I have about 4 GrandStream GXV 3000 video phones. I have been trying to integrate them into our asterisk environment. All works fine until someone trys to use the speakphone function or the conference call function (conferencing to inbound call together). As soon as they try either function previously listed the sound quality goes to garbage. We are using gsm as the codec. I have not tried to use the video support as we are stilling on asterisk 1.2. Has anyone experienced this problem?