Virgin Media Community

[TheChairman]

See my original thread https://community.virginmedia.com/t5/Forum-Archive/As-requested-by-Jen-A-very-poor-http-download/td-...

and when this was first spotted

https://community.virginmedia.com/t5/Speed/Very-poor-HTTP-download-speed/td-p/3026879/page/13

The issue was never resolved and came and went but spent more time away that being present.

Anyway the Virgin throttling of single http thread is back. I upgraded to 350 service last Friday and the single thread performance has been limited since then.

The following points.

1) The shrub 3 is in modem mode

2) The tests are cabled

3) The tests have been done on multiple devices.

4) The time of day doesn't matter the throttling is present at all times.

5) The connection to the hub are tight.

I've included two different test results to show that it's not the test that's the issue.

Speedtest,net won't show the issue as it's multi threaded

It would be nice to have the issue finally fixed as been around two years on and off

Modem stats

Channel Frequency (Hz) Power (dBmV) SNR (dB) Modulation Channel ID
1 211000000 -5.5 38 256 qam 10
2 187000000 -5 38 256 qam 7
3 195000000 -5.4 38 256 qam 8
4 203000000 -5.5 38 256 qam 9
5 219000000 -5.5 38 256 qam 11
6 227000000 -5.7 38 256 qam 12
7 235000000 -5.7 38 256 qam 13
8 243000000 -5.7 38 256 qam 14
9 251000000 -5.9 38 256 qam 15
10 259000000 -6 38 256 qam 16
11 267000000 -6.4 38 256 qam 17
12 275000000 -6.5 38 256 qam 18
13 283000000 -6.5 38 256 qam 19
14 291000000 -6.5 38 256 qam 20
15 299000000 -5.7 38 256 qam 21
16 307000000 -5.5 38 256 qam 22
17 315000000 -5.5 38 256 qam 23
18 323000000 -5.5 38 256 qam 24
19 379000000 -5.5 38 256 qam 25
20 387000000 -5.7 38 256 qam 26
21 395000000 -5.5 38 256 qam 27
22 403000000 -5.5 38 256 qam 28
23 411000000 -5.7 38 256 qam 29
24 419000000 -6 38 256 qam 30

Downstream bonded channels
Channel Locked Status RxMER (dB) Pre RS Errors Post RS Errors
1 Locked 38.6 33 0
2 Locked 38.6 68 0
3 Locked 38.6 50 0
4 Locked 38.9 38 1
5 Locked 38.9 40 0
6 Locked 38.6 40 0
7 Locked 38.9 46 0
8 Locked 38.9 36 0
9 Locked 38.6 50 0
10 Locked 38.6 44 0
11 Locked 38.6 48 0
12 Locked 38.9 46 0
13 Locked 38.6 54 0
14 Locked 38.9 56 2
15 Locked 38.6 52 0
16 Locked 38.9 48 0
17 Locked 38.9 57 5
18 Locked 38.9 55 0
19 Locked 38.9 105 0
20 Locked 38.6 123 0
21 Locked 38.9 113 15
22 Locked 38.9 161 0
23 Locked 38.6 190 0
24 Locked 38.6 233 0

Upstream bonded channels
Channel Frequency (Hz) Power (dBmV) Symbol Rate (ksps) Modulation Channel ID
1 25800000 3.875 5120 16 qam 4
2 32600000 3.8 5120 16 qam 3
3 39400000 3.75 5120 16 qam 2
4 46200000 3.725 5120 16 qam 1

Upstream bonded channels
Channel Channel Type T1 Timeouts T2 Timeouts T3 Timeouts T4 Timeouts
1 ATDMA 0 0 0 0
2 ATDMA 0 0 0 0
3 ATDMA 0 0 0 0
4 ATDMA 0 0 0 0

[jbrennand]

I'd say your downstream power levels need attention.
Downstream: no lower than -6dBmV and no higher than 10dBmV - Close to 0 is optimal.
Several of your channels are out of the recommended range and the rest are close to the limit.
Dunno whether that would contribute to your issue though, a Superuser should comment.

[legacy1]

Likely nothing you can do again could be a low speed multi-core processor with QoS per single thread connection to a core router.

But again how fast do you need to go on a single thread connection? I guess if its a VPN tunnel then it becomes important.

[legacy1]

---

@TheChairman wrote:

Speedtest,net won't show the issue as it's multi threaded

---

www.speedtest.net now let you test for single connection mode take a look.

[TheChairman]

Guess it's a case of waiting for Virgin to respond in regards to the power levels. Well actually to both issues.

[TheChairman]

Well you're paying for 350 so you should get 350. Not a crafty way of throttling connections which this is.
If you remember the original thread on this the initial response was "this was by design" Then after more protests it was an issue "with certain kit". However I pointed out numerous times that I was on Cisco UBR which didn't have this issue yet I had the same issue.
However I suspect till this day many people have this issue but don't notice it and since nobodies reporting it nothing needs to be done.

[TheChairman]

Well today I'm back to full speed on single thread download. I suspected as much as web pages are loading a lot quicker and a download fizzed down very rapidly. I was going to reboot the hub as the web page won't load anymore. However I'll leave it for now as everything else is working as it should.

However I guess the power levels need checking still so I'll wait for the Virgin staff to get around to answering. So I won't post for the next week.

[Alex_RM]

Morning TheChairman,

Thanks for your post,

I've popped you over a private message so I can take a closer look at things for you.

Get back to me when you can,

Alex_Rm

[TheChairman]

I've replied to your PM

[TheChairman]

Ahh an area fault in play as well. Thanks for the info Alex