Constant loss of Internet

[badrogh]

Another day of hell with Virgin Media broadband...

I can usually benefit 900MB+ of my connection until it caps at 60-70MB with heavy packet loss. Only a reboot of the modem allows to go back to acceptable level of connection speed. This happen at least once a week.

On top of which my connection will drop intermittently for microseconds, sometimes dropping for few minutes before to come back. This happen almost every day on certain period. Random days, random times, so no indication this is related to network congestion.

All lights green in internal network, only degradation is between modem and ISP.

https://www.thinkbroadband.com/broadband/monitoring/quality/share/18ada7954964b4488c8928cfb8e66d21cf...

Time Priority Description

Sat Apr 2 16:59:14 2022	3	No Ranging Response received - T3 time-out;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Sun Apr 3 03:57:21 2022	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Sun Apr 3 03:57:21 2022	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Sun Apr 3 22:48:02 2022	3	No Ranging Response received - T3 time-out;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Wed Apr 6 04:00:33 2022	4	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Wed Apr 6 04:00:33 2022	6	DHCP Renew - lease parameters tftp file-cmreg-vmdg640-bbt076-b.cm modified;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Wed Apr 6 07:19:52 2022	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Sat Apr 9 07:40:36 2022	3	No Ranging Response received - T3 time-out;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;
Sat Apr 9 07:57:41 2022	5	MIMO Event MIMO: Stored MIMO=-1 post cfg file MIMO=-1;CM-MAC=*:*:*:*:*:*;CMTS-MAC=*:*:*:*:*:*;CM-QOS=1.1;CM-VER=3.1;

[jpeg1]

For a full diagnosis you'll need to post the upstream and downstream data, but the BQM shows severe packet loss which would explain the results you are getting.

There is a possibility that this could be caused by something as simple as a loose coax connector, so do check that they are all tight.  Otherwise it's going to need a technician visit to find the fault.

[Anonymous]

Agree with the above. Just to add the earlier latency spike last night on the BQM appears to have been widespread. 

[badrogh]

Sadly the original post would not allow me to post Downstream and Upstream because of the limit of characters...
I have already checked coaxial and agree was worth a try. As seen on BMQ, I have got chronic packet loss.

Downstream

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

1	411000000	11.500000	40.366287	QAM256	1
2	419000000	11.199997	40.946209	QAM256	2
3	427000000	10.599998	40.366287	QAM256	3
4	435000000	10.099998	40.366287	QAM256	4
5	443000000	10.400002	40.366287	QAM256	5
6	451000000	10.699997	40.946209	QAM256	6
7	459000000	10.599998	40.946209	QAM256	7
8	467000000	10.699997	40.946209	QAM256	8
9	475000000	10.300003	40.366287	QAM256	9
10	483000000	10.599998	40.366287	QAM256	10
11	491000000	10.599998	40.366287	QAM256	11
12	499000000	10.199997	40.366287	QAM256	12
13	507000000	9.699997	40.366287	QAM256	13
14	515000000	10.000000	40.946209	QAM256	14
15	523000000	10.400002	40.946209	QAM256	15
16	531000000	10.099998	40.946209	QAM256	16
17	539000000	9.500000	40.946209	QAM256	17
18	547000000	9.500000	40.366287	QAM256	18
19	555000000	10.099998	40.366287	QAM256	19
20	563000000	10.500000	40.946209	QAM256	20
21	571000000	10.400002	40.946209	QAM256	21
22	579000000	10.000000	40.366287	QAM256	22
23	587000000	10.000000	40.946209	QAM256	23
24	595000000	10.699997	40.366287	QAM256	24
25	603000000	10.400002	40.366287	QAM256	25
26	611000000	9.900002	40.366287	QAM256	26
27	619000000	9.900002	40.366287	QAM256	27
28	627000000	10.000000	40.366287	QAM256	28
29	635000000	9.500000	40.366287	QAM256	29
30	643000000	8.599998	38.983261	QAM256	30
31	651000000	8.699997	38.605377	QAM256	31

Upstream

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

1	39400000	37.270599	5120 KSym/sec	64QAM	4
2	25800000	35.270599	5120 KSym/sec	64QAM	6
3	32600000	36.270599	5120 KSym/sec	64QAM	5
4	46200000	37.770599	5120 KSym/sec	64QAM	3

[jpeg1]

Those two peaks currently on the BQM are a widespread issue. I have them too. It's the solid red that will be causing the main problem. Does that recur on the BQM ? 

Your signal levels are OK. The downstream is a fraction over the specified peak but that's not going to knock you out. 

[Tudor]

18 out of 32 downstream power levels are out of spec and this is often indicative of your problem. You need a technician’s visit to adjust those power levels. 

Call Customer Services on 0345 454 1111/150 if you have a VM landline or wait a day or two for a VM staff member to get to your post.

[badrogh]

Thanks Tudor for the insight. I will wait for a staff member to come back on this as I am a broadband only customer.
BTW, care to explain the out of spec portion of your analysis?

I would love to understand better those readings and so far I have not been able to find much informations about signal modulation for Cable connections. Would be great if you can go into more details or link some literature about it. I have been through electronic A levels before to go into computing science and I am from a pre Internet era, when we never touched these subjects in details.

[badrogh]

About the widespread issue, it's happening all the time with Virgin, and almost never indicated on their useless "check my area" page. The only reason I am sticking to them is that none of the competition is able to deliver the speed I need.

[Tom_W1]

Hi @badrogh thanks for your post here in the community although I'm sorry to hear of your concerns raised.

I have ran the diagnostics on your network and I can too see that your power levels are out of specifications which will be causing the issues you're having.

We'll need to arrange a technician to get this sorted for you, so please expect a PM to arrive shortly and respond when you can!

Many thanks

[badrogh]

About "I can too see that your power levels are out of specifications".... can I understand what are the expected levels? What is out of specs? How can this be diagnosed? Is there any documentation on the values expected on those type of cable modem?