Port 8-Gbps Fibre Channel Module Bb_Credit Buffers - Cisco AP776A - Nexus Converged Network Switch 5020 Configuration Manual

Buffer Credit Allocation
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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48-Port 8-Gbps Fibre Channel Module BB_Credit Buffers

Table 15-7
Table 15-7
BB_Credit Buffer Allocation
Default BB_credit buffers
Maximum BB_credit buffers
Total Number of BB_Credit Buffers per Module
Ports 1 through 24
Ports 25 through 48
The following guidelines apply to BB_credit buffers on 48-port 8-Gbps Fibre Channel switching
modules:
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Each port group on the 48-port 8-Gbps Fibre Channel switching module consists of six ports. The ports
in shared rate mode in a port group can have a maximum bandwidth oversubscription of 10:1 considering
that each port group has 12.8-Gbps bandwidth.
The following example configurations are supported by the 48-port 8-Gbps Fibre Channel switching
modules:
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Cisco MDS 9000 Family CLI Configuration Guide
15-12
48-Port 4-Gbps Fibre Channel Module BB_Credit Buffers, page 15-15
24-Port 4-Gbps Fibre Channel Module BB_Credit Buffers, page 15-17
18-Port Fibre Channel/4-Port Gigabit Ethernet Multiservice Module BB_Credit Buffers,
page 15-184-Port 10-Gbps Switching Module BB_Credit Buffers, page 15-20
lists the BB_credit buffer allocation for the 48-port 8-Gbps Fibre Channel switching module.
48-Port 8-Gbps Switching Module BB_Credit Buffer Allocation
BB_credit buffers allocated for ports 1 through 24 and 25 through 48 can be a maximum of 6000
each so that the load is distributed.
BB_credit buffers for ISL connections can be configured from a minimum of 2 buffers to a
maximum of 500 buffers for dedicated rate mode.
BB_credit buffers for Fx port mode connections can be configured. The minimum is 2 buffers and
the maximum of 500 buffers for dedicated rate mode or 32 buffers for shared rate mode.
Performance buffers are not supported on this module.
Six ports with shared rate mode and 8-Gbps speed (4:1 oversubscription) (default)
One port with dedicated rate mode and 8-Gbps speed plus
five ports with shared rate mode and 8-Gbps speed (10:1 oversubscription)
Two ports with dedicated rate mode and 4-Gbps speed plus
four ports with shared rate mode and 4-Gbps speed (4:1 oversubscription)
One port with dedicated rate mode and 4-Gbps speed plus
three ports with dedicated rate mode and 2-Gbps speed plus
two ports with shared rate mode and 4-Gbps speed (4:1 oversubscription)
Six ports with dedicated rate mode and 2-Gbps speed
Chapter 15 Configuring Generation 2 and Generation 3 Switching Modules
BB_Credit Buffers Per Port
Dedicated Rate Mode
8-Gbps Speed
ISL Fx Port
250 32
500 500
6000
6000
Shared Rate Mode
8-Gbps Speed
Fx Port
32
32
OL-18084-01, Cisco MDS NX-OS Release 4.x