I am kind of new to this testing, I have a user working on intranet in the company connected to various routers with primary and secondary cascading routers in between to reach the target server. And also have two different users with a direct connection with a different IP directly hitting the target server via internet ( logging in from home or remotely). So what would be the best shot to test the performance of the whole architecture as what has to be tested and how this proxy testing is implemented.

Please help me with a solution ASAP.