Drop off in initial broadband speeds

[MacRencephal]

I am fairly new here so please be gentle!

In brief, my query is I have seen a big drop off (c.25%) in my broadband speed after three weeks and I'm curious what might have caused this and what I can do about it, if anything.

In more detail, I had 1Gig broadband installed in mid-March. For the first three and a half weeks when doing a speedtest it was showing download speeds of 1100Mbps+. I was very happy with this. It was consistently around that speed. However, for the last few days when running the same test on the same device in the same position relative to the router I am getting download speeds in the 800s with it not even reaching 900Mbps.

Don't get me wrong - that is still much quicker than I was getting with my previous provider, but it is very disappointing to me that it has dropped by around 25% from what I was initially (and consistently) getting.

I get there is inherently variability in speed depending on a number of factors, but nothing has changed in that time in terms of additional devices, usage of the wifi / broadband when doing the test, etc. etc. so I don't understand why there has been such a big drop off.

I'm hoping someone can explain to me a) what might be causing such a big drop off and b) whether there is anything I can do about it.

Thanks

Mac

[MacRencephal]

Trying again in case it's helpful

Downstream bonded channels

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

1	411000000	2.4	40	QAM 256	1
2	419000000	2.3	40	QAM 256	2
3	427000000	2.5	40	QAM 256	3
4	435000000	2.5	40	QAM 256	4
5	443000000	2.6	40	QAM 256	5
6	451000000	2.6	40	QAM 256	6
7	459000000	2.7	40	QAM 256	7
8	467000000	2.8	40	QAM 256	8
9	475000000	3	40	QAM 256	9
10	483000000	3.2	40	QAM 256	10
11	491000000	3.3	40	QAM 256	11
12	499000000	3.3	40	QAM 256	12
13	507000000	3.3	40	QAM 256	13
14	515000000	3.4	40	QAM 256	14
15	523000000	3.5	40	QAM 256	15
16	531000000	3.7	40	QAM 256	16
17	539000000	3.8	40	QAM 256	17
18	547000000	3.9	40	QAM 256	18
19	555000000	4.1	40	QAM 256	19
20	563000000	4.2	41	QAM 256	20
21	571000000	4.4	40	QAM 256	21
22	579000000	4.4	40	QAM 256	22
23	587000000	4.4	40	QAM 256	23
24	595000000	4.6	40	QAM 256	24
25	603000000	4.6	40	QAM 256	25
26	611000000	4.7	40	QAM 256	26
27	619000000	4.9	41	QAM 256	27
28	627000000	5	41	QAM 256	28
29	635000000	5.1	41	QAM 256	29
30	643000000	5.2	41	QAM 256	30
31	651000000	5.3	41	QAM 256	31

Downstream bonded channels

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

1	Locked	40	4202	0
2	Locked	40	5239	0
3	Locked	40	4491	0
4	Locked	40	4648	0
5	Locked	40	4538	0
6	Locked	40	6221	0
7	Locked	40	7870	0
8	Locked	40	9130	0
9	Locked	40	9679	0
10	Locked	40	9390	0
11	Locked	40	9524	0
12	Locked	40	10146	0
13	Locked	40	10062	0
14	Locked	40	9383	0
15	Locked	40	9544	0
16	Locked	40	9521	0
17	Locked	40	9807	0
18	Locked	40	9827	0
19	Locked	40	8397	0
20	Locked	41	8158	0
21	Locked	40	7227	0
22	Locked	40	7210	0
23	Locked	40	7459	0
24	Locked	40	6535	0
25	Locked	40	7222	0
26	Locked	40	6204	0
27	Locked	41	5369	0
28	Locked	41	5066	0
29	Locked	41	4537	0
30	Locked	41	3790	0
31	Locked	41	3580	0

Upstream bonded channels

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

0	60300000	35	5120	QAM 64	1
1	53700000	35.3	5120	QAM 64	2
2	46200000	35.5	5120	QAM 64	3
3	39400000	36	5120	QAM 64	4
4	32600000	36	5120	QAM 64	9
5	23600000	36	5120	QAM 64	10

Upstream bonded channels

Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts

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

Network Log

Time Priority Description

11-04-2023 17:53:22	notice	REGISTRATION COMPLETE - Waiting for Operational status
11-04-2023 17:53:15	notice	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2 3.;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
11-04-2023 17:53:03	warning	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
11-04-2023 17:53:01	notice	Honoring MDD; IP provisioning mode = IPv4
11-04-2023 17:52:59	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
11-04-2023 17:52:53	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
11-04-2023 17:52:41	critical	Cable Modem Reboot due to power button reset
04-04-2023 18:27:33	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-04-2023 18:27:30	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
04-04-2023 18:27:18	critical	Cable Modem reboot from UI
15-03-2023 15:16:05	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:42:42	critical	No Ranging Response received - T3 time-out;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:37:17	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:35:14	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:35:04	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:34:55	critical	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;
15-03-2023 14:34:42	critical	Cable Modem Reboot due to SW Upgrade
14-12-2022 13:55:36	critical	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=**:**:**:**:**:**;CMTS-MAC=**:**:**:**:**:**;CM-QOS=1.1;CM-VER=3.1;

[Vikki_M]

Hi MacRencephal 

Thank you for your post and welcome to our community.

I have taken a look at things from our side today and everything looks good and within the correct levels/speeds. 

How have things been since posting?

Please pop back to us when you can. 

[MacRencephal]

The same as it was. I was getting 1100Mbps consistently for the first three weeks, every time I tested it. It has dramatically dropped off to around 800Mpbs ever since. Nothing has changed in terms of location of the test, devices connected, etc. so I am comparing as like for like as I can. I just don't understand what has happened to cause such a dramatic drop off given how consistent it was initially.

Thanks

Mac

[Akua_A]

We can understand the inconvenience caused. Just to confirm, are you running these tests on wired or wireless devices? Also are you able to reboot your device as it has been running for a considerable amount of time?

Thanks,

[MacRencephal]

Morning. Haven't been on the forums for a while so not ignoring your message - honestly!

Have just tested my speed again and still "only" getting just over 800 download speed. Seems the 1,100+ I was consistently getting in the first three weeks was an aberration. I just don't understand what has caused this as - as far as I'm aware - literally nothing has changed other than the possibility that VM have made some changes behind the scenes. However, I'll just have to come to terms with the facts that a) I will just never find out an answer to that conundrum and b) I'll never get the actual 1,100+ speeds again.

To answer your questions I have only ever run the tests using the same wireless device in the exact same physical position relative to the router. I've rebooted the router a couple of times and the wireless device many times but never ever get any more than just over 800 these days. The line has proven it's very capable of a stable 1,100+ as that's what I had throughout the first three weeks.

I'll just have to crawl back into my hole and still take with me my theory that the automatic line optimisation stuff I suspect is being run in the background has seen fit to reduce the speed for some reason. Oh well. #FirstWorldProblems

[carl_pearce]

If the HUB is getting full speed there is nothing wrong with the connection.