High latency several times an hour

[DieHardNerd]

Hi there,

I'm being hit quite often over the last few days with intermittent spikes (and occasional complete dropouts/reconnects) on my Hub 3 in Modem Mode. This is on a wired connection and I've rebooted both hub and router several times as well as reset the hub once.

Today's BQM so far:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/d8187d1b7c2d0ffddf14ca0f68eb814816...

This has happened previously but usually lasts a day and then goes away for months but we've been suffering this for the third day in a row now and tempers are short (mine in particular as I spend my work days SSH'd into various remote server where these spikes are infuriating).

I'm wondering if someone far more savvy than me could review my connection levels - when my SH3 arrived to replace my SH2, I was told I didn't need to connect the attenuator ... I guess I just want to make sure that was reasonable advice and, of course, any other advice is very welcome. Thanks in advance!

Downstream bonded channels

Channel	Frequency (Hz)	Power (dBmV)	SNR (dB)	Modulation	Channel ID
1	475000000	-0.5	38	256 qam	9
2	483000000	-0.7	37	256 qam	10
3	491000000	-1	37	256 qam	11
4	499000000	-1.5	37	256 qam	12
5	507000000	-1.5	38	256 qam	13
6	515000000	-1.4	37	256 qam	14
7	523000000	-1.2	37	256 qam	15
8	531000000	-1.7	37	256 qam	16
9	539000000	-2.5	37	256 qam	17
10	547000000	-3.4	37	256 qam	18
11	555000000	-3.7	37	256 qam	19
12	563000000	-3.7	37	256 qam	20
13	571000000	-3.2	37	256 qam	21
14	579000000	-3	37	256 qam	22
15	587000000	-3.2	37	256 qam	23
16	595000000	-3.7	37	256 qam	24
17	603000000	-4	37	256 qam	25
18	611000000	-3.7	37	256 qam	26
19	619000000	-3.7	37	256 qam	27
20	627000000	-3.9	37	256 qam	28
21	635000000	-4.5	37	256 qam	29
22	643000000	-5	37	256 qam	30
23	651000000	-5.2	37	256 qam	31
24	659000000	-4.5	37	256 qam	32

Downstream bonded channels

Channel	Locked Status	RxMER (dB)	Pre RS Errors	Post RS Errors
1	Locked	38.6	16	0
2	Locked	37.6	5	0
3	Locked	37.6	6	0
4	Locked	37.6	2	0
5	Locked	38.6	8	0
6	Locked	38.6	9	0
7	Locked	37.6	6	0
8	Locked	37.6	17	0
9	Locked	37.6	14	0
10	Locked	37.6	9	0
11	Locked	37.6	11	0
12	Locked	37.3	8	0
13	Locked	37.3	6	0
14	Locked	37.6	5	0
15	Locked	37.6	7	0
16	Locked	37.6	0	0
17	Locked	37.6	10	0
18	Locked	37.6	4	0
19	Locked	38.6	8	0
20	Locked	37.3	8	0
21	Locked	37.3	16	0
22	Locked	37.3	6	0
23	Locked	37.6	15	0
24	Locked	37.6	6	0

Upstream bonded channels

Channel	Frequency (Hz)	Power (dBmV)	Symbol Rate (ksps)	Modulation	Channel ID
1	60300000	45.3	5120	64 qam	1
2	46200000	43.3	5120	64 qam	3
3	53700000	44.8	5120	64 qam	2
4	39399995	42.5	5120	64 qam	4

Upstream bonded channels

Channel	Channel Type	T1 Timeouts	T2 Timeouts	T3 Timeouts	T4 Timeouts
1	ATDMA	0	0	0	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

[jbrennand]

Hub stats look ok - post up the network logs too.

There have been a few threads recently (see below) where similarly poor BQM's were due to a badly connected router. Can you go back into normal router mode on the VM Hub and run that for a few hours and see in the BQM "cleans up".

https://community.virginmedia.com/t5/Networking-and-WiFi/Internet-connection-dropping/td-p/4781287/p...

[DieHardNerd]

Thanks for the swift response, it's comforting to hear the levels look OK.

After reading through that thread, I'll try swapping out the ethernet cable between SH3 and router (Asus RT-AC58U) and pop it back into router mode for a period (the fact that I have a router in front of it at all is because of latency spikes due to the poor CPU in the SH3).

Whilst writing this post it dropped out altogether and is now reconnecting <sigh> - the fact it drops/reconnects at times means I don't expect the ethernet swap to have an effect, but running it back in router mode for a bit might trigger something under the covers.

Thanks again.

[DieHardNerd]

And the network logs:

Network Log

Time	Priority	Description
06/08/2021 13:48:31	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/08/2021 17:15:39	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/08/2021 14:07:3	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/08/2021 03:55:54	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
31/07/2021 21:01:39	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/07/2021 11:51:57	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
26/07/2021 10:48:5	notice	LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/07/2021 13:37:8	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
24/07/2021 11:51:10	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
21/07/2021 08:02:11	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
20/07/2021 23:51:9	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
18/07/2021 09:49:15	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
17/07/2021 11:51:8	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 19:23:34	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/07/2021 00:05:23	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
10/07/2021 11:32:55	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
10/07/2021 10:36:56	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/07/2021 23:57:41	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/07/2021 22:36:55	Error	DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
04/07/2021 13:03:19	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[jbrennand]

Logs not too bad either. No real evidence of to many disconnections there. See if the BQM cleans up with the Hub in router mode.

[Steven_L]

Hey @DieHardNerd,

Welcome to the community and thanks for taking the time to post here on our forums.

I'm sorry to hear of the issues that you're having, how have things been looking now and over the weekend?

I've had a check on our side but can also not see anything that would be causing the issues that you're having. 

Regards,

Steven_L

[Andrew-G]

By my reckoning the 4.7 dBmV range of downstream power is too wide, and likely to cause a problem, and the live BQM link in the first post shows the problem is continuing.

@DieHardNerd  If you had an attenuator before and everything worked OK, try putting it back in and see if it makes a difference.  Failing that, put the hub in router mode, because staff can't remotely check the hub's status in modem mode.  Also, if changing hub mode, you'll get a different IP, so you need to edit your BQM settings to ensure continuity.  If the hub works perfectly in router mode, then the problem is probably with the connection to the Asus.  If the problem persists, then it's a coax problem and you'll need a technician.  As a short term measure to ensure decent wifi, put the hub in router mode but flip the Asus into access point mode.  

[DieHardNerd]

Hi Steven_L,

I've had it running most of the weekend back in router mode - the BQM graph looks different, worse in many ways (slightly thicker blue [avg latency] area and more unstable and bigger yellow area [max latency]):

I wasn't working over the weekend so couldn't really guage the pauses of a minute or so I've been suffering but the kids say it's been 'better' - frustratingly that could easily be due to it simply being transient (as has previously happened).

I plan to spend the working day with it in router mode (so I'll know straight away if it dips in and out again) and then switch back to modem mode this evening.

[DieHardNerd]

Thanks for taking a look Andrew - the attenuator was a long time ago (2 years+) and only ever attached to the SH2 before I was sent the SH3 and then later added the ASUS in front, not even sure where it is tbh but if the downstream power might be too wide, I'll go and look for it ... is there a simple ideal range (I've looked previously but never found any definitive answer)?

See my reply to Steven_L for status over the weekend - essentially I've had it in router mode most of Sat/Sun (I turned the ASUS off altogether and configured the SH3 with the same SSID/password, plus BQM is polling a duckdns DNS entry which one of my raspberry pi's updates every 5 minutes so there's continuity there too. I'm missing all my port forwarding etc. though so your access point mode suggestion is a really good one I hadn't thought of and it'll be interesting to see the BQM graph after offloading that work... will reconfigure that this evening after work and spend tomorrow in that state)

I'm conscious of only changing one thing at a time otherwise I'm not going to know what's had what effect...

[Andrew-G]

Just for reference, this is what a decent VM BQM looks like - my connection 5 August.  This is Hub 3 in modem mode with TP-Deco M4 mesh in router mode.  This is also what you should be seeing for your connection.  Looking at the last BQM you posted it appears to me to be a severe noise problem.