A voice communication device, supporting both Internet and public switched telephone network telephony, performs call session hand off between Internet and public switched telephone networks. Hand off, with or without user confirmation, may be half or full duplex, yielding common and differing incoming and outgoing call session pathways. In addition to mid-call hand offs, hand off may also be performed as part of the call session setup. Information regarding the destination network is exchanged on the network from which the hand off will occur. Voice communication devices are each configured with a plurality of communication interfaces including a public switched telephone network interface and an Internet interface. Basic full-duplex operations include immediate and mid-call hand offs between the public switched telephone network and Internet. Mixed pathway communication and handoffs using partly Internet and partly public switched telephone network are also contemplated.