Sudden speed loss 200 down to nothing, 80Mbs at best.

[hucknallred]

Have had 3 solid years & went up to 200 from 100 a couple of months ago.
In the last few days thigs have dropped off. Steaming YouTube can stutter & speeds are rock bottom, at best I get 80Mbs now.

Appreciate any tips, stats below, I noticed some No Ranging Response received in the network log which is also down below.

Cheers

Downstream bonded channels

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

1	203000000	8.6	37	256 qam	9
2	139000000	10.9	37	256 qam	1
3	147000000	10	37	256 qam	2
4	155000000	9.5	37	256 qam	3
5	163000000	9.8	37	256 qam	4
6	171000000	9.5	37	256 qam	5
7	179000000	9.4	37	256 qam	6
8	187000000	9.4	37	256 qam	7
9	195000000	9	37	256 qam	8
10	211000000	8.4	37	256 qam	10
11	219000000	8	37	256 qam	11
12	227000000	7.6	37	256 qam	12
13	235000000	7.3	37	256 qam	13
14	243000000	7.5	37	256 qam	14
15	251000000	7.5	38	256 qam	15
16	259000000	7.4	37	256 qam	16
17	267000000	7	38	256 qam	17
18	275000000	7	37	256 qam	18
19	283000000	6.9	37	256 qam	19
20	291000000	6.5	37	256 qam	20
21	299000000	6.1	37	256 qam	21
22	307000000	6.3	37	256 qam	22
23	315000000	6.8	37	256 qam	23
24	323000000	6.9	37	256 qam	24

Downstream bonded channels

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

1	Locked	37.3	4	0
2	Locked	37.6	0	0
3	Locked	37.3	17	0
4	Locked	37.3	5	0
5	Locked	37.6	5	0
6	Locked	37.6	0	0
7	Locked	37.6	0	0
8	Locked	37.6	5	0
9	Locked	37.6	5	0
10	Locked	37.6	5	0
11	Locked	37.6	4	0
12	Locked	37.3	4	0
13	Locked	37.6	0	0
14	Locked	37.6	5	0
15	Locked	38.6	6	0
16	Locked	37.6	5	0
17	Locked	38.6	0	0
18	Locked	37.3	5	0
19	Locked	37.6	5	0
20	Locked	37.6	13	0
21	Locked	37.6	1	0
22	Locked	37.6	6	0
23	Locked	37.6	6	0
24	Locked	37.6	3	0

.

Network Log

Time Priority Description

27/07/2021 16:59:3	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 16:57:17	Warning!	Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 16:57:13	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 16:57:12	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 16:57:12	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 16:57:12	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/07/2021 06:39:40	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/07/2021 11:40:26	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/07/2021 08:00:59	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/01/1970 00:01:40	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
25/07/2021 14:51:46	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
25/07/2021 01:21:56	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/07/2021 21:03:58	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 20:51:49	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 03:13:18	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 03:13:17	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 03:10:44	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 03:10:44	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
23/07/2021 03:10:43	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
22/07/2021 21:48:59	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jbrennand]

What is it when you connect a computer/laptop directly to the Hub on an ethernet cable?

[hucknallred]

It seems to have resolved now after a late night last night.
The hub is in the living room, Smart TV plugged into Hub, then a Cat5e from the hub to the garage where my Netgear switch is that everything else hangs off.
Long story short, I tried all sorts, Laptop into Hub, full speed, laptop into switch slower speed etc. I think there was a poor termination on the hub to garage switch cable. But, this doesn't explain the poor streaming on the TV, which has been OK today.
I think we can mark as solved for now...

Thanks

[Andrew-G · Accepted solution]

Keep an eye on it - the hub stats showed downstream power levels looking rather too high on a couple of channels, and with perhaps too wide a range, and the network log was indicating too high a number of channel loss events (Sync timing and RCS partial service errors).  These refer to the hub's connection with VM's network, and are unrelated to your own network arrangements.

Sometimes these things are area faults, they get fixed without you seeing and don't return.  Sometimes they're specific to your connection, and in that case a reboot or reset can temporarily sort them out, but often they'll return because the underlying cause will be noise related, and restarting won't eliminate the cause of noise, which can be faulty network equipment or noise ingress at a joint or damaged cable.  Noise faults are often intermittent, so can recur when you think they've vanished, and be a pain for the technicians to observe and fix.

If you experience speed, streaming or gaming problems and you see some combination of hub downstream power levels with a range greater than 4 dBmV, climbing post-RS errors on the downstream, recurring sync or partial service errors in the log, or a fair number of T3 timeouts on the upstream, then chances are the problem's not gone away and a technician will be needed.