Sun Microsystems 5802 用户手册

Chapter 6

Managing Ports

Longer distances can be spanned at full bandwidth on ports by extending credits to 
G_Ports, F_Ports, and E_Ports. Each port can donate 15 credits to a pool from which 
a recipient port can borrow. The recipient port also loses a credit in the process. For 
example, you can configure a recipient port to borrow 15 credits from one donor 
port for a total of 30 credits (15+15=30). This will support communication over the 
following approximate distances:

■

50 Km at 1-Gbit/sec (30÷0.6)

■

25 Km at 2-Gbit/sec (30÷1.2)

■

12 Km at 4-Gbit/sec (30÷2.4)

■

6 Km at 8-Gbit/sec (30÷4.8)

You can utilize unused donor ports with the Extended Credit Wizard only 

when pointing to a switch running firmware that supports this feature.

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

1. Extended Distance — explains the concepts and principles of extending port 

credits. Click the Next button.

2.  Extended Distance Requirements — specify speed and distance requirements for 

each port then click the Next button.

3.  Designate Donor Ports — select available ports and click >> to move the port into 

the Selected Donor Port column (

). Match the number of ports needed 

with the number of designated donor ports. Click the Next button.