Integrating Packet FEC into Adaptive Voice Playout Buffer Algorithms on the Internet

Transport of real-time voice traffic on the Internet is difficult due to packet loss and jitter. Packet loss is handled primarily through a variety of different forward error correction (FEC) algorithms and local repair at the receiver. Jitter is compensated for by means of adaptive playout buffer algorithms at the receiver. Traditionally, these two mechanisms have been investigated in isolation. In this paper, we show the interactions between adaptive playout buffer algorithms and FEC, and demonstrate the need for coupling. We propose a number of novel playout buffer algorithms which provide this coupling, and demonstrate their effectiveness through simulations based on both network models and real network traces. Keywords—Packetvoice, IP telephony, packet FEC, playout buffer adaptation