Which statement is NOT a key QoS recommended requirement for voice bearer traffic?（）
- AVoice traffic should be marked to DSCP EF per the QoS baseline and RFC3246.
- BVoice traffic loss should be no more than 3%.
- COne-way latency （mouth-to-ear） should be less than 150 msec.
- DAverage one way jitter should be targeted to less than 30 msec.
- E21-320 Kbps of guaranteed priority bandwidth is required per call depending on sample rate，codec，and layer 2 overhead.