Slow speeds during peak times - Slower speed after work was completed in my area

[Cyirak]

Over the past couple of weeks the achievable speed seem to have dropped on my broadband. I recently upgraded from M350 to M500 package. 

To build a bit of background..

Stupidly or not, I upgraded whilst there was multiple issues in my area but just so happened to be when I decided to do it. We were experiencing high packet loss, with periods of 50% loss at times or complete loss of service this was before and after the upgrade... We had an engineer come out and he checked the cable all the way from the Hub back to the cabinet and he advised that there were no issues with our line however he picked up on an issue that was effecting everyone down our road. Even with these issues in place my download was always 520Mbps+ even at peak times, however my upload was shot and sometimes wouldn't even hit 10Mbps.

The issues have now been resolved and stability wise, no packet loss or loss of service which is great however I'm finding my downloads speeds aren't as good as before the issue was resolved.  Sometimes only getting about 200mbps at peak times where as my friend about a mile away is getting full speed. I also noticed that the downstream power levels have dropped from around 4.x to 2.x. Upstream power seems to have stayed the same.

Before I call virgin and raise a issue I wanted to check if the stats are okay on my downstream and upstream..

Any help or advise would be appreciated. 

Stats are since Monday 14th June about 5 days of uptime on the modem.

There are RCS partial service in the logs however these were logged prior to me receiving notification on the 14th that the problem had been resolved.

Downstream bonded channels

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

1	234750000	2.2	38	256 qam	13
2	242750000	1.9	38	256 qam	14
3	250750000	1.9	38	256 qam	15
4	258750000	2	38	256 qam	16
5	266750000	2.2	38	256 qam	17
6	274750000	2.2	39	256 qam	18
7	282750000	2.5	40	256 qam	19
8	290750000	2.7	40	256 qam	20
9	298750000	2.9	38	256 qam	21
10	306750000	2.7	40	256 qam	22
11	314750000	3	38	256 qam	23
12	322750000	3.2	40	256 qam	24
13	330750000	3	40	256 qam	25
14	338750000	2.7	40	256 qam	26
15	346750000	2.7	40	256 qam	27
16	354750000	2.7	40	256 qam	28
17	362750000	2.7	40	256 qam	29
18	370750000	2.9	39	256 qam	30
19	378750000	3	38	256 qam	31
20	386750000	2.7	38	256 qam	32
21	394750000	2.5	38	256 qam	33
22	402750000	2.2	38	256 qam	34
23	410750000	2.2	38	256 qam	35
24	418750000	2.2	38	256 qam	36

Downstream bonded channels

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

1	Locked	38.9	182395	794
2	Locked	38.9	121045	393
3	Locked	38.9	74704	135
4	Locked	38.9	45207	21
5	Locked	38.9	25763	0
6	Locked	39.8	13596	0
7	Locked	40.3	7574	0
8	Locked	40.3	4334	0
9	Locked	38.9	2875	0
10	Locked	40.3	1958	0
11	Locked	38.9	2390	0
12	Locked	40.3	2810	0
13	Locked	40.3	2908	0
14	Locked	40.3	3514	0
15	Locked	40.3	3695	0
16	Locked	40.3	3743	0
17	Locked	40.9	3703	0
18	Locked	39.8	4074	0
19	Locked	38.9	4788	0
20	Locked	38.9	4570	0
21	Locked	38.9	3094	0
22	Locked	38.6	2029	0
23	Locked	38.9	912	0
24	Locked	38.6	376	0

Upstream bonded channels

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

1	60299899	38.8	5120	64 qam	1
2	39399994	38.3	5120	64 qam	4
3	46200055	38.3	5120	64 qam	3
4	53699819	38.5	5120	64 qam	2

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

Network Log
Time Priority Description
18/06/2021 06:27:7 critical No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
17/06/2021 12:40:38 Error DHCP RENEW WARNING - Field invalid in response v4 option;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;
14/06/2021 17:17:40 notice LAN login Success;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.0;

[Cyirak]

Hi John,

Thanks for confirming. I'm still experiencing some packet loss at times and drop in speed. I can see when this happens the upstream modulation drops on multiple channels down to 32qam or 16qam. The issue appears to be very intermittent.

Are there any issues in the area regarding snr?

Kind Regards

[Cyirak]

Just experienced packet loss which resulted in me losing connection to some services stats are as below,

Downstream bonded channels

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

1	330750000	4	40	256 qam	25
2	234750000	2.5	37	256 qam	13
3	242750000	2	37	256 qam	14
4	250750000	2	37	256 qam	15
5	258750000	3	38	256 qam	16
6	266750000	3.5	38	256 qam	17
7	274750000	3.7	38	256 qam	18
8	282750000	3.7	38	256 qam	19
9	290750000	3.9	38	256 qam	20
10	298750000	3.7	38	256 qam	21
11	306750000	3.5	40	256 qam	22
12	314750000	3.9	38	256 qam	23
13	322750000	4.1	40	256 qam	24
14	338750000	4	38	256 qam	26
15	346750000	4	40	256 qam	27
16	354750000	4	40	256 qam	28
17	362750000	3.7	39	256 qam	29
18	370750000	3.9	38	256 qam	30
19	378750000	3.5	38	256 qam	31
20	386750000	3	38	256 qam	32
21	394750000	3	38	256 qam	33
22	402750000	3	38	256 qam	34
23	410750000	3.2	38	256 qam	35
24	418750000	3.2	38	256 qam	36

Downstream bonded channels

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

1	Locked	40.3	51	0
2	Locked	37.6	170	0
3	Locked	37.6	205	0
4	Locked	37.6	266	0
5	Locked	38.6	120	0
6	Locked	38.9	68	0
7	Locked	38.9	52	0
8	Locked	38.9	47	0
9	Locked	38.9	42	0
10	Locked	38.9	52	0
11	Locked	40.3	45	0
12	Locked	38.9	55	0
13	Locked	40.3	63	0
14	Locked	38.9	52	0
15	Locked	40.3	40	0
16	Locked	40.3	41	0
17	Locked	38.9	57	0
18	Locked	38.9	55	0
19	Locked	38.9	68	0
20	Locked	38.9	63	0
21	Locked	38.6	77	0
22	Locked	38.9	99	0
23	Locked	38.6	104	0
24	Locked	38.6	48	0

Upstream bonded channels

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

1	60300000	44	5120	16 qam	1
2	46199161	43.7	5120	16 qam	3
3	39399537	43.7	5120	16 qam	4
4	53700122	43.7	5120	16 qam	2

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

Nothing in the network log for today.

[lotharmat]

Upstream looks bad - should be 64 QAM not 16.

[Cyirak]

Yeah thats the problem ive been having for months now, the upstream drops to 32 or 16 QAM and i'll then start seeing outbound packet loss. the downstream seems to be okay, but UDP based applications such as voice or gaming really suffer when and this will typically happen at the worst of times.

The upstream modulation is now back at 64QAM across all the channels and everything seems to be okay for the moment.

[Cyirak]

Is anyone from virgin media able to advise? Are there any outstanding SNR issues in my area?

[Cyirak]

Upload has dropped again and all upload channels are at 32QAM Again.

Upstream bonded channels

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

1	60300000	43	5120	32 qam	1
2	46200739	42.3	5120	32 qam	3
3	39399504	42.3	5120	32 qam	4
4	53700000	42.3	5120	32 qam	2

Is any one from Virgin able to help? 

Its a shame i was impressed with the responsiveness of the forum staff and seems that my posts are now going unnoticed 😞

[Cyirak]

Just phoned customer services and they have advised that there is yet another outage in my area due to be fixed tomorrow.

[Tom_F]

Apologies for the ongoing fault @Cyirak.

I've taken a look and confirm it's an issue with SNR that's currently estimated to be fixed by 17 AUG 2021 13:00. Hopefully the teams will get to the bottom of it before then - if you need any more updates please don't hesitate to pop back. 

Tom 

[Cyirak]

Hi Tom,

This still seems to be on going are you able to advise if the fault is still outstanding?

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

1	60299693	44.7	5120	16 qam	1
2	46200229	43.7	5120	16 qam	3
3	39399522	44	5120	16 qam	4
4	53699678	44.2	5120	16 qam	2

Upstream bonded channelsChannel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

[Cyirak]

Spoke to CS, this has been delayed until 23.08.2021, I'll be amazed if this is then resolved but one can only hope.