The present invention relates to packet-distributed data transmission of compressed data. According to the invention, parity bits are supplied to the compressed data. The parity bits are used in the entire transmission chain between an encoder having compressed the data, and a decoder which decompresses it. According to one embodiment, the data is speech and the packet-distributed network is a mobile radio network with packet-distribution in included links. However, sending in the radio link of the compressed speech is circuit switched.