Frequent packet loss, connection interruptions

[watercooled]

Hello,

Similar to an issue I was having about a year ago that turned out to be a network issue and was resolved at the time, I'm again getting connection interruptions, packet loss etc correlated with signal issues in the modem stats. Around the time it happens, I generally see upstream power levels climbing, T3 timeouts reported, partial service warnings, and occasionally lost upstream channels.

This being an upstream issue also seems to agree with observed behaviour e.g. in voice calls - I can generally still hear other people clearly but they report my voice cutting out. I set up a BQM and see red packet loss spikes nearly every day now. I've left it for a couple of weeks to see if it gets resolved but the problem remains.

I've checked all connections are tight, rebooted modem (several times), checked for problems with the automated checkers, etc. I wonder if a mod could look into this for me?

Thank you!

Network log from modem showing the sort of signal issues reported:

15/07/2021 20:54:4	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 17:46:57	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt060+voc-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 17:46:57	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 14:20:55	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 13:29:17	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 12:48:37	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 12:47:21	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 12:47:21	critical	Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 12:47:11	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
15/07/2021 12:47:11	critical	Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 21:22:22	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 21:15:34	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 15:04:11	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:35:22	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:35:22	critical	Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:24:46	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:24:22	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:15:58	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:13:47	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 12:00:14	Warning!	RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[Andrew-G]

Network log shows repeated channel loss, and I've flagged for staff to advice.  If you're using the hub in modem mode they'll need it flipping into router mode to check the status.  If it is in router mode already you don't need to do anything.

[David_Bn]

Good Morning watercooled,

Thanks for your post on our Community Forums and I'm sorry to hear of the connection issues.

It appears that we've been able to since advise that you monitor the connection for the next 24 hours as there may be possible interference in the local area

Have you set up for Broadband Quality Monitor on the connection?

Kindest regards,

David_Bn

[watercooled]

Hi and thanks for the replies. 🙂

That 24 hour monitor thing seemed to be as a result of me running the automated test to check for any reported network issues, but I've had that suggestion a few times before and nothing changes despite the wait (nor has it this time). It would make sense that there is some interference in the network so would be satisfied if I knew it was being investigated, but that doesn't seem to be the case as this has been happening for weeks now.

Nothing has changed on my end that I could think of impacting the connection, and I have double-checked all of the coax connections are tight. The hub is in standard router mode too.

Yes, I have the BQM set up on the connection. Here are graphs from the last few days, 14, 15 and 16th if you want to correlate the red spikes with the modem logs:

[Andrew-G]

Packet loss and latency spikes are clearly a problem for the hub's cable connection, what's causing them I wouldn't want to hazard a guess.  VM need to sort this out, but as the fault is intermittent the fix may involve progressive replacement and repairs until they can find where the fault occurs.  Although there's a persistent problem around midday, and that could be related to the sun warming up above-ground equipment leading to overheating, that doesn't explain the odd blips at other times.

In terms of any "looks good from our side" responses, the BQM shows a clear problem almost certainly somewhere on VM's network, they need to find and fix it. 

[Zak_M]

Good afternoon @watercooled 

Welcome back to the forums and thank you for taking the time to post. 

I am sorry to hear that you have some issue with your broadband,  I have just run though some checks on our end. 

There seems to be a downstream power level issue. 

I am going to pop you over a PM so that I can confirm your address and then we can go from there. 

Kind regards,

Zak_M

[watercooled]

Hello, I have replied to the PM.

For what it's worth, downstream power doesn't seem bad from what I'm seeing. I am on a fairly long drop cable so have generally been on the lower side for DS power over the years, but it seems to be better now than it has been in the past. The RF slope is also typical for this line, and there is a 4dB equaliser fitted.

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

1	371000000	-2.2	38	256 qam	28
2	219000000	1.2	40	256 qam	11
3	227000000	0.7	40	256 qam	12
4	235000000	0.5	40	256 qam	13
5	243000000	0.2	40	256 qam	14
6	251000000	-0.2	40	256 qam	15
7	259000000	-0.4	40	256 qam	16
8	267000000	-0.7	40	256 qam	17
9	275000000	-1	40	256 qam	18
10	283000000	-0.7	40	256 qam	19
11	291000000	-0.5	40	256 qam	20
12	299000000	-1.2	40	256 qam	21
13	307000000	-1.9	38	256 qam	22
14	315000000	-2.4	38	256 qam	23
15	323000000	-2.7	38	256 qam	24
16	347000000	-1.7	40	256 qam	25
17	355000000	-2	38	256 qam	26
18	363000000	-1.7	40	256 qam	27
19	379000000	-2.2	38	256 qam	29
20	387000000	-2	40	256 qam	30
21	395000000	-2.5	40	256 qam	31
22	403000000	-2.9	40	256 qam	32
23	411000000	-2.7	40	256 qam	33
24	419000000	-3.2	38	256 qam	34

However, as I briefly mentioned in the OP, if I check stats around the time a problem is occurring, I often see upstream power levels creep up to above 50dBmV before losing channel sync or dropping to lower modulation orders. Without knowing exactly what's happening, the often one-directional nature of the fault also seems to indicate an upstream issue - e.g. in voice calls, I can still hear others clearly but they report problems hearing my voice. This sometimes progresses to a full disconnection but often starts out like this.

[Zak_M]

Thank you for coming back to me, 

This was the only issues that I could find on the account and needs to be addressed. 

I have taken the opportunity to book this for you, you are able to find the time, date and make any further amendments via your my virgin media account. 

Kind regards,

Zak_M

[watercooled]

OK thank you, I just received the text message confirming the appointment.

[Zak_M]

Please do keep in touch and let us know how you get on. 

Kind regards,

Zak_M