Dual-Switch Quickloop; Quickloop Initialization - HP StorageWorks 2/16 - SAN Switch User Manual

Dual-switch QuickLoop

In a dual-switch QuickLoop, the initialization process is driven by one of the
switches, called the QuickLoop master. The role of the QuickLoop master is
dynamically assigned at each instance of QuickLoop initialization, according to
the following criteria:

QuickLoop Initialization

QuickLoop initialization includes two passes:
Quickloop Fabric Assist User Guide
F_Port—A fabric port that is not in loop mode. Able to transmit under fabric
protocol, and interface over links. N_Ports on equipment connect to F_Ports
on switches.
FL_Port—A fabric port on a switch that is in loop mode. Used to connect loop
capable NL_Ports to the switch in a loop configuration.
E_Port—Expansion port. A port is designated an E_Port when it is used as an
interswitch expansion port to connect to the E_Port of another switch, to build
a larger switch fabric, or to build a two-switch QuickLoop configuration.
Sometimes, a single fabric loop device is attached to a port. In this case, the
port would function as an FL_port. The attached device possesses either an
N_port (if the device is fabric-capable) or an NL_port, in which case the
device would be connected to the fabric in a loop configuration through an
FL_Port on a switch. In this latter case a looplet is created.
looplet—A set of devices connected in a loop to a port that is itself a member
of an arbitrated loop. By contrast, a single device rather than a loop might be
connected to a port.
Each device in a private loop must have a unique physical address. The
devices in a QuickLoop are assigned a unique phantom AL_PA.
AL_PA—Arbitrated loop physical address. A one-byte value used to identify
a device in an arbitrated loop.
During implementation and operation of switches in a QuickLoop, messages
are transmitted by devices as they come online. These messages, called Loop
Initialization primitives (LIPs), are in addition to normal data traffic.
If one switch receives LIPs from its looplets and the other does not, the switch
that receives the LIPs is the QuickLoop master.
If both switches receive LIPs from their respective looplets, the switch with
the lower domain ID is the QuickLoop master.
Using Quick Loop
23