48-Port 8-Gbps Advanced Fibre Channel Module BB_Credit Buffers
Table 14-1 lists the BB_credit buffer allocation for the 48-port 8-Gbps Advanced Fibre Channel switching module.
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The following guidelines apply to BB_credit buffers on 32/48-port Advanced 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 500 buffers for dedicated rate mode or 32 buffers for shared rate mode.
- Performance buffers are not supported on this module.
- The buffers should not be allocated automatically.
Each port group on the 32/48-port Advanced 8-Gbps Fibre Channel switching module consists of four/six ports. The ports in shared rate mode in a port group can have a maximum bandwidth oversubscription of 1.5:1 considering that each port group has 32-Gbps bandwidth. In case of 32 Port version, each port group of 4 ports has sufficient bandwidth (32 Gbps) to handle the line rate traffic without any oversubscription.
The following example configurations are supported by the 48-port Advanced 8-Gbps Fibre Channel switching modules:
- Six ports with shared rate mode and 8-Gbps speed (1.5:1 oversubscription) (default).
- Two port with dedicated rate mode and 8-Gbps speed plus four ports with shared rate mode and 8-Gbps speed (2:1 oversubscription).
- Two ports with dedicated rate mode and 8-Gbps speed plus four ports with shared rate mode and 8-Gbps speed (2:1 oversubscription) .
- One port with dedicated rate mode and 8-Gbps speed plus three ports with dedicated rate mode and 4-Gbps speed plus two ports with shared rate mode and 8-Gbps speed (1.33:1 oversubscription).
- Six ports with dedicated rate mode and 8-Gbps speed.
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