on 09-04-2023 10:54
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
on 13-04-2023 18:40
Trying again in case it's helpful
Downstream bonded channels
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
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
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
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
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; |
on 16-04-2023 10:30
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.
Vikki - Forum Team
New around here? To find out more about the Community check out our Getting Started guide
on 21-04-2023 19:52
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
on 24-04-2023 12:08
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,
on 27-05-2023 12:14
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
on 27-05-2023 12:16
If the HUB is getting full speed there is nothing wrong with the connection.