Polling in VB.NET

post more info please so I could help you are generalizing the subject to much. :)

Basically the the main office (server) will receive reports from their stores (clients) through the modem at the end of the night.  The main office can also send updates and reports to there stores as well.  Once they have received their reports, or possibly at anytime during the day (that is a separate issue).  The actual polling is just sending the server the client's reports.  What I need is a .net control, dll, or package that supports polling in this type of situation.  The main concern is being able to communicate to all these stores and not have any issues done the line because the server is busy.  Is that enough info, or is more needed?

does the server dial the clients through dialup connection or vise-versa , or is the connection through ADSL i.e. Always connected ?

what kind of data is sent are they files or a connection to the main server's database and execution of some queries ?

are the stores networked together or does the server contacts eah one separately?

Clients dialup to the server, send .ini files, csv files, etc., and are not networked together.

Sounds great however I have never used a vpn connection.  Do you know of any good tutorials on this topic.

I have found a couple of things so far but it seems like the internet is needed to do this, however none of our stores have internet connection.  is using the vpn still possible in this scenario?

yes through the dialup connection

you need to do the following :

on the server

open network connections in the my network places window
click create new connection
Select setup an advanced connection
click next
Select Accept incoming connections
click next
select the modem that you will accept calls on
click next
select allow Virtual private Connections
click next
Select the users that you will allow to connect through that connections (these are local users you can add or delete users as you wish)
click next
highlight Internet protocol (TCP/IP) and press Properties
Select Specify TCP/IP Addresses
AND enter 192.168.0.2 in from
               192.168.0.100 in to
then hit ok
click next
then click finish

on the clients
open network connection and click create new connection
select connect to the network at my workplace
click next
select dialup connection
click next
Name the connection
click next
enter the phone number of the server
click next
click finish

when you connect using this connection supply the user name and password that you selected at the server
 hope this helps you ....

Sorry to keep bugging you about this but how would I access this network to send files from the client to the server.

do you mean programmatically or manually while they are both basically the same...

you first need to share a folder by right clicking on it and selecting properties then sharing tab
enable file sharing and select allow network users to change the content of the folder

then ok

all you have to do then is open start then run then enter the following
\\the ip address of the server \the shared folder name
i.e.
\\192.168.0.5\mainshare
this should open the remote folder then you could access it normally

or you could type the server computer name instead of the ip address they are both the same

I know this is asking for a bit much but can you give me another example programmatically to do this.  I you could I would appreciate it and thanks for all of your help with this.  I really do appreciate it.

This function will copy the a file from src to dest

    Public Function CopyFile(ByVal Src As String, ByVal Dest As String) As Boolean
        Try
            Dim stSrc As New IO.FileStream(Src, IO.FileMode.Open)
            Dim Bytes(stSrc.Length - 1) As Byte
            stSrc.Read(Bytes, 0, stSrc.Length)
            Dim stDest As New IO.FileStream(Dest, IO.FileMode.Create)
            stDest.Write(Bytes, 0, Bytes.Length)
            stSrc.Close()
            stDest.Close()
            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function

all you have to do is call the function providing the src file path and the destination file path
i.e.
the file is located at C:\test.ini
the serverPc Shared folder is MainShare
so you call the function like this

CopyFile("C:\Test.ini","\\ServerPC\MainShare\Test.ini")
or
CopyFile("C:\Test.ini","\\192.168.0.2\MainShare\Test.ini")

Glad to be of service :)