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Zoning is an Fibre Channel switch function that enables node ports within the fabric to be logically segmented into groups and communicate with each other within the group. If zoning is not configured, the fabric controller sends an RSCN to all the nodes in the fabric. Involving the nodes that are not impacted by the change results in increased fabric-management traffic. Zoning also provides access control, along with other access control mechanisms, such as LUN masking. Zoning provides control by allowing only the members in the same zone to establish communication with each other. Types of Zoning: Port zoning : Uses the physical address of switch ports to define zones. In port zoning, access to node is determined by the physical switch port to which a node is connected. The zone members are the port identifier (switch domain ID and port number) to which HBA and its targets (storage devices) are connected. If a node is moved to another switch port in the fabric, port zoning mu...

Fabric services have three login types as explained below: FLOGI also known as Fabric Login . Performed between a N_Port and a F_Port. To log on to the fabric, a node sends a FLOGI frame with the WWNN and WWPN parameters to the login service at the pre-defined FC address FFFFFE (Fabric Login Server). In turn, the switch accepts the login and returns an Accept (ACC) frame with the assigned FC address for the node. Immediately after the FLOGI, the N_Port registers itself with the local Name Server on the switch, indicating its WWNN, WWPN, port type, class of service, assigned FC address and so on. After the N_Porth as logged in, it can query the name server database for information about all other logged in ports. PLOGI also known as Port Login . Performed between two N_Ports to establish a session. The initiator N_Portsends a PLOGI request frame to the target N_Port, which accepts it. The target N_Port returns an ACC to the initiator N_Port. Next, the N_Ports exchange service par...

Fibre Channel switches, regardless of the manufacturer, provide a common set of services as defined in the Fibre Channel standards. These services are available at certain pre-defined addresses. Some of these services are Fabric Login Server, Fabric Controller, Name Server, and Management Server. The Fabric Login Server is located at the predefined address of FFFFFE and is used during the initial part of the node’s fabric login process. The Name Server (also known as Distributed Name Server) is located at the predefined address FFFFFC and is responsible for name registration and management of node ports. Each switch exchanges its Name Server information with other switches in the fabric to maintain a synchronized, distributed name service. Fabric Controller located at the predefined address FFFFFD . The Fabric Controller provides services to both node ports and other switches. The Fabric Controller is responsible for managing and distributing Registered State Change Notific...

It is easier to understand a communication protocol by viewing it as a structure of independent layers. Fibre Channel Protocol defines the communication protocol in five layers: FC-0 through FC-4 (except FC-3 layer, which is not implemented). FC-0 Layer is the lowest layer in the Fibre Channel Protocol stack. This layer defines the physical interface, media, and transmission of bits. The FC-0 specification includes cables, connectors, and optical and electrical parameters for a variety of data rates. The Fibre Channel transmission can use both electrical and optical media. FC-1 Layer defines how data is encoded prior to transmission and decoded upon receipt. At the transmitter node, an 8-bit character is encoded into a 10-bit transmission character. This character is then transmitted to the receiver node. At the receiver node, the 10-bit character is passed to the FC-1 layer, which decodes the 10-bit character into the original 8-bit character. Fibre Channel links ...

Ports reserved in a switched fabric can be one of the following types: N_Port is an endpoint in the fabric. This port is also known as the node port. Typically, it is a host port (HBA) or a storage array port that is connected to a switch in a switched fabric. E_Port is a port that forms the connection between two FC switches. This port is also known as the expansion port. The E_Port on an FC switch connects to the E_Port of another FC switch in the fabric ISLs. F_Port is a port on a switch that connects to a N_Port, which is also known as a fabric port. G_Port is a   generic port on a switch that can operate as an E_Port or a F_Port and determines its functionality automatically during initialization.