Introduction to VoIP | ACMA

Introduction to VoIP

Voice over Internet Protocol (VoIP) is the name for the different technologies that allow telephone calls to be made over the internet, as opposed to the public switched telephone network (PSTN).

Advantages of VoIP

VoIP services offer:

free calls low cost calls to other numbers including international calls

Examples of VoIP charging structures include:

free calls, usually between users on the same service a one-off charge per connection connection flagfall plus charges for time connected charges per second or minute connected subscriptions offering monthly quotas

VoIP calls are cheaper than normal telephone calls because:

calls made using a PSTN phone line take up the full capacity of two phone lines for the duration of the call. the line is in use even when one party is listening and nothing is being transmitted from the other end.

Extended features

VoIP additional benefits include:

voicemail electronic notification of voicemails opportunity to block calls from certain numbers conference calls routing to a selected phone number instant messaging video calls file transfer ability to send text or visual information ability to send files, such as a photo or document higher definition voice conversation ability to use your VoIP phone number no matter where you are making and receiving VoIP calls over any broadband internet connection presence indication where you can tell if the person you want to call is available ‘follow me’ where the facilities are the same wherever you are logged on.

Some features of VoIP may only be available if both the person making a call and the person receiving a call are users of a PC-based VoIP service or are using the same provider.

VoIP services may offer:

  • instant messaging
  • video calls
  • data transfer integrated with the voice service - for sending images or documents
  • improved sound quality
  • the opportunity to use your VoIP phone number no matter where you are. This follow me service means you can make and receive calls over your VoIP service anywhere a broadband internet connection and relevant equipment is available, for example, from an internet cafe when travelling.
  • the ability to make calls to normal phone numbers
  • a phone number so you can receive calls from PSTN phone lines.

Some small businesses have benefited from the data characteristics of VoIP, using their VoIP service to transmit both voice and data.

Types of VoIP services

There are many different types of VoIP services on offer. Almost all VoIP services require a PC for setup of the route to the VoIP service provider.

Some VoIP products need PC with headset for making and receiving calls, while others use a small device known as an Analog Telephone Adaptor (ATA) to connect existing telephones.

Specialised Wifi connected handsets have become available which enable cordless connections directly from a router connected to the broadband modem.

Understanding the characteristics of VoIP services will help you decide whether to subscribe to a VoIP service, and which VoIP service best meets your needs.

VoIP service providers can give you information on:

features offered by a VoIP service equipment you require to access the services costs related to the service limitations of the service your rights when complaining about any aspect of the service.

For more information see the VoIP Service Providers Guide and Customer Booklet from the Communications Alliance.


A broadband connection is recommended for VoIP. Dial-up connections with a maximum speed of less than 56Kbps will have significantly poorer voice quality but will still work.

A broadband connection such as ADSL, cable modem or wireless will provide sufficient capacity but may still be affected by other simultaneous traffic such as downloading large files..

Other equipment needed to access a VoIP service may include:

a router - possibly with a Wifi ethernet connection an Analog Telephone Adaptor to connect traditional handsets a microphone and speakers or headseat for PC connection a free standing Wifi VoIP handset.

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Last updated: 01 May 2018