One of our clients host our cms on his in-house server, the employees are connected to the server, and also we can connect to the server, through a VPN, we are in a different country. The internet connection at the client's data center is fast, faster than ours.
If we generate the report, it takes 8 minutes to be done and everything works well. If the client's employees try to do the same, it takes 15 minutes, and then the browser says "connection reset", and they're never able to successfully generate it.
Both parties are using the latest google chrome, the client's employees are saying that there is no firewall running on their PC. There's a firewall running on the server, but both parties are connected to the same server, and the same MYSQL database, it takes significantly less time to do the task from our end and doesn't throw an error.
Also, no other client is having the same problem. It's a LAMP installation on centos 6.5, can this issue be debugged?