VoIP

VoIP turns your voice into packets of data, sends them across the network and reassembles them at the other end. A codec is the method used to compress the audio; common ones trade bandwidth for quality, and HD codecs sound noticeably better than the old phone network. Signaling, the setup and teardown of a call, usually uses SIP.

Because the call shares the network with everything else, its quality depends on latency, jitter and packet loss rather than on the phone. For a growing business that means the phone project is also a network project: enough bandwidth, QoS rules that put voice first, PoE switches for the handsets and a plan for when the internet fails.

Ask a provider which codecs they use and whether HD voice is standard, what network changes they require, how they measure call quality, how E911 is handled, and whether the phones you already own (Yealink, Polycom and others) can be reused. Ask for a network assessment before, not after, the cutover.