问题：

[多选] Which two statements are true about the digital audio in a VoIP network？（）

A . Standard encoding techniques create an uncompressed digital data rate of 4000 bps.
B . Standard encoding techniques create an uncompressed digital data rate of 8000 bps.
C . Standard encoding techniques create an uncompressed digital data rate of 64，000 bps.
D . Voice quality is not a concern if compression is not used.
E . Two methods of quantization are linear and logarithmic.
F . Two methods of compression are u-law and a-law.