Asynchronous Socket Thread closes after first receive

[AndreasS]

Good day,

I have a serious problem and need to get it done. Almost spend two days of frustration...

I have a Tcp-Server just waiting for incoming connections and forwarding the received data.
Everything works fine for the first time I receive data, but right after finishing the method my thread closes down - I have no clue why this happens.

Could you have a look at my code and tell me if there is anything wrong?

private byte[] fByteBuffer = new byte[fConstants.cBUFFERSIZE];
private Socket fServer;

        public void Start(){

            try {
                fServer = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
                IPEndPoint vEndPoint = new IPEndPoint(IPAddress.Any, ServerPort);
                fServer.Bind(vEndPoint);
                fServer.Listen(5);
                fServer.BeginAccept(new AsyncCallback(AcceptConnection), fServer);
            } catch ( Exception e ) {
                throw new Exception("TCVServer.Start() could not create Server", e);
            }
        }

        private void AcceptConnection(IAsyncResult aResult) {

            Socket vServer = (Socket)aResult.AsyncState;
            Socket vClient = vServer.EndAccept(aResult);
            Log("Connection: " + vClient.RemoteEndPoint.ToString());
            vClient.BeginReceive(fByteBuffer, 0, fByteBuffer.Length, SocketFlags.None,
                                          new AsyncCallback(ReceiveConnection), vClient);
        }

        private void ReceiveConnection(IAsyncResult aResult) {

            Socket vClient = (Socket)aResult.AsyncState;
            int vReceivedBytes = vClient.EndReceive(aResult);

            if ( vReceivedBytes > 0 ) {

                //These 3 lines handle the received data
                TXPacket vPacket = new TXPacket();
                vPacket.ReadFromBuffer(fByteBuffer);
                fOwner.RemoteAccess(vPacket);

                vClient.BeginReceive(fByteBuffer, 0, fByteBuffer.Length, SocketFlags.None,
                                              new AsyncCallback(ReceiveConnection), vClient);
            } else {
                fServer.BeginAccept(new AsyncCallback(AcceptConnection), fServer);
                Log("Connection lost");
            }
        }

[valaris]

What happens when it closes down? Do you get an exception? Does your log output "Connection lost"? Is your client persisting the connection or closing after it sends its payload?