请教：C#网络编程相关的知识，建立socket服务器时向客户端连接，就建立不了了？

我现在在做一个C/S的服务器模型了，用socket（C#）做的，服务器建立的是并发的模型，客户端连接服务器后服务器保存客户端的相关信息，然后启动新线程来处理这个连接了（命令连接），这个连接仅仅发送少量的命令（定义过的格式），当客户端需要服务器的大量的数据文件时，就在客户端新建一个socket并绑定到一个未使用的端口，然后把端口信息通过命令连接传给服务器，服务器受到后就新建一个socket连接客户端的这个侦听端口，但是现在怎么都连不上，不知道问题处在那了？原来的那个命令连接存在了。

建立的模型如下服务器：

public void Start()
        {
            listenSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            listenPort = 7000;
            MaxBufferLength = 16 << 10;
            listenEndPoint = new IPEndPoint(IPAddress.Any, this.listenPort);
            listenSocket.Bind(listenEndPoint);
            //get loacl ip;
            this.localIp = "192.168.0.100";/*((IPEndPoint) listenSocket.LocalEndPoint).Address.ToString();*/
            InitUsefulPortList();
            //init client list
            this.clientList = new ClientList();
            listenSocket.Listen(1000);
            while (true)
            {
                Socket tempsocket = listenSocket.Accept();
                ClientId item = new ClientId((IPEndPoint)tempsocket.RemoteEndPoint, tempsocket);
                //item.isAuthroize = true;
                //item.PdaId = sessionid.ToString();
                item.ServerSendConfigSigned = new ManualResetEvent(false);
                item.ServerSendConfigSigned2 = new ManualResetEvent(false);
                clientList.Add(item);
                //this.localIp = ((IPEndPoint)tempsocket.LocalEndPoint).Address.ToString();
                System.Threading.ThreadPool.QueueUserWorkItem(new System.Threading.WaitCallback(ProcessReceiveData), tempsocket);
            }
        }

处理连接的方法：

        private void ProcessReceiveData(object serversocket)
        {
            Socket tempsocket = (Socket)serversocket;
            IntPtr sessionid = tempsocket.Handle;
            Valid(tempsocket);
            //if (!Valid(tempsocket))
            //{
            //    //need transfer login error result;
            //    string result = "";
            //    LoginCommand login = new LoginCommand(false, result);
            //    login.SessionId = sessionid.ToString();
            //    SendCommand(tempsocket, login);
            //    return;
            //}
            ClientId item = clientList.GetClientIdByEndPoint((IPEndPoint)tempsocket.RemoteEndPoint);
            item.isAuthroize = true;
            item.PdaId = sessionid.ToString();
            //need transfer login success 
            //send login response;
            bool isneedupdateconfigfile = true;
            LoginCommand log = new LoginCommand(true, "Successful", false, isneedupdateconfigfile);
            
            log.SessionId = sessionid.ToString();
            
            SendCommand(tempsocket, log);
            if (isneedupdateconfigfile)
            {
                item.ServerSendConfigSigned.Set();
                item.ServerSendConfigSigned2.WaitOne();
                
            }
            ReceiveCommand(tempsocket, item);

        }
private void ReceiveCommand(Socket tempsocket,ClientId item)
        {
            while (tempsocket.Connected)
            {
                byte[] buffer = new byte[MaxBufferLength];
                int count = tempsocket.Receive(buffer);
                while (count < 1)
                    count = tempsocket.Receive(buffer);
                byte[] buf = new byte[count];
                Buffer.BlockCopy(buffer, 0, buf, 0, count);
                ReceiveCommand command = ReceivePacketManager.ReceiveCommand(buf);
                //notify high layer;
                //有些命令需要创建数据端口。

                   Socket serverdatasocket = null;
                if (IsNeedCreateDataPort(command))
                {
                    serverdatasocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    string filename = "";
                    ReceiveFile(serverdatasocket, filename);
                    //TODO:
                    if (ReceiveData != null)
                        ReceiveData(StaticDefine.TransferType.File, item,filename);
                    break;
                }
                //need send data;
                if (IsNeedSendData(command))
                {
                    IPEndPoint temp = GetClientDataPort(command);
                    item.ClientDataIpEndPoint = temp;
                    serverdatasocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    newConfigfile = @"D:\config.xml";
                    SendData(temp, serverdatasocket, newConfigfile);
                    //SendData(temp, tempsocket, newConfigfile);
                    serverdatasocket.Shutdown(SocketShutdown.Both);
                    serverdatasocket.Close();
                    //send data transfer over command 
                    SendCommand(tempsocket, new DataTransferOver());
                    serverdatasocket.Shutdown(SocketShutdown.Both);
                    serverdatasocket.Close();
                    break;
                }
                //datatransferover command need close socket;
                if (IsNeedCloseDataPort(command))
                {
                    CloseDataPort(serverdatasocket);
                    item.ServerDataIpEndPoint = null;
                    break;
                }
                if (IsNeedCreateNetInfoDataPort(command))
                {
                    serverdatasocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                    ReceiveNetInformation(serverdatasocket,tempsocket,item.PdaId,item);
                    break;
                }
                //TODO:
                if (ReceiveData != null)
                    ReceiveData(StaticDefine.TransferType.Command, item, command);
            }
        }
private void SendData(IPEndPoint clientdataipendpoint,Socket serverdatasocket,string filename)
        { 
            //仅发送配置文件。

              FileStream fileStream = null;
            IPEndPoint ip = CreateIPEndPoint();
            try
            {
                serverdatasocket.Connect(clientdataipendpoint);
                fileStream = File.OpenRead(filename);
                byte[] buffer = new byte[MaxBufferLength];
                while (0 < fileStream.Read(buffer, 0, MaxBufferLength))
                {
                    serverdatasocket.Send(buffer);
                }
                System.Diagnostics.Debug.WriteLine("发送配置文件成功");
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine("发送配置文件错误："+ex.Message);
            }
            if (fileStream != null)
            {
                fileStream.Close();
                fileStream = null;
            }
        }

客户端代码：

public void Start()
        {
            loginErrorCode = null;
            isAuthrize = false;
            MaxBufferLength = 16 << 10;
            localCommandSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
            //if (!ConnectionManager.Connect(false))
            //{
            //    System.Diagnostics.Debug.WriteLine("无法连接管理器");
            //    return;
            //}

            try
            {
                localCommandSocket.Connect(serverCommandIpEndPoint);
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine("建立连接失败："+ex.Message);
                //this.localCommandSocket.Shutdown(SocketShutdown.Both);
                this.localCommandSocket.Close();
                return;
            }
            this.user = "yangxingya";
            this.pass = "yangxingya";
            LoginCommand login = new LoginCommand(user, pass);
            SendCommand(localCommandSocket, login);
            if (!LoginSussess(localCommandSocket))
            {
                System.Diagnostics.Debug.WriteLine("登陆失败" + loginErrorCode);
                return;
            }
            System.Diagnostics.Debug.WriteLine("登陆成功");
            commandReceiveThread = new Thread(new ThreadStart(Receivecommand));
            commandReceiveThread.Start();
        }

        private void Receivecommand()
        {
            Receivecommand(localCommandSocket);
        }

        private bool LoginSussess(Socket localCommandSocket)
        {
            bool temp = false;
            byte[] buffer = new byte[MaxBufferLength];
            int count = 0;
            while (count < 1 && localCommandSocket.Connected)
            {
                count = localCommandSocket.Receive(buffer);
            }
            byte[] buf = new byte[count];
            Buffer.BlockCopy(buffer, 0, buf, 0, count);
            ReceiveCommand command = ReceivePacketManager.ReceiveCommand(buf);
            LoginResponseCommand login = command as LoginResponseCommand;
            if (login != null)
            {
                if (login.IsLogin)
                {
                    temp = true;
                    loginErrorCode = login.Code;
                }
                this.sessionId = login.SessionId;
                if (IsNeedCreateReceiveDataPort(command))
                {
                    this.clientDataIpEndPoint = new IPEndPoint(IPAddress.Any, 30000);
                    //this.dataReceiveThread = new Thread(new ThreadStart(ReceiveData));
                    //this.dataReceiveThread.Start();
                    ReceiveData();
                }
            }
            System.Diagnostics.Debug.WriteLine("登陆"+(temp?"成功":"失败"));
            return temp;
        }

        private void Receivecommand(Socket localCommandSocket)
        {
            //throw new NotImplementedException();
            while (localCommandSocket.Connected)
            {
                byte[] buffer = new byte[MaxBufferLength];
                int count;
                do
                {
                    count = localCommandSocket.Receive(buffer);
                } while (count < 1);
                ReceiveCommand command = ReceivePacketManager.ReceiveCommand(buffer);
                
                if (IsNeedSendFile(command))
                {
                    UploadDataRequestCommand uploadfile=command as UploadDataRequestCommand;
                    if(uploadfile!=null)
                    {
                        IPHostEntry iphost=Dns.Resolve(uploadfile.Ip);
                        IPAddress ipaddress=iphost.AddressList[0];
                        this.serverDataIpEndPoint=new IPEndPoint (ipaddress,uploadfile.Port);
                        Socket temp=new Socket (AddressFamily.InterNetwork,SocketType.Stream,ProtocolType.Tcp);
                        string filename="";
                        temp.Connect(this.serverDataIpEndPoint);
                        SendFile(temp,filename);
                        SendCommand(localCommandSocket, new SendDataPacket.DataTransferOverCommand());
                    }
                    
                }
                if (IsNeedSendNetInfo(command))
                {
                    UploadResponseCommand uploadnetinfo = command as UploadResponseCommand;
                    if (uploadnetinfo != null)
                    {
                        IPHostEntry iphost = Dns.Resolve(uploadnetinfo.Ip);
                        IPAddress ipaddress = iphost.AddressList[0];
                        this.serverDataIpEndPoint = new IPEndPoint(ipaddress, uploadnetinfo.Port);
                        if (SendNetInfo(this.serverDataIpEndPoint, netInfo))
                        {
                            SendCommand(localCommandSocket, new SendDataPacket.DataTransferOverCommand());
                            netInfo = null;
                        }
                    }
                }
                if (IsNeedCloseDataPort(command))
                {
                    if (this.configFileStream != null)
                    {
                        this.configFileStream.Close();
                        this.configFileStream = null;
                    }
                    if (localDataSocket != null)
                    {
                        localDataSocket.Shutdown(SocketShutdown.Both);
                        localDataSocket.Close();
                        localDataSocket = null;
                    }
                }
            }
        }
private void ReceiveData()
        {
            Socket temp = null;
            try
            {
                localDataSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                IPEndPoint end = new IPEndPoint(IPAddress.Any, clientDataIpEndPoint.Port);
                localDataSocket.Bind(end);
                localDataSocket.Listen(1000);
                //发送命令

                ConfigUpdateStartCommand configupdatestart = new ConfigUpdateStartCommand(((IPEndPoint)localCommandSocket.LocalEndPoint).Address.ToString(), clientDataIpEndPoint.Port);
                SendCommand(localCommandSocket, configupdatestart);

                temp = localDataSocket.Accept();
                byte[] buffer = new byte[MaxBufferLength];
                string configFileName = @"\config.xml";
                this.configFileStream = File.Create(configFileName);
                int count = temp.Receive(buffer);
                while (count < 1)
                {
                    count = temp.Receive(buffer);
                }
                while (count >0)
                {
                    configFileStream.Write(buffer, 0, count);
                    count = temp.Receive(buffer);
                }
            }
            catch (Exception ex)
            {
                System.Diagnostics.Debug.WriteLine("接受配置文件错误："+ex.Message);
               
                //if (this.localDataSocket != null)
                //{
                //    this.localDataSocket.Shutdown(SocketShutdown.Both);
                //    this.localDataSocket.Close();
                //}
               
            }
            if (temp != null)
            {
                temp.Shutdown(SocketShutdown.Both);
                temp.Close();
                temp = null;
            }
            if (this.configFileStream != null)
            {
                this.configFileStream.Close();
                this.configFileStream = null;
            }
        }

请高手给指点一下问题处在那里了？