[Resolved] UDP Client/Server Help Needed!

[Monkz]

I am very new to VB.net 2008, and i need to make a program where The client sends a number to the server, which notifies the client that it recieved that specific number, which then causes the client to automatically send a new number and wait for the notification before it sends again....

If anybody can help out, it would be greatly appreciated. Coming from VB 6.0 i am getting very confused with the way it is done in .NET.

This is my Current Code:

Server:

Imports System
Imports System.Net
Imports System.Net.Sockets
Imports System.Text
 
Public Class Server
    Public ipAddr As System.Net.IPAddress
 
 
    Private Sub receiver_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) _
 Handles MyBase.Load
        Dim t As New Threading.Thread(AddressOf listen)
        t.IsBackground = True
        t.Start()
    End Sub
 
    Private Sub receiver_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) _
    Handles Me.FormClosing
        If udp IsNot Nothing Then udp.Close()
    End Sub
 
    Private udp As Net.Sockets.UdpClient
    Private sendMessage As Net.Sockets.UdpClient
    Private Sub listen()
        Try
            udp = New Net.Sockets.UdpClient(6100)
 
            sendMessage = New Net.Sockets.UdpClient(6103)
 
            udp.EnableBroadcast = True
 
            Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6100)
            Do
 
                Dim b() As Byte = udp.Receive(ep)
                Me.Invoke(safeAddText, System.Text.Encoding.UTF32.GetString(b))
 
 
            Loop
        Catch ex As Exception
            MsgBox(ex.Message)
 
            ' If udp IsNot Nothing Then udp.Close()
        End Try
    End Sub
 
    Private Delegate Sub delAddText(ByVal text As String)
 
    Private safeAddText As New delAddText(AddressOf AddText)
 
    Private Sub AddText(ByVal text As String)
        ListBox1.Items.Add(text)
        Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6101)
        Dim b() As Byte = System.Text.Encoding.UTF32.GetBytes(text)
        sendMessage.Send(b, b.Length, ep)
 
    End Sub
 
End Class

Client:

Imports System.Net
Imports System.Net.Sockets
Imports System.Text
Imports Microsoft.VisualBasic.Strings
 
Public Class Frmmain
    Public Const Payload As String = "OCX000000FFFFFF"
    Public Counter As Integer = 1
    Public LastString As String
 
 
    Private Sub Frmmain_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim t As New Threading.Thread(AddressOf listen)
        t.IsBackground = True
        t.Start()
    End Sub
    Private udp As Net.Sockets.UdpClient
    Private sendMessage As Net.Sockets.UdpClient
 
    Private Sub listen()
 
        Try
            udp = New Net.Sockets.UdpClient(6101)
 
            udp.EnableBroadcast = True
 
            Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6101)
            Do
 
                Dim b() As Byte = udp.Receive(ep)
                Me.Invoke(safeAddText, System.Text.Encoding.UTF32.GetString(b))
 
            Loop
 
        Catch ex As Exception
            MsgBox("here:" & ex.Message)
 
            ' If udp IsNot Nothing Then udp.Close()
        End Try
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _
Handles Button1.Click
 
        Dim udp As New Net.Sockets.UdpClient()
        udp.EnableBroadcast = True
        Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6100)
        Dim b() As Byte = System.Text.Encoding.UTF32.GetBytes("Recieved")
        udp.Send(b, b.Length, ep)
 
    End Sub
 
    Private Delegate Sub delAddText(ByVal text As String)
    Private safeAddText As New delAddText(AddressOf AddText)
 
    Private Sub AddText(ByVal text As String)
        If (text.ToString = LastString.ToString) Then
            Counter += 1
        End If
        Listbox1.Items.Add(text)
        Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6101)
        Dim b() As Byte = System.Text.Encoding.UTF32.GetBytes(text)
        '  sendMessage.Send(b, b.Length, ep)
 
    End Sub
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
 
        Dim udp As New Net.Sockets.UdpClient()
        udp.EnableBroadcast = True
        Dim ep As New Net.IPEndPoint(IPAddress.Parse("127.0.0.1"), 6100)
        LastString = Counter.ToString.PadRight(4, "X") & Payload
        Dim b() As Byte = System.Text.Encoding.UTF32.GetBytes(LastString)
 
        udp.Send(b, b.Length, ep)
 
    End Sub
End Class

I would like the client to send packets in a sequence number that increases, ONLY increases when it gets the acknowledgement from the server that it recieved the sequence that the client sent. The payload attached never changes. If the server has not responded in 2 seconds that it recieved the sent sequence, it acknowledges the last sequence it received telling the client to send the same sequence number as it did before. And if the first one doesnt make it, the server acknowledges 0. I hope thats clear enough...

I also want the client to count how many times it needed to resend a packet twice or more before it got the acknowledgement from the server.

I think thats really all i need to change, and change the server from using a manual button and text from a textbox, to what i mentioned above.. If you can help me get these last bugs fixed i think ill be finished!

Thanks so much!