FW 07.00.00/HAFM SW 08.06.00 McDATA Products in a SAN Environment Planning Manual (620-000124-500, April 2005)

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McDATA Products in a SAN Environment - Planning Manual

Planning Considerations for Fibre Channel Topologies

Public Versus Private

Devices

Sphereon 4300 and 4500 Fabric Switches support connection of public

and private arbitrated loop devices as follows:

• Public device - A loop device that can transmit a fabric login

(FLOGI) command to the switch, receive acknowledgement from

the switch’s login server, register with the switch’s name server,

and communicate with fabric-attached devices is a public device.

Sphereon

4300 and 4500 Fabric Switches provide loop connectivity

for the Fibre Channel architectural limit of 127 devices per Fibre

Channel port, when configured as an FL_Port. Each FL_Port is

assigned one arbitrated loop physical address (AL_PA), leaving

126 AL_PAs per port available for device connections. Up to 32

public devices can be connected to each of the FL_Ports (12 ports

for the Sphereon 4300 Switch, 24 ports for the Sphereon 4500

Switch). As shown in Figure 3-3, server S

is a public loop device

connected to a Sphereon 4500 Switch and can communicate with

fabric-attached device D

Figure 3-3 Public Device Connectivity

Public devices support normal fabric operational requirements,

such as fabric busy and reject conditions, frame multiplexing, and

frame delivery order.