Q-Logic 8C Switch User Manual


 
59042-01 A 3-1
Section 3
Planning
Consider the following when planning a fabric:
Devices
Multiple chassis fabrics
Performance
Device access
Fabric management
Fabric security
3.1
Devices
When planning a fabric, consider the number of devices and the anticipated
demand. This will determine the number of ports that are needed and in turn the
number of switches. Consider how many and what types of switches are needed.
Consider the distribution of public and private devices as well as targets and
initiators. Public devices have full Fibre Channel addressing capability, and
therefore can communicate with any other public device on the fabric. An F_Port
supports a single public device. An FL_Port can support up to 126 public devices
in an arbitrated loop.
Private devices do not have full Fibre Channel addressing capability, only the
Arbitrated Loop Physical Address (ALPA) portion. A TL_Port provides a proxy for
a loop of private initiator or target devices allowing communication with off-loop
public and private devices. Consider the number of private devices in the fabric
and the number of off-loop devices with which the private devices must
communicate.
A TL_Port can support up to 125 private initiator devices and maintain
communications with up to 64 off-loop target devices.
A TL_Port can support up to 124 private target devices and maintain
communications with up to 63 off-loop initiator devices.
The Fibre Channel switch uses SFP optical transceivers, but the device host bus
adapters you are using may not. Consider whether the device adapters use SFP
transceivers or Gigabit Interface Converters (GBIC), and choose fiber optic cable
accordingly. Use LC-type cable connectors for SFP transceivers and SC-type
cable connectors for GBIC transceivers.