Slow Broadband Connection


  I have installed a new Dlink DSL-300T ADSL modem, it all connects fine to the internet. But when I browse any site on the internet its slow, slower than dial-up. I have checked all the settings all seem fine, changed the MTU size to varying sizes, changed microfilters and cables.

All to no avail.

I have made windows XP use the DNS servers of the ISP and thats makes no difference.

I have installed the latest firmware from dlink makes no difference. I have attached a laptop to the modem and thats the same. I have tested the modem on another line and its fine. BT say there is no problems with the line. there any option that I may be missing...

Cheers in advance
Who is Participating?
Find the modem's line status page, and post the bit rates and line parameters here.

Hello dwelldon, If I understand your statement, The modem in question works just fine on another line.True? If so then it has to be your incoming line that is the problem. Call BT 2x a day for 3 days in a row and complain, tell them you will discontinue service if it isn't fixed. That will escalate you from the call center tech support agent to the BT tier1 support team. They will try to scare you off by saying they'll charge you for the housecall if the problem is on your end. Make sure you are using the proper cables, turn off 900 mhz phones,fax machine, house arrest ankle bracelet.(if applicable). and see if it helps. Check for bridge taps or load coils on the area phone lines. This almost certainly assures you that the problem is theirs, and they won't charge you anything, unless they have to physically work on something on your side of the SNI.  Hope this helps...Booda2us
>The modem in question works just fine on another line.True? If so then it has to be your incoming line that is the problem.

That is why you need to post the current line status page from the modem.
First up the Dlink routers are a fairly good brand, so that is not an immediate factor

First up we need to isolate the line or a bandwidth issue from your ISP
if you can log into your router (typically on usename admin  and then password admin)

Depending on which DSL router firmware you are using you then scroll to the bottom under summary and select *Line condition*. If you can copy this down and post it to the forum this will help.

If it has a low attainable line speed (*Downstream speed*) this will show you that the quality of the line is the issue as apposed to a bandwidth from the ISP issue.

Also if you check what your distance is from the exchange (or also called CO overseas) This is listed as *Loop Distance* this will be a major factor for speed is the possibly reach of ADSL (18,000 or 5.5 km from exchange is the maximum distance that ADSL is really going to be working fast and well within)

So if you have Low Attainable and High Loop distance this means you are far away from the exchange, and the DSL signal becomes weaker, - then distance is your issue. Possibly try using someone elses modem that handles distance better (In New Zealand Nokia M1122, or some of the Alcatel ones work well at distance, but I am not sure what brands are like in your part of the world).

OK, so if you got High Attainable line speed, and Low Loop distance, then you clearly have everything working fine - no need to do any isolation tests, and there is nothing wrong with your line. The fault would lie clearly in data bandwidth allocation from your ISP, this could be out at the DSLAM or into your ISP. In which case, do several speed tests during offpeak times to check this out using the following link. If it is fast during off peak (normally early morning) this would indicate bandwidth as the issue.

If you have Low attainable and Low Loop distance this would mean that you are close to the exchange but there is noise on the line. Simply do an isolation test (fancy name for unplugging every phone from every jackpoint except the DSL router), and this will show you if it is anything inside your house. If the Isolation test meant that suddenly your attainable line speed as well as your speed test results went up then I would check the following:

Key CPE (Customer Premise Equipment) to keep in mind:
- Remembering to filter all phones whether you are using them or not
- Alarms, even though not monitored, (also Sky Digital TV) this will still slow things down and cause disconnections
- Some of the installs may not be to a perfect standard (I am not just talking Telecom techs, I have heard of some pretty average installs from both Sky as well as some done by the Alarm electricians)
- Faulty filters (to isolate, plug each filter
in using one phone one by one, and testing after each filter)
 if they are all fine, then it is more likely to be the phones
- Faulty phones (to isolate, plug each phone in in sequence and see if this causes issues)
- Too many phones (often if you have more than 5 phones or other devices plugged in this can cause a drop in voltage on the line, that would reduce the gain on the line, and in turn the speed could also be affected.

So if you have Low attainable and Low Loop distance, and the Isolation test didn't do anything, then the fault is more likely to lie in your line, though often line faults don't impact that greatly on DSL.
In NZ I have found if you call Telecom Faults and ask for a line test (not calling the ISP side) then you get a much more helpful tests and fixing for complaints about voice issues than if you mention DSL speeds. If you call them and no joy, then your only option is to call your ISP back and get someone to do some tests or possibly a port reset. (though I am not thinking a port reset would do that much)

Hope this is of assistance,
Jay Best
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.