Cisco Systems DSC9148D8G48PK9 manual Total BB credit buffers

Chapter 4 Configuring Interface Buffers

Information About Interface Buffers

Note The 48-port and 24-port 8-Gbps modules have dual global buffer pools. Each buffer pool in the 48-port modules support 24 ports and in the 24-port modules each buffer pool supports 12 ports.

Figure 4-1shows the allocation of BB_credit buffers on line cards (24-port and 48-port 4-Gbps line cards).

Figure 4-1 Receive Buffers for Fibre Channel Ports in a Global Buffer Pool

Maximim Receive

buffers

Reserved Internal Buffers (not user configurable)

Performance Buffers (Shared Pool)

Common unallocated buffer pool for BB_credits

1	2	3	Allocated BB_credit buffers	N
			for each front panel FC ports

Total BB credit buffers 185164

Figure 4-2shows the default BB_credit buffer allocation model for 48-port 8-Gbps switching modules. The minimum BB_credits required to bring up a port is two buffers.

Figure 4-2 BB_Credit Buffer Allocation in 48-Port 8-Gbps Switching Modules

48-port module

All ports
shared (8 Gpbs)		Mixed
32 BB credits
	Dedicated

All ports

dedicated (2 Gbps)

250 BB credits

Shared

32 BB credits

1Gbps

250 BB credits

2Gbps

250 BB credits

4Gbps

250 BB credits

8Gbps

250 BB credits

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	Cisco MDS 9000 Family NX-OS Interfaces Configuration Guide
OL-29284-01, Release 6.x		4-3