Intermittent disconnections

[krentz]

Hi all,

I hope someone will be able to help me with this. I firstly have to say that I am, overall, impressed with the connection, and despite the issues, it's probably the best overall that I've had while living at this address (particularly given that our local BT cabinet has been indefinitely passed over for FTTC).

However the one thing that's preventing me from giving it a perfect rating is the intermittent connectivity issues I appear to be having. I was reluctant to report it given that it is intermittent and difficult to replicate, however on the days that it occurs it can be quite frustrating especially if I'm trying to e.g. play an online game.

My current setup is a Hub 3 in Modem-only mode using an Asus RT-AX82U as a router. What often happens is that I get a "No Unicast maintenance opportunities received: T4 Timeout" error message in the logs (or sometimes a B-INIT-RNG failure) and at this time the connection drops out, the light on the Hub goes to green and it goes into ranging, before reconnecting. This can happen once a day or, often enough, multiple times in the same day.

However it will then be completely fine and more or less rock solid for days or even weeks afterwards, before causing problems again. The day of the week seems random. more often than not it's a Sunday, but it's happened today (Thursday) too for example.

I'll have to continue this message as apparently there's a 20k character limit, but I will give my stats in the next post.

[krentz]

Here's yesterday's BQM:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/8dbe065c01efa454ad488770b48c3c8a0e...

And here's today's:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/a5bbcd4093604223e1fed91c4414587789...

I'm currently on the M500 service, here's my stats.

Acquired Downstream Channel (Hz)	331000000	Locked
Ranged Upstream Channel (Hz)	46200012	Locked
Provisioning State	Online

Downstream bonded channels

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

1	331000000	12	40	256 qam	25
2	251000000	13.5	40	256 qam	15
3	259000000	13.5	40	256 qam	16
4	267000000	13.4	40	256 qam	17
5	275000000	13.1	40	256 qam	18
6	283000000	13	40	256 qam	19
7	291000000	12.8	40	256 qam	20
8	299000000	12.5	40	256 qam	21
9	307000000	13	40	256 qam	22
10	315000000	13.1	40	256 qam	23
11	323000000	12.4	40	256 qam	24
12	339000000	12.9	40	256 qam	26
13	347000000	13	40	256 qam	27
14	355000000	12.4	40	256 qam	28
15	363000000	12	40	256 qam	29
16	371000000	11.9	40	256 qam	30
17	379000000	11.5	40	256 qam	31
18	387000000	11.8	40	256 qam	32
19	491000000	10.3	40	256 qam	33
20	499000000	9.6	40	256 qam	34
21	507000000	9.5	40	256 qam	35
22	515000000	9.9	40	256 qam	36
23	523000000	9.6	40	256 qam	37
24	531000000	9.1	40	256 qam	38

Downstream bonded channels

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

1	Locked	40.3	0	0
2	Locked	40.9	5	0
3	Locked	40.9	5	0
4	Locked	40.9	4	0
5	Locked	40.9	6	0
6	Locked	40.9	5	0
7	Locked	40.9	12	0
8	Locked	40.3	0	0
9	Locked	40.3	4	0
10	Locked	40.3	6	0
11	Locked	40.9	0	0
12	Locked	40.9	6	0
13	Locked	40.9	4	0
14	Locked	40.3	5	0
15	Locked	40.9	4	0
16	Locked	40.9	4	0
17	Locked	40.9	6	0
18	Locked	40.3	0	0
19	Locked	40.3	0	0
20	Locked	40.3	0	0
21	Locked	40.9	7	0
22	Locked	40.9	11	0
23	Locked	40.9	5	0
24	Locked	40.3	0	0

Upstream bonded channels

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

1	46200012	35.8	5120	64 qam	1
2	25799971	34.3	5120	64 qam	4
3	32599959	35.8	5120	64 qam	3
4	39399998	35.8	5120	64 qam	2

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

[krentz]

And my network log:

Network Log

Time Priority Description

28/10/2021 22:12:14	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 22:11:42	Warning!	B-INIT-RNG Failure - Retries exceeded;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 22:09:43	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 22:09:41	Warning!	B-INIT-RNG Failure - Retries exceeded;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 22:08:3	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 22:06:48	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=3.0;
28/10/2021 21:52:6	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 21:51:5	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=3.0;
28/10/2021 21:49:5	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 21:49:5	critical	Unicast Maintenance Ranging attempted - No response - Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 21:49:5	critical	Ranging Request Retries exhausted;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 21:33:37	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 21:32:4	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=3.0;
28/10/2021 19:49:12	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
28/10/2021 19:48:2	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=3.0;
28/10/2021 12:43:23	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/10/2021 17:59:10	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt053+voc-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/10/2021 17:59:10	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
25/10/2021 04:59:39	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/10/2021 23:10:13	notice	DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt053+voc-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

I haven't contacted support about this on the phone, as I thought it would be easier to give more detailed information on the forums (despite that word every technician hates to hear: 'intermittent').

But if anyone could either provide any assistance or point me in the right direction I would be very grateful, as I have to admit, it's becoming increasingly annoying over time.

[Adduxi]

Downstream power levels are too high and Upstream a tad too low.  VM will need to send a technician to sort it out. 

[krentz]

I see, thanks for your prompt response! That's actually a relief as at least there's something concrete to go on (I know more about DSL than DOCSIS so don't always know how to interpret the numbers)

That being the case, I'll await response from the forum team to investigate on their end. Cheers 🙂

[krentz]

Just posting so this isn't forgotten about, and also because problems are ongoing again this morning:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/556abb27f4c2e4434ead18cc9a4f4f1d00...

Is there anyone from the VM Forum Team who can either investigate or contact me with regard to arranging an engineer visit as advised?

Or am I better off calling up customer services? My only concern is that in the latter case, the graphs and modem logs wouldn't be as readily accessible.

[jbrennand]

I flag for them to come here

[Zoie_P]

Hi Krentz.

Thank you for your post 🙂
I am so sorry to hear you are having intermittent service issues.

I have managed to locate your account and can see you are currently affected by an SNR outage, these outages will affect your broadband and tv, cause the service to be slower, and may cause drops. The estimated  fix is 08 NOV 2021 11:55

Zoie

[krentz]

Hi Zoie, thanks for checking this, I appreciate your help.

Have these SNR outages also occurred in the past? As this is not strictly a new issue - I don't have records of BQM's going back for several months unfortunately but here is one from the 7th September for example:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/f9fe59ae6549c70923125c9058e4a81ea9...

It's an insidious one because we can go for consecutive days with normal connectivity and then issues suddenly reoccur again. It seemed quite severe in early September but by the middle of the month, it stabilised. With the exception of 03/10 the connection was basically fine for the entire month, however problems started reoccurring again around 28/10 and again today.

I understand there are a lot of variables at play, but this can be quite disruptive when it occurs (especially during a working day).

Do I simply have to wait until 08/11 and monitor the situation? And are Adduxi's observations regarding my power levels accurate? If so, then would this also not be something a technician would need to address directly, independently of the SNR issue?

[jbrennand]

If your down powers are still what they were in the earlier post then it will need a Tech visit to bring them down. Are they?

Unfortunately you may be well caught in the classic VM Catch22... all Tech visits are auto-cancelled whilst there is a known fault in the location !

Monitor yours at the “check service,” Area status webpage" (link at top right of this forum)

But also try the “free & automated” Service Status number - 0800 561 0061 - which usually gives the most up to date info. and tells you of more local issues down to postcode level