To ensure that only valid initiators connect to storage arrays, administrators most commonly run iSCSI only over logically-isolated backchannel networks.
In this deployment architecture, only the management ports of storage arrays are exposed to the general-purpose internal network, and the iSCSI protocol itself is run over dedicated network segments or virtual LANs (VLAN). This mitigates authentication concerns; unauthorized users aren't physically provisioned for iSCSI, and thus can't talk to storage arrays. However, it also creates a transitive trust problem, in that a single compromised host with an iSCSI disk can be used to attack storage resources for other hosts.

Related:

fiber network cards

fiber modem

http://www.zimbio.com/PCI+Express/articles/jHbhuJC104d/Telecom+Italia+Build+Fiber+Optic+Network+Vatican