HP Cisco Nexus 5000 Cisco MDS 9000 Family CLI Configuration Guide - Release 4. - Page 398

Buffer Credit Allocation Chapter 15 Configuring Generation 2 and Generation 3 Switching Modules Send documentation comments to [email protected] 4/44-Port 8-Gbps Host-Optimized Fibre Channel Module BB_Credit Buffers Table 15-9 lists the BB_credit buffer allocation for the 4/44-port 8-Gbps Fibre Channel switching module. Table 15-9 4/44-Port 8-Gbps Switching Module BB_Credit Buffer Allocation BB_Credit Buffer Allocation Default BB_credit buffers Maximum BB_credit buffers Total number of BB_credit buffers per module BB_Credit Buffers Per Port Dedicated Rate Mode Shared Rate Mode 8-Gbps Speed 8-Gbps Speed ISL Fx Port Fx Port 125 32 32 250 250 32 6000 The following guidelines apply to BB_credit buffers on 4/44-port 8-Gbps Fibre Channel switching modules: • 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 250 buffers for dedicated rate mode or 32 buffers for shared rate mode. • Performance buffers are not supported on this module. Each port group on the 24-port 8-Gbps Fibre Channel switching module consists of 12 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 4/44-port 8-Gbps Fibre Channel switching modules: • Twelve ports with shared rate mode and 4-Gbps speed (5:1 oversubscription) (default) • One port with dedicated rate mode and 8-Gbps speed plus eleven ports with shared rate mode and 4-Gbps speed (10:1 oversubscription) • One port with dedicated rate mode and 4-Gbps speed plus three ports with dedicated rate mode and 3-Gbps speed plus eight ports with shared rate mode and 4-Gbps speed (2:1 oversubscription) • Twelve ports with dedicated rate mode and 1-Gbps speed 15-14 Cisco MDS 9000 Family CLI Configuration Guide OL-18084-01, Cisco MDS NX-OS Release 4.x