Specifications

2 Getting Started with the McDATA Intrepid FICON Director
1.1 Basic Fibre Channel terminology
This section discusses some general terms used in the Fibre Channel (FC) environment.
These terms are also used in FICON environments when installing, configuring, and
operating in a switched point-to-point or cascaded FICON Director configuration, therefore,
you will find these terms throughout this document.
Node
A node is an endpoint that contains or uses information. It can be a computer (host), a device
controller, or a peripheral device (such as disk or tape drives). A node has a unique 64-bit
identifier known as the Node_Name. The Node_Name is typically used for management
purposes.
Port
Each node must have at least one port (hardware interface) to connect the node to the FC
topology. This node port is referred to as an N_Port.
Each N_Port has a Port_Name which is a unique 64-bit identifier that is assigned when it is
manufactured. The N_Port associates an access point to a node’s resources.
Other port types present in an FICON switched environment include:
E_Port An
expansion port is used to interconnect switches and build a switched fabric.
F_Port A
fabric port is used to connect a N_Port to a switch that is not loop-capable.
G_Port A
generic port is a port that has not assumed a role in the fabric.
Switched fabric
One or more FC switches (FC-SW) can be interconnected to create a fabric, to which N_Ports
are connected. A switched fabric takes advantage of aggregated bandwidth via switched
connections between N_Ports using
packet-switching. FC switches (FICON Directors) allow
multiple concurrent I/O operations (read and write) between multiple FICON-capable servers
and multiple FICON-capable control units (devices).
FC link
The port connects to the topology through an FC link (see Figure 1-1). The transmission
medium for the FC link (FICON interface) is a fiber optic cable. Physically, it is a pair of optical
fibers that provide two dedicated, unidirectional, serial-bit transmission lines. Information in a
single optical fiber flows, bit by bit, and always in the same direction. At any link interface, one
optical fiber is used to receive data while the other is used to transmit data. Full duplex
capabilities are exploited for data transfer. The Fibre Channel Standard (FCS) specifies that
for normal I/O operations, frames flow serially in both directions, allowing several concurrent
read and write I/O operations on the same link.