Characteristics Of Arbitrated Loop Operation - McDATA StorageWorks 2/140 - Director Switch Planning Manual

Planning Considerations for Fibre Channel Topologies
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Characteristics of Arbitrated Loop Operation

McDATA Products in a SAN Environment - Planning Manual
3-2
• Arbitrated loop - This topology uses a Sphereon 4000-series
fabric switch to connect multiple device node loop ports
(NL_Ports) in a Fibre Channel arbitrated loop (FC-AL) or hub
configuration without benefit of a multiswitch fabric. Both
switches support a switched mode topology that provides a
single, logical connection between two device NL_Ports. The
switches dynamically configure different logical transmission
paths, and in all cases, connected NL_Ports have access to 100%
of the available bandwidth.
Loop devices communicate with switches through a fabric loop
port (FL_Port). If peripheral loop devices are expected to
communicate with fabric-attached devices, consider installation
of a Sphereon 4000-series fabric switch to form a fabric-loop
hybrid topology. For information, refer to
for Fibre Channel Topologies,
Connectivity, and Planning for Fabric-Attached Loop
• Multiswitch fabric - This topology provides the ability to connect
directors and fabric switches through expansion ports (E_Ports)
and interswitch links (ISLs) to form a Fibre Channel fabric.
Director or fabric switch elements receive data from a device and,
based on the destination N_Port address, route the data through
the fabric (and possibly through multiple switch elements) to the
destination device. For additional information, refer to
for Multiswitch Fabric Support
Considerations.
When implementing Fibre Channel arbitrated loop topology,
consideration must be given to switch operating mode, device
connectivity, and loop configuration. This section describes the
characteristics of arbitrated loop operation, including:
• Switch operation in shared mode or switched mode.
• Connectivity of public loop devices and private loop devices.
• Configuration of public arbitrated loops and private arbitrated
loops.
Planning Considerations
Planning for Private Arbitrated Loop
Connectivity.
and General Fabric Design
Planning