Fl_Port Connectivity; Planning For Private Arbitrated Loop Connectivity - McDATA StorageWorks 2/140 - Director Switch Planning Manual

Planning Considerations for Fibre Channel Topologies
3

FL_Port Connectivity

Planning for Private Arbitrated Loop Connectivity

McDATA Products in a SAN Environment - Planning Manual
3-10
Sphereon 4000-series fabric switch
through GX ports that are active as FL_Ports. The ports provide port
addressing, physical connectivity, and Fibre Channel frame routing.
Each FL_Port (and the embedded FL_Port) has a 24-bit address
identifier. The address identifier is expressed in hexadecimal format
as DD AA PP, where:
• DD is the domain identifier. This identifier is assigned one of 31
values (60 through 7F).
• AA is the area identifier. Each physical FL_Port (12 or 24 ports) is
assigned one of up to 24 values (04 through 1B).
• PP is the port identifier. Each device (node) attached to an
FL_Port is assigned one of 126 AL_PA values (01 through EF). The
embedded FL_Port is assigned an AL_PA of 00.
Private arbitrated loop topology supports the clustering of isolated
servers and storage subsystems into workgroup or departmental
SANs. This topology is well-suited to small and mid-sized
configurations where modest connectivity levels and high data
transmission speeds are required. The topology also supports
low-cost switching and connectivity in environments where the
per-port cost of a switched fabric director is prohibitive. Private
arbitrated loop topology:
• Supports the connection of up to 126 NL devices per loop plus the
switch's embedded FL_Port (127 connections).
• Reduces connection costs by distributing the routing function
through each loop port (loop functionality is a small addition to
normal Fibre Channel port functionality).
• Provides a fully-blocking architecture that allows a single
connection between any pair of loop ports. Connections between
a third loop port and busy ports are blocked until communication
between the first connection pair ends.
provide loop connectivity
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