Socket connected but send doesn't seem to work

[flyingpan]

I have an old vb6 desktop application which communicates with a mainframe server using socket (winsock 2) that i need to convert to .net. I found the small code which seems correct to me using System.Net.Socket. When running the console window just hang there showing blank.

        Dim s As Socket = ConnectSocket(server, port)

        If s Is Nothing Then
            Return "Connection failed"
        End If
        ' Send request to the server.

        Dim numSent As Integer
        numSent = s.Send(bytesSent)


        Dim bytes As Int32

        Do
            bytes = s.Receive(bytesReceived, bytesReceived.Length, 0)
            Console.WriteLine(bytes.ToString())

        Loop While bytes > 0

Here is the connect function

Private Function ConnectSocket(server As String, port As Integer) As Socket
        Dim s As Socket = Nothing
        Dim hostEntry As IPHostEntry = Nothing

        ' Get host related information.
        hostEntry = Dns.GetHostEntry(server)

        ' Loop through the AddressList to obtain the supported AddressFamily. This is to avoid
        ' an exception that occurs when the host host IP Address is not compatible with the address family
        ' (typical in the IPv6 case).
        Dim address As IPAddress

        For Each address In hostEntry.AddressList
            Dim endPoint As New IPEndPoint(address, port)
            Dim tempSocket As New Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp)

            tempSocket.Connect(endPoint)

            If tempSocket.Connected Then
                s = tempSocket
                Exit For
            End If

        Next address

        Return s
    End Function

So I run wireshark on the port the app is communicating (port in the code above) I can see package sent and received with connectSocket, but no package is detected with s.Send(bytesSent). I wonder why.