Opc.Ua.Bindings.UaTcpChannelListener.Start C# (CSharp) Method

        public void Start()
        {
            lock (m_lock)
            {
                // ensure a valid port.
                int port = m_uri.Port;

                if (port <= 0 || port > UInt16.MaxValue)
                {
                    port = Utils.UaTcpDefaultPort;
                }

                // create IPv4 socket.
                try                    
                {
                    IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, port);
                    m_listeningSocket = new Socket(endpoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
                    SocketAsyncEventArgs args = new SocketAsyncEventArgs();
                    args.Completed += OnAccept;
                    args.UserToken = m_listeningSocket;
                    m_listeningSocket.Bind(endpoint);
                    m_listeningSocket.Listen(Int32.MaxValue);
                    m_listeningSocket.AcceptAsync(args);
                }
                catch (Exception ex)
                {
                    // no IPv4 support.
                    m_listeningSocket = null;
                    Utils.Trace("failed to create IPv4 listening socket: " + ex.Message);
                }

                // create IPv6 socket
                try                    
                {
                    IPEndPoint endpointIPv6 = new IPEndPoint(IPAddress.IPv6Any, port);
                    m_listeningSocketIPv6 = new Socket(endpointIPv6.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
                    SocketAsyncEventArgs args = new SocketAsyncEventArgs();
                    args.Completed += OnAccept;
                    args.UserToken = m_listeningSocketIPv6;
                    m_listeningSocketIPv6.Bind(endpointIPv6);
                    m_listeningSocketIPv6.Listen(Int32.MaxValue);
                    m_listeningSocketIPv6.AcceptAsync(args);
                }
                catch (Exception ex)
                {
                    // no IPv6 support
                    m_listeningSocketIPv6 = null;
                    Utils.Trace("failed to create IPv6 listening socket: " + ex.Message);
                }

                if (m_listeningSocketIPv6 == null && m_listeningSocket == null)
                {
                    throw ServiceResultException.Create(
                        StatusCodes.BadNoCommunication,
                        "Failed to establish tcp listener sockets for Ipv4 and IPv6.\r\n");
                }
            }
        }