Firstly, it’s important to realise what a reasonable connect rate is and what affects it. It’s also important to mention we’re talking about physical connection rates here, not your throughput over the connection. Explained more simply, we’re talking about how wide a hose is, not how much water we’re trying to push through it.
The rate at which your modem connects to the exchange is determined by 3 main factors. Primarily, the length of the cable running from your house to the exchange plays a big part on this as well as attenuation, and resistance on this cable. These are things more often than not you cannot change, short of moving closer to the exchange or Telecom installing a cabinet near you.
With that in mind to find this information you’ll need to log in to your router and take a look at your ‘ADSL Status’ page and find your ‘connect rates’. The process for this differs for every modem, so if you’re unsure check your user manual.
If you believe the rates you’ve discovered you’re connecting at aren’t as good as they should be then I urge you to take note of these, before performing an isolation test.
An isolation test consists of removing each and every single device and attached cable completely from all jack points in your house, leaving only the modem plugged in. This includes the ADSL Line filter that you may have in the Internet jack point, due to the fact from time to time these are often found faulty as well.
You may need to find yourself one of these cables in order to bypass the filter to which the modem was connected. Borrow one from a cordless phone or other device, or pick up an ‘RJ11 – BT Cable’ at an electronics store.
With only the modem connected to the phone line, remove the power for 30 seconds and plug it back in if you haven’t already. Log in to the router once more and record your results.
If you notice a significant difference, this indicates your Internet connection speed was influenced by another device, or potentially degraded cable being used on the line or a filter being plugged in where it shouldn’t be.
What is a filter?
ADSL and your phone line operate over different frequencies on the same cable. Your phone uses the lower frequencies, while the Internet uses the higher ones. In order to prevent cross over of these frequencies, an ADSL filter is used. If cross over does occur, you may hear bursts of static on your phone, or experience drops in the ADSL connection.
I have noticed there is a large amount of confusing regarding ADSL filters, and how they’re used properly. Refer to the following picture
It’s important to note, you only need an ADSL filter plugged in to jack points in which you’re using a phone, fax or any telephony device other than an ADSL modem.
The picture above illustrates a correct setup. If however, the phone didn’t exist there, you wouldn’t need a filter on this jack point. However, if for example, this jack point was in the office and you had a phone in the kitchen you would need a filter on the jack point in the kitchen to prevent the signal that’s being transmitted across every wire in the house crossing over to the phones.
ADSL SPLITTERS (MASTER FILTER - PREFERRED OVER FILTERS)
Unfortunately, some houses have corroded, damaged, or badly installed internal wiring/jack points. If an isolation test doesn’t resolve your connect rate issue, you may need an ADSL Splitter installed.
An ADSL splitter is a dedicated jack point for your Internet. A technician will visit your premise, and wire a splitter at the front of the line before it reaches your house. He then installs a dedicated box labeled ‘ADSL’ mounted on a wall, and runs a cable from that splitter to that jack point.
This gives you the cleanest possible connection the line due to the fact it bypasses everything internally. This also makes the use of filters on each jack point redundant due to the fact an ADSL signal is filtered out beforehand, and not transmitted over the internal wiring of the house.
With all the above in mind and the figures in hand after a completed isolation test you’re ready to get an idea on your distance from the exchange.
Borrowing an example from a well known Australia ISP named Internode here is a graph showing degradation over length/attenuation.
And some interesting statistics that should give you a fair idea of which bracket you sit in.
In December 2006 we took a random sample 7,305 Internode Extreme® ADSL2+ broadband. Each service was connected to an Internode DSLAM and using the ADSL2+ protocol (G992.5 Annex A ADSL2+ over POTS). We found the following distribution:
• 13.4% achieve a download synch speed of higher than 20 Mbps
• 27.7% achieve a download synch speed of between 15 Mbps and 20 Mbps
• 22.1% achieve a download synch speed of between 10 Mbps and 15 Mbps
• 23.0% achieve a download synch speed of between 5 Mbps and 10 Mbps
• 13.8% achieve a download synch speed of less than 5 Mbps
YOU STILL WANT TO START A DISCUSSION
Most of the speed problems in New Zealand will be one of these things:
- You are using WiFi in a place with lots of interference
- You don't have the correct filters installed or your house wiring needs maintenance
- Your modem is not running the latest firmware or is incorrectly configured to the wrong modulation
- You are on a LLU plan but in a cabinetised area
Most importantly post your modem DSL stats. Post as much information as possible in the first post, otherwise you will have to keep coming back to answer some questions.
If you're still experiencing issues, then I'd suggest contacting your service provider first of all as there may be a fault on your line. Things like a break in the cable or a bad connection at the exchange can also have huge detrimental effects on your connection speed, not to mention the reliability and quality of your phone line for voice calls as well.
If your connection is with Telecom/Xtra and you’re experiencing throughput or connect rate issues you may email ADSL_Helpdesk@telecom.co.nz with the relevant phone number, account details and description of your issue. You can also call 0800 22 55 98.
Customers with other service providers will need to contact or email their support lines via the relevant service channels.
Important: All images are copyrights of their respective owners.