How can I tell if drop outs to server are due to network or a bottle neck?

Hi guys,

We are, very sadly, using managed offices for a remote office. We have a decent HP DL380e Gen8 server with a Windows 2012 R2 OS.

One LAN port is connected to a port on the wall and another port, ILO, is connected to the next available port on the wall.

To eliminate possible issues from my side, I am connected to our Watchguard firewall at the remote site and pinging the server. Every 70 pings or so, it times out to both the server IP and the ILO IP.

Now, I ran a long ping overnight and had it converted into text so I could see the results. NO TIMEOUTS.
The office management company are atrocious, as I have sent them all sorts of diagnostics/tests but to no response.

I have ZERO visibility of the switches it is connected to, so I do not know if they are gigabit switches that my fileserver is connected to or if they are 10/100mb (possible) or if they are encountering collisions on those ports.

My question is:

How can I check on the server by looking at the resource monitor or something which can tell me that the network is being flooded or it has a bottle neck?

I will take a picture and post it so you can see what I have on the server.

Thanks a lot for helping
Yashy
Network-resource.jpg