Hi obaid7400,
The VPN environment you mean is the server environment or the client side pc environment? If you mean the server, then please refer to http://www.ajaxuploader.com/FAQ.htm#16 "How do I handle a large file upload?" section, ensure that your large file upload settings are correct.
Regards,
Ken
Hi,
I am talking about client side, our client use VPN to access our website.
client side use vpn will work. If the pc has low network speed with vpn, then try increase your server side timeout setting.