kbit/s of the bandwidth is dedicated to the lower sub-band and the other 16 kbit/s is allocated to the higher sub-band. RTP encapsulation G.722 VoIP is typically carried in RTP payload type 9. Note that IANA records the clock rate for type 9 G.722 as 8 kHz (instead of 16 kHz), RFC 3551 clarifies that this is due to a historical error and is retained in order to maintain backward compatibility. Consequently, correct implementations represent the value 8,000 where required but encode and decode audio at 16 kHz. Whilst G.722 allows for bitrates of 64, 56 and 48 kbit/s, in practice, data is encoded at 64 kbit/s, with bits from the lower sub-band being used to encode auxiliary data. The greater the number of bits allocated to aux data, the lower the bit rate. e.8 See also List of codecs Comparison of audio coding formats Wideband audio References External links ITU-T Recommendation G.722: 7 kHz audio-coding within 64 kbit/s- technical specification Audio codecs Speech codecs Wideband codecs ITU-T recommendations ITU-T G Series Recommendations