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Can someone confirm my area is oversubscribed?

Last few days peak time service has been abysmal, with downloads testing at well below 1Mbps, and uploads testing frequently failing due to timeouts. I've tried reporting this problem to your offshore staff, but as I was unprepared to stand on one leg, with the SuperHub balanced on my head, reciting the Virgin Media T&C's backwards whilst affecting a Scottish accent, 'Larry', was alas, unable to proceed with his diagnostic efforts. 

Area is L23, I can provide more specific account information to VM staff via PM if required.

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Message 2 of 18
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Re: Can someone confirm my area is oversubscribed?

Not answering your question directly, but just to observe that VM have done a lot of work over recent years and as a result over-subscription is far less common than it used to be.  It may be worth seeing if there's the evidence of line quality problems, because if it is power levels or SNR then those need fixing by the field technicians, if it is over-subscription AND you're using a Superhub or Superhub 2, then simply getting a Hub 3 for self install may be enough to improve things, because the Hub 3 spreads loads over more channels, and is less prone to area congestion.

Feel free to ignore my suggestion, but if you want to check out the cause, as a start connect to your hub, don't log in, just click "check router status" and post the contents of the Upstream, Downstream and Logs tabs in replies to this.  Somebody will take a look and be able to see if there's power or noise issues.

To try and establish if there's a congestion problem (although that may be related to both an older hub and any line quality problems), you could trundle over to thinkbroadband.com and create an account and set up a Broadband Quality Monitor.  After a few days you should have a trace, and on a good connection it would look something like below.  On yours I'm expecting to see lots more yellow, a thicker blue band, and some red fringing across the top, but the relevant part will be if the problems become dramatically worse at peak times.

My Broadband Ping - VM number 2

If it is pure and simple over-subscription, and a Hub 3 can't fix it, that's bad news because it usually requires capital investment to fix, and VM appear to carry out capex in a random manner, and in some circumstances simply won't make the necessary local changes to fix it (an area in Reading, for example...).

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Re: Can someone confirm my area is oversubscribed?

I did  setup BQM, but it was showing 100% packet loss so I've had to change some router settings and will now have to wait for data to accumulate. My Super Hub 3.0 stats are as below...

 

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 267000000 -4.2 38 256 qam 17
2 139000000 -0.2 37 256 qam 1
3 147000000 -1 37 256 qam 2
4 155000000 -0.9 37 256 qam 3
5 163000000 -1.2 37 256 qam 4
6 171000000 -1.4 37 256 qam 5
7 179000000 -1.5 37 256 qam 6
8 187000000 -2 37 256 qam 7
9 195000000 -2 38 256 qam 8
10 203000000 -2.5 37 256 qam 9
11 211000000 -2.5 38 256 qam 10
12 219000000 -3 37 256 qam 11
13 227000000 -3.2 37 256 qam 12
14 235000000 -3.2 38 256 qam 13
15 243000000 -3.5 37 256 qam 14
16 251000000 -3.5 38 256 qam 15
17 259000000 -3.9 38 256 qam 16
18 275000000 -4.7 37 256 qam 18
19 283000000 -4.4 37 256 qam 19
20 291000000 -4 37 256 qam 20
21 299000000 -3.9 37 256 qam 21
22 307000000 -4.2 37 256 qam 22
23 315000000 -3.7 37 256 qam 23
24 323000000 -2.9 38 256 qam 24


Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.9 34 0
2 Locked 37.6 21364 0
3 Locked 37.3 38617 0
4 Locked 37.6 14244 0
5 Locked 37.6 20714 0
6 Locked 37.3 12838 1093
7 Locked 37.6 917 0
8 Locked 37.3 47 0
9 Locked 38.6 22 0
10 Locked 37.6 23 0
11 Locked 38.6 13 0
12 Locked 37.6 30 0
13 Locked 37.6 36 0
14 Locked 38.6 20 0
15 Locked 37.6 39 0
16 Locked 38.6 20 0
17 Locked 38.6 29 0
18 Locked 37.6 51 1
19 Locked 37.6 26 13
20 Locked 37.6 26 0
21 Locked 37.6 31 0
22 Locked 37.6 24 24
23 Locked 37.6 39 0
24 Locked 38.6 21 0

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Message 4 of 18
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Re: Can someone confirm my area is oversubscribed?

Nothing stands out to my untrained eye, although I'm open to being better educated by any of our resident experts.

Some power levels are edging towards the -6 dBmV lower limit*, but none are actually reaching that.  Previous discussions suggest a nice tight cluster around 0 dBmV is ideal, but whether range and quantum of power levels would explain the problems you're seeing I don't know.  Likewise the SNR levels are down as low as 37.3 dB which is a little bit borderline in a practical context, but strictly breaching no limit* that I know of.  And the error levels also have the faintest whiff of some minor niggle - nothing there that looks an outright problem, and error correction is working to catch and correct most errors (those pre-RS errors are corrected), and the uncorrected errors on channel 6 shouldn't be causing any serious issues.

Possibly our lovely helpful mods could get the power levels checked out for you, and advise if there is an area fault or congestion.  And we'll have to see whether the BQM shows anything instructive.

* More sort of guidelines, just like the Pirate's Code.

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Message 5 of 18
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Re: Can someone confirm my area is oversubscribed?

The network logs would be helpful, just copy and paste.

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Hub 3.0, TP-Link Archer C8, TP-Link TL-SG1008D 8-port gigabit switch, V6
My Broadband Ping - Roger's VM Broadband Connection
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Re: Can someone confirm my area is oversubscribed?

Network Log
Time Priority Description
27/09/2019 02:31:33 Error DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/09/2019 10:01:57 Error DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/09/2019 10:01:57 notice DHCP Renew - lease parameters tftp file-cmreg-vmdg505-rtsl10016u-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
27/09/2019 11:41:12 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
30/09/2019 14:57:26 Error DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/10/2019 11:56:15 Error DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
01/10/2019 11:56:15 notice DHCP Renew - lease parameters tftp file-cmreg-vmdg505-rtsl10016u-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/10/2019 07:53:48 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/10/2019 10:15:31 critical Unicast Ranging Received Abort Response - initializing MAC;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
02/10/2019 10:15:31 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/10/2019 21:52:39 Error DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
05/10/2019 22:50:51 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
06/10/2019 12:19:26 Error DHCP RENEW sent - No response for IPv4;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/10/2019 02:46:17 Error DHCP REBIND WARNING - Field invalid in response;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
07/10/2019 02:46:17 notice DHCP Renew - lease parameters tftp file-cmreg-vmdg505-rtsl10016u-b.cm modified;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
08/10/2019 12:51:37 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
10/10/2019 07:34:32 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
10/10/2019 09:19:21 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
12/10/2019 19:25:55 Warning! RCS Partial Service;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/10/2019 11:47:46 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

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Message 7 of 18
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Re: Can someone confirm my area is oversubscribed?

Although there are some dropouts there's not too many and most are not at peak periods. And where are the upstream stats? Let's also see what your BQM shows.

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Hub 3.0, TP-Link Archer C8, TP-Link TL-SG1008D 8-port gigabit switch, V6
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Re: Can someone confirm my area is oversubscribed?

Upstream bonded channels

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

1461999715.1512064 qam3
2326000685.1512064 qam5
3394000145.1512064 qam4
4536999445.1512064 qam2



Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1ATDMA0000
2ATDMA0000
3ATDMA0000
4ATDMA0000

 

 

BQM is still dud as packet loss is 100%

 

 

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Message 9 of 18
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Re: Can someone confirm my area is oversubscribed?

Your upstream power levels are too high. Unless there is an area fault you need a technician visit.

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Message 10 of 18
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Re: Can someone confirm my area is oversubscribed?

I saw this in another thread which would suggest upstream levels are ok

 

Upstream Power:

Taken from Table B-15 in the DOCSIS 3 spec (DOCSIS 2 is used for Upstream) - VM supplies 2 or 3 or 4 x upstream channels according to your contracted upstream speed. VM are also moving to 10:1 ratio so that upstream would be 10% of the downstream headline speed once implemented.:

DOCSIS 2 @ 5120 Ksyms/sec

Single Channel Locked

2 Channels Locked

3 or 4 Channels Locked

UPSTREAM 16QAM

+23 to +58 dBmv

+23 to 55 dBmv

+23 to 52 dBmv

UPSTREAM 64QAM

+23 to +57 dBmv

+23 to 54 dBmv

+23 to 51 dBmv

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