Virgin Media Community

[Daveoc644]

For about a week now I've noticed packet loss on my connection.

Back on Tuesday/Wednesday the automated phone line reported that there was a fault in the area.

I got a text message yesterday morning saying that the fault has been corrected, but nothing has improved. The line no longer reports any faults (like the website).

My 3.1 downstream channel seems to have a really weak signal since this started.

BQM shows little packet loss in the last 24 hours:

https://www.thinkbroadband.com/broadband/monitoring/quality/share/63bbe1da56d09add6cedbb5467e045c98a...

I've tried all the obvious things like making sure everything's plugged in and rebooting the Hub 4.

I'm pretty sure this will need an engineer.

3.0 Downstream channels

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

25	331000000	5.199997	36.609653	QAM256	25
10	211000000	1.599998	36.386890	QAM256	10
11	219000000	2.000000	36.386890	QAM256	11
12	227000000	2.500000	36.609653	QAM256	12
13	235000000	3.500000	36.386890	QAM256	13
14	243000000	4.099998	36.609653	QAM256	14
15	251000000	4.000000	36.609653	QAM256	15
16	259000000	4.300003	36.609653	QAM256	16
17	267000000	4.599998	36.609653	QAM256	17
18	275000000	5.099998	36.609653	QAM256	18
19	283000000	5.199997	36.386890	QAM256	19
20	291000000	5.199997	36.609653	QAM256	20
21	299000000	5.300003	36.609653	QAM256	21
22	307000000	5.300003	36.609653	QAM256	22
23	315000000	5.300003	36.609653	QAM256	23
24	323000000	5.199997	36.386890	QAM256	24
26	339000000	5.000000	36.386890	QAM256	26
27	347000000	4.599998	35.779911	QAM256	27
28	355000000	4.699997	35.779911	QAM256	28
29	363000000	5.099998	35.779911	QAM256	29
30	371000000	5.599998	35.779911	QAM256	30
31	379000000	6.099998	35.779911	QAM256	31
32	387000000	6.500000	35.779911	QAM256	32
33	395000000	6.300003	35.595078	QAM256	33
34	403000000	6.000000	35.595078	QAM256	34
35	411000000	5.900002	35.779911	QAM256	35
36	419000000	6.099998	35.595078	QAM256	36
37	427000000	6.500000	35.595078	QAM256	37
38	435000000	6.800003	35.779911	QAM256	38
39	443000000	7.000000	35.595078	QAM256	39
40	451000000	6.900002	35.779911	QAM256	40

3.0 Downstream channels

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

25	Locked	36.609653	0	0
10	Locked	36.386890	0	0
11	Locked	36.386890	0	0
12	Locked	36.609653	0	0
13	Locked	36.386890	0	0
14	Locked	36.609653	0	0
15	Locked	36.609653	0	0
16	Locked	36.609653	0	0
17	Locked	36.609653	0	0
18	Locked	36.609653	0	0
19	Locked	36.386890	0	0
20	Locked	36.609653	0	0
21	Locked	36.609653	0	0
22	Locked	36.609653	0	0
23	Locked	36.609653	0	0
24	Locked	36.386890	0	0
26	Locked	36.386890	0	0
27	Locked	35.779911	0	0
28	Locked	35.779911	0	0
29	Locked	35.779911	0	0
30	Locked	35.779911	0	0
31	Locked	35.779911	0	0
32	Locked	35.779911	0	0
33	Locked	35.595078	0	0
34	Locked	35.595078	0	0
35	Locked	35.779911	0	0
36	Locked	35.595078	0	0
37	Locked	35.595078	0	0
38	Locked	35.779911	0	0
39	Locked	35.595078	0	0
40	Locked	35.779911	0	0

3.1 Downstream channels

Channel Channel Width (MHz) FFT Type Number of Active Subcarriers Modulation (Active Profile) First Active Subcarrier (Hz)

41

96

4K

1840

QAM1024

759

3.1 Downstream channels

Channel ID Lock Status RxMER Data (dB) PLC Power (dBmV) Correcteds (Active Profile) Uncorrectables (Active Profile)

41

Locked

33

-13.0

72877150

0

3.0 Upstream channels

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

1	23600000	44.270599	5120 KSym/sec	32QAM	10
2	49600000	47.020599	5120 KSym/sec	64QAM	6
3	43100000	46.020599	5120 KSym/sec	64QAM	7
4	36600000	45.520599	5120 KSym/sec	64QAM	8
5	30100000	45.520599	5120 KSym/sec	64QAM	9

3.0 Upstream channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	US_TYPE_ATDMA	0	0	0	0
2	US_TYPE_ATDMA	0	0	0	0
3	US_TYPE_ATDMA	0	0	0	0
4	US_TYPE_ATDMA	0	0	0	0
5	US_TYPE_ATDMA	0	0	0	0

3.1 Upstream channels

Channel Channel Width (MHz) Power (dBmV) FFT Type Modulation

12

10.8

43.0

2K

QAM128

3.1 Upstream channels

Channel Channel Type Number of Active Subcarriers First Active Subcarrier (Hz) T3 Timeouts T4 Timeouts

12

OFDMA

220

53.4

0

0

[Tudor]

That is low and there is one upstream on 32QAM that is wrong.

Check with Area faults on 0800 561 0061 If you have a VM landline 150 this goes down to post code level. You could also try the web page status, but this is not recommended as it only covers issues that affect a very large number of customers.

VM will not dispatch any technicians while an area fault exists.

If no area faults found:

The primary place to report faults or for service requests is Customer Services on 0345 454 1111/150 if you have a VM landline or wait two or three days for a VM staff member to get to your post.

[Gareth_L]

Hello Daveoc644,

Thank you very much for popping back on our Community.
Can I just apologise for service issues with your broadband.
We can run a few tests from here and check on your equipment.
Sadly it is showing an issue with the downstream power levels, So I will need to send you a private message to gain account access and arrange an engineers visit.
If you can check the purple envelope top right of your screen that would be great. 
Regards     
Gareth_L
 

[IPFreely]

Going by the roll off looks like there's a component in the line somewhere that tops out at 750 MHz.

If there isn't a very old attenuator in the home and others are seeing the same thing one for access networks.

HFC/CATV components top out at 550, 750, 860, 1000, 1218 and 1800 MHz. When VM did an upgrade in the area to make the room for the 3.1 downstream they may have missed an amplifier so left the customers served by it restricted to 750 MHz. The 3.1 signal is above that so isn't getting amplified with the rest.

[IPFreely]

Looks a lot like when the area's network was upgraded a 750 MHz component was left in place leaving the spectrum above partially amplified. Given the 3.1 signal starts at 759 MHz there's going to be a big roll off there.

One for networks. 

[Gareth_L · Accepted solution]

Hello Daveoc644.

Thanks fort those details.

I have booked the Technician to attend and sent the date by private message.

Can you please let us know how the visit goes.

Gareth_L

[Daveoc644]

---

@IPFreely wrote:

Looks a lot like when the area's network was upgraded a 750 MHz component was left in place leaving the spectrum above partially amplified. Given the 3.1 signal starts at 759 MHz there's going to be a big roll off there.

One for networks. 

---

That's an interesting theory, but we've had DOCSIS 3.1 channels on both downstream and upstream for a long time, and the power levels across everything were always OK until about two weeks ago.

Will have to wait and see what the engineer thinks!