How to fix and improve your ADSL at home

Internet connectivity problems on an ADSL service can be caused by multiple issues, often making it difficult to pinpoint where a fault lies.

Calling an ISP’s or Telkom’s tech support to resolve the issues can also be a frustrating back-and-forth between company and consumer.

Telkom can also charge you a call-out fee if a technician is dispatched to fix your line – even if it turns out the problem was a trivial one.

To save time and money, read below to see how you can troubleshoot ADSL connection woes yourself.

1. Are all devices on your LAN having the same issue?

Windows 7 copy dialog progress bar guesstimation

If only some of the computers or smartphones on your home network are having connection trouble, the problem is probably not related to your line or ISP.

Fix: Check the network settings of affected devices, reboot them, and reboot your router. If that doesn’t work, hunt for tech support specific to the issue.

If all your devices are affected, proceed to the next step.


2. Is someone maxing out your line’s bandwidth?

Telkom LTE-Advanced BitTorrent test (downloading Ubuntu 14.04.1)

Check that someone on your network isn’t using up all your download or upload bandwidth.

While it may seem counter-intuitive, if your upstream bandwidth is saturated, it will affect download speeds.

If someone on your network leaves a bunch of BitTorrents running without limiting their upload speed, for example, it could affect the performance of everyone on the network.

Fix: Rate limit or restrict downloads to a certain time in your household. If you can afford it, and if it is available in your area, you can also upgrade your line speed.


3. Is your Wi-Fi broken or congested?

Wi-Fi power glowing in the palm of your hand

If you’ve been testing your connection on a device connected via Wi-Fi, try plugging it into your router with a network cable.

Some ISPs have reported that a large number of support queries relating to slow speeds end up being caused by congested or malfunctioning Wi-Fi.


  • Reboot your router.
  • Reduce the number of devices connected to your router via Wi-Fi.
  • Check whether the Wi-Fi band you are using is picking up noise from other people’s routers. Manually select a band for your router if needed.
  • Buy an additional Wi-Fi access point or a new router if the Wi-Fi module in your current router is broken.


4. Is your ADSL modem or router broken?

ADSL Modem

Testing whether your ADSL modem or router is broken can be difficult, unless you have a spare unit that you know is working.

If the router isn’t switching on or loses power intermittently, then you’ll have to buy at least a new power supply, if not a new router.

Other telltale signs that you might have to buy a new router include: being unable to log into its configuration web portal, or if it is unable to synchronise your line.


5. Is it your Internet service provider?

South Africa ISPs

If you are experiencing slow speeds, it is possible your Internet service provider is managing its bandwidth.

ISPs may choose to throttle peer-to-peer traffic, such as BitTorrent, and other bulk downloads during peak usage periods.

If your Internet access is offline, or if services other than downloads are running slowly, it may still be your ISP.

Check: Test an ADSL account from another ISP to see if you get similar performance issues on all service providers. Many ISPs offer free accounts with a limited amount of data – such as Afrihost, Axxess, Crystal Web, and Web Africa.

Fix: Change ISPs, or switch to an ADSL account that better suits your usage needs.


6. Is your ADSL modem or router misconfigured?

Fibre and DSL routers

Your ADSL router may lose its settings due to a glitch, or have its settings tampered with by a hacker.

Settings to look out for are your ADSL username and password, the VPI/VCI numbers (which should be 8/35), and DNS server addresses.

If a hacker has messed with your DNS settings, it is a security risk and can also cause your ADSL to under-perform.


  • If you know your settings, compare them to see if there are any anomalies.
  • If you don’t know what your settings are, consider restoring your router to its factory settings and configuring it from scratch.
  • Ensure you have all the necessary details to configure your router before resetting it, such as its default administrator password, and your ADSL username and password.


7. Is there noise on the phone line between your ADSL router and the wall socket?

Telephone line wall jack

There are a few components other than your router that can be the issue.

If your router can get line synchronisation and you can access its web portal, take a look at the ADSL statistics that your router reports.

It should tell you what upstream and downstream speeds it was able to synchronise at, and report signal-to-noise and line attenuation ratios (usually measured in decibels, or dB).

Compare these to what the values should be. If they are too low:

  • Disconnect any telephones that share the line with your ADSL router or modem.
  • Remove the POTS filter and connect your router directly to the phone jack.
  • Remove long telephone extension cables between the router and the wall jack. Plug your router into the telephone line with the shortest cable you have.

Fix: Replace any faulty equipment identified in the above checks.


8. Are you the only one affected?

MyBroadband forum screenshot

The last thing you can check before calling Telkom or your ISP is whether there is a fault in your area, or with your service provider.

MyBroadband’s forums are a great place to check this – if you have a backup Internet connection.


Should you not see any posts about general problems, feel free to ask. Remember to be specific about the problem you’re seeing, and which area you are in.


9. Is there a line fault on your ADSL link?

Telkom logo

Figuring out whether there is a fault on your line is mostly a process of elimination. Determining where the fault is will require the help of Telkom’s call centre.

If you’ve gone through all of the steps above, it is time to call your ISP or Telkom – depending on who manages your line.

Telkom also offers a number of other channels for fault logging if you would prefer to avoid calling in.

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How to fix and improve your ADSL at home