How To Use NT Simple TCP/IP Services for Winsock Testing

Windows NT has a Simple TCP/IP Services service that can be used to test applications that use the Winsock API and/or the Winsock Control. Rather than having to create both a client and server in Visual Basic, you can test the client against this service.

A list of well-known ports available through this service can be found on an NT machine in the text document C:\WINNT\SYSTEM32\DRIVERS\ETC\SERVICES.

The following sample describes how to use the Microsoft Winsock Control that shipped with Visual Basic to call the Echo service and the Quote Service.

Verify that Simple TCP/IP Services is Running

Check to see if you can contact the server you are trying to attach to by running Ping <servername> at the command prompt. If the server responds, go to the control panel on the server and start the Services icon. Check the list that comes up for Simple TCP/IP Services.

The Simple TCP/IP Services service must be running for these samples to work correctly. If Simple TCP/IP Services is not listed, double-click Network in the Control Panel.

In Windows NT 3.51, click Add Software, choose TCP/IP Protocol and related components, and click OK. In the dialog box that appears, click Simple TCP/IP Services and click OK.

In Windows NT 4.0, click Add, choose Simple TCP/IP Services, and click OK.

The install program may ask you to provide the path to the Windows NT installation CD-ROM and will require that you restart the computer when it is finished.

Using the Echo Service

1. Create a new Standard EXE project in Visual Basic.
2. From the Projects menu, choose Components. Make sure that Microsoft Winsock Control is checked and click OK.
3. Add a Winsock Control to the form and leave it named Winsock1.
4. Add three CommandButtons named cmdConnect, cmdEcho, and cmdDisconnect, and then change the captions to Connect, Echo and Disconnect, respectively.
5. Add two text boxes and leave them named Text1 and Text2, but change the MultiLine property on each to True.
6. Add the following code to the form:

         Option Explicit
         Const EchoPort = 7
   
         Private Sub cmdConnect_Click()
            Dim temp As String
            temp = InputBox$("Enter a server name...", _
                   "Connect to the Echo Service", Winsock1.RemoteHost)
            If temp <> "" Then
            If Winsock1.State <> sckClosed Then Winsock1.Close
               Winsock1.RemoteHost = temp
               Winsock1.RemotePort = EchoPort
               Winsock1.LocalPort = 0
               Winsock1.Connect
            End If
         End Sub
   
         Private Sub cmdDisconnect_Click()
            If Winsock1.State <> sckClosed Then Winsock1.Close
            cmdConnect.Enabled = True
            cmdDisconnect.Enabled = False
            cmdConnect.SetFocus
         End Sub
   
         Private Sub cmdEcho_Click()
            Winsock1.SendData Text1.Text
            cmdEcho.Enabled = False
         End Sub
   
         Private Sub Winsock1_Close()
            If Winsock1.State <> 0 Then Winsock1.Close
         End Sub
   
         Private Sub Winsock1_Connect()
            cmdConnect.Enabled = False
            cmdEcho.Enabled = True
            cmdDisconnect.Enabled = True
         End Sub
   
         Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
   
            Dim temp As String
            temp = String(bytesTotal, "*")
            Winsock1.GetData temp, vbString, bytesTotal
            Text2.Text = temp
            cmdEcho.Enabled = True
         End Sub
   
         Private Sub Winsock1_Error(ByVal Number As Integer, _
                                    Description As String, _
                                    ByVal Scode As Long, _
                                    ByVal Source As String, _
                                    ByVal HelpFile As String, _
                                    ByVal HelpContext As Long, _
                                    CancelDisplay As Boolean)
            MsgBox "Error: " & Number & vbTab & Description, vbOKOnly, _
                   "Winsock Control 1 Error"
            CancelDisplay = True
         End Sub
   
   					

Using the Quote and Time Services

1. Create a new STANDARD EXE project in Visual Basic.
2. From the Projects menu, choose Components. Make sure that Microsoft Winsock Control is checked and then click OK.
3. Add a Winsock Control to the form and leave it named Winsock1.
4. Add two CommandButtons named cmdQuote and cmdTime, then change the captions to Quote and Time, respectively.
5. Add a text box and leave it named Text1, but change the MultiLine property on it to True.
6. Add the following code to the form:

         Const TimePort = 13, QuotePort = 17
         Private Sub cmdQuote_Click()
            Dim temp As String
            temp = InputBox$("Enter a server name...", _
                             "Get a Quote", Winsock1.RemoteHost)
            If temp <> "" Then
               If Winsock1.State <> sckClosed Then Winsock1.Close
               Winsock1.RemoteHost = temp
               Winsock1.RemotePort = QuotePort
               Winsock1.LocalPort = 0
               Winsock1.Connect
            End If
         End Sub
   
         Private Sub cmdTime_Click()
            Dim temp As String
            temp = InputBox$("Enter a server name...", _
                             "Get the time", Winsock1.RemoteHost)
            If temp <> "" Then
               If Winsock1.State <> sckClosed Then Winsock1.Close
               Winsock1.RemoteHost = temp
               Winsock1.RemotePort = TimePort
               Winsock1.LocalPort = 0
               Winsock1.Connect
            End If
         End Sub
   
         Private Sub Winsock1_Close()
            If Winsock1.State <> 0 Then Winsock1.Close
         End Sub
   
         Private Sub Winsock1_Connect()
            Beep
         End Sub
   
         Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
            Dim temp As String
            temp = String(bytesTotal, " ")
            Winsock1.GetData temp, vbString, bytesTotal
            Text1.Text = temp
         End Sub
   
         Private Sub Winsock1_Error(ByVal Number As Integer, _
                           Description As String, _
                           ByVal Scode As Long, _
                           ByVal Source As String, _
                           ByVal HelpFile As String, _
                           ByVal HelpContext As Long, _
                           CancelDisplay As Boolean)
            MsgBox "Error: " & Number & vbTab & Description, _
                   vbOKOnly, "Winsock Control 2 Error"
            CancelDisplay = True
         End Sub