//转载 - sip codec

编码速率(Codec Bit Rate)=编码采样大小(Codec Sample Size)/采样频率(Codec Sample Interval) G.711:64kbps=80Bytes/10ms=640bit/10ms=640bit/0.01s=64000bit/s=64kbps G.729:8kbps=10Bytes/10ms=80bit/10ms=80bit/0.01s=8000bit/s=8kbps G.723.1:6.3kbps=24Bytes/30ms=8Bytes/10ms=8*8bit/0.01s=6400bit/s=6.4kbps Mos：语音质量评级，范围从1(差)-5（好） Voice Payload Size(Bytes):语音载荷bytes/bits数量，支持多种采样大小 Voice Payload Size(ms):在编码采用中可以体现 G.711:160Bytes/20ms=8Bytes/ms=64kbps G.729:20Bytes/20ms=1Bytes/ms=8kbps G.729:60Bytes/30ms=2Bytes/ms=16kbps PPS:每秒传递packets的数量，等于编码速率/载荷大小 G.711:50pps=64kbps/1280bits pre packet=64kbps/160Bytes G.729:50pps=8kbps/160bits pre packet=8kbps/20Bytes 带宽计算 包大小=L2(FRF.12/Ethernet)+IP/UDP/RTP包头+语音载荷 每秒包的数量(PPS)=编码速率/载荷大小 带宽=包大小*PPS 固定包头大小(66bytes)=L2(26)+IP(20)+UDP(8)+RTP(12) G.711 包大小=(26/L2+20/IP+8/UDP+12/RTP+160/G711)*8=1808bit 带宽=1808*50=90.4kbps G.729 包大小=(66+20)*8=688 带宽=688*50=34.4kbps