This annex describes an algorithm extending ITU-T G.711.1 for the lossless compression of ITU-T G.711 bitstream in an efficient way.Annex C is organized as follows. The abbreviations, acronyms and conventions used throughoutthis annex are defined in clauses C.3 and C.4, respectively. The general description of the ITU-T G.711.1 LLC coder is discussed in clause C.5. Clauses C.6 and C.7 describe the ITU-T G.711.1 LLC encoder and decoder, respectively. Clause C.8 describes the transmittedparameter indices, and clause C.9 describes the reference software.