Methods, devices, and software are provided for generating and sending data packets that contain redundant voice data over VoIP connections made under an unreliable network protocol. The redundant data is packaged either in redundant data packets, or in expanded original packets, to repeat data that originally belongs in other packets. Generation of the redundant voice data is either from the transmitting device or from a retransmitting device, such as a router in the network. Generation is triggered either when errors are detected, or simply when the network resources permit it, or both. The received voice data is processed by the second party to the connection, which is typically a telephone call. The redundant voice data that is actually received is discarded. The invention thus ensures that less voice data is lost than in the prior art over VoIP connections made under an unreliable network protocol.