Initializing "NetworkInterface" echos sound without send or receive

[dstechs]

Intialialize (onCreate())

initFrameTransmissionConfig();
initNetwork();

 private void initFrameTransmissionConfig() throws Exception {
        transmitterConfig = new FrameTransmitterConfig(
                this,
                "audible-7k-channel-0");
        receiverConfig = new FrameReceiverConfig(
                this,
                "audible-7k-channel-0");

        conf = new NetworkInterfaceConfig(
                receiverConfig,
                transmitterConfig);
    }

private void initNetwork() throws Exception {
       intf = new NetworkInterface(conf);
}

once I call initNetwork() sound transmittion plays audio for min 3 times
Please check video for more clarification
issue_video.zip