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
14-9
Cisco MDS 9000 Family CLI Configuration Guide
OL-16184-01, Cisco MDS SAN-OS Release 3.x
Chapter 14 Configuring Generation 2 Switches and Modules
Buffer Credit Allocation
Note
The default BB_credit buffer allocation is the same for all port speeds.
BB_Credit Buffers for Switching Modules
This section describes how buffer credits are allocated to Cisco MDS 9000 switching modules, and
includes the following topics:
•
48-port 4-Gbps Fibre Channel Module BB_Credit Buffers
•
24-port 4-Gbps Fibre Channel Module BB_Credit Buffers, page 14-11
•
18-Port Fibre Channel/4-Port GigabitEthernet Multiservice Module BB_Credit Buffers, page 14-12
•
Figure 14-5Example Speed and Rate Configuration on a 24-Port 4-Gbps Switching Module,
page 14-12
•
4-Port 10-Gbps Switching Module BB_Credit Buffers, page 14-13
48-port 4-Gbps Fibre Channel Module BB_Credit Buffers
Table 14-5
lists the BB_credit buffer allocation for 48-port 4-Gbps Fibre Channel switching modules.
The following considerations apply to BB_credit buffers on 48-port 4-Gbps Fibre Channel switching
modules:
24-port module
Mixed
All ports
shared (4 Gpbs)
16 BB credits
1 Gbps
250 BB credits
2 Gbps
250 BB credits
4 Gbps
250 BB credits
All ports
dedicated (2 Gbps)
250 BB credits
Dedicated
Shared
16 BB credits
144856
Table 14-5
48-Port 4-Gbps Switching Module BB_Credit Buffer Allocation Defaults
BB_Credit Buffer Allocation Type
BB_Credit
Buffers Per
Module
BB_Credit Buffers Per Port Defaults
Dedicated Rate Mode
4-Gbps Speed
Shared Rate Mode
4-Gbps Speed
ISL
1
1.
ISL = E port or TE port.
Fx Port
ISL
1
Fx Port
User configurable BB_credit buffers
6000
125
16
16
16