If the end devices are running full throttle, then just look at the show interface fcip X and that will give a good idea. But, yes, there is too known as SAN extension tuner. You will need to have another gigEthernet port up to act as a virtual initiator and target. And it has to be zoned as well. I usually just put it a vsan with default permit and then trunk that vsan over the fcip link. There is some documentation in the configuration guides but it might be best to call TAC and get a sample config.