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High Latency Spikes

Hi all,

I've been experiencing it for a few months now but its getting to the point where I want it looking into.

I have a feeling it's caused by congestion upstream (in VMs network based on my MTR testing) but it's making gaming impossible.

Screenshot 2020-08-17 at 08.03.20.png 

The above is from the last 24 hours.  I actually feel like the weekdays are worse so the above is quite alarming.

I moved the hub into modem mode but it didn't change anything unfortunately.

Chances are VM won't be able to do anything but I want it confirmed.

Thanks,

Mcleish

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Re: High Latency Spikes

It could be congestion, but sometimes there's resolvable faults that seem to occur at busy times.  Post up your hub's status data (Downstream, Upstream, Network log), making sure that you copy and paste as formatted text - images and screenshots aren't a good idea.  Then we can take a look for anything obvious. 

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Re: High Latency Spikes

Hi Andruser,

Thanks for the reply.

See below for the outputs.

Downstream:

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

13870000008.840256 qam26
21870000006.938256 qam7
31950000006.838256 qam8
42030000006.838256 qam9
52110000006.838256 qam10
62190000006.438256 qam11
72270000006.538256 qam12
82350000006.538256 qam13
92430000006.838256 qam14
102510000006.838256 qam15
112590000006.640256 qam16
122670000006.838256 qam17
132750000006.538256 qam18
142830000006.938256 qam19
15291000000738256 qam20
162990000007.938256 qam21
173070000008.538256 qam22
183150000008.838256 qam23
193230000009.138256 qam24
20379000000940256 qam25
213950000008.940256 qam27
224030000008.938256 qam28
23411000000938256 qam29
244190000008.840256 qam30



Downstream bonded channels

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

1Locked40.3723131
2Locked38.9580603
3Locked38.9621789
4Locked38.9615485
5Locked38.9421221
6Locked38.9525452
7Locked38.942933
8Locked38.947559
9Locked38.9595910
10Locked38.978558
11Locked40.3937708
12Locked38.968553
13Locked38.674533
14Locked38.944559
15Locked38.983523
16Locked38.9542567
17Locked38.9512338
18Locked38.9883216
19Locked38.9565984
20Locked40.3362220
21Locked40.3661923
22Locked38.9472210
23Locked38.9862747
24Locked40.3632459

 

 

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Re: High Latency Spikes

Upstream:

Upstream bonded channels

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

1537002244.35512016 qam10
2394000754.4512016 qam12
3462000464.35512016 qam11
4603000704.35512016 qam9

 

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA000

0

 

Network logs:

 

Network Log

Time Priority Description

17/08/2020 07:13:4noticeLAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 15:45:21criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:51:27Warning!Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:51:22Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:51:22criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:51:22Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:51:22criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:50:41Warning!Lost MDD Timeout;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:50:37criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:50:37Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:50:36criticalSYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/08/2020 13:42:51Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
13/08/2020 03:59:21criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/08/2020 13:55:59ErrorDHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/08/2020 11:56:24Warning!RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
11/08/2020 23:53:21ErrorDHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/08/2020 00:43:36criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/08/2020 00:43:36criticalUnicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/08/2020 00:42:16criticalNo Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/08/2020 00:42:16criticalUnicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
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Message 5 of 8
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Re: High Latency Spikes

Below is the latency from this morning.

Screenshot 2020-08-17 at 11.59.41.png

I knew it was bad but that's unacceptable.

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Re: High Latency Spikes

Do I have to accept this is the new norm now?  Seems a lot of people are having the same issue.

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Re: High Latency Spikes

There is something going on that's wrong with your connection - I think the line is too noisy.  Although your measured downstream SNR is good, there's all the uncorrected (post-RS) errors, downstream power levels are all on the high side, the upstream is only operating at 16 QAM (should be four channels at 64 QAM), and the network log is full of serious timeouts and channel loss problems.  I'll flag this for the forum staff to advise.

There is also a firm hint of local congestion in the shape of your BQM (see how it is much better during the small hours when there's stuff all traffic?), but whilst your connection is ropey we can't be certain.  Sometimes insignificant levels of congestion are made much worse if your particular connection is poor, although whether this is the case we won't know until the line quality issue is checked out.  If it comes to that, be aware that VM are slow to address congestion issues, and often do nothing other than issue fix dates that keep moving forward (as in this example).

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Re: High Latency Spikes

Thank you for the post Mcleish.

 

I'll pop you over a private message so we can book an engineer appointment due to the above diagnosis by our helpful community.

 

Thanks, Emily.

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