understanding adsl2 modem data and connection speed

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mcb

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#113878 30-Jan-2013 19:03

Hello
can you help me understand how the data from my ADSL2 modem (telecom thomson 585v7 - on xtra) makes sense alongside the speedtest results i get. Basically the way i read it, the dsl connection rate is too slow for the speedtest results i'm getting to be possible:

DSL Connection

Uptime: 0 days, 0:38:11
DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 945 / 12.283
Data Transferred (Sent/Received) [kB/kB]: 0,00 / 0,00
Output Power (Up/Down) [dBm]: 12,0 / 19,5
Line Attenuation (Up/Down) [dB]: 13,0 / 24,0
SN Margin (Up/Down) [dB]: 15,0 / 12,5
Vendor ID (Local/Remote): TMMB / BDCM
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): 0 / 0
FEC Errors (Up/Down): 0 / 2
CRC Errors (Up/Down): 0 / 0
HEC Errors (Up/Down): 699 / 0

I assume that means its connected at 945 kbps upstream and 12.28 kbps downstream - but I must be wrong as my speedtest today is:

Ping: 44ms
Download speed: 10.59Mbps
Upload speed: 0.77Mbps.

so:
1. can you help me understand the modem's up/down bandwidth figures.
2. I assume the HEC and FEC errors may reflect a sometimes scratchy line... correct? should i be worried?

The context here is we're getting slow-downs and I want to make sure its not our wiring. I'm about to put CAT5e cable in from the master filter to the modem, as currently its old phone cable with a join in it. I want to measure any differences before and after the work. We're in mt eden (Auckland), the attenuation rate suggests 1.7km from the exchange whereas google says its 1.2km to walk, and i'd say less to fly. we're in a hole between cabinets on chorus's SAT map.

Thanks for any help you can offer

Mike

plambrechtsen

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#753443 30-Jan-2013 19:22

If you email Mr your home phone number to pl at telecom dot co dot nz I can post your line test results or just email them back to you if you prefer. If you've got a properly installed master filter you should be gettiing around 16-18 with your attenuation rate. But the graphs out of the network analyzer tell a far better story.

RunningMan

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#753446 30-Jan-2013 19:29

The 12.28 kbps downstream will actually be 12.28 Mb/s, which would be consistent with your speedtest. Probably just a typo in the modem's interface.

Will be interesting to see what the line analyzer comes back with to see if that sync rate could be improved.

alexx

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#753448 30-Jan-2013 19:34

> * Bandwidth (Up/Down) [kbps/kbps]: 945 / 12.283

Thomson are a French company aren't they?

So they use a decimal comma instead of a decimal point... and what looks like a decimal point is used as the thousands separator.
http://en.wikipedia.org/wiki/Decimal_mark

In which case, in most English speaking countries the above would be:

* Bandwidth (Up/Down): 945 kbps / 12,283 kbps

#include <standard.disclaimer>

mcb

18 posts

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#753456 30-Jan-2013 19:52

Runningman and Alexx - between the 2 of you, you must be right. that's lateral thinking alexx!

plambrechtsen - thanks I'll email you my info now.

johnr

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#753463 30-Jan-2013 20:19

I swapped out one of these thomson 585v7 modems for a better quality and the speed doubled at my sisters place and WIFI was better

chevrolux

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#753467 30-Jan-2013 20:35

I get your speed with 30dB attenuation.

Check line cords. Try different modem. Install splitter (Coffeebaron will do this in Auckland/Waikato) or disconnect all other jacks - and before you say it, it doesn't matter if there is nothing plugged in to the other ones. The wire is still their and causes issues. If things don't improve THEN call your ISP and get them to get Chorus out.

HP

Shop now for HP laptops and other devices (affiliate link).

plambrechtsen

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#753490 30-Jan-2013 21:18

So here are some of your stats. And first read some good info about ADSL here: http://www.internode.on.net/residential/adsl_broadband/easy_broadband/performance/

DELT estimated distance 1.44 km

To me what's particularly telling is the upper ranges from 300-500 that's where your drop off in speed is coming from.

Then the other view of your bitloading as a graph.

It shouldn't be dropping to zero bits at 500, it should still be well above 6.

Lastly the SNR graph.

This is the last indicator, the big dip after 360 or so. then it tapers off to nothing...

If I was to guess (and again it's my guess so don't hold me to it :) what you "could" get.. I would say ~18mb range would sound about right to me.

In short... Either contact the Broadband Helpdesk on 0800 225598 and ask for a Master Filter to be installed, or you could contact CoffeeBaron aka Fraser here on Geekzone.

mcb

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#753494 30-Jan-2013 21:32

plambrechtsen - thanks for your tests and analysis. unfortunately i can't load the graphs... not sure why??? any chance you could load them again?

i'm guessing from your comments you are summing its my house wiring...

i have a master filter installed, tho i've found one old 3-wire socket in the house and i'll check if the alarm is wired after the filter. I've also half a roll of cat5e so i'll renew the setup over the weekend. after that, i'm guessing if my modem attenuation and bandwidth speeds improve i'll have found a cause. if not i'll call in the experts.

cheers

Mike