Virgin Media Community

[glenmore3685]

Hi All

I'm a new customer looking for some assistance to understand why my speeds aren't as expected.

I had my broadband installed on Saturday. I signed up for Vivid 350. Using speedtest.net and trying modem mode and hardwiring my laptop to the Superhub etc. I can't seem to get anything quicker than 280mbps. Does this suggest I have been setup for 250 rather than 350 in error?

Some stats:

Thanks in advance for any help!

[Ernie_C]

The upstream is below the recommended level of 31 dBmV as documented in @Sephiroth ’s excellent sticky at the top of this forum section.

I suggest Virgin Media need to review and confirm this and arrange for a visit to correct this.

You can either phone in to arrange or wait here for Virgin Media to reach your thread which can take around a week at times.

[glenmore3685]

Thanks Ernie

So does upstream being below the recommended level impact the download speeds or does this just pertain to upload speeds?

[glenmore3685]

OK just to update this thread, spoke to customer support, apparently there is an issue impacting my area that is going to be addressed with an hour (fingers crossed).

Details from the chat with Customer Services:

Vidyasagar

 at 11:11, Feb 4:

I have had a word with our IT expertise and explained the entire issue regarding the speed, upstream and all of the steps we have gone through.
They have checked the system and found that the 'Data Corrupt Error' has caused the speed issue.

Vidyasagar

 at 11:12, Feb 4:

They are now aware and the engineer has been scheduled on high priority to work on it.

Vidyasagar
 at 11:18, Feb 4:

Thank you for your time, Gareth.

The IT advisor has mentioned, "Slow speeds due to FEC errors on cable. Raised outage and staged work order #16084808."

Fingers crossed.

[Sephiroth]

Thanks Ernie.

The network log might reveal what was happening. As the stats sit, the downstream is fine. The upstream power is below the generally accepted threshold; if that is a fault with the hub's output, then there wouldn't be sufficient power to successfully push data back to the VM end. The VM bods can see whether or not there are data errors on the upstream.

If the network log show no T3 events but do show T4 events, then the modem is flapping (resetting) and that would most likely be a downstream issue; does that happen?

Upstream issues do affect downstream as ACKs back to a data source may not be going through.

The telephone support person said there were "FEC errors". "FEC" means Forward Error Correction and is conventionally applied to the customer's downstream. Of course your upostream is their downstream, but I don't think offshore support is that smart.

So please let's see the Network Log next. And a full repeat of the power levels.

[glenmore3685]

Hi Sephiroth

Unfortunately despite being told by the CS agent my issue would be resolved in 30-40 minutes 7 hours ago, it remains the same 

So as requested:

Network Log

Time Priority Description

1970-01-01 00:01:27.00	Warning!	Lost MDD Timeout;CM-MAC=********;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
1970-01-01 00:01:27.00	Warning!	MDD message timeout;CM-MAC=********;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-02 16:34:03.00	notice	SW Download INIT - Via Config file
2019-02-02 16:36:36.00	Error	Disruption during SW download - Power Failure
2019-02-02 16:36:40.00	notice	SW Download INIT - Via Config file
2019-02-02 16:40:51.00	notice	SW download Successful - Via Config file
2019-02-02 20:30:06.00	critical	No Ranging Response received - T3 time-out;CM-MAC=********;CMTS-MAC=**********;CM-QOS=1.1;CM-VER=3.0;
1970-01-01 00:01:30.00	Warning!	Lost MDD Timeout;CM-MAC=***********;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
1970-01-01 00:01:31.00	Warning!	MDD message timeout;CM-MAC=1*********;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
2019-02-04 10:55:19.00	critical	No Ranging Response received - T3 time-out;CM-MAC=********;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[glenmore3685]

Downstream bonded channels

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

1	299000000	3.2	38	256 qam	21
2	323000000	3	38	256 qam	24
3	315000000	2.9	38	256 qam	23
4	307000000	2.9	38	256 qam	22
5	291000000	3	38	256 qam	20
6	283000000	3	38	256 qam	19
7	275000000	2.9	38	256 qam	18
8	267000000	3	38	256 qam	17
9	259000000	3	38	256 qam	16
10	251000000	3.2	38	256 qam	15
11	243000000	3.4	38	256 qam	14
12	235000000	3.7	38	256 qam	13
13	227000000	3.7	38	256 qam	12
14	219000000	3.9	38	256 qam	11
15	211000000	3.7	38	256 qam	10
16	203000000	3.9	38	256 qam	9
17	195000000	3.9	38	256 qam	8
18	187000000	4	38	256 qam	7
19	179000000	3.9	38	256 qam	6
20	171000000	3.9	38	256 qam	5
21	163000000	4	38	256 qam	4
22	155000000	4	38	256 qam	3
23	147000000	4.5	38	256 qam	2
24	139000000	4.5	38	256 qam	1

Downstream bonded channels

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

1	Locked	38.6	7	0
2	Locked	38.9	9	0
3	Locked	38.6	5	0
4	Locked	38.6	7	0
5	Locked	38.9	9	0
6	Locked	38.9	11	0
7	Locked	38.6	5	0
8	Locked	38.9	6	0
9	Locked	38.9	7	0
10	Locked	38.6	7	0
11	Locked	38.6	4	0
12	Locked	38.9	6	0
13	Locked	38.9	8	0
14	Locked	38.9	4	0
15	Locked	38.9	12	0
16	Locked	38.9	6	0
17	Locked	38.6	6	0
18	Locked	38.6	10	0
19	Locked	38.6	18	0
20	Locked	38.9	8	0
21	Locked	38.9	6	0
22	Locked	38.9	6	0
23	Locked	38.6	6	0
24	Locked	38.9	6	0

Upstream bonded channels

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

1	53700000	30.5	5120	64 qam	2
2	60300000	30.8	5120	64 qam	1
3	39400000	30.3	5120	64 qam	4
4	46200000	30.5	5120	64 qam	3

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

1	ATDMA	0	0	1	0
2	ATDMA	0	0	0	0
3	ATDMA	0	0	0	0
4	ATDMA	0	0	0	0

[Sephiroth]

I can't see anything wrong. I would guess that the events on 02-Feb around 16:36 concerned a factory reset you did, hence the software download,

The subsequent events on 04-Feb might have been when you rebooted the hub. The 1970 date occurs when the hub loses its time base, usually at the first moments of a hard reset.

If that's not the case, then what happened at 10:55 this morning or weren't you there?

[glenmore3685]

---

@Sephiroth wrote:
I can't see anything wrong. I would guess that the events on 02-Feb around 16:36 concerned a factory reset you did, hence the software download,

This is when the broadband was first installed by the engineer, assume he must have reset it.

If that's not the case, then what happened at 10:55 this morning or weren't you there?

This was when I did another reset which I was requested to do by the Customer service agent when troubleshooting the issue. 

---

So everything works fine, it mostly gets mid to high 200mbps which would be fine if I wasn't paying for 350! Que the chat to customer services this morning where after about 45mins of going through the standard script to troubleshoot all the things I'd already checked they told me there was a FEC issue affecting my area, that a ticket had been raised and this would not only resolve my speed issue it would also resolve my low(ish) upstream level in 30/40 minutes, needless to say nothing has changed 9 hours on.

[Sephiroth]

So, my analysis was essentially correct. There is nothing wrong with the circuit itself. If the upstream power was actually too low, you'd have a whole series of T3s and T4s in the network log.

FEC noise would show in the downstream stats as post-RS (uncorrectable) errors. There are none. The agent was either pulling your plonker or had found upstream noise which we can't see, but I don't think they can either.

The VM bods will get to this thread in about a week and have tools to say what's wrong, if anything and tell you what the ticket reference is.

At least you've got 200+ for the time being.