You will need one of the following VoIP devices:
- An IP Telephone. This is like a normal phone, but it communicates using an IP connection. These phones plug straight into your router or LAN hub.
- A Softphone. This is an application that runs on your PC and uses your PC's soundcard for audio transmission. We recommend using Eyebeam or X-Lite.
- A VoIP Gateway. This device converts analogue traffic from your analogue phones into VoIP traffic. They are usually referred to as FXS (Foreign Exchange Station) devices.
- A VoIP Adaptor. This device is similar to a VoIP Gateway device but is designed to interface a single analogue phone.
In addition to a VoIP device you will require an Internet connection (preferably broadband) and an IP router.
Ideally, you should have a broadband connection of 128 kpbs or above (more than 515kbps if you require video conferencing). There are various reasons for this.
You need at least 64 kbps download plus 64 kbps upload bandwidth to make an uncompressed VoIP call. Otherwise you will need to compress your VoIP traffic using compression codecs such as G.723 or G.729 which can decrease the bandwidth to approximately 20 kbps. However, such methods of compression are usually used in situations where multiple calls are going over the same connection, not when bandwidth is restricted to under 128 kbps. If you have dial-up you will be very fortunate to achieve decent call quality, even when using compression.
A broadband connection is usually 'always-on' thereby ensuring that you can receive and make calls with minimum interruption.
Depending on how you use your Internet connection, you want to make sure that you have enough bandwidth leftover for typical Internet traffic (eg emails, web browsing, file downloads).