Hi,We've been having intermittent issues with our broadband for the past few weeks - We're on a 1GB package but it will drop to next to nothing randomly (Mbps will fall off a cliff on samknows.com) and I'm constantly having to power cycle the router to get it to kick start again. Prior to this, we were having visual corruption on some tv channels. After a painfully long experience speaking to telephone support over numerous calls, they finally succumbed to booking an engineer. By the time the appointment came around, the issue appeared to resolve itself, so I cancelled the visit.I'm thinking that there is more of an issue at play here, as we are now experiencing this prolonged internet issue. Working from home part time, remotely connecting to my office workstation is a nightmare, as every time it drops, I lose connection. The forum admin team have been a HUGE help to me in the past, so I'm posting on here in the hope that they can please work their magic again, and help me avoid having to go through another telephone support nightmare!Any help much appreciated!

Thank you - I'm seeing that the 3.1 downstream channel is way too low.

Intermittent internet speed issues | Virgin Media Community

26 Replies

gingamonkey
On our wavelength
12 months ago
Hi, I think I’ve fixed it myself!
I looked inside the new brown box on the outside of the house (it was loose to the wall due to being partially installed into old mortar - fixed now). Turns out the heads of the cables screwed into this box were all suffering from water ingress! Gave them a spot of electric contact cleaner and dried them off… not one drop out since I did it!
I think rain water must have got in due to the dodgy install of the box. I know I probably shouldn’t have gone in there, but I’ve been at my wits end, paying for a service that I’m not receiving. All working now, saved an engineer visit, and now my box is securely fitted too!
Result!👍🏼
Sephiroth
Alessandro Volta
12 months ago
Well done.
- gingamonkey
  On our wavelength
  12 months ago
  Actually no, spoke too soon. Been okay since around 4pm yesterday….. now it’s happening again! Looks like I still need that engineer visit! 😭
  - gingamonkey
    On our wavelength
    12 months ago
    Just managed to book a slot for Tuesday via the Virgin Media app! First time its actually worked for me 🎉
Sephiroth
Alessandro Volta
12 months ago
What you did in the brown box has likely been worth while. Micro-reflections occur when electrolytes form in components that have water ingress.
If you'd care to provide your stats, we can see the difference your work has made (if any).
- gingamonkey
  On our wavelength
  11 months ago
  Cancelled the appointment - Seems to be stable connection now with no dropouts...

gingamonkey

On our wavelength

11 months ago

3.0 Downstream channels

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

1	331000000	8	40	QAM 256	25
2	139000000	12.1	40	QAM 256	1
3	147000000	12	40	QAM 256	2
4	155000000	11.7	40	QAM 256	3
5	163000000	11.6	40	QAM 256	4
6	171000000	11.4	40	QAM 256	5
7	179000000	11.6	40	QAM 256	6
8	187000000	11.2	40	QAM 256	7
9	195000000	11.3	40	QAM 256	8
10	203000000	11.3	40	QAM 256	9
11	211000000	11.3	40	QAM 256	10
12	219000000	11.2	40	QAM 256	11
13	227000000	10.7	40	QAM 256	12
14	235000000	10.5	40	QAM 256	13
15	243000000	10	40	QAM 256	14
16	251000000	9.4	40	QAM 256	15
17	259000000	9.3	40	QAM 256	16
18	267000000	8.9	40	QAM 256	17
19	275000000	9.1	40	QAM 256	18
20	283000000	8.6	40	QAM 256	19
21	291000000	8.8	40	QAM 256	20
22	299000000	7.8	39	QAM 256	21
23	307000000	8.1	40	QAM 256	22
24	315000000	7.8	39	QAM 256	23
25	323000000	7.8	39	QAM 256	24
26	339000000	8	39	QAM 256	26
27	347000000	8.2	39	QAM 256	27
28	355000000	7.6	40	QAM 256	28
29	363000000	7.8	40	QAM 256	29
30	371000000	7.7	40	QAM 256	30
31	379000000	7.5	40	QAM 256	31
32	387000000	7.3	39	QAM 256	32

3.0 Downstream channels

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

1	Locked	40	150	0
2	Locked	40	7	0
3	Locked	40	10	0
4	Locked	40	8	0
5	Locked	40	5	0
6	Locked	40	8	0
7	Locked	40	6	0
8	Locked	40	9	0
9	Locked	40	6	0
10	Locked	40	8	0
11	Locked	40	5	0
12	Locked	40	8	0
13	Locked	40	6	0
14	Locked	40	8	0
15	Locked	40	7	0
16	Locked	40	5	0
17	Locked	40	6	0
18	Locked	40	9	0
19	Locked	40	49	0
20	Locked	40	76	0
21	Locked	40	144	0
22	Locked	39	211	0
23	Locked	40	240	0
24	Locked	39	164	0
25	Locked	39	257	0
26	Locked	39	269	4
27	Locked	39	226	92
28	Locked	40	176	216
29	Locked	40	162	242
30	Locked	40	126	336
31	Locked	40	122	331
32	Locked	39	130	383

3.1 Downstream channels

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

159

1840

QAM 4096

1108

3.1 Downstream channels

Channel ID Locked Status RxMER Data (dB) PLC Power (dBmV) Corrected errors (Active Profile) Uncorrectable errors (Active Profile)

159

Locked

-1.2

1340177953

2949

3.0 Upstream channels

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

0	49600000	38.5	5120	QAM 64	1
1	43100000	38.3	5120	QAM 64	2
2	36600000	37.5	5120	QAM 64	3
3	30100000	37.5	5120	QAM 64	4
4	23600000	37.5	5120	QAM 64	5

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation

32.7

QAM 256

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts

OFDMA

200

74000000

Network Log

Time	Priority	Description
15-07-2024 20:58:07	notice	GUI Login Status - Login Success from LAN interface
14-07-2024 08:28:25	warning	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;
14-07-2024 08:28:25	notice	US profile assignment change. US Chan ID: 6; Previous Profile: 13; New Profile: 11 13.;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:21	notice	REGISTRATION COMPLETE - Waiting for Operational status
14-07-2024 08:28:16	warning	Dynamic Range Window violation
14-07-2024 08:28:16	warning	Dynamic Range Window violation
14-07-2024 08:28:16	warning	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:16	warning	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:15	warning	RNG-RSP CCAP Commanded Power Exceeds Value Corresponding to the Top of the DRW;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:15	warning	Dynamic Range Window violation
14-07-2024 08:28:15	warning	REG-RSP-MP Mismatch Between Calculated Value for P1.6hi Compared to CCAP Provided Value;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:10	notice	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:09	notice	TLV-11 - unrecognized OID;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:02	warning	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:28:00	notice	Honoring MDD; IP provisioning mode = IPv4
14-07-2024 08:27:36	critical	No Ranging Response received - T3 time-out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:27:30	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=:::::;CM-QOS=1.1;CM-VER=3.1;
14-07-2024 08:27:29	critical	Cable Modem Reboot because of - HW or Power-On Reset
13-07-2024 15:42:05	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:36:40	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=:::::;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:36:02	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:35:49	critical	No Ranging Response received - T3 time-out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:35:49	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:48	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=:::::;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:43	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:35	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:34	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:17	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:24:14	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:23:55	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:23:54	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:23:15	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;
13-07-2024 15:23:14	critical	Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=##:##:##:##:##:##;CMTS-MAC=##:##:##:##:##:##;CM-QOS=1.1;CM-VER=3.1;

Sephiroth
Alessandro Volta
11 months ago
The stats you posted today and 13-July have a marked difference from the ones you posted in May. Your downstream channels are at the same frequency but the power levels have risen - as if attenuation has been removed. Did you remove any attenuators/splitters (the latter being more likely) or is it down to a dry connection which is an equal possibility?
- gingamonkey
  On our wavelength
  11 months ago
  Nope, nothing has changed inside the house at all since the rewire from the pavement outside. Only thing I've done is dry the connections in the box outside the house.
  
  Don't want to tempt fate, but all still working as expected. Thanks!
IPFreely
Fibre optic
11 months ago
Issue wasn't noise or micro reflections. If you're curious look at the phenomenon 'suck-out'.
- Sephiroth
  Alessandro Volta
  11 months ago
  https://www.duckware.com/tech/solving-intermittent-cable-modem-issues.html#:~:text=If%20you%20see%20a%20'suckout,consistent%2Flevel%2Fflat).
  Item 5.

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Intermittent internet speed issues

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