Time-out/Server setup (Forging)

We have set up a server (secure server switzerland) for forging with about 110'000 MHC on it. We have seen that we have a 2 stare rating and it indicates, that there a substantial amout of server time-outs.

Could you help me how we can eliminate this time outs? So we can support your network structure and be a reliable partner for your infrastructure.

Our infrastructure:
HP DL 380 g7, Dual Xeon e5645, 65GB ram, 1.8 tb storage, 4x600 GB SAS 10k disks in raid 5, Debian 9.8

The port 9999 is constantly accessable from outside (tested & monitored).

Thank you for your advice and kind regards, Mark