public void Listen()
{
    try
    {
    CommCleanup();
        ThreadPool.QueueUserWorkItem(new WaitCallback(SockThreadFunc));
    }
    catch (Exception e)
    {
      Console.WriteLine(
            "*** Exception *** ConnectionManager::ConnectionManager(), 
              Description: " + e.Message);
    }   
}
void SockThreadFunc(Object state)
{
    Socket listener;               
    listener = new Socket(AddressFamily.InterNetwork, 
                                 SocketType.Stream, ProtocolType.Tcp);
    listener.Blocking = true;
    IPEndPoint endPoint = new IPEndPoint(IPAddress.Any, m_listenPort);
    try
    {
        listener.Bind(endPoint);
    }
    catch(SocketException e)
    {
        // If there is already a listener on this port, listen on another port
        if(e.ErrorCode == 10048)
        {
            endPoint = new IPEndPoint(IPAddress.Any, ++m_listenPort);
            —m_connectPort;

           listener.Bind(endPoint);
        }
        else
        {
            throw e;
        }
    }
    catch(Exception e)
    {
        Console.WriteLine("Exception - {0}", e.Message);
        Debug.Assert(false);
        return;
    }
    m_listening = true;
    m_sink.OnStartListening(m_listenPort);              
    listener.Listen(m_listenPort);
    m_sock = listener.Accept();
    m_listening = false;

    // Notify the sink that a connection was accepted
    m_sink.OnConnectionAccepted();
    
    m_stream = new NetworkStream(m_sock);
    m_writer = new StreamWriter(m_stream);
    m_writer.AutoFlush = true;

    AsyncCallback readReadyCallback = new AsyncCallback(OnReadReady);
    m_stream.BeginRead(m_inBuff, 0, BUFF_SIZE, readReadyCallback, this);
}

Example 4: The communication layer of Cosurfer.