How to Record VoIP Calls on Your Network Voice over internet protocol (VoIP) is audio delivered in information packets on a regular computer network or over the internet. VoIP call recording works differently than recording trunk or extension lines or handsets. VoIP call recording taps into your network lines at a hub, or at the SPAN port on a switch. In this way as network traffic travels over your Ethernet cables, our recorders can detect compatible VoIP packets and record them. Use a network analyzer to check the SPAN or mirror port configuration.