Cisco Systems DSC9148D8G48PK9 manual Port 4-Gbps Switching Module BBCredit Buffers

Chapter 4 Configuring Interface Buffers

Information About Interface Buffers

Figure 4-8 Example Speed and Rate Configuration on a 24-Port 4-Gbps Switching Module

1		2		3		4	5		6
	4-Gbps		4-Gbps		4-Gbps	1-Gbps		1-Gbps		1-Gbps
											144857
Dedicated		Dedicated		Dedicated		Shared		Shared		Shared

18-Port Fibre Channel/4-Port Gigabit Ethernet Multiservice Module BB_Credit Buffers

Table 4-7lists the BB_credit buffer allocation for 18-port 4-Gbps multiservice modules.

Table 4-7 18-Port 4-Gbps Multiservice Module BB_Credit Buffer Allocation

	BB_Credit Buffers Per Port
	Dedicated Rate Mode		Shared Rate Mode
	4-Gbps Speed		4-Gbps Speed
BB_Credit Buffer Allocation	ISL1	Fx Port	ISL1	Fx Port
Default BB_credit buffers	250	16	16	16
Maximum BB_credit buffers	250	250	16	16
Total number of BB_credit buffers per module	4509

1. ISL = E port or TE port.

The following considerations apply to BB_credit buffers on18-port 4-Gbps Fibre Channel switching modules:

•BB_credit buffers for ISL connections can be configured from a minimum of 2 buffers to a maximum of 250 buffers for dedicated rate mode or 16 buffers for shared 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 16 buffers for shared rate mode.

•Performance buffers are not supported on this module.

12-Port 4-Gbps Switching Module BB_Credit Buffers

Table 4-8lists the BB_credit buffer allocation for 12-port 4-Gbps switching modules.

Table 4-8 12-Port 4-Gbps Switching Module BB_Credit Buffer Allocation

	BB_Credit Buffers Per Port
	Dedicated Rate Mode
	4-Gbps Speed
BB_Credit Buffer Allocation Type	ISL 1	Fx Port
Default BB_credit buffers	250	16
Maximum BB_credit buffers	250	16
Default Performance buffers	145	12

	Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x		4-13