Setting up Voice over IP (VoIP)

VoIP is a service that uses the internet to make voice calls to any other phone number in the world, instead of your traditional landline connection. The term stands for “Voice Over Internet Protocol” or, in simple terms, a telephone service that works over the internet.

There are two ways to use VoIP – using software on your computer (sometimes also called “softphones”), or using fairly ordinary phone handset hardware.

This page provides information on setting up a VoIP service using a phone handset. It does not cover using software-based services.

What internet connection do I need?

Any internet connection can run VoIP.

However, for the best possible handset-based service, contact your service provider and ask about their dedicated VoIP services.

nbn™ internet service providers have access to a dedicated voice channel (called Traffic Channel 1, or TC1), in addition to the everyday internet channel (TC4).

TC1 sets aside 150kbps of the overall internet “pipeline” for this voice data.

Using TC1 for your VoIP calls ensures your phone calls are the best quality available. Your service provider can then provide you with the right equipment, and make setting up your service much easier.

You will need to sign up to a specific VoIP plan with your service provider to access the TC1 channel, and there may be some additional costs on top of your usual monthly internet cost.

  • Additional monthly cost (roughly between $0 – $30 on top of your existing monthly cost)
  • Cost per phone call (anywhere between 1c – 50c per call or per minute, depending on the call type).
  • Once-off cost of the equipment (around $100-$200, depending on which specific equipment you need).

Not all nbn™ services have access to the TC1 channel, and not all providers will use the TC1 channel for VoIP services. Talk to your provider first when making a decision about VoIP plans.

At time of writing, nbn™ Sky Muster™ Plus plans do not have access to the TC1 channel.

What happens to my landline?

If you have an nbn™ fixed line service, your phone services are exclusively provided via VoIP. Once you change over to an nbn™ fixed line service, your landline will be disconnected.

If you have an nbn™ Sky Muster™ or Fixed Wireless service, VoIP is an optional extra. You can have both a landline and VoIP service.

VoIP will only work while your internet connection is working.

If you are in a location which has regular power outages, emergencies such as fire, flood, or cyclones, or weather conditions that may interfere with a reliable internet connection, it’s a good idea to keep a landline connected.

In nbn™ Fixed Line areas, you should use the mobile network for a backup service if you have coverage.

What equipment do I need?

  • An existing internet connection with a router, or combined modem/router.

The phone will be plugging into the router, in order to use your internet connection to make its calls.

    • Your existing phone handset and an Analogue Telephone Adaptor (ATA), or a router with built-in ATA (ATA+router). The ATA takes an ordinary phone plug and converts it to the digital signal required to travel over the internet.


    • An IP phone handset. This is a phone specifically designed to plug directly into the router via an ethernet cable, not an ordinary phone cable.

Your internet service provider can help you get the right equipment for your connection.

Connecting your existing phone handset

You’ll need to follow the specific instructions supplied with your equipment, but broadly speaking, this is how the equipment is set up.

  1. Plug the phone line of your handset into the ATA box, or into the “phone” port of your ATA+router.
  2. If your phone has its own power, make sure it’s plugged in and turned on.
  3. Plug the ATA box into your existing router using an ethernet cable, OR plug your ATA+router into your internet modem.
  4. Ensure everything is turned on and that your internet connection is working.
  5. Lift your handset. You should have a dial tone.
  6. Make phone calls as usual.

Connecting your IP handset

You’ll need to follow the specific instructions supplied with your equipment, but broadly speaking, this is how the equipment is set up.

  1. Plug your IP handset into your router via an ethernet cable.
  2. Follow any instructions required to set up the phone, via your computer.
  3. Lift your handset. You should have a dial tone.
  4. Make phone calls as usual.

Can I make emergency calls on my VoIP?

Yes, but check that with your provider before ordering your service.

Can I use my current phone number on the VoIP service?

Yes, but it will have to be “ported” across, which means it’s no longer associated with your landline.

If you plan to keep your landline as well as using VoIP, you’ll need a new phone number for either the VoIP service or the landline.

Can I get caller ID, MessageBank and other similar features on my VoIP service?

It depends on your service provider, and on the equipment you’re using.

In most cases yes, you’ll have all the same services as you’ve had on your landline, except for MessageBank.

MessageBank is owned and provided by Telstra. It works over VoIP, but only on an internet connection (including nbn) provided by Telstra.

It is not available on VoIP services provided by any other provider, including nbn.

What about satellite lag?

The dedicated TC1 channel, plus the use of dedicated VoIP equipment, does overcome the satellite lag to a certain extent. You may notice a slight delay when making the initial call, but the software then does its best to make the service as quick as possible.

How much data does a VoIP call use?

An active VoIP phone call uses between 30Mb and 80Mb of data per hour.

It varies depending on the “codec” (coder-decoder) that your service provider and equipment uses.

There are two codecs used in Australia:

  1. G.729. This is the most common, and a lower-quality codec. The TC1 channel can support up to four simultaneous calls at the same address using the G.729 codec. Each call uses about 30Mb of data per hour.
  2. G.711. This is a higher-quality codec. The TC1 channel can support one call at a time using this codec. Each call uses about 80Mb of data per hour.

VoIP equipment does use some data when not making actual phone calls, but it’s a very small amount.

VoIP calls are unmetered on nbn™ Sky Muster™ Plus plans. Note, however, that at time of writing, the TC1 channel is not available with Plus plans.

Do I have to use my service provider’s VoIP service?

No. There are third-party suppliers of VoIP services, generally to support business or complex phone setups. They’re called “Voice Service Providers”, or VSPs.

However, going through your service provider is generally the easiest option.

Discuss your requirements with your trusted technical advisor to make the best decision for your needs.