Software to test users connection quality - are there any?

Hello :)

We're massively deploying users on remote via Internet and faced usual problem with links quality vs our systems/network quality. We need some tool/software that can be installed centrally in our datacenters and have a client part that can be started with simple command or a button push and provide a simple test - bandwidth, RTT/jitter, packet loss from client to central part.

Don't you know what we can use?

Thanks!