File Transfer App

I wrote a File Trasfer App that runs as a command line program. It times out and doesn't send the file.
Any ideas?
Thanks In Advance

Imports System.Net.Sockets
Imports System.Net
Imports System
Imports System.IO
Imports System.Console

Module Globals
Sub Main(ByVal args As String())
If args.Length < 1 Then InvalidUsage() : Return

Select Case args(0).ToLower()
Case "-s", "/s" 'Sending
If args.Length < 4 Then WriteLine("Insufficient arguments") : Return

Dim address As IPAddress
If Not IPAddress.TryParse(args(1), address) Then _
WriteLine("Invalid IP Address") : Return

Dim port As Integer
If Not Integer.TryParse(args(2), port) Then _
WriteLine("Invalid Port") : Return

DoSend(args(3), address, port)
Case "-r", "/r" 'Receiving
If args.Length < 3 Then WriteLine("Insufficient arguments") : Return

Dim port As Integer
If Not Integer.TryParse(args(1), port) Then _
WriteLine("Invalid port") : Return

DoReceive(args(2), port)
Case "-?", "/?"
ShowUsage()
Case Else
InvalidUsage()
End Select
End Sub

Sub CopyStream(ByVal source As Stream, ByVal destination As Stream)
Dim buffer As Byte() = New Byte(255) {}
Dim bytesRead As Integer

Do
bytesRead = source.Read(buffer, 0, buffer.Length)

If bytesRead = 0 Then Return

destination.Write(buffer, 0, bytesRead)
Loop
End Sub

Sub DoSend(ByVal filePath As String, ByVal address As IPAddress, ByVal port As Integer)
If Not File.Exists(filePath) Then
WriteLine("Specified File does not exist")
Return
End If

Dim remoteEP As IPEndPoint = New IPEndPoint(address, port)

Using connection As New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp), _
file As New FileStream(filePath, FileMode.Open)

connection.Connect(remoteEP)
Dim netStream As New NetworkStream(connection, False)

CopyStream(file, netStream)
End Using
End Sub

Sub DoReceive(ByVal filePath As String, ByVal port As Integer)
Dim listener, connection As Socket
Dim file As FileStream
Dim netStream As NetworkStream

If IO.File.Exists(filePath) Then
WriteLine("The specified file name already exists!")
Write("Overwrite [y/n]? ")
If ReadLine().ToUpper()(0) <> "Y"c Then Return
End If

Try
listener = New Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp)
listener.Bind(New IPEndPoint(IPAddress.Any, port))
listener.Listen(1)

Dim ar As IAsyncResult = listener.BeginAccept(Nothing, Nothing)

If Not ar.AsyncWaitHandle.WaitOne(TimeSpan.FromSeconds(15), False) Then
WriteLine("Timed out")
Return
End If

connection = listener.EndAccept(ar)
netStream = New NetworkStream(connection)
file = New FileStream(filePath, FileMode.Create)

CopyStream(netStream, file)
Catch ex As Exception
Write("Exception Encountered!: ") : WriteLine(ex.Message)
Finally
IDispose(listener, connection, file)
End Try
End Sub

Sub InvalidUsage()
WriteLine("Invalid Usage")
WriteLine()
ShowUsage()
End Sub

Friend Sub IDispose(ByVal ParamArray disposables As System.IDisposable())
If disposables Is Nothing Then Return

For Each disposable As System.IDisposable In disposables
If Not disposable Is Nothing Then disposable.Dispose()
Next
End Sub

Sub ShowUsage()
WriteLine("Usage:")
WriteLine("SendFile.exe -s ipAddress port filePath")
WriteLine("SendFile.exe -r port filePath")
WriteLine()
WriteLine("-s Sending mode")
WriteLine()
WriteLine("-r Receiving mode")
WriteLine()
WriteLine("ipAddress The IPv4 address of the computer to")
WriteLine(" which 'filePath' will be sent")
WriteLine()
WriteLine("port The port used for sending/receiving")
WriteLine()
WriteLine("filePath The path of the file being sent with '-s'")
WriteLine(" -OR-")
WriteLine(" The filename underwhich the received data")
WriteLine(" will be saved with '-r'")
End Sub
End Module