[Asterisk-Users] g729 + GSM + g723

[Kanuri, Seshu]

Folks!

We have purchased G729 and have been testing the codec on mUltiple Gateways. Here is what we have found.

Here is the config I have used:
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Asterisk Server On Dual Pentium Xeons with 6GB of RAM, running on Fedora Core 2

User1 is in USA on Broadband Cable
User2 is in India on 64Kbps ISDN Line

User1 using SIPURA SPA 2000
user2 using Xten professsional(X-pro) that has g711, g723 and GSM

Test Conducted as below:
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User1=SIPURA(Codec set as g729 ) --> Asterisk( converts g729 to GSM ) --> User2=Xten/Xpro(GSM )


Conversion at Asterisk:
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user1 to user2 - From g729 to GSM
user2 to user1 - From GSM to g729

Results:
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1) User1 Can hear the User2's voice at a quality level of 6 out of 10
2) User 1 can hear User2's Voice as muffled noise rather than clear voice
3) User2 can hear User1's voice at a quality level of 3-4 out of ten
4) User2 can hear User1's voice as noisy craclkle with a lot of ticking

Conclusions:
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1)Codec g729 does not help in the connectivity between two users using GSM at one end.
2)Xten does not have support for G729 and hence is not the right choice for connectivity to Asterisk.

Recommendation:
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1)Asterisk community should work on passthrough connectivity for g723(Currently it does not work, though I read that it is there)

I will post results of tests with our own Brand of SIP Phone "eezeephone *Ship" in the next post.

Seshu Kanuri
eezeePhone.com