Overland Storage REO 9000 setup guide Fibre Channel FC, Port Type Represents Associated Topology

Overland Storage REO 9000 with ProtectionPAC Software

Fibre Channel (FC)

Instead of, or in addition to, using iSCSI and the TCP/IP protocol to transmit information over a network, you also have the option of using a SAN that makes use of the FC and Small Computer System Interface (SCSI) protocols. The FC protocol uses two additional protocols to communicate at the hardware level: Fibre Channel Arbitrated Loop (FC- AL), which communicates with hubs, and Fibre Channel Switched (FC- SW), which communicates with switches. The SCSI protocol provides the communication link at the higher level, between the hardware and the software.

You can use all three basic FC SAN topologies with the REO Appliance:

„Point-to-point.This topology provides a direct connection between two N_Ports.

„Arbitrated loop. In an arbitrated loop, NL_Ports and FL_Ports are daisy-chained with hubs, which means that only one device can send data at a time.

„Switched fabric. Switched fabric consists of one or more switches that are interconnected, and multiple nodes connected to the switches.

The REO Appliance supports the following types of ports for FC:

Port Type	Represents	Associated Topology
N_Port	Node Port	Connects point-to-point or to F_Port
NL_Port	Node Loop Port	N_Ports that can connect to an arbitrated loop

FC uses strict naming conventions to support unique, 64-bit names for the worldwide node name (WWNN) and the worldwide port name (WWPN). These names are pre-assigned by the manufacturers of the different hardware components used in an FC.

12 X Reviewing REO 9000 Concepts and Requirements