The codec preference list for the " Dallas-REG " region is " Factory Default low loss " . This list includes the following codecs in order of preference:
G.729
G.711
OPUS
MP4A-LATM
The codec preference list for the " Austin-REG " region is " Factory Default low loss " . This list includes the following codecs in order of preference:
G.729
G.711
OPUS
MP4A-LATM
Since both regions have the same codec preference list, the codec that will be used for a call made between " Dallas-REG " and " Austin-REG " is G.729.
G.729 is a narrowband speech codec that was developed by the ITU-T in 1988. It is a low-bitrate codec that provides good quality speech at a bitrate of 8 kbps. G.729 is widely used in VoIP applications and is the default codec for many VoIP systems.
G.711 is a wideband speech codec that was developed by the ITU-T in 1972. It is a high-bitrate codec that provides excellent quality speech at a bitrate of 64 kbps. G.711 is not as widely used as G.729 due to its high bitrate requirements.
OPUS is a lossy audio codec that was developed by the IETF in 2012. It is a low-bitrate codec that provides good quality speech at a bitrate of 6 kbps. OPUS is widely used in VoIP applications and is the default codec for many VoIP systems.
MP4A-LATM is a lossy audio codec that was developed by the IETF in 1999. It is a high-bitrate codec that provides excellent quality speech at a bitrate of 24 kbps. MP4A-LATM is not as widely used as G.729 or OPUS due to its high bitrate requirements.