Supported Fabric Configurations

Isolated Private Arbitrated Loop

Figure 1-1 “Isolated Private Arbitrated Loop Configuration” shows a typical Isolated Private Loop configuration without fabric. This is most likely your current configuration.

Figure 1-1 Isolated Private Arbitrated Loop Configuration

This isolated private loop is a typical configuration. It uses two hubs for some redundancy to the target devices. This configuration will continue to be supported.

Direct Fabric Attachment

A simple migration to a fabric configuration is to replace the two hubs with two Fibre Channel switches. Redundant paths to the targets are maintained while each link is isolated from each other providing better performance and reliability.

Figure 1-2 “Direct Fabric Attachment Configuration” illustrates this fabric configuration.

Figure 1-2 Direct Fabric Attachment Configuration

The advantages of this configuration are:

QuickLoop Attachment for Fabric

A migration path to a fabric configuration with devices that are not fabric capable is to use the QuickLoop fabric configuration. In this configuration, a host connected to a F_Port or FL_Port on the switch can communicate with private target devices connected to QL ports in the same or different loop. Through translative mode (a function of Brocade switch), the switch creates phantom loop addresses which allow private target devices to communicate with public hosts across the fabric. Translative mode allows private loop target devices to appear as public targets.

	NOTE: Translative mode does not allow private hosts to communicate with public devices on the switch.

An example of a QuickLoop fabric configuration is to replace the two hubs shown in the previous illustration with a single Fibre Channel switch. You can connect Host 1 and Host 2 to F_Ports on the switch, and connect each private target device to a QuickLoop port.

Figure 1-3 “QuickLoop Fabric Configuration” shows that Host 1 and Host 2 are now public hosts, each having access to any of the QuickLoop target devices through the translative mode function.

Figure 1-3 QuickLoop Fabric Configuration

QuickLoop Attachment for Private Devices

	NOTE: The following configuration can be used when you are in the process of migrating to fabric but your fabric environment is not yet fully functional.

In a private loop environment, a QuickLoop configuration can allow private hosts with a Tachyon adapter attached to a QL_Port to access private devices on the loop by using the switch as a hub.

Figure 1-4 “QuickLoop Attachment for Private Devices” shows that Tachyon Host 1 is a private host which has access to the private target devices connected to a QuickLoop port. TL Host 2, a public host connected to a fabric port, also has access to the private devices and any future public devices.

Figure 1-4 QuickLoop Attachment for Private Devices

For Tachlite hosts:

Public Loop

A public loop is an arbitrated loop where at least one of the ports on the loop is a switch port (FL_Port), which allows hosts or devices on the loop to communicate with hosts or devices attached to other FL_Ports.

Figure 1-5 “Public Loop Attachment” shows that Host 1 and Host 2 are public hosts connected through a hub to an FL_Port on the switch. The target devices are public devices (NL_Ports) connected to other FL_Ports. Host 1 and 2 have access to any of the public devices.

Figure 1-5 Public Loop Attachment

To use this or any other configuration shown in this guide, check to see if your devices support the configuration. For a list of HP supported topologies and devices, visit the ITRC web site, mentioned on page 6, to access Fibre Channel HBA support information.