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The quality of VoIP calls depends on the codec used for the transmission and on the bandwidth of Internet connection. I want to use best optimized codec for my Internet connection.

I have to select codecs from the following list:

  • G.722
  • G.711 u law
  • G.711 a law
  • G.726
  • G.729

Which one to choose and why?

I want to have best high quality voice on both sides.

I have ADSL2+ Internet connection with bit rates:

  • download 6 Mbit/s
  • upload 0.5 Mbit/s
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up vote 2 down vote accepted

Take a look at this link, it will help you. Pay attention to the last column.

However g729 is not royalty free from what I understand. I use g711, the quality is great and at 64k per call you would need 8 calls to fill your pipe.

g729 is most effective and utilizes the bandwidth the best so you can make more calls at one time on your 512K pipe. If this is a SMB then using g711 would be a good way to go.

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