Many businesses still rely on PSTN / analogue lines as their main source of connectivity, but also want to benefit from modern conference phone audio quality and features with an eye on eventually converting to VoIP. This is exactly the problem the CPN10 PSTN adapter solves. The Yealink CPN10 adapter simply connects to your CP920’s USB port and to your analogue phone line to enable PSTN interoperability. Additionally, USB call recording remains possible via the USB breakout port. Simplify your transition to VoIP with the Yealink CPN10 PSTN adapter.