HP 2/8q Fibre Channel manual Extending port credits, Designating donor ports

Switch Manager

3.Select one of the following in the Port Symbolic Name dialog box:

—Enter a new name for the port in the Set Port Symbolic Name box.

—Check the Restore Default Port Symbolic Name check box to restore the default name.

4.Click OK.

Extending port credits

Each port is supported by a data-buffer with a 16-credit capacity; that is, 16 maximum sized frames. For fiber optic cables, this enables full bandwidth service over a distance of 10 kilometers at 2 Gbps. For fiber optic cables, this enables full bandwidth service over a distance of 13 kilometers at 2 Gbps (1.2 credits/Km). Longer distances can be spanned at full bandwidth by borrowing credits from designated donor ports thus pooling the buffer capacities. This is called credit extension. Each donor port contributes 15 credits to the pool from which the recipient ports can draw. The recipient port also loses one credit in the process. For example, one donor port contributes 15 credits to the pool from which a recipient draws for a total of 30 credits (15+15). This provides approximately 25 Km at 2 Gbps (30÷1.2).

To extend credits, select Wizards > Ext Credit Wizard. The Extended Credit Wizard leads you through the following process to extend credits based on transmission distance requirements:

1.Extended Distance on Switch—Explains the concepts and principles of extending port credits. Click Next.

2.Extended Distance Requirements—Specify speed and distance requirements for each port. Click Next.

3.Designate Donor Ports—Select available ports and then click >> to move the port into the Selected Donor Port column (Figure 32). Match the number of ports needed with the number of designated donor ports. Click Next.

Figure 32: Designating donor ports

88 HP StorageWorks 2/8q Fibre Channel Switch Management User Guide