A client device comprises a plurality of audio input ports, at least one audio output port, a MIDI input port, a MIDI output port, a video input port, a video output port, a processor and a network interface. The processor generates outgoing IP messages that carry at least one audio input signal received from the audio input ports, a first MIDI signal received from the MIDI input port and a first video signal received from the video input port. From incoming IP messages, the processor extracts a second MIDI signal for the MIDI output port, a second video signal for the video output port, and at least one audio output signal for the at least one audio output port. A network interface sends the outgoing IP messages within a VoIP call via a network and receives the incoming IP messages within the VoIP call via the network.