50 MB install done properly?

oldhuman · 28-10-2009, 00:15

Hi, I've recently had 50 MB installed and am currently getting pretty poor speedtest results, here are the details: http://www.speedtest.net/result/604685624.png

Could this be due to these readings below?

http://img509.imageshack.us/img509/5184/vm1k.jpg
You'll notice that the 4th column ("DS4") is blank unlike this example below posted by a member on thinkbroadband: http://img15.imageshack.us/img15/7016/50mb.jpg
I'm just wondering if that's a mistake made by the installer. Also I've just read in the sticky on this forum that an ideal downstream power level is +/- 3. my readings are: 6.86 6.55 6.19. Is that a cause for concern?

Cable Modem Downstream:
Frequency 299000000 307000000 315000000 N/A
Lock Status
(QAM Lock/FEC Sync/MPEG Lock) Y/Y/Y Y/Y/Y Y/Y/Y N/N/N
Channel Id 30 31 32 N/A
Modulation 256QAM 256QAM 256QAM N/A
Symbol Rate
(Msym/sec) 6.952 6.952 6.952 N/A
Interleave Depth I=12
J=17 I=12
J=17 I=12
J=17 N/A
Power Level
(dBmV) 6.86 6.55 6.19 N/A
RxMER
(dB) 37.94 37.94 37.94 N/A
Correctable
Codewords 23 19 16 N/A
Uncorrectable
Codewords 277 281 278 N/A

Cable Modem Upstream:

US-1 US-2 US-3 US-4
Channel Type 1.0 N/A N/A N/A
Channel ID 3 N/A N/A N/A
Frequency
(Hz) 25808000 N/A N/A N/A
Ranging Status Success N/A N/A N/A
Modulation 16QAM N/A N/A N/A
Symbol Rate
(KSym/sec) 2560 N/A N/A N/A
Mini-Slot Size 2 N/A N/A N/A
Power Level
(dBmV) 49.75 N/A N/A N/A
T1 Timeouts 0
T2 Timeouts 0 0 0 0
T3 Timeouts 1 0 0 0
T4 Timeouts 0 0 0 0

Thanks to anyone who can help!

Ignitionnet · 28-10-2009, 00:17

Those are all fine sir.

I did notice a very low upload on your test so I suspect there is an SNR problem which you'll need to contact Virgin to report if they aren't already aware but your numbers above are ok. Some areas only have 3 downstreams 'lit' so don't worry about that.

oldhuman · 28-10-2009, 00:52

Thanks for the reply Broadbandings. In that case then, given that there doesn't seem to be anything technically wrong with the cable modem what could be the cause for the abysmal speed readings? Also, is there anything I can possibly do at my end to get a lower downstream power reading to get it near to zero?

Update: just done 2 speedtests at thinkbroad with completely different results from the ones above:
http://www.thinkbroadband.com/speedt...402027956.html
http://www.thinkbroadband.com/speedt...222427983.html

and another one at speedtest: http://www.speedtest.net/result/604720230.png

Obviously not perfect but nearer to what one would expect. All very weird, especially as the London server I used for speedtest was giving speeds in the single figures about an hour ago. I knew cable suffers from congestion, but surely not this badly?

Peter_ · 28-10-2009, 06:20

Try this speedtest

Here is how the speedtest works below.

If you are a Virgin Media customer then the best speedtest is from the links below.

click on these 2 gamefiles battlefield_2142_demo.exe and bfme2demo_english_final.exe and save them to your desktop, and then wait a couple of minutes then write down the transfer rates on the files that are running add them together then multiply them by 8 and you will get a truer download speed.

Remember to stop and delete the files.

i.e : 250Kbps X 8 = 2Mbps, 500Kbps X 8 = 4Mbps, 1250Kbps X 8 = 10Mbps, 2500Kbps X 8 = 20Mbps

Then add 10% to the final figure to account for any processes running on your computer.

http://www.virginmedia.com/testmyspeed/manual.php

If you are still not happy then call the 50Mb support line number.

0800 052 0431

ajeffo · 28-10-2009, 22:37

I agree the above method works really well, i also find the speedtest from www.speedtest.bbmax.co.uk to be more consistant as i cannot get more that 20Mbps from speedtest.net

AbyssUnderground · 28-10-2009, 22:44

Correct me if I'm wrong but doesn't 50Mbps have to be between -6dBmV and +3dBmV on the downstream? Pretty sure that's what I read a few days ago. 6.5dBmV is a bit high if that's so... I generally go by the rule of thumb of -5 to +5 dBmV...

Peter_ · 29-10-2009, 08:02

Quote:

Originally Posted by AbyssUnderground

Correct me if I'm wrong but doesn't 50Mbps have to be between -6dBmV and +3dBmV on the downstream? Pretty sure that's what I read a few days ago. 6.5dBmV is a bit high if that's so... I generally go by the rule of thumb of -5 to +5 dBmV...

If on the Knowsley platform then they are within spec for QAM256 as per the sticky.