VoIP (Voice over IP)

VoIP (Voice over Internet Protocol) carries calls as data traffic over IP networks rather than a dedicated telephone circuit end to end. A solution may include endpoints, a PBX, SIP, codecs, provider, DNS, NAT, firewall and internet connectivity. Successful phone registration does not guarantee two-way audio or quality; latency, jitter, loss and prioritisation matter. Design should define numbering, concurrent calls, emergency calling where applicable, security, fraud controls, recording, power and failure routes. QoS can manage contention but cannot create bandwidth. Tests should cover inbound and outbound calls, transfer, caller identity, codecs and recovery after loss of connectivity or service. Cost and resilience depend on the specific contract, network and architecture.