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Speed Thread (Before and after transfer speed comparisons)

Word_Warrior
Grafter
Posts: 503
Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

While the upload speeds have improved but by no means to a level that would be considered earth shattering, the download speeds are a huge disappointment at the moment. (see graph attached).
It would be too simplistic to say that as I was getting around 50% ± of the "up to 8M" connection that I could expect around 50%± of 24M but to actually get around the same after several reboots of the modem indicates that there is a long way to go yet. No doubt someone at PN is beavering away at these results (and others) to see what is going on. If PN would like me to do any specific tests within my technical limits I am more than willing to help. After all this is a trial and is reliant on feedback.
Word_Warrior
Grafter
Posts: 503
Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

By way of a real world speed test I tried this link:-
http://www.apple.com/trailers/universal/duplicity/hd/
On this page there are three HD trailers for the same film in three different resolutions 480p 720p 1080p The latter two can't keep up with playback for me but  the less than perfect 480p keeps up but hardly full HD
This was viewed in full screen mode too with the same result on an Apple iMac Intel Core2duo 20" Incidentally, the film looks good too. Before the 21CN switch on I always had to wait for even lower quality video to download beforew starting to play.
Conclusion:
Some improvement but not great yet.
greyposter
Grafter
Posts: 235
Registered: ‎27-06-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Today 10:17 4975 kbps (622kB/s) 886 kbps (111kB/s)  Not what I had hoped for.
Update-
Your DSL connection rate: 8064 kbps(DOWN-STREAM),  1056 kbps(UP-STREAM)
    IP profile for your line is - 6500 kbps
    Actual IP throughput achieved during the test was - 5145 kbps
gm4jjj
Rising Star
Posts: 697
Thanks: 7
Fixes: 3
Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Everything was great on ADSL1 since the 21CN update yesterday, was getting a (forced) 4096 sync at 56dB att and 10dB S/N, then suddenly at 12:39 I lose connection and now can only sync at 3072 with same Att BUT 15dB S/N even when forced with DMT tool - what is going on?  Angry
James
Grafter
Posts: 21,036
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Registered: ‎04-04-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Have you tried rebooting your router since the drop and increase in SNR?
gm4jjj
Rising Star
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Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Yes James I just did that and this time I have not forced anything with DMT tool, just left it to sync up at whatever it likes and it has chosen ADSL2+ Sync 3023 59.5dB att  9.6dB S/n.
From what I could see ADSL1 no longer would let me force a lower S/N (It chose 15dB as the target whatever I did) this started today.
My line has absolutely no data above about 795KHz as it is so long, so ADSL2+ is of no benefit to me I am afraid.
James
Grafter
Posts: 21,036
Thanks: 5
Registered: ‎04-04-2007

Re: Speed Thread (Before and after transfer speed comparisons)

I'm afraid that there will be some people like you in the same boat.
However, it's certainly worthwhile seeing if there are any improvements over the initial training period.
gm4jjj
Rising Star
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Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Yes James, I am happy to continue testing as it does give us some idea of how this all works in real world difficult line conditions.
I am wondering if I mucked things up by forcing a lower S/N figure here? - It now appears that the exchange have somehow limited sync to just over 3000 and I cannot get above that figure whatever I do with DMT tool. Pre 21CN I always ran the router forced as far as it would go and got a reliable 10dB S/N at 59dB Att and over 3000 sync,  then post 21CN yesterday the Att for ADSL1 dropped to 56dB and I got 4000 sync at 10dB. Now today the Att is still 56dB but the S/N is up to 15dB and 3000 sync, so it looks as is some logic at BT has decided 3000 is the max it is going to try, despite the great results I was getting at 4000 yesterday and earlier this morning.
Edit: I note that Interleaving is on and on the downstream it is at depth: 8 (ADSL1)
The other figure noted is RCO which is at 64%(4832kbps) - I am sure this % figure was much higher earlier today.
James
Grafter
Posts: 21,036
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Registered: ‎04-04-2007

Re: Speed Thread (Before and after transfer speed comparisons)

I think that over the first week, it's best to leave it find it's naturally best position rather than trying to force it to do something else.
We'll see how it goes over the weekend Smiley
VileReynard
Hero
Posts: 12,616
Thanks: 582
Fixes: 20
Registered: ‎01-09-2007

Re: Speed Thread (Before and after transfer speed comparisons)

How would wireless be expected to affect ADSL2+ performance?
Is there any way to remove the overhead of wireless to give an equivalent wired speed figure?

"In The Beginning Was The Word, And The Word Was Aardvark."

gm4jjj
Rising Star
Posts: 697
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Registered: ‎30-07-2007

Re: Speed Thread (Before and after transfer speed comparisons)

OK James, I will reboot the router and just leave it alone, even though performance on up and down will be lower and see how it goes. (I am on MAX DSL and normally get 768 UP here on ADSL1, but it is lower on ADSL2+ unfortunately, presumably because of the poor performance of my line at high frequencies means that the downstream has to use more of the lower frequencies, leaving less for upstream use.
pnf
Grafter
Posts: 269
Registered: ‎07-11-2007

Re: Speed Thread (Before and after transfer speed comparisons)

More stats taken today - 05/12/2008:
Router Information - 09:20 router rebooted:
Uptime: 0 days, 0:05:34
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 976 / 11,705
Data Transferred (Sent/Received) [KB/KB]: 46.00 / 105.00
Output Power (Up/Down) [dBm]: 12.0 / 22.5
Line Attenuation (Up/Down) [dB]: 17.0 / 33.5
SN Margin (Up/Down) [dB]: 8.5 / 6.5
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 10 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 3,551 / 72
HEC Errors (Up/Down): 5,146 / 41
Router Information - 12:10 router lost connection (SN Margin down was 5.0 dB):
Uptime: 0 days, 0:51:54
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 952 / 11,814
Data Transferred (Sent/Received) [MB/MB]: 7.70 / 88.59
Output Power (Up/Down) [dBm]: 12.5 / 22.5
Line Attenuation (Up/Down) [dB]: 17.0 / 33.0
SN Margin (Up/Down) [dB]: 5.0 / 6.5
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 1 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 30 / 0
FEC Errors (Up/Down): 0 / 3,013,351
CRC Errors (Up/Down): 5,333 / 0
HEC Errors (Up/Down): 6,475 / 0
The information above indicates that the connection is still adjusting.  After rebooting the router this morning, the downstream SN Margin was at 6.5 dB but this dropped to 5.0 dB at about 12:10 at which point the DSL connection dropped and the router resynced (see errors and loss of signal information).  I imagine that this will happen a few more times later today as the SN Margin drops.
I notice that the downstream line attenuation was 30.0 dB on ADSL1, but on ADSL2+ this rose to 33.0 dB and then 33.5 dB and is now back at 33.0 dB.  Is there a reason why this should be higher on ADSL2+ than it was on ADSL1?
Speedtests today using www.mybroadbandspeed.co.uk are below:
Fri 05/12/2008 09:30 - IP Profile 9000 kbps  Actual Throughput Up/Down: 816/5973 kbps
Fri 05/12/2008 09:35 - IP Profile 9000 kbps  Actual Throughput Up/Down: 815/8706 kbps
Fri 05/12/2008 09:40 - IP Profile 9000 kbps  Actual Throughput Up/Down: 816/8699 kbps
Fri 05/12/2008 11:10 - IP Profile 9000 kbps  Actual Throughput Up/Down: 813/8706 kbps
Fri 05/12/2008 12:40 - IP Profile 9000 kbps  Actual Throughput Up/Down: 776/8438 kbps
Fri 05/12/2008 13:40 - IP Profile 9000 kbps  Actual Throughput Up/Down: 795/8327 kbps
So far I have generally seen a 30% increase in download speeds and a 110% increase in upload speeds based on the figures from the speed tests.  Using the graph that was posted in this forum, which can be seen here http://www.internode.on.net/residential/internet/home_adsl/extreme/, I had initially anticipated getting a downstream sync speed of about 16000 kbps based on the 30.0 dB attentuation on my line.  As the attenuation has increased on ADSL2+ this original expectation was obviously too high.  Based on my current attenuation figure of 33.0 dB the graph indicates an expected downstream sync speed of about 13000 kbps which is a bit closer to what I am seeing - 11814 kbps.
*** Edited 06/12/2008 - changed Thu to Fri ***
zubel
Community Veteran
Posts: 3,793
Thanks: 4
Registered: ‎08-06-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Regarding attenuation:
ADSL2+ uses the frequency range from ~26kHz to 2.2MHz.  Vanilla ADSL uses ~26kHz to 1.1MHz.
Each "bucket" is 4.3125 kHz wide, and will have it's own attenuation figure.  The line attenuation reported by your router is a weighted average of all the "buckets" that are deemed usable during the initial training period.
So, the net effect is that now, on ADSL2, you are likely using more buckets at the high end of the frequency range, which will have higher attenuation, which is why your overall attenuation is now reported as higher.
For people on better quality (read: shorter) lines, the attenuation figures at the higher end of the scale are likely more similar to the existing attenuation and as such will not show much of a difference in the attenuation figure reported by the router.
HTH
B.
pnf
Grafter
Posts: 269
Registered: ‎07-11-2007

Re: Speed Thread (Before and after transfer speed comparisons)

Re: Attenuation.
Thanks for the information Barry, that's very helpful.  Obviously this sort of thing will need to be taken into account when trying to give people a real feel for what they are likely to expect from ADSL2+.  Easier said than done!
As part of the current sign-up process for the 'Up to 8Mb' service there is a tool that gives people an estimate of the speed that their line is likely to provide.  I wonder if there are plans for the line speed checker to be tested as part of this trial?

VileReynard
Hero
Posts: 12,616
Thanks: 582
Fixes: 20
Registered: ‎01-09-2007

Re: Speed Thread (Before and after transfer speed comparisons)

My Netgear DG834GT doesn't appear to be coping very well with ADSL2+ - regardless of firmware updates.
I'm on PAYG Option 3 - is it possible to get a decent free/cheap wireless router from Plusnet?
What are the penalties?

"In The Beginning Was The Word, And The Word Was Aardvark."