	QAM256	8
9	475000000	4.3	40.4	QAM256	9
10	483000000	4.7	40.9	QAM256	10
11	491000000	4.7	40.4	QAM256	11
12	499000000	4.9	40.4	QAM256	12
13	507000000	4.7	40.9	QAM256	13
14	515000000	4.7	40.4	QAM256	14
15	523000000	4.6	40.9	QAM256	15
16	531000000	4.9	40.4	QAM256	16
17	539000000	5.1	40.9	QAM256	17
18	547000000	5.2	40.4	QAM256	18
19	555000000	5	40.4	QAM256	19
20	563000000	4.8	40.4	QAM256	20
21	571000000	4.9	40.4	QAM256	21
22	579000000	4.9	40.9	QAM256	22
23	587000000	5	40.4	QAM256	23
24	595000000	5.1	40.9	QAM256	24
25	603000000	4.8	40.9	QAM256	25
26	611000000	4.1	40.4	QAM256	26
27	619000000	4.1	40.4	QAM256	27
28	627000000	4.2	40.4	QAM256	28
29	635000000	4.2	40.4	QAM256	29
30	643000000	3.9	40.4	QAM256	30
31	651000000	3.6	40.4	QAM256	31

3.0 Downstream channels

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

1	Locked	40.946209	0	0
2	Locked	40.366287	0	0
3	Locked	40.366287	0	0
4	Locked	40.366287	0	0
5	Locked	40.366287	0	0
6	Locked	40.946209	0	0
7	Locked	40.366287	0	0
8	Locked	40.366287	0	0
9	Locked	40.366287	0	0
10	Locked	40.946209	1	0
11	Locked	40.366287	0	0
12	Locked	40.366287	0	0
13	Locked	40.946209	0	0
14	Locked	40.366287	0	0
15	Locked	40.946209	0	0
16	Locked	40.366287	0	0
17	Locked	40.946209	0	0
18	Locked	40.366287	0	0
19	Locked	40.366287	2	0
20	Locked	40.366287	0	0
21	Locked	40.366287	0	0
22	Locked	40.946209	0	0
23	Locked	40.366287	0	0
24	Locked	40.946209	0	0
25	Locked	40.946209	0	0
26	Locked	40.366287	0	0
27	Locked	40.366287	0	0
28	Locked	40.366287	0	0
29	Locked	40.366287	1	0
30	Locked	40.366287	1	0
31	Locked	40.366287	2	0

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)

159

96

4K

1880

QAM4096

728

3.1 Downstream channels

Channel ID Lock Status RxMER Data (dB) PLC Power (dBmV) Correcteds (Active Profile) Uncorrectables (Active Profile)

159

Locked

43

3.1

84912340

0

[risc19]

3.0 Upstream channels

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

1	39400000	38	5120 KSym/sec	64QAM	4
2	25800000	37.8	5120 KSym/sec	64QAM	6
3	32600000	38.3	5120 KSym/sec	64QAM	5
4	46200000	38.3	5120 KSym/sec	64QAM	3

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	US_TYPE_STDMA	0	0	0	0
2	US_TYPE_STDMA	0	0	0	0
3	US_TYPE_STDMA	0	0	0	0
4	US_TYPE_STDMA	0	0	0	0

Network Log

Time Priority Description

Thu 01/01/1970 00:01:24	4	Missing Mandatory MDD TLV on primary DS Channel;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
Wed 03/11/2021 17:41:50	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

[risc19]

Cable Modem StatusItem Status CommentsChannel Overview Downstream Upstream

Cable Modem Status	Online	DOCSIS 3.1
Primary downstream channel	Locked	SC-QAM
DOCSIS 3.0 channels	31	4
DOCSIS 3.1 channels	1	0

Refresh data

General Configuration

Network access	true
Maximum Number of CPEs	1
Baseline Privacy	true
DOCSIS Mode	3.1
Config file	wrkldJKDHSUBsgvca69834ncx

Primary Downstream Service Flow

SFID	984
Max Traffic Rate	1200000450
Max Traffic Burst	42600
Min Traffic Rate	0

Primary Upstream Service Flow

SFID	983
Max Traffic Rate	55000270
Max Traffic Burst	42600
Min Traffic Rate	0
Max Concatenated Burst	16320
Scheduling Type	bestEffort