Virgin Media Community

[cadogi]

Hi all,

I got a new Hub 4 delivered on 29th September and set it up as the Hub 3 was set up. However when speed testing on M500 I was regularly over 400Mbps (often over 500Mbps) and ~35 down, now that I have a shiny new Hub 4 with Gig1 package I am lucky to get 350Mbps most tests are under 300Mbps to my own router (nighthawk R8000) or laptop (both Gigabit ports) plugged directly into the hub 4 (cat5e/6/7 all tested) to be fair I am getting about 52Mbps upload (so Gig1 is enabled).

The problem is that https://samknows.com/realspeed/ shows 1Gbps so VM support don't care that my usable speed has dropped a couple of hundred meg. I have done file transfers >4GB from a 20Gbps capable source that used to go at >50MB/s 2 days ago which are now 19MB/s.

I realise these are still good speeds but I grudge paying more to upgrade and getting less than I had before with my entire network online (Hub 4 in modem mode), or if I just have 1 laptop plugged directly into into the Hub 4 (in router mode).

I have seen posts about dBmV being a red flag beyond +/- 6 so I've included the downstream channel information below too. 

Any help would be appreciated.

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

25	331000000	-7.099998	38.605377	QAM256	25
8	195000000	-1.700001	40.946209	QAM256	8
9	203000000	-1.799999	40.366287	QAM256	9
10	211000000	-2.200001	40.366287	QAM256	10
11	219000000	-2.400002	40.366287	QAM256	11
12	227000000	-3.000000	38.983261	QAM256	12
13	235000000	-3.400002	40.946209	QAM256	13
14	243000000	-3.700001	38.983261	QAM256	14
15	251000000	-4.500000	38.983261	QAM256	15
16	259000000	-4.500000	38.983261	QAM256	16
17	267000000	-3.900002	38.983261	QAM256	17
18	275000000	-4.299999	38.983261	QAM256	18
19	283000000	-4.799999	38.983261	QAM256	19
20	291000000	-5.000000	38.983261	QAM256	20
21	299000000	-4.599998	38.605377	QAM256	21
22	307000000	-5.000000	38.605377	QAM256	22
23	315000000	-5.599998	38.605377	QAM256	23
24	323000000	-6.400002	38.605377	QAM256	24
26	339000000	-7.400002	38.605377	QAM256	26
27	347000000	-7.400002	37.636276	QAM256	27
28	355000000	-7.900002	37.636276	QAM256	28
29	363000000	-7.900002	37.636276	QAM256	29
30	371000000	-8.299999	37.355988	QAM256	30
31	379000000	-8.900002	37.355988	QAM256	31
32	387000000	-9.500000	37.355988	QAM256	32
33	395000000	-9.900002	37.355988	QAM256	33
34	403000000	-9.799999	37.355988	QAM256	34
35	411000000	-9.900002	37.355988	QAM256	35
36	419000000	-10.200001	36.609653	QAM256	36
37	427000000	-10.099998	37.355988	QAM256	37
38	435000000	-10.200001	37.355988	QAM256	38

[MikeRobbo]

Most of your Downstream Power Levels are very high with some too high.

This will need an engineer visit to put them back into spec.

[cadogi]

Hi Mike,

Thanks for your reply, would the high power levels have a negative impact on download speeds? I just don't understand how there can be such a drop off after installing the Hub 4. Or maybe the activation of the faster package did it?

[MikeRobbo · Accepted solution]

My mistake they are too low. Min Power Level is -6dBmV.

Yes it will affect the download speeds the Hub will be struggling.

When you phone in the CS staff should check the levels.

They will probably ask you to reboot /factory reset the Hub. This will possibly be a short term fix.

Be firm with them and insist on an engineer visit.

[cadogi]

ah ok,

so I guess the DOCSIS 3.1 power level is not ideal either then. I am on hold again to talk to support again. 

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

159

Locked

-25.9

750278384

0

Thanks again Mike

==============================================================

*UPDATE*

That was the fastest I have ever gone through that queue. As soon as they looked at my power levels they said they will send an engineer out before I could even ask, so it's booked for Friday. Fingers crossed it gets sorted.

[cadogi]

Final update on this for anyone who gets this far.

It turns out there were 2 line faults (both fractures in the old cabling), these were causing the low Power (dBmV) readings. once they were sorted the Power (dBmV) reading are now between -1.900002 and 2.599998, as well as the 3.1 power level being reduced to -6.3.

The really important thing to highlight here is that before the fix I could tell there was an issue from day to day usage and every speed test other than SamKnows showed my connection was now slower (between 200 and 400 Mbps). However SamKnows (via the hub 4) stated I was getting 1Gbps speeds the entire time. Now, and only now, that the faults have been fixed I am seeing other speed tests come in between 700 and 900 Mbps and SamKnows still shows 1Gbps (which it probably should now). I can also tell from my own usage that things are moving faster.

I think Virgin Media should be very careful about using the RealSpeed metrics on their own because there is clearly a flaw in that plan which is detrimental to customers actual speeds. Especially since their own engineers said they didn't think I could have been getting 1Gbps with the issues which have now been resolved.

[jamstar2k]

I find it really dissapointing that VM try to fob you off with SamKnows results when they know full well that there could be issues when you quesry the 1Gigga service. Im having the same issue right now, but we as customers shouldnt have to jump through hoops to get this sorted. it seems this service should only be sold to techies!