VoIP services transform a user’s voice from digital audio to digital data, then transmitted over Ethernet or Wi-Fi to another user—or group of users. VoIP will use codecs to achieve this.
Large volumes of VoIP data are compressed and decompressed using either hardware- or software-based codecs. Although using compression may result in a reduction in voice quality, compression also requires less bandwidth. Additionally, equipment suppliers will employ their complete codecs.
Encapsulating audio into data packets, delivering the packets over an IP network, and decapsulating the packets back into the audio signals at the other end of the connection are all steps in transmitting data to other users.
A typical VoIP system also includes gateways, which connect networks and provide failback or local survival rate in the event of a network outage, and session border controllers, which provide security, call policy management, and internet connectivity. An IP PBX manages user phone numbers, devices, features, and clients.