VoIP is a technology and set of protocols that allow voice telephone calls to travel over the Internet. Your analog speech patterns are continually sampled and converted into numeric values, representing the instantaneous voice frequency at the moment of sampling.

By sampling at a rate of at least twice the highest frequency (based on the Nyquist Theorem) your voice can be accurately reproduced at the far end. The device that accomplishes this conversion is the “Codec? There are many Codec protocols, each offering some trade-off between voice quality, available bandwidth, echo and processor overhead.

Every time you place a VoIP call the phones on each end “negotiate?and agree upon a codec protocol that will provide the best voice quality at the available bandwidth.

The two major protocols for call set-up are SIP and H323. They define and enforce the “rules?of the network and supply the “dialing plan?