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Standard User HarveyMears
(newbie) Thu 31-Dec-20 15:42:51
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Virgin Media, latency & jitter


[link to this post]
 
Hello all,

I have been trying to understand why my Virgin Media M100 broadband with a Hub 3 router is giving these poor results especially in the evenings. I am assuming that other users can get a more stable M100 latency plot and that mine is not typical.

My goal is to reduce latency and jitter such that the delay and buffering on a real time music app called Jamulus get to lower latency and less buffer drops.

I am thinking that the data is pointing towards either an outside house cabling or a bandwidth issue with the cable supplier. An second question is around if the Hub 3 firmware version is after the PUMA 6 jitter issue resolution.

The BQM data makes me consider the largest cause is the data from my router/modem outwards. There will be some optimisation I can do with my internal network but to me this seems to be the lesser of the problem areas. [Very willing to take advice that differs!]

And the question I have wanted to get an answer to is "Does anyone know if the DOCSIS coding is inherently a cause of packet jitter?"

If I have not provided enough information as an intermediate knowledge of networks then please tell me what extra information would help diagnose where I am.

Here's the data if anyone can help.
First BQM speed test from tweet:
http://tbb.st/1609428023493440455

Next is the BQM monitor for the last 24 hours (typical pm/evening reduction in quality)
https://www.thinkbroadband.com/broadband/monitoring/...

Now the Hub 3 configuration:
Network status
Router status
Status
Downstream
Upstream
Configuration
Network Log
Refresh data
General Configuration
Network access
Allowed
Maximum Number of CPEs
1
Baseline Privacy
Enabled
DOCSIS Mode
Docsis30
Config file
vca69834ncxv9873254k;fg87


Primary Downstream Service Flow
SFID 6790
Max Traffic Rate 117000047
Max Traffic Burst 42600
Min Traffic Rate 0


Primary Upstream Service Flow
SFID 6789
Max Traffic Rate 10500047
Max Traffic Burst 16320
Min Traffic Rate 0
Max Concatenated Burst 16320
Scheduling Type BestEffort

Now Hub 3 Downstream data:
Network status
Router status
Status
Downstream
Upstream
Configuration
Network Log
Refresh data
Downstream bonded channels
Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 611000000 6.4 38 256 qam 26
2 475000000 6.3 38 256 qam 9
3 483000000 6.5 38 256 qam 10
4 491000000 6.3 38 256 qam 11
5 499000000 6.3 38 256 qam 12
6 507000000 6.5 38 256 qam 13
7 515000000 6.3 38 256 qam 14
8 523000000 5.9 38 256 qam 15
9 531000000 6 38 256 qam 16
10 539000000 6.1 38 256 qam 17
11 547000000 6 38 256 qam 18
12 555000000 6.5 38 256 qam 19
13 563000000 6.8 38 256 qam 20
14 571000000 6.5 38 256 qam 21
15 579000000 6 38 256 qam 22
16 587000000 5.9 38 256 qam 23
17 595000000 6.1 38 256 qam 24
18 603000000 6.3 38 256 qam 25
19 619000000 6.5 38 256 qam 27
20 627000000 6.5 38 256 qam 28
21 635000000 6 38 256 qam 29
22 643000000 5.5 38 256 qam 30
23 651000000 5.9 38 256 qam 31
24 659000000 6.3 38 256 qam 32


Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.6 75188 0
2 Locked 38.9 29154 9
3 Locked 38.9 30420 0
4 Locked 38.6 32793 0
5 Locked 38.9 34993 0
6 Locked 38.6 39281 0
7 Locked 38.9 39575 1
8 Locked 38.9 45658 0
9 Locked 38.6 47649 0
10 Locked 38.6 49400 0
11 Locked 38.6 54292 0
12 Locked 38.6 51808 0
13 Locked 38.9 54464 0
14 Locked 38.9 56740 0
15 Locked 38.9 63274 0
16 Locked 38.9 63047 0
17 Locked 38.9 69288 0
18 Locked 38.9 71049 0
19 Locked 38.6 79302 0
20 Locked 38.6 81295 0
21 Locked 38.6 84087 0
22 Locked 38.6 86654 0
23 Locked 38.6 92910 3
24 Locked 38.9 94255 0

and the Hub 3 Upstream data:
Network status
Router status
Status
Downstream
Upstream
Configuration
Network Log
Refresh data
Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 53700000 42.5 5120 64 qam 2
2 39400000 42.5 5120 64 qam 4
3 46200000 42.5 5120 64 qam 3
4 60300000 42.5 5120 64 qam 1


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

and the Hub 3 Network log:
Network status
Router status
Status
Downstream
Upstream
Configuration
Network Log
Refresh data
Network Log
Time Priority Description
31/12/2020 15:25:51 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
31/12/2020 15:25:38 Warning! LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
31/12/2020 11:01:42 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
29/12/2020 20:44:30 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
29/12/2020 15:38:11 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
28/12/2020 19:55:13 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
28/12/2020 10:40:27 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
28/12/2020 03:18:1 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
27/12/2020 15:35:47 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
25/12/2020 21:13:57 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
24/12/2020 22:36:42 notice DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt057-b.cm modified;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
24/12/2020 22:36:42 Error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
21/12/2020 23:39:12 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
21/12/2020 21:08:5 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
21/12/2020 21:07:44 Warning! LAN login FAILED : Incorrect Username / Password / ConnectionType;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
21/12/2020 16:10:53 notice LAN login Success;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
19/12/2020 06:37:35 critical No Ranging Response received - T3 time-out;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
19/12/2020 04:45:49 notice DHCP Renew - lease parameters tftp file-cmreg-vmdg505-bbt057-b.cm modified;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
19/12/2020 04:45:49 Error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
19/12/2020 04:45:47 Error DHCP RENEW sent - No response for IPv4;CM-MAC=4c:38:d8:27:4c:fb;CMTS-MAC=04:62:73:e4:91:5a;CM-QOS=1.1;CM-VER=3.0;
Administrator MrSaffron
(staff) Sat 02-Jan-21 11:00:43
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Re: Virgin Media, latency & jitter


[re: HarveyMears] [link to this post]
 
Given evening rises in jitter/latency looks like a busy area which is not uncommon on the DOCSIS network

No big point in optimising your local network as unless you are using power plug devices any improvement is wasted when the local node is as busy as it looks.

If latency is important (e.g. gaming) you might want to look at a FTTC line for actual game play.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Saltank
(committed) Wed 06-Jan-21 08:55:05
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Re: Virgin Media, latency & jitter


[re: HarveyMears] [link to this post]
 
As a side note about the Puma 6, I don't think it's been resolved.
I have tried using Stadia, and on a 550/35Mbps connection, it sufffers from stuttering which can only be described as jitter. After asking around, the best explanation was that the modem can't handle it and is chocking as a result of the defect.

I have asked VM if they're going to be offering a non-defective modem any time soon and was sent in circles, they don't really know.

Am now considering going to FTTC again.

In my area, during the first lockdown upload speeds plummeted to 3Mbps. As of yesterday they are down to 10Mbps... It is likely too many people at home using their connections.


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Standard User jchamier
(eat-sleep-adslguide) Wed 06-Jan-21 09:56:58
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Re: Virgin Media, latency & jitter


[re: Saltank] [link to this post]
 
In reply to a post by Saltank:
In my area, during the first lockdown upload speeds plummeted to 3Mbps. As of yesterday they are down to 10Mbps... It is likely too many people at home using their connections.
Looks as if you have two problems, congestion may be increasing the latency worse than the Puma chipset issues.VM is lots of separate Hybrid-Fibre-Coax areas, and so congestion in one area is not reflected nationally.

A thinkbroadband BQM can often show if this varies by time.

21 years of broadband connectivity since 1999 trial - Live BQM
Standard User srkain
(newbie) Wed 06-Jan-21 10:17:40
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Re: Virgin Media, latency & jitter


[re: HarveyMears] [link to this post]
 
I'm suffering the same issue with VM in the Bromley area (BR1).

Your latency issue looks like a breeze compared to mine BQM test:
https://www.thinkbroadband.com/broadband/monitoring/...

It looks like in my area there is a huge problem of over-utilization and I'm moving to FTTC in a couple of weeks to see if this solves the issue.
It is a shame as I am moving from 200Mbit to around 48Mbit if I am lucky (no FTTP around here and not too close to a cabinet as well). But VM is unusable for gaming and VoIP as it currently stands and it is impacting my day to day working from home.
Standard User Saltank
(committed) Wed 06-Jan-21 12:49:51
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Re: Virgin Media, latency & jitter


[re: jchamier] [link to this post]
 
This is my BQM, in my opinion the latency spikes aren't normal and they're definitely worse than, say, a FTTC connection on Zen.

My Broadband Ping

I've had numerous issues (VM Business) so might share similar problems as OP. It has been more or less 'stable' since early October, after weeks of complaining and having random outages and getting an engineer out, who put an attenuator on the cable. Though this week upload is again around 10Mbps.. but at least it's not going down smile
Standard User jchamier
(eat-sleep-adslguide) Wed 06-Jan-21 14:41:03
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Re: Virgin Media, latency & jitter


[re: Saltank] [link to this post]
 
In reply to a post by Saltank:
This is my BQM, in my opinion the latency spikes aren't normal and they're definitely worse than, say, a FTTC connection on Zen.
I'm in the Surrey/Hants border area, and my live BQM. Speeds are fine on the M200 service, latency is variable as I expected from cable. I moved from 45 down, 4 up FTTC, and I don't game, but my BQM is a lot better than yours.

21 years of broadband connectivity since 1999 trial - Live BQM
Standard User gav76
(newbie) Wed 06-Jan-21 14:57:26
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Re: Virgin Media, latency & jitter


[re: srkain] [link to this post]
 
that looks remarkably similar to mine - i've never had an issue with speed or general connectivity, but i've been doing more gaming recently and i'm getting terrible latency and packet loss issues.

My BQM

I've not raised it with Virgin yet. I think the service is oversubscribed in my area (Manchester M33) so I'm guessing not a lot can be done about it. Anyone had any success with getting this resolved?
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