scope:

This standard addresses the use of 32-kbit/s Adaptive Differential Pulse-Code Modulation (G.726 32-kbit/s ADPCM)¹⁾ in 4-kHz voiceband network connections and limits the number of G.726 32-kbit/s ADPCM links allowed. It relates to the transport of signals processed by the 32-kbit/s ADPCM algorithm specified in ITU-T Recommendation G.726. Although G.726 defines other ADPCM algorithms designed for operation at 16, 24, and 40 kbit/s, the performance implications of these algorithms are not addressed in this standard. This standard does not purport to describe the service offerings of any particular carrier.

Purpose

This standard stipulates appropriate limits on the use of G.726 32-kbit/s ADPCM while retaining, for all carriers, the capability to provide quality transmission performance to end-users.

¹⁾ In this standard, the abbreviation, G.726 32-kbit/s ADPCM, refers explicitly to the 32-kbit/s ADPCM algorithm as specified in ITU-T Recommendation G.726, 40, 32, 24, 16 kbit/s adaptive differential pulse code modulation (ADPCM), Geneva, 1990