A system and method for using forward error correction (FEC) to improve transmission reliability for data packets transmitted over packetized data networks, such as voice packets transmitted over an Internet Protocol (IP) network is disclosed. Packets containing error data are transmitted separately from corresponding voice packets. The error packets are transmitted a predetermined number of frames before the voice packets, to increase the probability that either the voice packet or error packet will be received. The error packets are preferably created using a Reed-Solomon algorithmn. The amount of error correction transmitted may be adaptively adjusted based on the reliability of the network connection.