Abstract: This disclosure describes computer architectures, software, and methods by which a custom signaling protocol is implemented for communicating between an app on a mobile device and an app that is either on a local area network or on a mobile device using a special-purpose cloud service. The cloud service translates messages from the mobile app protocol into SIP and also tracks the power state of the mobile app, and translates the SIP protocol back to the mobile app protocol when sending the signaling messages to the mobile app. The decentralized architecture maintains interoperability with SIP networks and presents an interface better suited to the needs of mobile apps. Additional embodiments provide computer architectures, software, and methods for transmitting audio-video data between mobile apps with changing IP addresses without the need to drop the call.