Qt, send UDP through VPN(Hamachi) - c++

Question

I`m writing application, which send voice from one computer to other. I have simple implementation of "sender"
VoiceSender::VoiceSender(QAudioFormat &format, QString ip){
input = new QAudioInput(format);
QUdpSocket* socket = new QUdpSocket();
socket->connectToHost(ip, 14433);
input->start(socket);
}
Just get all data from mic and send it as UDP to specified IP.
In the other side I have program, which get all data received by UDP, and play it by audio system
Interlocutor::Interlocutor(QAudioFormat &format){
socket = new QUdpSocket();
socket->bind(QHostAddress::Any, 14433);
QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());
if (!info.isFormatSupported(format))
format = info.nearestFormat(format);
output = new QAudioOutput(format);
device = output->start();
connect(socket, SIGNAL(readyRead()), this, SLOT(playData()));
}
void Interlocutor::playData()
{
qDebug() << QDateTime::currentDateTime();
while (socket->hasPendingDatagrams())
{
QByteArray data;
data.resize(socket->pendingDatagramSize());
socket->readDatagram(data.data(), data.size());
device->write(data.data(), data.size());
}
}
If both computers locating in the local network this works well, i can transfer my voice between computers. I tried to run it in the VPN. For it I run Hamachi in both computers, and got nothing. Slot playData() is never called. I run Wireshark and seen that computer get UDP packages, but Qt doesnt. What should I do to fix it.
Thanks.

Answer 1

You should check the result of the QUdpSocket::bind function.
bool QUdpSocket::bind ( const QHostAddress & address, quint16 port )
On success, the functions returns true and the socket enters
BoundState; otherwise it returns false.
if (!socket->bind(QHostAddress::Any, 14433))
{
QMessageBox::warning(0, "Error", "Binding Failed");
}
If binding is failed check if firewall is not blocking you or this port is not used by another application.