# attenuation and SNR



## jdtek (Jan 25, 2005)

hi! i need an help :sad: these are my ethernet modem values about my adsl line: are they good for you to support a broadband speed of 4 megabps? is it possible to calculate my maximum teoric speed? 

Upstream Bitrate (TX) 352000 Bits/Second
Downstream Bitrate (RX) 5056000 Bits/Second
Current ADSL mode G.Dmt
SNR margin (x10) 215 dB
Attenuation (x10) 255 dB
Line status 1
Total LOFS count 0
Total LOSS count 13
Total Errors count 0
Current 15-min LOFS 0 Seconds
Current 15-min LOSS 0 Seconds
Current 15-min Errors 0 Seconds

thanks..


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## JamesO (Mar 30, 2005)

Looks like a good link to me. You should support 5 mbps second downloads?

Try a speed test at:

http://bandwidthplace.com/speedtest/

http://www.dslreports.com/stest

See what results you actually get and post details here.

Your modem info is as follows:

Upstream speed is 352 kbps
Downsteam speed is 5.056 Mbps
SNR margin is 21.5 dB (Signal To Noise)
Attenuation is 25.5 db
No errors, however, it shows the link has dropped 13 times under Total Loss Count. Could be due to resets or physical disconnects, keep an eye on this to make sure it does not increase much.

A few questions:

Who is your DSL provider?
Where are you located?
What is the make and model of your DSL modem?
How did you get this info, web interface or modem utility?

JamesO


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## jdtek (Jan 25, 2005)

first of all, thanks for your interest!! :smile: 
I'm from italy, my web provider is Libero Adsl 4 Mbps and my ethernet modem is an Ericsson hm220dp.
I have tried to make tests that you suggest me and the results are:

905.5 kilobits per second from bandwidthplace.com

Your download speed : 571119 bps, or 557 kbps.
A 69.7 KB/sec transfer rate.
Your upload speed : 285759 bps, or 279 kbps. from dslreports.com

i have taken those infos from my modem utility. What does Total Loss Count mean? sorry for my ignorance -razz: 
what do you think?


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## JamesO (Mar 30, 2005)

If you are in Italy, you should use a download speed test site in Europe to verify your speed. Any bit of latency can reduce the download performance. I just ran a few tests from Europe and one was 1/2 my US speed test and the other was 1/10 of my US speed test. See if your ISP can support a speed test, this is the logical place to start when you think there is a problem.

Also try these European links and see what happens:

http://www.helpadsl.it/modules.php?name=speedtest

http://testmy.net/o-VanBuren

http://mediahopper.com/portal.htm?http://mediahopper.com/speedtest/europe.htm

http://www.speedtest.nl/TestSuite/TestController.asp

You should perform a ping test to a few sites to see what your response times are as well as perform a ping test during the download test. If you saturate the link beteen yourself and the Telco/PTT, the ping times should increase from what you see on an idle link. But you need to make sure you are pinging the first hop from your location.

Also run some trace routes to see if there is high latency somewhere along the link. This will also allow you to find the first hop on the Telco/PTT side, which is important to know for troubleshooting.

Post this information here if you can.

As for the disconnects, this is a counter that shows how many times the DSL modem has lost the connection to the Telco. As long as it does not keep increasing you should be in good shape.

I have tested some local DSL (here Stateside) links that usually test very close to the download speed. 

It is interesting that your upload speed is close to your upload rate on your DSL modem, but your download speed is not. Overall the information on your modem looks like your actual link between your house and the Telco/PTT is very good.

I am wondering if your service provider has QOS enabled or is oversubscribing on their end. Keep your speed test results and run a few more tests, even on "off" hours to see if you every get any faster downloads, but also try some local European sites for more consistent results.

Hope this is helpful.

JamesO


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## jdtek (Jan 25, 2005)

i have made speedtests with those results:

www.mclink.it/azienda/meter.htm DL 3117Kbps
UL 298Kbps
http://internet.sunrise.ch/it/adsl/ads_ser_speed.asp 2818Kbps
http://www.speedtest.nl/TestSuite/TestController.asp DL 2244 Kbps
UL 274 Kbps
http://testmy.net/o-VanBuren 11067 Kbps

Then i have made some ping tests with those results

















and i have repeat those tests while i was downloading a file using all broadband (about 500 KByte/sec)


















i'm sorry for bewilderment, but i'm not so expert -razz: 
what do you suggest? i hope i've been clear (more or less :grin: )


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## jdtek (Jan 25, 2005)

..and these are some traceroute. I hope i've understood well -razz:


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## JamesO (Mar 30, 2005)

Looks like your link is pretty much working as expected from what I can tell. Not sure most speedtest sites can saturate a 5 Mbps link?? Maybe I am wrong??

Looking at the pings while downloading, the response times did not go up high enough to indicate you had saturated the link. I am also not sure you were pinging the first hop outside your home network, but in this case, it really does not matter as the ping times did not increase signifigantly. 

You might try downloading something big like Adobe Reader 7.0 and see what kind of file transfer speeds your computer shows and see if you can get your first hop ping times upwards of 300-500 ms. Then you might get an idea if you can saturate your 5 Mbps link.

JamesO


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## jdtek (Jan 25, 2005)

JamesO said:


> Looks like your link is pretty much working as expected from what I can tell. Not sure most speedtest sites can saturate a 5 Mbps link?? Maybe I am wrong??


i don't know but i have seen that some other people with those tests have as result 4 mbps..



JamesO said:


> You might try downloading something big like Adobe Reader 7.0 and see what kind of file transfer speeds your computer shows and see if you can get your first hop ping times upwards of 300-500 ms. Then you might get an idea if you can saturate your 5 Mbps link.


i have tried to download adobe reader with a download accelerator to saturate all bandwith and time ping to my first hop is about 50-60 ms..why this? :4-dontkno 
what do you think?
however thank you very much for your help :winking:


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## jdtek (Jan 25, 2005)

now i'm observing that if i saturate upload bandwith ping time to my first hop can go to 300 ms or more..


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## JamesO (Mar 30, 2005)

Correct, I find as you saturate your link you ping times will increase by 200 ms or more from where you start. Sometimes even timing out if you can really saturate the link. If you are not seeing the ping times on the download increase by more than 20-40 ms, then you are probably not getting close to saturation of the link. 

Some links may also allow for burst capacity, making it really hard to find where you can hit a wall with link performance.

JamesO


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## johnwill (Sep 26, 2002)

FWIW, being in the US, I tried several of the European sites, and I got from 1/4 to 2/3 of my speeds clocked from www.dslreports.com here.


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## jdtek (Jan 25, 2005)

Hi!i have known that other people with my same provider (libero) are having same problems..now i will try to contact provider assistance..however thanks very much for your help!! :sayyes: :smile: :smile: 
if there will be news, i will write here..


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