(DRAFT, work in progress last update 2019.10.09 New Screen Images and videos will be available within the next days)
The RDMA Activity Performance Counter can give you some useful information
RDMA Accepted Connections will increase for each new connection. The Picture show a lab system with a RoCE Error. RDMA Accepted Connections will normally only change if you move VMs (SOFS), disable/enable pNIC/vNIC or reboot a Node.
The picture show that I have thousands of Accepted Connections and after just a few seconds I have 4 Accepted Connections. With no change in the Cluster.
Show the Active Connections on each vNIC/pNIC to see the connect use the "netstat -xan"