No Voice when using Voip in Qtopia

[左 国坤]

Hi, all

I am using VOIP by compile Qtopia 4.3.1 Open source for Neo1973 Phase1.
I need your help to clear some problems.

1, Incoming call
 ringtone OK, Answer OK, Hold OK, But No VOICE from Caller, and vice versa.

2, Out Call
 Keeping with 'Dialing' status, NO Call Tone, No connection to the other
end

I am a newbie in using Qtopia, maybe something missed in setting when
building.

Looking forward to your kind and prompt help.

Regards.

George