whats irp protocol ?

after installing https://community.emc.com/blogs/keith/2017/01/26/isilon-data-insights-connector--do-it-yourself-isilon-monitoring

we see for graph Cluster Protocol Operations and CPU for $cluster

irp very high

I am trying to understand a bit more about this.

From https://www.dellemc.com/resources/en-us/asset/white-papers/products/storage/h12428-wp-best-practice-guide-isilon-file-system-auditing.pdf

I see a reference to

"Starting with OneFS 7.1, a likewise input/output (LWIO) filter manager was created. The filter manager provides a plug-in framework for pre- and post-input/output request packet (IRP). The IRP provides the mechanism to encode a protocol request handled by LWIO and encodes the request handled by the file system drivers."

can it be elaborated on in particular in reference to the graph. My suspicion is this is audit event info correlating to external protocol activity, ie NFS or SMB ?