One of our Windows/Coldfusion/IIS webservers has been experiencing a very odd pattern of high inbound network traffic.
In the picture above the red hum is out-bound traffic, and the yellow line is in-bound network traffic. It's very usual for a webserver which is sending out hundreds of requests per second of image and webpage data for the inbound traffic to be spiking that high. The IIS logs do not show users constantly uploading massive files either and generally our applications send out far more data than they receive.
I've attempted to use Microsoft Network Monitor but I really don't even know where to start with it. From the graph below it seems I should be able to detect some period spike of very large data transferring, but how do I detect that to find out exactly what it is the cause of this behavior?