Extended Bb_Credits On Generation 2 And Generation 3 Switching Modules; Configuring Extended Bb_Credits - Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual

Buffer Credits
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
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The extended BB_credit configuration takes precedence over the receive BB_credit and performance
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buffer configurations.

Extended BB_credits on Generation 2 and Generation 3 Switching Modules

To use this feature on Generation 2 or Generation 3 switching modules, you must meet the following
requirements:
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Extended BB_credits are not supported on the Cisco MDS 9124 Fabric Switch.
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Configuring Extended BB_credits

To configure extended BB_credits for an MDS-14/2 interface, for a Generation 2 switching module
interface, or for an interface in a Cisco MDS 9216i switch using Fabric Manager, follow these steps:
Cisco MDS 9000 Family Fabric Manager Configuration Guide
20-28
The last two Fibre Channel ports (port 13 and port 14) and the two Gigabit Ethernet ports
Note
do not support the extended BB_credits feature (see
Explicitly enable this feature in the required Cisco MDS switch.
Disable the remaining three ports in the 4-port group if you need to assign more than 2,400
BB_credits to the first port in the port group.
– If you assign less than 2,400 extended BB_credits to any one port in a port group, the remaining
three ports in that port group can retain up to 255 BB_credits based on the port mode.
Note The receive BB_credit value for the remaining three ports depends on the port mode.
The default value is 16 for the Fx mode and 255 for E or TE modes. The maximum value
is 255 in all modes. This value can be changed as required without exceeding the
maximum value of 255 BB_credits.
If you assign more than 2,400 (up to a maximum of 3,500) extended BB_credits to the port in
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a port group, you must disable the other three ports.
Be aware that changing the BB_credit value results in the port being disabled and then reenabled.
Disable (explicitly) this feature if you need to nondisruptively downgrade to Cisco SAN-OS Release
1.3 or earlier. When you disable this feature, the existing extended BB_credit configuration is
completely erased.
You see the interface configuration in the Information pane (see
Obtain the Enterprise package (ENTERPRISE_PKG) license (see
Installing Licenses").
Configure this feature in any port on a Generation 2 switch module. See the
section on page 22-23 for more information on extended BB_credits on Generation 2 switching
modules.
Chapter 20 Configuring Interfaces
Figure 20-2).
Figure 20-14).
Chapter 10, "Obtaining and
"Extended BB_Credits"
OL-17256-03, Cisco MDS NX-OS Release 4.x