"The underlying connection was closed: The connection was closed unexpectedly"

Hi,
Im working with this Arquitecture : 
Web Service  -> DLL(Xml Translator)  -> Asp.net.
Everything works fine, but,i have a process that takes about 23 minutes, in that time i show a "loading screen" that avoid the user to do anything, but  after 20 mins while the web service is working and after debug my code, i get this error :
"The underlying connection was closed: The connection was closed unexpectedly"
Then, my "loading screen" keep visible until  the web service completes the work, and after that, the "loading" hides and the web form shows my gridview empty.(its should show data).
Regards and thanks.




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