ADSL Speed issue

Connection issues, drop outs or speed related faults for ADSL and ADSL2+ services
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Lawrie
Posts: 313
Joined: Mon Jun 09, 2008 10:45 pm
Location: Unanderra

ADSL Speed issue

Post by Lawrie » Wed Feb 26, 2014 4:57 pm

This afternoon I received a Facebook message from Exetel suggesting that I should look at https://www.mybroadband.communications.gov.au/ so I did.

This web site says that based on my distance from the local exchange and all things being equal, houses in my area should have:
1. Asymmetric Digital Subscriber Line (ADSL) quality > A
2. The estimated median ADSL speed for your area is (Mbps): > 21.56

However when I run a speed test from the Exetel Member's Facility page I get a MUCH DIFFERENT result:
1. Your current bandwidth reading is 3.34 Mbps

I am not really expecting to ever get anything close to 21.5 Mbps, but how can I improve my ADSL speed to my house?

Lawrie

James
Exetel Staff
Posts: 2028
Joined: Mon May 09, 2005 10:27 pm

Re: ADSL Speed issue

Post by James » Wed Feb 26, 2014 4:59 pm

Lawrie wrote:This afternoon I received a Facebook message from Exetel suggesting that I should look at https://www.mybroadband.communications.gov.au/ so I did.

This web site says that based on my distance from the local exchange and all things being equal, houses in my area should have:
1. Asymmetric Digital Subscriber Line (ADSL) quality > A
2. The estimated median ADSL speed for your area is (Mbps): > 21.56

However when I run a speed test from the Exetel Member's Facility page I get a MUCH DIFFERENT result:
1. Your current bandwidth reading is 3.34 Mbps

I am not really expecting to ever get anything close to 21.5 Mbps, but how can I improve my ADSL speed to my house?

Lawrie
It's wrong, i get the same thing;
symmetric Digital Subscriber Line (ADSL) quality >
A

This is the highest ADSL quality rating as the average speed of ADSL services delivered over the copper network in your area are high when compared to ADSL services available in other areas.
The estimated median ADSL speed for your area is (Mbps): > 21.56

What does this site give you?
http://adsl2exchanges.com.au/

Lawrie
Posts: 313
Joined: Mon Jun 09, 2008 10:45 pm
Location: Unanderra

Re: ADSL Speed issue

Post by Lawrie » Wed Feb 26, 2014 5:13 pm

I am assuming that you meant for me to run their Speed test?

Broadband Speed Test Results

Test run on 26/02/2014 @ 05:12 PM

Mirror: Exetel
Data: 11 MB
Test Time: 10 secs

Your line speed is 9.35 Mbps (9354 kbps).
Your download speed is 1.14 MB/s (1169 KB/s).

James
Exetel Staff
Posts: 2028
Joined: Mon May 09, 2005 10:27 pm

Re: ADSL Speed issue

Post by James » Wed Feb 26, 2014 5:24 pm

Lawrie wrote:I am assuming that you meant for me to run their Speed test?

Broadband Speed Test Results

Test run on 26/02/2014 @ 05:12 PM

Mirror: Exetel
Data: 11 MB
Test Time: 10 secs

Your line speed is 9.35 Mbps (9354 kbps).
Your download speed is 1.14 MB/s (1169 KB/s).
No, i meant put your address in, so see what the average speed should be.

Dazzled
Volunteer Site Admin
Posts: 6021
Joined: Mon Nov 13, 2006 1:16 pm
Location: Sydney

Re: ADSL Speed issue

Post by Dazzled » Wed Feb 26, 2014 5:57 pm

The only way to know what speed you can get is to know the condition of your phone line, both the big part in the street, and the little bit at home. Fortunately every modem tests this, and all will give a quick summary. Most can be persuaded to divulge all the details to someone with some technical skills.

For the overview, read the modem status page, and look for downstream attenuation. The common suburban PIUT phone cable, with no faults, attenuates 13.81 dB/km at 300 kHz. Knowing this we can graph line speed as a function of cable length, as at http://www.exetel.com.au/pdf/downstream.pdf. The cable is run along footpaths, so you can usually estimate the distance along the roads to your local telephone exchange. If the modem download rate approximates the speed chart all is well. Only a site with a very short cable run gets the sorts of speeds some websites promise.

Speed tests are nothing more than timed downloads, and are unlikely to be more than indicative, as there are several variables to account for. Some, particularly browser based ones, are way short of the mark. Doing several simultaneously gives a closer estimate.

The detailed modem analysis can be read by someone with modest computer skills on many models as I described in a previous thread. A technically minded person would normally only do this to establish interference or sometimes spot a particular type of fault for a line that already had failed the overview above.

Dazzled
Volunteer Site Admin
Posts: 6021
Joined: Mon Nov 13, 2006 1:16 pm
Location: Sydney

Re: ADSL Speed issue

Post by Dazzled » Wed Feb 26, 2014 6:10 pm

BTW, for my own address the mybroadband site got little right except the exchange area. Speeds were wrong as was HFC and mobile broadband. Far from getting 4G, we cannot even get GSM. I looked up a family member who can't use a mobile phone either, and found a similar glowing report.

Broadbrush sites like this exist mainly to mislead.

James
Exetel Staff
Posts: 2028
Joined: Mon May 09, 2005 10:27 pm

Re: ADSL Speed issue

Post by James » Wed Feb 26, 2014 8:38 pm


Lawrie
Posts: 313
Joined: Mon Jun 09, 2008 10:45 pm
Location: Unanderra

Re: ADSL Speed issue

Post by Lawrie » Thu Feb 27, 2014 8:10 am

why did Exetel send a link to the site via its Facebook account?

Lawrie
Posts: 313
Joined: Mon Jun 09, 2008 10:45 pm
Location: Unanderra

Re: ADSL Speed issue

Post by Lawrie » Thu Feb 27, 2014 8:07 pm

What does this site give you?
http://adsl2exchanges.com.au/
Your Results
Line of Sight: 534 m
Estimated Cable: 854 m
Estimated Attenuation: 12
Estimated Maximum Speed: 22000

Dazzled
Volunteer Site Admin
Posts: 6021
Joined: Mon Nov 13, 2006 1:16 pm
Location: Sydney

Re: ADSL Speed issue

Post by Dazzled » Thu Feb 27, 2014 11:08 pm

That site for some unknown reason always makes a reasonable stab at attenuation in perfect circumstances, and then comes to a hopelessly optimistic downstream rate.

The modem and the exchange between them measure the line over a large range of frequencies, low and high, and then allowing a noise margin, compute and agree on a maximum line speed. Depending on your modem you may be able to change the noise margin and see the extra speed to be gained at the risk of noise drop outs. The resulting rate is recorded under line status.

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