c# - Client not receiving message in time (TcpClient) -

i have 2 applications "talk" each other tcp, problem when send something, application doesn't receives @ same time, when requests second time, 'he' receives duplicated. example:

client request connection (income string: 00200001 0050);

server accept connection(acknowledge) (output string: 00570002);

the client doesn't receives acknowledge, when requests connection again, receives output string of: 00570002 00570002 (duplicated).

this happens in application connects mine.

            private int listenerport = 4545;             private tcplistener listener;             private tcpclient socket;              public communicator()             {                 try                 {                     this.listener = new tcplistener(ipaddress.parse("127.0.0.1"), listenerport);                     listenerport++;                     listener.start();                     this.connecttopendingrequest();                 }                 catch (exception ex)                 {                     listener.stop();                     throw new exception(ex.message);                 }             }              /// <summary>             /// try connect pending requests             /// </summary>             public void connecttopendingrequest()             {                 try                 {                     if (socket == null || !socket.connected)                         if (listener.pending())                         {                             this.socket = listener.accepttcpclient();                             this.socket.nodelay = true;                         }                 }                 catch (invalidoperationexception) { throw new exception("listener not started!"); }                 catch (exception ex) { throw new exception("error has ocurred when connecting device: " + ex.message); }             }              /// <summary>             /// send messages device             /// </summary>             public void sendmessages(string stringmessage)             {                 if (socket.connected)                 {                     try                     {                         byte[] outstream = encoding.ascii.getbytes(stringmessage);                         socket.getstream().write(outstream, 0, outstream.length);                         socket.getstream().flush();                     }                     catch (exception ex)                     {                         throw new exception("message not sent.\nerror: " + ex.message);                     }                  }                 else { throw new exception("no device connected"); }              }          /// <summary>         /// message socket         /// </summary>         /// <returns></returns>         public string getmessagefromsocket()         {             try             {                 byte[] instream = new byte[10025];                  socket.getstream().read(instream, 0, (int)socket.receivebuffersize);                 return system.text.encoding.ascii.getstring(instream);             }             catch (exception ex)             {                 throw new exception("message not read.\nerror: " + ex.message);             }         } 

am forgetting something? have way ensure message has arrived ? (guess tcp should but...)

ps: don't have issues when receiving messages.

thanks in advance!

1. listenerport++; not needed. several clients can connect same listener on same port
2. i don't see client code here or entangled server code
3. socket.getstream().flush() not needed.
4. .pending() non-blocking can miss moment of connection
5. look @ tcplistener , tcpclient code samples