Which codec uses the least bandwidth?

Which codec uses the least bandwidth?

• A. G.711
• B. G.729
• C. G.722
• D. G.726

Answer: (B)

Understanding bitrate is the key. The amount of bandwidth a voice call consumes mirrors the codec’s bits-per-second output. G.711 encodes voice as uncompressed PCM at 64 kbps, so it uses a lot of bandwidth. G.722 is a wideband codec typically around 64 kbps, offering better quality but not lower bandwidth. G.726 can operate at several rates (lower than G.711 but higher than the lowest option). G.729 compresses speech to about 8 kbps, making it the most bandwidth-efficient choice among these options. It trades some audio fidelity for a much smaller stream, which is why it uses the least bandwidth. Note that licensing and CPU requirements can be considerations with G.729 in real deployments. Therefore, the codec that uses the least bandwidth is G.729.

Understanding bitrate is the key. The amount of bandwidth a voice call consumes mirrors the codec’s bits-per-second output. G.711 encodes voice as uncompressed PCM at 64 kbps, so it uses a lot of bandwidth. G.722 is a wideband codec typically around 64 kbps, offering better quality but not lower bandwidth. G.726 can operate at several rates (lower than G.711 but higher than the lowest option). G.729 compresses speech to about 8 kbps, making it the most bandwidth-efficient choice among these options. It trades some audio fidelity for a much smaller stream, which is why it uses the least bandwidth. Note that licensing and CPU requirements can be considerations with G.729 in real deployments. Therefore, the codec that uses the least bandwidth is G.729.