No. You do not need a computer + headset or IP phone to use the OBi. The OBi is a stand-alone, dedicated device, built with a high-performance system-on-a-chip platform to ensure high-quality voice conversations. It is 'always-on' to make or receive a call. With the OBi, a computer is not required and a computer does not need to be on to talk on the phone or use the OBi's powerful service bridging features.