c# - Listening to Port 5060

Question

I developing an SIP client. For this I must listen to port 5060 for incoming SIP Server messages. For this I coded something. (Also I take admin rights in program.)

    WindowsPrincipal pricipal = new WindowsPrincipal(WindowsIdentity.GetCurrent());
    bool hasAdministrativeRight = pricipal.IsInRole(WindowsBuiltInRole.Administrator);
    if (hasAdministrativeRight == true)
    {
        TcpListener server;
        Int32 port = 5060;
        IPAddress localAddr = IPAddress.Parse("127.0.0.1");
        server = new TcpListener(localAddr, port);
        server.Start();
        Byte[] bytes = new Byte[256];
        String data = null;
        while (true)
        {
            Console.Write("Waiting for a connection... ");
            TcpClient client = server.AcceptTcpClient();
            Console.WriteLine("Connected!");
            data = null;
            NetworkStream stream = client.GetStream();
            int i;
            while ((i = stream.Read(bytes, 0, bytes.Length)) != 0)
            {
                data = System.Text.Encoding.ASCII.GetString(bytes, 0, i);
                Console.WriteLine("Received: {0}", data);
                data = data.ToUpper();

                byte[] msg = System.Text.Encoding.ASCII.GetBytes(data);
                stream.Write(msg, 0, msg.Length);
                Console.WriteLine("Sent: {0}", data);
            }

            client.Close();
        }
    }

I get SocketException: "An attempt was made to access a socket in a way forbidden by its access permissions" (Native error code: 10013)...

Do you have a suggestion for this?

Answer 1

It seems that you were running two applications, and they are trying to access the same socket.

What Microsoft says about your problem:

WSAEACCES (10013)

• Translation: Permission denied

• Description: An attempt was made to access a socket in a way that is forbidden by its access permissions. For example, this error occurs when a broadcast address is used for sendto but the broadcast permission is not set by using setsockopt(SO_BROADCAST).

  Another possible reason for the WSAEACCES error is that when the bind (Wsapiref_6vzm.asp) function is called (in Microsoft Windows NT 4 .0 Service Pack 4 [SP4] or later), another program, service, or kernel mode driver is bound to the same address with exclusive access. Such exclusive access is a new feature of Windows NT 4.0 SP4 and later, and it is implemented by using the SO_EXCLUSIVEADDRUSE option.