port type
All components (that is, devices) in a Fibre Channel network use ports as connections to the network. The ports in the Fibre Channel network include the following basic types: N-port port, F-port port, L-port port, NL-port port, FL-port port, E-port port, G-port port.
Among them, the N, L and NL ports are used for the termination node in the Fibre Channel network, and the F, FL, E and G ports are implemented in the optical switch.
①N-port port and F-port port
The original fiber channel network includes two types of ports: one is the network port of the N-port port; the other is the switched fiber port of the F-port port.
The N-port port is a port for accessing storage devices and computer systems on the Fibre Channel network. The task is to initialize and receive frames. If there is no N-port port, there will be no data communication on the network; F-port port is a fiber optic port. The port on the switch is used to provide management and connection services on behalf of the N-port ports. These services are provided for the communication between each pair of N-port ports (host system and storage device).
There is a one-to-one relationship between N-port ports and F-port ports. On the optical switch in the optical storage area network, only one N-port port is connected to the F-port port, and the communication between other N-port ports in the optical fiber channel network and the N-port port is carried out through their respective ports on the switch. It is realized by the communication between the port initialization process on the N-port and the N-port port. Whether the N-port port is sending or receiving data, it always communicates with the F-port port. When there is no data transmission, the N-port port sends an IDLE frame to the corresponding F-port port on the switch, and a "heartbeat" is established between the N-port port and the F-port port, so that the possibility of A problem occurred in the connection.
②L-port port
L-port ports exist in a Fibre Channel ring. Unlike switched networks, nodes in a ring network share a structure of cable bandwidth. Similar to the way N-port ports are used to initiate communication with F-port ports in switched fabrics, L-port ports are designed to initiate direct communication with other L-port ports in the ring.
However, there is no port name corresponding to the F-port port in the optical ring network. Because a fiber optic ring is a logical ring and is designed to work without a hub, the hub cannot provide the intended port functionality for the ring if not required. The hub in the fiber optic ring network only plays the role of connection and protection against failure.
③NL-port and FL-port
When a Fibre Channel loop is added to a Fibre Channel network, communication between N-port port nodes and L-port port nodes must be allowed. Two new ports are defined for this purpose: FL-port port and NL-port port .
The FL-port port is the port on the fiber switch, which is allowed to join as a special node in the fiber channel network. The fiber channel ring network reserves only one address for the FL-port port, that is, it is impossible for two fiber switches to communicate at the same time.
The NL-port port is located in the ring network. It has the dual capabilities of N-port port and L-port port, and supports both switched optical network and optical ring network, so that the communication between the switched optical network and the optical fiber ring network can be achieved. became possible.
④E-port port and G-port port In the optical switch, there are two common ports, they are E-port port and G-port port. The G-port port is a "universal" port, which can be used for different ports in the switch such as F-port port and FL-port port. E-port port is a special port used for cascading of fiber switches.
These are the various ports that can be encountered in a Fibre Channel network. The fabric switches that we use in the storage platform of the Ministry of Land and Resources are Brocade fabric switches. The ports of this fabric switch support the self-configuration function. Self-configuring ports can detect the port mode of the other end of all connections and automatically configure the mode of operation to support that mode.
