Sending multiple request to server

My code is hosted on amazon web service server and I m using Hathway Internet Service Provider (India based ISP). Previously my code was working perfectly with Hathway ISP but from few days back my code is not working as expected. I tried to execute same code from another user of Hathway ISP there also I faced same issue. I thought there was something wrong with my code, after debugging I found everything was perfect, this I came to know when I executed my code with some other ISP. What is happening with Hathway ISP is, it's sending multiple request to server. Browser sending only one request to the server this I checked in browser Network tab but doesn't know what happening in the middle that server getting multiple request. Let me give some overview of my code,

1. It is written in php
2. Excel file is being downloaded
3. Code has huge calculation so it takes 10 to 15 min for excel file to get downloaded

Thanks

via Chebli Mohamed