Physical Connectivity of cinder in Open Stack

[LuckyTyagi]

I have just started with Open Stack and almost done with the configuration in lab. I searched about cinder connectivity but couldn't come up with satisfying answer. I'm talking about physical connectivity of cinder with either Compute or Controller using iSCSI or optical connectivity. As, cinder-api is on controller but compute is where actually is your VM. Or; my concept here is somewhere faulty. Kindly respond.