What do I need to use VoIP?

In order to use VoIP technology, you must have a data communication line capable of transferring the quantity of data needed to contain the voice, and a low enough bandwidth. A common ADSL line is usually a good choice. The band requirement is of a minimum of 128 Kbit/sec bidirectional, and the latency requirement is of 150 ms of RTT.

You must also have a computer with a sound card and a headset, or an adaptor, or a specific router.