Hi, To test the webservice use SOAPUI tool. This is open Source and a completely free tool. You can also use .NET tool provided to test the webservice. Check the following for your webservice response Network response. Database. Resources. Do the ping or telnet request to the objects and servers your webservice is trying to access.

I suggest you to download the data first, instead of keeping such a huge data in in-memory. You can download the data to the client and store it in MSAccess or .TXT. Later use your code to do the calculation on the data.

use Response.Redirect

You can use session if data is not that big or you can use cross page posting like PreviousPage.FindControl