There are a number of reasons ADSL can stop working. To find out what is going on, follow these troubleshooting steps:
When an ADSL modem loses line sync, it cannot contact the DSLAM at your telephone exchange. Here are some things to check - in order - before contacting Support.
If one step solves your problem, there is no need to progress to the next step.
This may happen if an ADSL filter/splitter is not connected correctly or has become faulty. Check that all phones connected to your ADSL line have filters installed correctly.
This frequently happens if filters/splitters are faulty or improperly connected. Check that all telephones have line filters installed correctly.
This may mean you are suffering a complete drop-out of your ADSL service - your modem has lost contact with the telephone exchange and has to re-synchronise and re-establish the connection.
Consult our FAQ about line synchronisation loss to troubleshoot this problem.
First, try the Broadband Speed Test - this will upload and download a test file and estimate your line speed. Please note: if your computer is an older model your speed test may report slower than it actually is - it may report the limitations of your computer or local network before reaching the limitations of your ADSL service.
Next, try downloading a file from our Mirror server (http://mirror.internode.on.net).
The Internet is not a single network - it is a complex mesh of many networks. There are many potential causes of low performance when using any Internet access service.
We’ll explain below some common performance problems, provide guidance, and (if pain persists) tell you how to report a potential performance issue with our Support Team - with enough information to assist in diagnosing the issue swiftly.
First, let’s define some terms relevant to performance issues:
Latency is the period of time taken to move information from one location to another - it is the delay in moving a packet of data. This is commonly expressed by ADSL users as their ‘ping time’ - which is actually a measure of the latency in moving a packet from one location to another and back again - the Round Trip Time.
By way of analogy, you might think about latency as being like the time it takes to drive to a destination and return home again.
Packet loss refers to the percentage of packets which, when transmitted in the network, fail to reach their destination. Packet loss, as indicated by tools such as 'ping', indicates loss in either the outbound or the return direction, but does not indicate the location or direction in which that loss occurred. It is commonly referred to as a percentage, with 0% loss meaning all packets were carried successfully.
By way of analogy, you might think of this as the likelihood that you will actually manage to drive to a destination and get home again (!).
NOTE: the TCP protocol uses the loss of packets as part of its rate control and adjustment mechanisms, so a small level of packet loss is normal during TCP-based data transfers.
Also called download speed or throughput, your Transfer Rate is the rate at which data is transferred over a connection. It is often expressed as a speed in KiloBITS per second or in KiloBYTES per second.
It is common to confuse these, as they can both be abbreviated to just 'K/sec', and it's important to be clear which one you are referring to at a given time.
It is also important to understand that transfer rates can be expressed in terms of total data rate (including overheads, like ATM cell tax, and IP packet header data), or payload data rate (the resulting download rate for the data you actually wanted to transfer).
By way of analogy, you might think of this as the speed at which you can drive somewhere - something which is constrained by the speed limit, traffic signals, and the potential presence of other cars on the road (and consequent traffic jams!).
The factors that affect download performance are varied and latency, packet loss, and transfer rate are interdependent.
These three factors matter differently to different people.
Someone who plays online games may care more about latency and packet loss than about transfer rate. This is because latency affects gameplay responsiveness - it defines the delay (or ‘lag’) between instructing an in-game character to take an action, and seeing the results reflected by the game server. Naturally, packet loss also adversely affects game play.
However, transfer rate (throughput) is not always affected by high latency or even by moderate packet loss. The responsiveness of the Internet in terms of web browsing, access to email, and similar functions, may not be significantly affected by higher latency.
The Internet protocols used for most data transfers (TCP) are designed to automatically adapt to the latency and packet loss present in any given end-to-end network path, and to deliver the best possible transfer rate under current circumstances. They are adaptive protocols and benefit from 30 years of performance tuning.
Your MTU, or Maximum Transmission Unit, is the configured packet size your computer uses when sending packets of data to other computers. In the context of ADSL, an MTU is commonly set between 1400 and 1500 bytes.
There are some critical sizes for the MTU, and performance problems can arise if your MTU is set too high. Contrary to what might seem sensible, lowering your MTU can actually raise your data transfer speeds (to a point).
Some problems you may see if your MTU is too large:
Try lowering your MTU to resolve these issues. This webpage and utility may
assist with MTU issues.
Yes, it does.
For instance, peer-to-peer file sharing software can completely consume bandwidth to the exclusion of your own additional use of the ADSL service. Performance may remain low even after exiting P2P software, as other P2P users attempt to connect to your system for some time after you have disconnected. These attempts will consume ADSL capacity and
affect performance.
You should also expect that concurrent uploads will have a significant impact on download speeds - particularly with ADSL, which has less capacity for uploading than for downloading.
All data transfers send information in both directions - when you download a file, a stream of ‘ACK’ (acknowledgement) packets flow in the return direction, managing data flow and ensuring your download works properly.
Typically, ACK packets require 1/4 to 1/8th of your download transfer rate (this varies significantly). For example, if you are downloading at 512 kilobits per second on a 512/128 ADSL connection, your ACK packets may take up 64 − 128k of your upload capacity - up to 100%. If you decide to upload a file while downloading, this places more demand on your upstream capacity - slowing the ACK packets and your entire data transfer.
Because of the asymmetrical nature of ADSL, you should expect download speeds to be very seriously impacted by any file uploads you are undertaking at the same time.
Unfortunately, yes - some ADSL devices may get slower over time.
ADSL works over copper telephone lines - which are imperfect transmission paths. The ADSL device determines which parts of the copper line ‘spectrum’ are usable, and confines activity to those parts. Normally there is enough ‘good’ spectrum to allow ADSL to run at its
full rated speed.
Occasionally copper lines may be degraded by external factors - for example, in some areas of the Telstra copper network, line quality may be affected after rain if moisture works its way through defective insulation around copper wires.
ADSL devices compensate for these situations by confining themselves to working parts of the spectrum - reducing your throughput. However, once the problem has cleared, some ADSL devices don’t necessarily ‘spring back’ and use all available spectrum again. Because of this, it is worthwhile power-cycling your ADSL device if your performance has
degraded noticeably.
Yes, some software drivers affect ADSL performance.
All USB or PCI-based ADSL devices require software drivers to work, however some drivers aren’t written well - contributing to low speeds or variable latency. For example, you may see poor performance during games - as the game demands more resources, it leaves insufficient CPU cycles available to your ADSL device.
To minimise the requirement for special software drivers, we recommend
Ethernet-based ADSL devices.
Troubleshooting problems with USB/PCI devices:
If you feel that your ADSL performance is below expectations:
If you wish to report a performance issue, please contact our Support Team online ensuring you are as specific and accurate as possible in your report. Please provide the following information:
Internode prides itself on exceptional customer service - it is one of the most important things we do. There are a number of ways to seek support:
| What we support: | What we do not support: |
|---|---|
|
|
Your issue should be addressed in a timely manner by our staff. You also have the option to escalate should you need to - for more information, see Complaints Handling.