What Are The Requirements For VoIP?
All VoIP services require an Internet connection, and the faster the better. A pretty standard 512 kbps downstream, 128 kbps upstream connection would be adequate, though if you have more than one person using VoIP at the same time on the same connection, the requirements increase.
Hardware requirements are not all that stringent; any machine purchased in the last 18 months (or even a bit earlier) should be able to handle VoIP. Exact requirements may vary from provider to provider, however. An audio-in device (microphone) and audio-out device (headset or speakers) are also required.
Exact Figures Please?
For the tech savvy in the audience, or those who just like numbers, David Allen Stratton, CTO of VoIP service provider BroadVoice has the answers. The figures depend on the "last mile" technology (how the home connects to the Internet service provider) and the voice codec used. Many VoIP providers use the G.711 codec with a 20 ms sample rate, which requires 64 kbps. When you add in IP overhead, this increases to 71.6 kbps. If a Frame-Relay-based DSL loop (also similar to cable modem) is used for Internet connectivity, bandwidth further increases to about 81.6 kbps. And if you are on an ATM-based DSL loop (the most common case), bandwidth used jumps to 106 kbps. Note that this bandwidth use is for each direction of a call, both talking and listening (upstream and downstream, as far as your Internet connection is concerned).
What Kind Of VoIP Peripherals Can You Get?
As well as headsets and microphones, there is an increasing market for VoIP peripherals. These include wireless and USB handsets, which are used in conjunction with computer-based VoIP services.