Expansion (Derivative) of the above presented ITU standardised coder G.729. In 1994 this recommendation was decided to describe the digital (multimedia) simultaneous voice and data (DSVD) speech coder. Initially the G.723.1 was considered but rejected caused by the too great delay. No reduction in the performance requirements of G.729 were permitted. The complexity was limited to 2000 words of RAM and 10 MIPS . This was realised by using a number of shortcuts resulting in a small loss in performance but is generally not statistically significant. Several annexations followed.

Annex B describes a voice activity detector and a comfort noise generator. Annex C describes an interoperable floating point version permitting implementation of a lower-delay internet telephone than that based on G.723.1. Annex D and E deal with extensions of the G.729 algorithm to upper and lower bit rates.