网络编程求助

Question

昨天发的求助帖给沉啦，今天再发一帖
http://bbs.csdn.net/topics/390342556（昨天的帖子）
增加几点说明：
1、通讯双方的所有信息（内网IP，公网IP和端口）都可以告诉对方，这样是不是就不需要穿透NAT啦，这样两个不同内网应该是怎么建立TCP连接的
2、这种点对多的通讯是使用异步通讯好呢还是使用同步加多线程好，是不是使用同步通讯还要处理TCP消息无边界的问题
3、如果有例子程序最好，没有的话给出设计方案以及可能还会存在的问题，万分感谢！网络编程

Answer 1

1--NAT?是什么?不明白! 有内网ip,还有公网ip ,双网卡?  内网中,两个不同网段的ip.可以通过交换机组成可以互访的吧.(好像配置过思科的交换机).或者找台机器,双网卡,接入两个网段,做服务器端.2--点对多?   指的是 S对多C? 服务器端做监听端?来个客户端就开个线程处理消息交互不就好了. 点多的话,可以考虑 iocp3--
private class ConnectionInfo
        {
            public Socket Socket;
            public byte[] Buffer;        }        private List<ConnectionInfo> _connections = new List<ConnectionInfo>();        private void SetupServerSocket()
        {
            // Resolving local machine information
            IPHostEntry localMachineInfo =
                Dns.GetHostEntry(Dns.GetHostName());
            IPEndPoint myEndpoint = new IPEndPoint(
                localMachineInfo.AddressList[0], _port);            // Create the socket, bind it, and start listening
            _serverSocket = new Socket(myEndpoint.Address.AddressFamily,
                SocketType.Stream, ProtocolType.Tcp);
            _serverSocket.Bind(myEndpoint);
            int max = (int)SocketOptionName.MaxConnections;
            _serverSocket.Listen(max);
        }        public void Start()
        {
            _fm.Print("开始工作站启动网络..\r\n");
            //_fm.logWrite("开始Start连接..");            SetupServerSocket();
            for (int i = 0; i < 10; i++)
                _serverSocket.BeginAccept(
                    new AsyncCallback(AcceptCallback), _serverSocket);
        }        private void AcceptCallback(IAsyncResult result)
        {
            ConnectionInfo connection = new ConnectionInfo();
            try
            {
                Socket s = (Socket)result.AsyncState;
                connection.Socket = s.EndAccept(result);
                connection.Buffer = new byte[255];                lock (_connections) _connections.Add(connection);
                // Start Receive and a new Accept
                connection.Socket.BeginReceive(connection.Buffer, 0,
                    connection.Buffer.Length, SocketFlags.None,
                    new AsyncCallback(ReceiveCallback), connection);
                _serverSocket.BeginAccept(new AsyncCallback(AcceptCallback),
                    result.AsyncState);
            }
            catch (SocketException exc)
            {                CloseConnection(connection);
                //_fm.logWrite("Socket exception: " + exc.SocketErrorCode);
            }
            catch (Exception exc)
            {                CloseConnection(connection);
                //_fm.logWrite("Exception: " + exc);
            }        }  
        private void ReceiveCallback(IAsyncResult result)
        {
            int termNo;
            ConnectionInfo connection = (ConnectionInfo)result.AsyncState;
            try
            {
                int bytesRead = connection.Socket.EndReceive(result);
                if (0 != bytesRead)
                {
                    // get addr snd;
                    termNo = RefHzPtl.getTermNo(connection.Buffer, bytesRead);
                    if ((termNo != 0) && (termNo != -1))
                    {
                        _fm._mUt._asyIoSever.TcpSend(termNo, connection.Buffer, bytesRead);
                    }
                    connection.Socket.BeginReceive(connection.Buffer, 0,
                        connection.Buffer.Length, SocketFlags.None,
                        new AsyncCallback(ReceiveCallback), connection);
                }
                else CloseConnection(connection);
            }
            catch (SocketException exc)
            {                CloseConnection(connection);
                //_fm.logWrite("Socket exception: " + exc.SocketErrorCode);            }
            catch (Exception exc)
            {
                CloseConnection(connection);
                //_fm.logWrite("Exception: " + exc);
            }
        }        private void CloseConnection(ConnectionInfo ci)
        {
            try
            {                ci.Socket.Close();
                lock (_connections) _connections.Remove(ci);            }
            catch (SocketException exc)
            {
                //_fm.logWrite("Socket close: " + exc);
            }
            catch (Exception exc)
            {                //_fm.logWrite("Socket close ception: " + exc);
            }
        }

Answer 2

1 如果你有公网ip端口，其实就是做好了nat端口映射(虚拟服务器,upnp），这样tcp是可以连接的。
但是如果没有在路由器做这个端口映射(或路由器不开upnp)，则tcp无法连接。
2 异步(线程池)。
3 你首先解决寻址和端口开放的问题，然后才能下一步的tcp连接。看你的说明寻址是手工输入tcp ip端口，那可以。但是输入的端口要保证在对方路由器上是开放的。