Can I send data using the same TCP port?

I have a TCP listener working but doesn't send anything. To get this TCP listener working I have a thread in a endless loop.

Now I need to answer to some specific packets and also be able to send data when the user request it using the same port that the TCP listener is using. The remote device keeps the connection open to be able to receive new data.

So, I must to create a new TCP client to send data to the current connected client or use the current listener socket?

Public Sub StopServer()
    TcpOpen = False
    Server.Stop()
    ServerThread = Nothing
End Sub
Public Sub InitServer(ByVal Port As Integer)
    Server = New TcpListener(IPAddress.Any, Port)
    ServerThread = New Thread(AddressOf ConnectionListener)
    ServerThread.IsBackground = True
    ServerThread.Start()
    TcpOpen = True
End Sub
Private Sub ConnectionListener()
    Server.Start()
    While True
        If TcpOpen Then
            If Server.Pending Then
                Dim client As TcpClient = Server.AcceptTcpClient()
                Dim T As New Thread(AddressOf StartTcpClient)
                client.ReceiveBufferSize = 128000
                T.IsBackground = True
                T.Start(client)
            Else
                System.Threading.Thread.Sleep(10)
            End If
        Else
            Exit While
        End If
    End While
End Sub
Private Sub StartTcpClient(ByVal client As TcpClient)
    Dim bytesRead As Integer
    Dim RxBuffer(1500) As Byte 'Original 1024
    Dim RxDataStr As String = ""
    Dim TxBuffer(1500) As Byte
    Dim TxDataStr As String = ""
    Dim TempData As String
    Dim DataReceived As Boolean = False

    Dim TimeX As Integer = 0

    Dim RemoteIP As Net.IPEndPoint = client.Client.RemoteEndPoint
    Dim RemoteIPStr As String = RemoteIP.Address.ToString

    WriteRTBLog("Se inicio una nueva conexion TCP con la IP " & RemoteIPStr, Color.DarkViolet)
    WriteRTBLog("Esperando datos...", Color.Black)

    client.ReceiveTimeout = 30000

    Try
        While True
            If client.GetStream.DataAvailable Then
                bytesRead = client.GetStream.Read(RxBuffer, 0, RxBuffer.Length)
                TimeX = 0 'Reset timer

                If bytesRead > 0 Then
                    TempData = System.Text.ASCIIEncoding.UTF8.GetString(RxBuffer, 0, bytesRead) 'UTF8 

                    RxDataStr += TempData
                    If Not DataReceived Then
                        DataReceived = True
                        WriteRTBLog("Se estan recibiendo datos...", Color.Purple)
                    End If

                    If RxDataStr.Contains("<") Then
                        'Process data
                        TxDataStr = AnswerProcessor(RxDataStr)

                        'New code- trying to send data
                        If TxDataStr.Length > 5 Then
                            TxBuffer = System.Text.Encoding.ASCII.GetBytes(TxDataStr)
                            client.Client.Send(TxBuffer)
                        End If

                        RxDataStr = "" 'Clean buffer
                    End If
                End If
            Else
                If Not client.Connected Then
                    Exit While 'Close connection
                Else
                    System.Threading.Thread.Sleep(10)
                End If
            End If

        End While

        If RxDataStr.Length > 0 Then

            WriteRTBLog(String.Format("Se recibieron {0} bytes desde {1}", RxDataStr.Length.ToString, RemoteIPStr), Color.ForestGreen)
            If Not client.Connected Then
                WriteRTBLog("Conexion cerrada", Color.Black)
            End If
        End If

    Catch ex As Exception
        client.Close()
        WriteRTBLog("Error en la conexion a " & RemoteIPStr, Color.Red)
        WriteRTBLog(ex.Message, Color.Red)
        WriteRTBLog(ex.StackTrace, Color.Red)

        If RxDataStr.Length > 0 Then
            ' Create the file. 
            Dim PathX As String = Application.StartupPath & "\TCP_File_err" & CLng(DateTime.UtcNow.Subtract(New DateTime(1970, 1, 1)).TotalMilliseconds) & ".TCP"
            Using fs As FileStream = File.Create(PathX)
                Dim data As Byte() = New ASCIIEncoding().GetBytes(RxDataStr)
                ' Add some information to the file.
                fs.Write(data, 0, data.Length)
            End Using
            WriteRTBLog(String.Format("Se recibieron {0} bytes desde {1} y se guardaron en {2}.", RxDataStr.Length.ToString, RemoteIPStr, PathX), Color.ForestGreen)
        End If
    End Try
End Sub